Dose escalation with 3D conformal treatment: five year outcomes,treatment optimization,and future directions

Purpose: To report the 5-year outcomes of dose escalation with 3D conformal treatment (3DCRT) of prostate cancer.Methods and Materials: Two hundred thirty-two consecutive patients were treated with 3DCRT alone between 6/89 and 10/92 with ICRU reporting point dose that increased from 63 to 79 Gy. The median follow-up was 60 months, and any patient free of clinical or biochemical evidence of disease was termed bNED. Biochemical failure was defined as prostate-specific antigen (PSA) rising on two consecutive recordings and exceeding 1.5 ng/ml. Morbidity was reported by the Radiation Therapy Oncology Group (RTOG) scale, the Late Effects Normal Tissue (LENT) scale, and a Fox Chase modification of the latter (FC-LENT). All patients were treated with a four-field technique with a 1 cm clinical target volume (CTV) to planning target volume (PTV) margin to the prostate or prostate boost; the CTV and gross tumor volume (GTV) were the same. Actuarial rates of outcome were calculated by Kaplan-Meier and cumulative incidence methods and compared using the log rank and Gray’s test statistic, respectively. Cox regression models were used to establish prognostic factors predictive of the various measures of outcome. Five-year Kaplan-Meier bNED rates were utilized by dose group to estimate logit response models for bNED and late morbidity.Results: PSA <10 ng/ml: No dose response was demonstrated using estimated bNED rates or by analysis of PSA nadir vs. dose. PSA 10–19.9 ng/ml: A bNED dose response was demonstrated (p = 0.02) using the log rank test. The logit response model showed 5-year bNED rates of 35% at 70 Gy and 75% at 76 Gy (p = 0.0049) and illustrated the relative ineffectiveness of conventional dose treatment. PSA 20+ ng/ml: A bNED dose response was demonstrated (p = 0.02) using the log rank test. The logit response model indicated a 5-year bNED rate of 10% at 70 Gy and 32% at 76 Gy (p = 0.10). Morbidity: Dose response was demonstrated for FC-LENT grade 2 and grade 3,4 GI morbidity and for LENT grade 2 GU sequelae. RTOG grade 3,4 GI morbidity at 5 years was <1%. Factors associated with bNED, cause-specific survival, and metastasis were studied using Cox multivariate analysis. Pretreatment PSA (p = 0.0001), Gleason score 7–10 (p = 0.0001), and dose (p = 0.017) were significantly predictive of bNED. For each 1 Gy increase in dose, the hazard of bNED failure decreased by 8%. Palpation stage was associated with cause-specific survival (p = 0.002) and distant metastasis (p = 0.0004). Gleason score was also predictive of distant metastasis (p = 0.02).Conclusions: A dose response was observed for patients with pretreatment PSA >10 ng/ml based on 5-year bNED results. No dose response was observed for patients with pretreatment PSA <10 ng/ml. Dose response was observed for FC-LENT grade 2 and grade 3,4 GI sequelae and for LENT grade 2 GU sequelae. Optimization of treatment was made possible by the results in this report. The improvement in 5-year bNED rates for patients with PSA levels >10 ng/ml strongly suggests that clinical trials employing radiation should investigate the use of 3DCRT and prostate doses of 76–80 Gy.     

Dose escalation with three-dimensional conformal radiation therapy affects the outcome in prostate cancer

Purpose: Three-dimensional conformal radiation therapy (3D-CRT) is a technique designed to deliver prescribed radiation doses to localized tumors with high precision, while effectively excluding the surrounding normal tissues. It facilitates tumor dose escalation which should overcome the relative resistance of tumor clonogens to conventional radiation dose levels. The present study was undertaken to test this hypothesis in patients with clinically localized prostate cancer.Methods and Materials: A total of 743 patients with clinically localized prostate cancer were treated with 3D-CRT. As part of a phase I study, the tumor target dose was increased from 64.8 to 81 Gy in increments of 5.4 Gy. Tumor response was evaluated by post-treatment decrease of serum prostate-specific antigen (PSA) to levels of ≤1.0 ng/ml and by sextant prostate biopsies performed ≥2.5 years after completion of 3D-CRT. PSA relapse-free survival was used to evaluate long-term outcome. The median follow-up was 3 years (range: 1–7.6 years).Results: Induction of an initial clinical response was dose-dependent, with 90% of patients receiving 75.6 or 81.0 Gy achieving a PSA nadir ≤1.0 ng compared with 76% and 56% for those treated with 70.2 Gy and 64.8 Gy, respectively (p < 0.001). The 5-year actuarial PSA relapse-free survival for patients with favorable prognostic indicators (stage T1-2, pretreatment PSA ≤10.0 ng/ml and Gleason score ≤6) was 85%, compared to 65% for those with intermediate prognosis (one of the prognostic indicators with a higher value) and 35% for the group with unfavorable prognosis (two or more indicators with higher values) (p < 0.001). PSA relapse-free survival was significantly improved in patients with intermediate and unfavorable prognosis receiving ≥75.6 Gy (p < 0.05). A positive biopsy at ≥2.5 years after 3D-CRT was observed in only 1/15 (7%) of patients receiving 81.0 Gy, compared with 12/25 (48%) after 75.6 Gy, 19/42 (45%) after 70.2 Gy, and 13/23 (57%) after 64.8 Gy (p < 0.05).Conclusions: The data provide evidence for a significant effect of dose escalation on the response of human prostate cancer to irradiation and defines new standards for curative radiotherapy in this disease.     

Importance of margin extent as a predictor of outcome after adjuvant radiotherapy for Gleason score 7 pT3N0 prostate cancer

PURPOSE: To evaluate, in Gleason score 7, pT3N0 prostate cancer patients with positive surgical margins, the predictors of progression-free survival and to identify a patient subgroup that would benefit from immediate adjuvant postoperative radiotherapy (ART). METHODS AND MATERIALS: Between November 1989 and August 1998, 76 men underwent radical prostatectomy and were found to have capsular penetration (pT3N0), surgical Gleason score 7, tumor present at the resection margin, and an undetectable postoperative prostate-specific antigen (PSA) level. All surgical specimens underwent whole-mount serial sectioning to determine the degree of margin positivity (focal vs. extensive). Of the 76 men, 45 underwent early ART (within 6 months with a median dose of 64.8 Gy), and 31 had no immediate treatment. We defined freedom from PSA failure (bNED) as the absence of two consecutive PSA rises >0.2 ng/mL. RESULTS: The median follow-up time was 5.1 years (range, 2-10 years). The ART and non-ART patients were similar with respect to preoperative PSA level, Gleason score (4 + 3 vs. 3 + 4), presence of seminal vesicle invasion, and margin extent. On univariate analysis, margin extent was predictive for improved bNED (5-year bNED rate of 92% vs. 58%, p = 0.010, for men with focal and extensive margins, respectively). Gleason score (4 + 3 vs. 3 + 4), seminal vesicle invasion, and ART were not statistically significant predictors. On multivariate analysis, the preoperative PSA level, margin extent, and ART were independent significant factors. In the group with extensive surgical margins, men receiving ART had a significantly greater 5-year bNED survival rate compared with the non-ART patients (73% vs. 31%, p = 0.004). CONCLUSION: These data suggest that the amount of microscopic residual tumor significantly affects bNED after radical prostatectomy for Gleason score 7, pT3N0 prostate cancer. In addition, men with pathologic evidence of microscopic local disease appear to benefit from early ART compared with untreated controls.     

The efficacy of early adjuvant radiation therapy for pT3N0 prostate cancer: a matched-pair analysis.

PURPOSE: This study examines the effect of adjuvant radiation therapy (RT) on outcome in patients with pT3N0 prostate cancer and makes comparisons to a matched control group. METHODS AND MATERIALS: At our center, 149 patients undergoing radical prostatectomy were found to have pT3N0 prostate cancer, had an undetectable postoperative prostate-specific antigen (PSA) level, and had no immediate hormonal therapy. Fifty-two patients received adjuvant RT within 3 to 6 months of surgery. Ninety-seven underwent radical prostatectomy alone and were observed until PSA failure. From these two cohorts, we matched patients 1:1 according to preoperative PSA (<10 ng/ml vs. >10 ng/ml), Gleason score (<7 vs. > or =7), seminal vesicle invasion, and surgical margin status. Seventy-two patients (36 pairs) were included in the analysis. Median follow-up time was 41 months. We calculated a matched-pairs risk ratio for cumulative risk of PSA relapse (a rise above 0.2 ng/ml). RESULTS: After controlling for the prognostic factors by matching, there was an 88% reduction (95% confidence interval [CI]: 78-93%) in the risk of PSA relapse associated with adjuvant RT. The 5-year freedom from PSA relapse rate was 89% (95% CI: 76-100%) for patients receiving adjuvant RT as compared to 55% (95% CI: 34-79%) for those undergoing radical prostatectomy alone. CONCLUSIONS: These data suggest that adjuvant RT for pT3N0 prostate cancer may significantly reduce the risk of PSA failure as compared to radical prostatectomy alone. Its effect on clinical outcome awaits further follow-up.     

Conformal technique dose escalation for prostate cancer: Biochemical evidence of improved cancer control with higher doses in patients with pretreatment prostate-specific antigen ≥10 ng/ml

: Conformal radiation technology results in fewer late complications and allows testing of the value of higher doses in prostate cancer.

: We report the biochemical freedom from disease (bNED) rates (BNED) failure in Prostate Specific Antigen (PSA) ≥ 1.5 ng/ml and rising) at 2 and 3 years for 375 consecutive patients treated with conformal technique from 66 to 79 Gy. Median follow-up was 21 months. Biochemical freedom from disease was analyzed for patients treated above and below 71 Gy as well as above and below 73 Gy. Each dose group was subdivided by pretreatment PSA level (<10, 10–19.9, and ≥20 ng/ml). Dose was stated to be at the center of prostate gland.

: There was significant improvement in bNED survuval for all patients divided by a dose above or below 71 Gy (p = 0.007) and a marginal improvement above or below 73 Gy (p = 0.07). Subdividing by pretreatment PSA level showed no benefit to the PSA < 10 ng/ml group at the higher dose but there was a significant improvement at 71 and 73 Gy for pretreatment PSA 10–19.9 ng/ml (p = 0.03 and 0.05, respectively) and for pretreatment PSA ≥ 20 ng/ml (p = 0.003 and 0.02, respectively).

: Increasing dose above 71 or 73 Gy did not result in improved bNED survuval for patient with pretreatment PSA < 10 ng/ml at 2 or 3 years. Further dose escalation studies may not be useful in the patients. A significant improvement in bNED survuval was noted for patients with pretreatment PSA ≥ 10 ng/ml treated above 71 of 73 Gy; further dose escalation studies are warranted.     

Adjuvant radiotherapy after radical prostatectomy

Background:Within 5 years following radical prostatectomy, between 15 and 60% of patients with pT3 prostate carcinomas show an increasing prostate specific antigen (PSA)as a sign of local and/or systemic tumour progression. Adjuvant radiotherapy (RT)for positive margins (R1)aims to reduce residual tumour cells in the prostatic bed, thus possibly reducing the biochemical progression rate. Apart from a large number of retrospective investigations, available results are presented from three randomised studies which have either been published completely (or in abstract form).Results:For pT3 prostate carcinomas, agreeing data are presented from three randomised studies, which show around a 20% reduced biochemical progression rate (bNED)after 4 to 5 years. With these data the results of numerous retrospective studies were conformed. The majority of the authors used total doses of 60 Gy. From one randomised study an increased local control rate was demonstrated as basis for the extended freedom of biochemical progression. The rate of acute and late side effects after three dimensional (3-D)planned radiotherapy with 60 Gy is very small and the rate of severe side effects is below 2%. The data situation for pT2 prostate carcinomas with positive margins is worse. Here, controversial data are presented, which require further investigation. Only retrospective data demonstrated a 25% advantage for adjuvant RT. Therefore, adjuvant radiotherapy also seems reasonable for pT-2 carcinomas with positive margins.Conclusions:The effectiveness of adjuvant radiotherapy for patients with pT-3 tumours with positive margins with and without undetectable PSA levels with 60 Gy total dose has been demonstrated. A survival advantage has not been shown until now. 3-D treatment planning remains the standard technique for these patients.For patients with positive margins in organ-limited prostate carcinomas (pT2 R 1)randomised studies are recommended.It remains unclear whether the adjuvant RT is superior to the radiotherapy for rising PSA levels out of the undetectable range after radical prostatectomy.     

Adjuvant and salvage radiotherapy after radical prostatectomy

BACKGROUND: Following radical prostatectomy, between 15 and 60% of all patients with pT3 prostate cancer experience persistence or increasing levels of prostate-specific antigen (PSA) as a sign of tumor persistence or progression within 5 years. Retrospective studies have shown a rate of 35-55% of positive biopsies from the vesicourethral anastomosis in this situation. Best treatment for these disease conditions is under debate, current strategies include adjuvant radiotherapy (RT), 'wait-and-see' and salvage RT or hormone therapy for increasing PSA. RESULTS: A number of retrospective studies have shown an increased rate of local control and 'freedom from treatment failure' following adjuvant RT with doses in the range of 50-60 Gy. However, no survival benefit could be demonstrated by now. Results of three major phase III studies are pending. In case of persisting or increasing PSA levels following radical prostatectomy, 30-70% of these patients will reach an undetectable PSA level after conformal RT with total doses of 60-70 Gy, which will stay undetectable or at least stable within the next 2-5 years in about 50% and therefore offering a chance of cure. When starting RT, PSA should be as low as possible (<2 ng/ml). With higher PSA levels the chance of achieving an undetectable PSA again decreases below 35%. High Gleason scores of 8-10, seminal vesicle involvement and a short PSA doubling time are adverse prognostic factors. Severe late side effects of conformal RT are infrequent (<3%). In contrast, hormonal treatment is of palliative nature in the long run, with a median time to development of metastases of 4-7 years, and can be offered to patients with progressive disease after RT. CONCLUSIONS: Adjuvant RT following radical prostatectomy for pT3 prostate cancer offers higher local control rates and an increase in 'freedom from treatment failure', but no prolongation of survival has yet been shown. In the situation of increasing PSA levels after radical prostatectomy, salvage RT seems to offer a chance of cure in selected patients, although it is difficult to draw firm conclusions because of generally too short follow-up times.     

Adjuvant and salvage radiotherapy after radical prostatectomy for prostate cancer

PURPOSE: The optimal role of radiotherapy (RT) to the prostate bed after radical prostatectomy (RP) is the subject of much debate. In this study, the results of adjuvant RT (ART) and salvage RT (SRT) were compared. METHODS AND MATERIALS: A total of 146 lymph node-negative patients were treated postoperatively after RP with RT to the prostate bed between 1987 and 1998. Of these, 75 patients had an undetectable prostate-specific antigen (PSA) level and were treated with ART for adverse pathologic features only to a median dose of 60 Gy (range 51-70). A positive margin was identified in 96%, and two of the three with negative margins had seminal vesicle involvement (SVI). SRT was administered for either a persistently detectable PSA level after RP (n = 27) or for a delayed rise in PSA (n = 44) to a median dose of 70 Gy (range 60-78). Adjuvant androgen ablation was given to 37 patients; 2 who had received ART and 35 had who received SRT. The median duration of androgen ablation was 24 months. The primary end point was freedom from biochemical failure (bNED), which was considered to be an undetectable PSA level. The median follow-up was 53 months for all patients: 68 months for the ART patients and 35 months for the SRT patients. RESULTS: For the ART group, 8 patients subsequently developed a rising PSA level. The 5-year bNED rate was 88%. SVI was the strongest predictor of outcome, with a 5-year bNED rate of 94% for those without SVI and 65% for those with SVI (p = 0.0002). SVI was the only significant factor in Cox proportional hazards regression analysis in the ART cohort. For the SRT group, 20 patients developed a rising PSA level after RT. The 5-year bNED rate was 66% for all SRT patients, and 43% and 78% in those with a persistently detectable PSA and those with a delayed rise in PSA, respectively. In the Cox proportional hazards regression analysis, this subdivision of SRT was statistically significant. Moreover, when the Cox model included all patients and variables, the timing of RT (ART vs. SRT) was an independent correlate of bNED, as was androgen ablation. CONCLUSION: For RP patients with high-risk pathologic features, the timing of postoperative RT and the PSA status after RP were strong determinants of outcome. Because of the potential confounding factors, direct comparisons of ART and SRT are problematic; however, ART is extremely effective and offers the surest approach for maintaining biochemical control.     

Outcome and predictive factors for patients with Gleason score 7 prostate carcinoma treated with three-dimensional conformal external beam radiation therapy

BACKGROUND: The purpose of this study was to determine the biochemical outcome and factors predictive of outcome in prostate carcinoma patients with Gleason score 7 tumors who were treated with three-dimensional conformal radiation therapy (3DCRT). METHODS: Between August 1990 and October 1997, 163 T1-T3NXM0 prostate carcinoma patients with Gleason score 7 were treated with definitive 3DCRT alone. The median follow-up, International Commission on Radiological Units dose, and pretreatment prostate specific antigen (PSA) for the entire group were 50 months, 76 grays (Gy), and 11.4 ng/mL, respectively. Independent predictors based on multivariate results were used to stratify the patients into prognostic groups for which biochemical no evidence of disease (bNED) control was reported. Biochemical NED failure was defined according to the American Society for Therapeutic Radiology and Oncology Consensus Panel definition. RESULTS: The 5-year bNED control for all patients was 66%. Stratified by pretreatment PSA, 5-year bNED control rates were 83%, 65%, and 21% for 0-9.9 ng/mL, 10-19.9 ng/mL, and > or =20 ng/mL, respectively. Dose to the central axis was found to be a significant treatment factor, with patients receiving > or =76 Gy experiencing 76% 5-year bNED control versus 54% when treated with <76 Gy to isocenter. Pretreatment PSA, dose, and palpation stage were significant independent predictors for bNED control upon multivariate analysis. Patients with a PSA <10 ng/mL who received a dose of > or =76 Gy had excellent 5-year bNED control of 100% compared with 50% bNED if patients had PSA >10 ng/mL or received radiation therapy doses of <76 Gy. CONCLUSIONS: Patients with Gleason score 7 adenocarcinoma who had a pretreatment PSA <10 ng/mL and received doses of > or =76 Gy had excellent 5-year bNED control, emphasizing the importance of higher central axis doses in treating Gleason 7 tumors. Patients with intermediate PSA (10-19.9 ng/mL) also required doses > or =76 Gy. Pretreatment PSA > or = 20 ng/mL portends a very poor bNED outcome for Gleason 7 patients treated with radiation therapy alone, and thus efforts should be directed toward multimodal or long term hormonal treatment strategies.     

Positive resection margin and/or pathologic T3 adenocarcinoma of prostate with undetectable postoperative prostate-specific antigen after radical prostatectomy: to irradiate or not?

PURPOSE: To evaluate the efficacy of postoperative adjuvant radiotherapy (RT) for positive resection margin and/or pathologic T3 (pT3) adenocarcinoma of the prostate with undetectable postoperative prostate-specific antigen (PSA) levels. METHODS AND MATERIALS: We retrospectively analyzed 125 patients with a positive resection margin and/or pT3 adenocarcinoma of the prostate who had undetectable postoperative serum PSA levels after radical prostatectomy. Seventy-three patients received postoperative adjuvant RT and 52 did not. Follow-up ranged from 1.5 to 12.0 years (median 4.2 for the irradiated group and 4.9 for the nonirradiated group). PSA outcome was available for all patients. Freedom from failure was defined as the maintenance of a serum PSA level of < or =0.2 ng/mL, as well as the absence of clinical local recurrence and distant metastasis. RESULTS: No difference was found in the 5-year actuarial overall survival between the irradiated and nonirradiated group (94% vs. 95%). However, patients receiving adjuvant RT had a statistically superior 5-year actuarial relapse-free rate, including freedom from PSA failure, compared with those treated with surgery alone (88% vs. 65%, p = 0.0013). In the irradiated group, 8 patients had relapse with PSA failure alone. None had local or distant recurrence. In the nonirradiated group, 15, 1, and 2 had PSA failure, local recurrence, and distant metastasis, respectively. On Cox regression analysis, pre-radical prostatectomy PSA level and adjuvant RT were statistically significant predictive factors for relapse, and Gleason score, extracapsular invasion, and resection margin status were not. There was a suggestion that seminal vesicle invasion was associated with an increased risk of relapse. The morbidity of postoperative adjuvant RT was acceptable, with only 2 patients developing Radiation Therapy Oncology Group Grade 3 genitourinary complications. Adjuvant RT had a minimal adverse effect on urinary continence and did not cause serious gastrointestinal toxicity. CONCLUSION: Postoperative adjuvant RT was associated with a lower risk of relapse, including freedom from PSA failure, compared with observation alone for pT3 and/or margin-positive disease with undetectable postoperative PSA levels. This was accomplished with a minimal risk of serious RT morbidity.     

Perineural invasion and Gleason 7-10 tumors predict increased failure in prostate cancer patients with pretreatment PSA <10 ng/ml treated with conformal external beam radiation therapy

Purpose: It has been well established that prostate cancer patients with pretreatment PSA<10 ng/ml enjoy excellent bNED control when treated with definitive external beam radiation therapy. This report identifies predictors of failure for patients with pretreatment PSA <10 ng/ml. These predictors are then used to define favorable and unfavorable prognostic subgroups of patients for which bNED control is compared.

Methods and Materials: Between 3/87 and 11/94, 266 patients with T1-T3NXM0 prostate cancer and pretreatment PSA values <10 ng/ml were treated with definitive external beam radiation therapy. Median central axis dose and median follow-up for the entire group was 72 Gy (63–79 Gy) and 48 months (2–120 months). Predictors of bNED control were evaluated univariately using Kaplan-Meier methodology and the log-rank test and multivariately using Cox proportional hazards modeling. Covariates considered were pretreatment PSA, palpation stage, Gleason score, presence of perineual invasion (PNI) and central axis dose. Independent predictors based on multivariate results were then used to stratify the patients into two prognostic groups for which bNED control was compared. bNED failure is defined as PSA ≥ 1.5 ng/ml and rising on two consecutive determinations.

Results: Univariate analysis according to pretreatment and treatment factors for bNED control demonstrates a statistically significant improvement in 5-year bNED control for patients with Gleason score 2–6 vs. 7–10, patients without evidence of perineural invasion (PNI) vs. those with PNI, and patients with palpation stage T1/T2AB vs. T2C/T3. Multivariate analysis demonstrates that Gleason score (p = 0.0496), PNI (p = 0.0008) and palpation stage (p = 0.0153) are significant independent predictors of bNED control. Based on these factors, patients are stratified into a more favorable prognosis group (Gleason 2–6, no PNI, and stage T1/T2AB, n = 172) and a less favorable prognosis group (Gleason 7–10 or PNI or T2C/T3, n = 94). A comparison of the two groups reveals that bNED control is significantly lower in the less favorable prognosis group (74% vs. 91% at 5 years, p = 0.0024).

Conclusions: (1) This report identifies Gleason 7–10 and the presence of PNI as well as palpation stage T2C/T3 as factors that predict worse bNED outcome for patients with pretreatment PSA < 10 ng/ml who are treated with radiation therapy alone. (2) Patients with these pretreatment prognostic factors may benefit from adjuvant therapies or altered treatment programs. (3) In order to make fair comparisons between radiation therapy and prostatectomy series, the distribution of perineual invasion and Gleason 7–10 must be taken into account.     

Treatment results of adjuvant radiotherapy and salvage radiotherapy after radical prostatectomy for prostate cancer

Background The indications for and the efficacy of radiation therapy after radical operation for patients with prostate cancer are not clear. We analyzed the treatment results of adjuvant radiotherapy and salvage radiotherapy after radical prostatectomy. Methods Between September 1997 and November 2004, 57 patients received adjuvant radiotherapy or salvage radiotherapy after radical prostatectomy. Fifteen patients received radiation therapy because of positive margins and/or extracapsular invasion in surgical specimens (adjuvant group). Forty-two patients received radiation therapy because of rising prostate-specific antigen (PSA) during follow-up (salvage group). Radiation therapy was delivered to the fossa of the prostate ± seminal vesicles by a three-dimensional (3-D) conformal technique to a total dose of 60–66 Gy (median, 60 Gy). Biochemical control was defined as the maintenance of a PSA level of less than 0.2 ng/ml. Results The median follow-up period after radiation therapy was 33 months (range, 12–98 months). Three-year biochemical control rates were 87% for the adjuvant group and 61% for the salvage group. For patients in the salvage group treated without hormone therapy, the preradiation PSA value was the most significant factor for the biochemical control rate. The 3-year biochemical control rate was 93% in patients whose preradiation PSA was 0.5 ng/ml or less and 29% in patients whose preradiation PSA was more than 0.5 ng/ml. No severe adverse effects (equal to or more than grade 3) were seen in treated patients. Conclusion Radiation therapy after radical prostatectomy seemed to be effective for adjuvant therapy and for salvage therapy in patients with a preradiation PSA of 0.5 ng/ml or less. Also, radiation to the fossa of the prostate ± seminal vesicles, to a total dose of 60–66 Gy, using a three-dimensional (3-D) conformal technique, seemed to be safe.     

Durable efficacy of adjuvant radiation therapy for prostate cancer: will the benefit last?

Radical prostatectomy can be an effective therapy for men with organ-confined disease. However, extension beyond the confines of the prostate (pT3) can be found in many men, and this is often associated with longterm prostate-specific antigen (PSA) failure. Not all patients will progress with pT3 disease. The identification of additional adverse prognostic features (high Gleason score, PSA greater than 10 ng/mL, and seminal vesical invasion) can help identify those men at highest risk of progression following definitive surgery. The role of postoperative therapy in patients with high-risk features is often controversial. The lack of long-term survival benefit, toxicity, and cost are often cited. We reviewed our experience with a unified approach to this patient population and performed matched-pair analysis of patients with similar adverse prognostic features treated with and without postoperative radiation therapy. For our series, the results indicate that the addition of adjuvant radiation therapy is associated with a significantly reduced risk of PSA recurrence. The 5-year bNED rate after adjuvant radiation therapy was 89% (95% CI: 76% to 100%) compared with 55% (95% CI: 34% to 79%) after surgery alone (P = .002). This benefit also appears to hold true for men with pathological involvement of their seminal vesicles. A dose-response curve was observed with improved disease control above a level of 61.2 Gy. Appropriate patient selection and delivery of an adequate dose of radiation can improve the PSA recurrence of most patients with pT3 disease.     

Dose selection for prostate cancer patients based on dose comparison and dose response studies

PURPOSE: To better define the appropriate dose for individual prostate cancer patients treated with three-dimensional conformal radiation therapy (3D CRT). METHODS AND MATERIALS: Six hundred eighteen patients treated with 3D CRT between 4/89 and 4/97 with a median follow-up of 53 months are the subject of this study. The bNED outcomes were assessed by the American Society for Therapeutic Radiology and Oncology (ASTRO) definition. The patients were grouped into three groups by prostate-specific antigen (PSA) level (<10 ng/ml, 10-19.9 ng/ml, and 20+ ng/ml) and further subgrouped into six subgroups by favorable (T1, 2A and Gleason score < or =6 and no perineural invasion) and unfavorable characteristics (one or more of T2B, T3, Gleason 7-10, perineural invasion). Dose comparisons for bNED studies were made for each of the six subgroups by dividing patients at 76 Gy for all subgroups except the favorable <10 ng/ml subgroup, which was divided at 72.5 Gy. Five-year bNED rates were compared for the median dose of each dose comparison subgroup. Dose response functions were plotted based on 5-year bNED rates for the six patient groupings, with the data from each of the six subgroups divided into three dose groups. The 5-year bNED rate was also estimated using the dose response function and compares 73 Gy with 78 Gy. RESULTS: Dose comparisons show a significant difference in 5-year bNED rates for three of the six subgroups but not for the favorable <10 ng/ml, the favorable 10-19.9 ng/ml, or the unfavorable > or =20 ng/ml subgroups. The significant differences ranged from 22% to 40% improvement in 5-year bNED with higher dose. Dose response functions show significant differences in 5-year bNED rates comparing 73 Gy and 78 Gy for four of the six subgroups. Again, no difference was observed for the favorable <10 ng/ml group or the unfavorable > or =20 ng/ml group. The significant differences observed in 5-year bNED ranged from 15% to 43%. CONCLUSIONS: Dose response varies by patient subgroup, and appropriate dose can be estimated for up to six subdivisions of prostate cancer patients. The appropriate use of high dose with 3D CRT results in 5-year cure rates that equal or exceed other treatments. The national practice must be upgraded to allow the safe administration of 75-80 Gy with 3D CRT.     

A Dose–Response Study for I-125 Prostate Implants

Purpose: No dose–response study has ever been performed for I-125 prostate implants using modern techniques of implant evaluation and modern treatment outcome end points. The amount of activity per volume implanted was increased over time based on review of postimplant dosimetry. This resulted in different delivered dose levels. This study explores the relationship between dose, biochemical failure, and biopsy results.Materials and Methods: 134 patients with T1–T2 prostate cancer were implanted with I-125 radioactive seeds and followed from 12 to 74 months (median: 32) postimplant. No patient received external beam irradiation or hormonal therapy. All patients implanted with I-125 had Gleason scores ≤6. One month postimplant, a CT-based three-dimensional dosimetric evaluation was performed on all patients. Using TG43 guidelines, dose–volume histograms were calculated. The dose delivered to the gland was defined as the D90 (dose delivered to 90% of prostate tissue as defined by CT). The D90s ranged from 26.8 to 256.3 Gy (median: 140.8 Gy). Biochemical failure was defined as two consecutive rises in prostate specific antigen (PSA) or a nadir level above 1.0 ng/ml. Posttreatment prostate biopsies (six to eight core samples) were routinely performed at 2 years postimplant.Results: Improvements in freedom from biochemical failure (FFBF) rates were seen with increasing D90 levels. The 4-year FFBF rates for patients with D90 values <100 Gy, 100–119.9 Gy, 120–13.9 Gy, 140–159.9 Gy, and ≥160 Gy were 53, 82, 80, 95, and 89%, respectively (p = 0.02). Patients receiving a D90 <140 Gy (65 patients) were similar with respect to presenting disease prognostic factors to those receiving a D90 ≥140 Gy (69 patients). Patients receiving a D90 <140 Gy had a 4-year FFBF rate of 68% compared to a rate of 92% for those receiving a D90 ≥140 Gy (p = 0.02). Two-year posttreatment biopsies were negative in 70% (33 of 47) of patients with a D90 < 140 Gy compared to a rate of 83% (24 of 29) in patients with a D90 ≥140 Gy (p = 0.2). A multivariate analysis using dose, PSA, score, and stage revealed that dose was the most significant predictor of biochemical failure (p = 0.001). This dose response was more pronounced in patients presenting with PSA levels >10 ng/ml. In these patients, the 4-year FFBF rates were 51 and 100% for the low and high dose groups, respectively (p = 0.009) and the negative biopsy rates were 64% (14 of 22) and 100% (8 of 8), respectively (p = 0.05). In patients with presenting PSA <10 ng/ml, the 4-year FFBF rates were 82 and 88% for the low and high dose groups, respectively (p = 0.29).Conclusion: A dose response was observed at a level of 140 Gy. Adequate I -125 implants should deliver a dose of 140–160 Gy using TG43 guidlines.     

Radiation therapy (RT) after prostatectomy: The case for salvage therapy as opposed to adjuvant therapy

Patients with pathologic stage T3 or T4 prostate cancer who have undetectable PSA levels following radical retropubic prostatectomy (RRP) have a substantial risk of recurrence. Radiotherapy (RT) can be administered immediately following the RRP (immediate adjuvant RT) or may be postponed until the PSA level has risen to a level that is indicative of residual or recurrent prostate cancer (salvage RT). Immediate adjuvant RT can significantly reduce the risk of relapse, but does not appear to increase the rate of survival. Approximately two-thirds of patients with rising PSA levels after RRP can be salvaged with RT alone. This result was achieved in patients treated with an adequate dose of radiation before the PSA rose to > 1.1 ng/ml. While no one can be certain which approach (adjuvant or salvage RT) is better, future studies should examine this issue. Whether immediate postoperative adjuvant RT is of value to patients is the subject of two randomized prospective studies. The benefit of adjuvant RT is a matter of controversy. Salvage RT treats only those patients with proven residual prostate cancer. The salvage RT approach has several advantages. This approach spares approximately 40% of patients who have had an RRP for T3 or T4 prostate cancer and eliminates the risks and costs associated with adjuvant RT. Additionally, it appears that the results of immediate adjuvant RT are similar to those achieved with early salvage RT.     

A comparison of external beam radiation therapy versus radical prostatectomy for patients with low risk prostate carcinoma diagnosed, staged, and treated at a single institution

BACKGROUND: The authors retrospectively reviewed their institution's long term experience treating a group of comparably staged low risk prostate carcinoma patients with either radical prostatectomy or external beam radiation therapy (RT) to determine whether the method of treatment resulted in significant differences in biochemical control and/or survival. METHODS: From January of 1987 through December of 1994, 382 patients (157 who underwent radical prostatectomy and 225 who received external beam RT) were treated with curative intent for localized prostate carcinoma at William Beaumont Hospital. All patients had a pretreatment serum prostate specific antigen (PSA) level < or =10.0 ng/mL and a biopsy Gleason score or =0.2 ng/mL at any time after prostatectomy. For RT patients, biochemical failure was defined according to the American Society for Therapeutic Radiology and Oncology Consensus Panel definition. Pretreatment PSA levels and Gleason scores were not significantly different between patients treated with radical prostatectomy or RT. The median follow-up in each treatment group was 5.5 years. RESULTS: The 7-year actuarial rates of biochemical control and cause specific survival were not significantly different between patients treated either with radical prostatectomy or RT (67% vs. 69% for biochemical control and 99% vs. 97% for cause specific survival, respectively). A number of clinical, pathologic, and treatment-related factors were analyzed for an association with biochemical failure (i.e., age, pretreatment PSA, Gleason score, and treatment modality). Only pretreatment PSA and Gleason score were significantly related to outcome in both univariate and multivariate analyses. CONCLUSIONS: Low risk prostate carcinoma patients with similar pretreatment PSA levels and biopsy Gleason scores treated at the same institution with either radical prostatectomy or RT achieved similar 7-year rates of biochemical control and cause specific survival, regardless of treatment technique. These findings suggest that for patients with pretreatment PSA levels 相似文献   

External beam radiotherapy dose response characteristics of 1127 men with prostate cancer treated in the PSA era

PURPOSE: To characterize the relationship of radiotherapy dose to prostate cancer patient outcome, with an emphasis on the influence of pretreatment prognostic variables. METHODS AND MATERIALS: The 1127 Stage T1-T4 prostate cancer patients examined were treated consecutively with definitive external beam radiotherapy at the University of Texas-M.D. Anderson Cancer Center from 1987 to 1997. All had a pretreatment prostate-specific antigen (PSA) level. Treatment failure was defined as two consecutive PSA elevations on follow-up. There were 994 patients treated with a four-field box throughout to 60-70 Gy after a small reduction at 46 Gy and 161 treated with a six-field conformal boost after 46 Gy to 74-78 Gy. No patient received neoadjuvant or adjuvant androgen ablation. Median follow-up was 51.8 months. RESULTS: Patients were divided into three radiotherapy dose groups consisting of 67-77 Gy (n = 495), and >77 Gy (n = 132). Relative to other prognostic factors, there were fewer patients treated to the highest dose level with a pretreatment PSA (PSAB) 20 ng/ml, Stage T3/T4 disease, or a Gleason score of 2-6. Actuarial 4-year freedom from biochemical failure (bNED) rates for the entire cohort were 54%, 71%, and 77% (p < 0.0001) for the low-, intermediate-, and high-dose groups. PSAB, palpable stage, and Gleason score were also highly significant. In Cox proportional hazards regression, dose (p < 0. 0001 as a continuous or categorical variable) was an independent predictor of bNED, as were the other prognostic factors. Pairwise univariate comparisons showed that an increase in dose from 67-77 Gy was associated with improved bNED rates for all PSAB (10), stage (T1/T2 and T3/T4), and Gleason score (2-6 and 7-10) subgroups tested. In contrast, the only prognostic group that benefited from raising dose from >67-77 Gy to >77 Gy was patients with a PSAB >10 ng/ml; although trends were noted for Stage T1/T2 and Gleason 2-6 patients. Patients with the combined features of a PSAB >10 ng/ml and Stage T1/T2 disease had 4-year bNED rates of 61% and 93% at the intermediate- and high-dose levels. A strongly significant linear association between dose (60-78 Gy) and 4-year actuarial bNED was demonstrated for patients with these intermediate-risk features. CONCLUSION: Prostate cancer dose response to external beam radiotherapy should be considered in the context of pretreatment prognostic factors. Our data indicate that, for favorable patients with a PSAB of 67-77 Gy provide the same rate of control as higher doses. However, longer follow-up may reveal a benefit to dose escalation >77 Gy, even in this favorable subset. Substantial and clinically relevant enhancements in bNED were seen at all dose levels for moderate-risk patients, such as those having a PSAB >10 ng/ml and Stage T1/T2 disease. Sustained bNED was not realized for high-risk patients, even using 78 Gy; these patients may be best treated with higher doses, whole pelvic irradiation, and/or androgen ablation plus radiation.     

Dose response in prostate cancer with 8-12 years' follow-up

PURPOSE: This communication reports the long-term results of the original group of prostate cancer patients who participated in the first prospective Fox Chase Cancer Center radiation dose escalation study for which 8-12 years of follow-up is now available. METHODS AND MATERIALS: Between March 1, 1989 and October 31, 1992, 232 patients with clinically localized prostate cancer received three-dimensional conformal radiotherapy only at Fox Chase Cancer Center in a prospective dose-escalation study. Of these patients, 229 were assessable. The 8-, 10-, and 12-year actuarial rates of biochemical control (biochemically no evidence of disease [bNED]), freedom from distant metastasis (FDM), and morbidity were calculated. The Cox proportional hazards model was used to assess multivariately the predictors of bNED control and FDM, including pretreatment prostate-specific antigen (PSA) level (continuous), tumor stage (T1/T2a vs. T2b/T3), Gleason score (2-6 vs. 7-10), and radiation dose (continuous). The median total dose for all patients was 74 Gy (range 67-81). The median follow-up for living patients was 110 months (range 89-147). bNED control was defined using the American Society for Therapeutic Radiology and Oncology consensus definition. RESULTS: The actuarial bNED control for all patients included in this series was 55% at 5 years, 48% at 10 years, and 48% at 12 years. Patients with pretreatment PSA levels of 10-20 ng/mL had statistically significant differences (19% vs. 31% vs. 84%, p = 0.0003) in bNED control when stratified by dose (<71.5, 71.5-75.6, and > 75.6 Gy, respectively) on univariate analysis. For the 229 patients with follow-up, 124 (54%) were clinically and biochemically without evidence of disease. Sixty-nine patients were alive at the time of last follow-up, and 55 patients were dead of intercurrent disease. On multivariate analysis, radiation dose was a statistically significant predictor of bNED control for all patients and for unfavorable patients with a pretreatment PSA <10 ng/mL. For the patients with a pretreatment PSA level of 10-20 ng/mL, the radiation dose was a statistically significant predictor across all groups. No radiation dose response was seen for those patients with a pretreatment PSA level >20 ng/mL, although large numbers of patients are required to demonstrate a difference. The radiation dose, Gleason score, and palpation T stage were significant predictors for the entire patient set, as well as for those with pretreatment PSA levels between 10 and 20 ng/mL. The FDM rate for all patients included in this series was 89%, 83%, and 83% at 5, 10, and 12 years, respectively. For patients with pretreatment PSA levels <10 ng/mL, all four covariates (radiation dose, Gleason score, pretreatment PSA, and palpation T stage) were significant predictors of distance metastasis. Using the Radiation Therapy Oncology Group morbidity scale, no difference was noted in the frequency of Grade 2 and 3 genitourinary and Grade 3 gastrointestinal morbidity when patients in this data set were stratified by radiation dose. However, a significant increase occurred in Grade 2 gastrointestinal complications as the radiation dose increased. CONCLUSION: The long-term results of the original Fox Chase radiation dose escalation study with >9 years of median follow-up confirm the existence of a dose response for both bNED control and FDM. The dose response in prostate cancer is real, and the absence of biochemical recurrence after 8 years demonstrates the lack of late failure and suggests cure.     

Patterns and fate of PSA bouncing following 3D-CRT.

PURPOSE: The goals of this study were to quantify the frequency of post-treatment prostate-specific antigen (PSA)-level bouncing following three-dimensional conformal radiation therapy (3D-CRT) for prostate cancer and to identify any relationships that may exist between bouncing activity and biochemical control (bNED). METHODS: Between May 1989 and July 1995, 306 patients were treated with 3D-CRT alone. All patients had 6 or more post-treatment PSA levels and at least 5 years of PSA follow-up. The median total follow-up and total dose to the center of prostate was 79 months and 74 Gy, respectively. A bounce was defined by a minimum rise in PSA of 0.4 ng/mL over a 6-month period, followed by a drop in PSA of any magnitude. Estimates of bNED control rates were made using Kaplan-Meier methodology and comparisons were made using the log-rank test. Multivariate analysis of bNED control predictors was accomplished using a stepwise Cox proportional hazards model. RESULTS: Nearly one third of the patients experienced at least one bounce. Bouncers were found to present with higher pretreatment PSA levels and were treated with lower dose levels to the center of prostate. Five-year bNED control estimates for nonbouncers vs. bouncers were 69% and 52%, respectively (p = 0.0024). After controlling for dose and pretreatment PSA level, total number of bounces emerged as a significant predictor of bNED control (p = 0.02). CONCLUSIONS: Bouncing PSA levels occur in approximately one third of the patients treated with 3D-CRT alone, with bouncing occurring at a constant rate from 2 to 5 years post-treatment. Bouncing is associated with lower radiation dose levels, higher pretreatment PSA levels, and decreased bNED control. Nearly half of the bouncers are bNED controlled; thus, clinicians should not use bouncing as a sole indicator of relapse.