Androgen deprivation-induced changes in prostate anatomy predict urinary morbidity after permanent interstitial brachytherapy

PURPOSE: To evaluate the cytoreductive consequences of neoadjuvant androgen deprivation therapy on International Prostate Symptom Score (IPSS) normalization, catheter dependency, and the need for surgical intervention secondary to bladder outlet obstruction after permanent interstitial brachytherapy. METHODS AND MATERIALS: A total of 116 patients (median follow-up, 30 months) with preandrogen and postandrogen deprivation therapy ultrasound studies and no history of preimplant transurethral resection of the prostate were evaluated. Androgen deprivation-induced changes in prostate volume, transition zone (TZ) volume, and urethral location were correlated with IPSS resolution, catheter dependency, and the need for postimplant surgical intervention. Prostate gland and TZ dimensions and volumes were measured by prolate ellipsoid calculation from the static ultrasound images. The urethral location was determined by identification of a urinary catheter. Additional clinical, treatment, and dosimetric parameters evaluated included patient age, pretreatment prostate-specific antigen, Gleason score, clinical T stage, preimplant IPSS, pre- and postandrogen deprivation ultrasound studies, treatment planning volume, supplemental external beam RT, isotope, total implant activity, Day 0 maximal dose received by 90% of the prostate gland, Day 0 percentage of prostate volume receiving 100%, 150%, and 200% of the prescribed minimal peripheral dose, and urethral dose. RESULTS: For hormonally manipulated patients, the prostate volume at implantation did not have a statistical influence on the percentage of patients returning to IPSS baseline, the time for IPSS normalization, the incidence of catheter dependency, the catheter-dependency time, or the need for postimplant surgical intervention. However, when compared with the hormone-naive cohort, hormonally manipulated patients were more likely to undergo postimplant surgical intervention (5.2% vs. 0.3%, p = 0.001). Greater androgen deprivation-induced reductions in prostate and TZ volumes, along with movement of the urethra closer to the posterior border of the prostate gland, resulted in a decreased incidence of postimplant urinary morbidity. Using Cox regression analysis, the time to IPSS resolution was best predicted by the percentage of TZ volume reduction. Stepwise linear regression analysis demonstrated that the catheter-dependency time was best predicted by the prehormonal therapy prostate volume, posthormonal therapy TZ volume, and the change in the urethral position; prolonged catheter dependency by the percentage of TZ volume reduction, prehormonal therapy TZ index, and the change in the urethral position; and the need for postimplant surgical intervention by the posthormonal therapy TZ index and the change in the urethral location. CONCLUSION: After neoadjuvant androgen deprivation therapy for volume reduction, some brachytherapy-related urinary morbidity parameters are highly related to the preandrogen deprivation prostate volume, variants in the TZ volume, and changes in the urethral location.     

Detailed urethral dosimetry in the evaluation of prostate brachytherapy-related urinary morbidity

PURPOSE: To evaluate the relationship between urinary morbidity after prostate brachytherapy and urethral doses calculated at the base, midprostate, apex, and urogenital diaphragm. METHODS AND MATERIALS: From February 1998 through July 2002, 186 consecutive patients without a prior history of a transurethral resection underwent monotherapeutic brachytherapy (no supplemental external beam radiation therapy or androgen deprivation therapy) with urethral-sparing techniques (average urethral dose 100%-140% minimum peripheral dose) for clinical T1c-T2b (2002 AJCC) prostate cancer. The median follow-up was 45.5 months. Urinary morbidity was defined by time to International Prostate Symptom Score (IPSS) resolution, maximum increase in IPSS, catheter dependency, and the need for postimplant surgical intervention. An alpha blocker was initiated approximately 2 weeks before implantation and continued at least until the IPSS returned to baseline. Evaluated parameters included overall urethral dose (average and maximum), doses to the base, midprostate, apex, and urogenital diaphragm, patient age, clinical T stage, preimplant IPSS, ultrasound volume, isotope, and D90 and V100/150/200. RESULTS: Of the 186 patients, 176 (94.6%) had the urinary catheter permanently removed on the day of implantation with only 1 patient requiring a urinary catheter >5 days. No patient had a urethral stricture and only 2 patients (1.1%) required a postbrachytherapy transurethral resection of the prostate (TURP). For the entire cohort, IPSS on average peaked 2 weeks after implantation with a mean and median time to IPSS resolution of 14 and 3 weeks, respectively. For the entire cohort, only isotope predicted for IPSS resolution, while neither overall average prostatic urethra nor segmental urethral dose predicted for IPSS resolution. The maximum postimplant IPSS increase was best predicted by preimplant IPSS and the maximum apical urethral dose. CONCLUSIONS: With the routine use of prophylactic alpha blockers and strict adherence to urethral-sparing techniques, detailed urethral dosimetry did not substantially improve the ability to predict urinary morbidity. Neither the average dose to the prostatic urethra nor urethral doses stratified into base, midprostate, apex, or urogenital diaphragm segments predicted for IPSS normalization. Radiation doses of 100%-140% minimum peripheral dose are well tolerated by all segments of the prostatic urethra with resultant tumoricidal doses to foci of periurethral cancer.     

Transperineal brachytherapy in patients with large prostate glands

The purpose of this study is to help clarify the use of prostate size as a selection factor for prostate brachytherapy. From 1997 to 1998, 33 patients with a TRUS-based prostate volume greater than 50 cc were treated at the University of Washington by I-125 (144 Gy) or Pd-103 (115 Gy) implantation for prostatic carcinoma. These 33 patients comprised 7% of the total implants performed. Each patient underwent a preimplant TRUS study in the lithotomy position, taking serial axial images of the prostate at 0.5 cm intervals from the base of the gland to the apex. The contours on the preimplant TRUS images were used to calculate the prostate volumes reported here. Only one patient received supplemental external beam irradiation prior to implantation. Twelve patients were treated with neoadjuvant androgen ablation prior to implantation. The prostate volumes quoted here are those taken after hormonal downsizing. Postimplant axial CT images were digitized to calculate the CT-based target coverage. Preimplant urinary obstructive symptoms were quantified by the criteria of the American Urologic Association. Each patient was contacted at the time of this article preparation to update postimplant morbidity information. In all cases, at least 80% of the postimplant volume was covered, despite a median implant-related volume increase of 15%. Five of the 33 patients' postimplant CT scans showed some degree of incomplete target coverage of the anterior/lateral prostate margin. There was no clear association between inadequate anterior/lateral coverage and the degree of interference. Twelve of the 33 patients developed acute postimplant urinary retention, all occurring within 24 hr of implantation. Within this group of 33 patients with a large prostate volume, there was no relationship between the likelihood of acute or chronic urinary retention and preimplant prostate size or obstructive symptoms. Patients who developed postimplant retention lasting more than one week were generally managed by intermittent self-catheterization. By one month, 85% of patients were catheter-free. Based on the data reported here, we are more inclined to accept patients with a large prostate for implantation without insisting on preimplant size reduction. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 199-205 (2000).     

Urinary Incontinence in Patients Who Have a TURP/TUIP Following Prostate Brachytherapy

Purpose: To determine urinary morbidity in patients who have transurethral resection of the prostate (TURP) after ¹²⁵I brachytherapy.Materials and Methods: A total of 109 patients with Stage T1–T2 prostatic carcinoma were treated with ¹²⁵I implantation from 1991 through 1995. Ten patients underwent TURP/transurethral incision of the prostate (TUIP) after brachytherapy to relieve urinary obstruction refractory to nonsurgical management.Results: Patients who developed refractory urinary retention had a slightly larger preimplant prostate volume than those who did not (62 vs. 54 ml; p = 0.16). Seven of the 10 patients developed some degree of permanent urinary incontinence following TURP/TUIP. Urinary incontinence was mild in three patients [Late Effects Normal Tissue Radiation Oncology Group (LENT) score = 1] and severe in four additional patients (LENT score = 3). There was no obvious relationship between the degree of incontinence and use of TURP vs. TUIP, amount of tissue resected, or time between brachytherapy and TURP/TUIP. In five patients for whom detailed urethral radiation dose information was available, the doses were higher than generally recommended.Conclusion: Permanent urinary incontinence is common in patients who require a TURP or TUIP after prostate brachytherapy. Its cause is apparently multifactorial and may include the degree of physical damage to the urinary sphincters and the radiation dose to the urethral region.     

Dysuria after permanent prostate brachytherapy

PURPOSE: Although numerous prostate cancer quality-of-life studies have been reported, a paucity of data exists regarding brachytherapy-related dysuria. In this study, we evaluated the incidence and temporal resolution of dysuria, along with the influence of multiple treatment, clinical, and dosimetric parameters. MATERIALS AND METHODS: Five hundred eighty-one consecutive patients without a preimplant history of transurethral resection of the prostate underwent brachytherapy between January 1998 and December 2001 for clinical T1c-T3a (1997 AJCC) adenocarcinoma of the prostate gland. The evaluated population consisted of the 546 patients who had completed at least two postimplant dysuria evaluations. The median patient follow-up was 26.4 months. In all patients, alpha-blocker therapy was initiated before implantation and continued at least until the International Prostate Symptom Score (IPSS) returned to baseline. The frequency of dysuria was assessed on a 1-5 scale using the IPSS scoring criteria. The dysuria severity was scored on a 1-10 scale. The clinical parameters evaluated included age, T stage, preimplant IPSS, ultrasound volume, and elapsed time since implantation. The treatment parameters included the use of neoadjuvant hormonal manipulation, use of supplemental external beam radiotherapy, isotope, and total implanted seed strength. The dosimetric parameters included values of the minimal dose received by 90% of the prostate, the percentage of prostate volume receiving 100%, 150%, and 200% of the prescribed minimal peripheral dose, and the median and maximal urethral doses. RESULTS: The incidence of dysuria peaked at 52% 1 month after implantation. The median dysuria frequency score was 0 of 5 for all patients and 2 of 5 for those reporting dysuria. The median severity score was 0 of 10 for the entire cohort and 3 of 10 for those reporting dysuria. For the entire group, both the frequency and the severity of dysuria steadily improved with time, with near complete resolution of dysuria at 45 months. For those patients reporting dysuria, neither the frequency nor the severity revealed any durable improvement for approximately 36 months. Patients with dysuria displayed higher postimplant IPSSs. Of the 7 IPSS questions, nocturia and incomplete voiding were the best surrogates for dysuria. The isotope, supplemental external beam radiotherapy, hormonal status, minimal dose received by 90% of the prostate, and urethral dose did not predict for dysuria. CONCLUSIONS: After permanent prostate brachytherapy, dysuria is a relatively common event, but only rarely severe in frequency or intensity. At approximately 45 months after brachytherapy, dysuria appears to resolve in almost all patients.     

Urinary morbidity following ultrasound-guided transperineal prostate seed implantation.

PURPOSE: To assess the urinary morbidity experienced by patients undergoing ultrasound-guided, permanent transperineal seed implantation for adenocarcinoma of the prostate. METHODS AND MATERIALS: Between September 1992 and September 1997, 693 consecutive patients presented with a diagnosis of clinically localized adenocarcinoma of the prostate, and were treated with ultrasound-guided transperineal interstitial permanent brachytherapy (TPIPB). Ninety-three patients are excluded from this review, having received neoadjuvant antiandrogen therapy. TPIPB was performed with 125I in 165 patients and with 103Pd in 435 patients. Patients treated with implant alone received 160 Gy with 125I (pre TG43) or 120 Gy with 103Pd. One hundred two patients received preimplant, pelvic external beam radiation (XRT) to a dose of either 41.4 or 45 Gy because of high-risk features including PSA > or = 10 and/or Gleason score > or = 7. Combined modality patients received 120 Gy and 90 Gy, respectively for 125I or 103Pd. All patients underwent postimplant cystoscopy and placement of an indwelling Foley catheter for 24-48 h. Follow-up was at 5 weeks after implant, every 3 months for the first 2 years, and then every 6 months for subsequent years. Patients completed AUA urinary symptom scoring questionnaires at initial consultation and at each follow-up visit. Urinary toxicity was classified by the RTOG toxicity scale with the following adaptations; grade 1 urinary toxicity was symptomatic nocturia or frequency requiring none or minimal medical intervention such as phenazopyridine; grade 2 urinary toxicity was early obstructive symptomatology requiring alpha-blocker therapy; and grade 3 toxicity was considered that requiring indwelling catheters or posttreatment transurethral resection of the prostate for symptom relief. Log-rank analysis and Chi-square testing was performed to assess AUA score, prostate size, isotope selection, and the addition of XRT as possible prognosticators of postimplant urinary toxicity. The prostate volume receiving 150% of the prescribed dose (V150) was studied in patients to assess its correlation with urinary toxicity. RESULTS: Median follow-up was 37 months (range 6-68). Within the first 60 days, 37.3% of the patients reported grade 1 urinary toxicity, 41% had grade 2, and 2.2% had grade 3 urinary toxicity. By 6 months, 21.4% still reported grade 1 urinary toxicity, whereas 12.8% and 3% complained of grade 2 and 3 urinary difficulties, respectively. Patients with a preimplant AUA score < or = 7 had significantly less grade II toxicity at 60 days compared to those with an AUA score of >7 (32% vs. 59.2%, respectively, p = 0.001). Similarly, prostatic volumes < or = 35 cc had a significantly lower incidence of grade II urinary toxicity (p = 0.001). There was no difference in toxicity regarding the isotope used (p = 0.138 at 60 days, p = 0.45 at 6 months) or the addition of preimplant XRT (p = 0.069 at 60 days, p = 0.84 at 6 months). Twenty-eight patients (4.7%) underwent TURP after 3 isotope half-lives for protracted obstructive symptoms. Five of these men (17%) developed stress incontinence following TURP, but all patients experienced relief of their obstructive symptoms without morbidity at last follow-up. The percent of the prostate receiving 150% of the prescribed dose (V150) did not predict urinary toxicity. CONCLUSIONS: TPIPB is well tolerated but associated with mild to moderate urinary morbidity. Pretreatment prostatic volume and AUA scoring were shown to significantly predict for grade 2 toxicity while the use of preimplant, pelvic XRT and isotope selection did not. Patients undergoing TURP for protracted symptoms following TPIPB did well with a 17% risk of developing stress incontinence. V150 did not help identify patients at risk for urinary morbidity. As transperineal prostate implantation is used more frequently the associated toxicities and the definition of possible pretreatment prognostic factors is necessary to     

Prostate brachytherapy can be performed in selected patients after transurethral resection of the prostate

PURPOSE: To evaluate urinary function and bother after prostate brachytherapy (PB) in patients who have had prior transurethral resection of the prostate (TURP). METHODS AND MATERIALS: A total of 171 patients with stage T1a-T2b prostate cancer, Gleason score 相似文献   

Long-term urinary quality of life after permanent prostate brachytherapy

PURPOSE: To evaluate late urinary function after permanent prostate brachytherapy using a validated, patient-administered quality-of-life instrument. METHODS AND MATERIALS: A total of 225 consecutive patients underwent prostate brachytherapy between April 1995 and March 1998. Of the 225 patients, 17 had died and 3 had been institutionalized secondary to Alzheimer's disease. Of the remaining 205 patients, each was mailed a self-administered questionnaire (the urinary function component of the Expanded Prostate Cancer Index [EPIC] and the International Prostate Symptom Score [IPSS]). Of the 205 surveys mailed, 195 (95.1%) were returned. The mean and median follow-up was 66.3 and 64.0 months, respectively. The clinical parameters evaluated included age, pretreatment prostate-specific antigen level, Gleason score, stage, risk group, prostate volume, presence of diabetes and hypertension, and tobacco consumption. The treatment parameters included the ultrasound planning volume, hormonal status, use of supplemental external beam radiotherapy, isotope, and follow-up. The dosimetric parameters included values of the minimal dose received by 90% of the prostate gland and the percentage of prostate volume receiving 100%, 150%, and 200% of the prescribed minimal peripheral dose. Because detailed baseline urinary function was not available, a cross-sectional survey was performed in which 51 newly diagnosed prostate cancer patients of comparable demographics served as controls. RESULTS: When the survey scores for the implant patients were compared with the control group, no significant differences in either the IPSS or function, bother, incontinence, or irritation/obstruction subscales of the urinary EPIC were discernible. In addition, no significant difference was observed between the implant and control groups when the EPIC and IPSS surveys were evaluated by each individual question. Of all the evaluated parameters, the use of tobacco was the best predictive variable for diminished quality of life. CONCLUSION: No significant difference was noted in the overall long-term urinary quality of life when brachytherapy patients were compared with a group of newly diagnosed prostate cancer patients of comparable demographics. Of all parameters evaluated, tobacco consumption was the single strongest predictor of late urinary function.     

Factors predicting for urinary morbidity following 125iodine transperineal prostate brachytherapy.

PURPOSE: To assess factors related to the risk of acute urinary retention and other morbidity indices in patients undergoing transperineal seed implantation of the prostate. MATERIALS AND METHODS: One hundred and seventy-three consecutive patients treated with (125)Iodine transperineal interstitial permanent prostate brachytherapy (TIPPB) were evaluated. Various demographic, pathological, symptomatic, urodynamic and dosimetric values were assessed in relation to the incidence of acute urinary retention as well as the International Prostate Symptom Score (IPSS) dynamics. Patients were routinely placed on alpha-blockade postimplant. Dosimetry was based on CT scan one month postimplant. RESULTS: Acute urinary retention developed in thirty-four patients (19.7%), at a median time of four days. Peak urinary flow rate was the only independent factor which varied significantly between those suffering retention and those not (median of 16 and 19.5 ml/s respectively, P=0.005). Median preimplant IPSS was 4.0, with a median peak of 16 at 3 months. Actuarial median time to return to baseline IPSS was at 15 months. The peak IPSS above preimplant levels was correlated significantly in multivariate analysis with the number of seeds implanted superior to the physician-nominated anatomical base level of the prostate (P<0.009), as well as lower preimplant IPSS values. CONCLUSIONS: In our series, preimplant urinary flow rate was the most important factor predictive of postimplant acute urinary retention. The patients' risk of having heightened IPSS change following implantation was correlated to a lower preimplant IPSS and an increased number of seeds implanted above the level of the prostatic base, possibly reflecting bladder base rather than urethral irritation in the development of acute urinary morbidity.     

Factors predicting for urinary incontinence after prostate brachytherapy

PURPOSE: To define risk factors that predict for urinary incontinence after (125)I prostate brachytherapy. METHODS AND MATERIALS: Urinary incontinence after (125)I prostate brachytherapy was evaluated using a patient self-assessment questionnaire based on the NCI Common Toxicity Criteria (version 2). Grade 0 is defined as no incontinence; Grade 1 incontinence occurs with coughing, sneezing, or laughing; Grade 2 is spontaneous incontinence with some control; and Grade 3 is no control. One hundred fifty-three patients received monotherapy (145 Gy) (125)I implants between October 1996 and December 2001, and 112 (75%) responded to our survey. Median follow-up was 47 months (range, 14-74 months). Patient characteristics included a preimplant prostate-specific antigen < or =10, Gleason score < or =6, and stage < or =T2b. CT-based postimplant dosimetry was analyzed approximately 30 days after the procedure, and dose-volume histograms of the prostate and the prostatic urethra were generated based on contoured volumes. Dosimetric parameters evaluated as predictive factors for incontinence included the prostate volume; total activity implanted; number of needles; number of seeds; seed activity; urethral D(5), D(10), D(25), D(50), D(75), and D(90) doses; prostate D(90) doses; and prostate V(100), V(200), and V(300). Clinical parameters evaluated included age, Gleason score, prostate-specific antigen, preimplant International Prostate Symptom Score (I-PSS), and length of follow-up. RESULTS: Urethral D(10) dose and preimplant I-PSS predicted for urinary incontinence on multivariate analysis (p = 0.002 and p = 0.003, respectively). Twenty-eight patients reported Grade 1 incontinence (26%), and 5 patients reported Grade 2 (5%). Patients with Grade 1 and 2 incontinence were analyzed together, because of the small number of patients who experienced Grade 2. No patients reported Grade 3 incontinence. Mean urethral D(10) was 314 +/- 78 Gy in patients with Grade 0 compared with 394 +/- 147 Gy in patients with Grades 1, 2 incontinence (p = 0.002). The incidence of incontinence doubled as the urethral D(10) dose increased above 450 Gy. Patients with Grade 0 had a mean preimplant I-PSS score of 6.6 +/- 4.5 compared with 10.0 +/- 6.4 for Grades 1, 2 (p = 0.003). A significant increase in the incidence of incontinence was noted when the preimplant I-PSS was greater than 15. No relationship was noted between incontinence and prostate volume, total activity implanted, or the number of needles used (p = 0.83, p = 0.89, p = 0.36, respectively). CONCLUSION: Urethral D(10) dose and preimplant I-PSS are predictive for patients at higher risk of urinary incontinence. To decrease the risk of this complication, an effort should be made to keep the urethral D(10) dose as close to the prescribed dose as possible, and the preimplant I-PSS should be thoroughly evaluated in an attempt to select patients with scores less than 15.     

Sequential evaluation of prostate edema after permanent seed prostate brachytherapy using CT-MRI fusion

PURPOSE: To analyze the extent and time course of prostate edema and its effect on dosimetry after permanent seed prostate brachytherapy. METHODS AND MATERIALS: Twenty patients scheduled for permanent seed (125)I prostate brachytherapy agreed to a prospective study on postimplant edema. Implants were preplanned using transrectal ultrasonography. Postimplant dosimetry was calculated using computed tomography-magnetic resonance imaging (CT-MRI) fusion on the day of the implant (Day 1) and Days 8 and 30. The prostate was contoured on MRI, and the seeds were located on CT. Factors investigated for an influence on edema were the number of seeds and needles, preimplant prostate volume, transitional zone index (transition zone volume divided by prostate volume), age, and prostate-specific antigen level. Prostate dosimetry was evaluated by the percentage of the prostate volume receiving 100% of the prescribed dose (V(100)) and percentage of prescribed dose received by 90% of the prostate volume (D(90)). RESULTS: Prostate edema was maximal on Day 1, with the median prostate volume 31% greater than preimplant transrectal ultrasound volume (range, 0.93-1.72; p < 0.001) and decreased with time. It was 21% greater than baseline at Day 8 (p = 0.013) and 5% greater on Day 30 (p < 0.001). Three patients still had a prostate volume greater than baseline by Day 30. The extent of edema depended on the transition zone volume (p = 0.016) and the preplan prostate volume (p = 0.003). The median V(100) on Day 1 was 93.6% (range, 86.0-98.2%) and was 96.3% (range, 85.7-99.5%) on Day 30 (p = 0.079). Patients with a Day 1 V(100) >93% were less affected by edema resolution, showing a median increase in V(100) of 0.67% on Day 30 compared with 2.77% for patients with a V(100) <93 % on Day 1. CONCLUSION: Despite the extreme range of postimplant edema, the effect on dosimetry was less than expected. Dose coverage of the prostate was good for all patients during Days 1-30. Our data indicate that postimplant dosimetry on the day of implant is sufficient for patients with good dose coverage (Day 1 V(100) >93%).     

Erectile function after prostate brachytherapy

PURPOSE: To evaluate erectile function after permanent prostate brachytherapy using a validated patient-administered questionnaire and to determine the effect of multiple clinical, treatment, and dosimetric parameters on penile erectile function. METHODS AND MATERIALS: A total of 226 patients with preimplant erectile function determined by the International Index of Erectile Function (IIEF) questionnaire underwent permanent prostate brachytherapy in two prospective randomized trials between February 2001 and January 2003 for clinical Stage T1c-T2c (2002 American Joint Committee on Cancer) prostate cancer. Of the 226 patients, 132 were potent before treatment and, of those, 128 (97%) completed and returned the IIEF questionnaire after brachytherapy. The median follow-up was 29.1 months. Potency was defined as an IIEF score of > or =13. The clinical, treatment, and dosimetric parameters evaluated included patient age; preimplant IIEF score; clinical T stage; pretreatment prostate-specific antigen level; Gleason score; elapsed time after implantation; preimplant nocturnal erections; body mass index; presence of hypertension or diabetes mellitus; tobacco consumption; the volume of the prostate gland receiving 100%, 150%, and 200% of the prescribed dose (V(100/150/200)); the dose delivered to 90% of the prostate gland (D(90)); androgen deprivation therapy; supplemental external beam radiotherapy (EBRT); isotope; prostate volume; planning volume; and radiation dose to the proximal penis. RESULTS: The 3-year actuarial rate of potency preservation was 50.5%. For patients who maintained adequate posttreatment erectile function, the preimplant IIEF score was 29, and in patients with brachytherapy-related ED, the preimplant IIEF score was 25. The median time to the onset of ED was 5.4 months. After brachytherapy, the median IIEF score was 20 in potent patients and 3 in impotent patients. On univariate analysis, the preimplant IIEF score, patient age, presence of nocturnal erections, and dose to the proximal penis predicted for postimplant erectile function. However, in multivariate analysis, only the preimplant IIEF score and the D(50) to the proximal crura were statistically significant predictors of brachytherapy-related erectile function. CONCLUSIONS: Using a patient-administered validated quality-of-life instrument, brachytherapy-induced ED occurred in 50% of patients at 3 years. On multivariate analysis, preimplant erectile function and the D(50) to the proximal crura were the best predictors of brachytherapy-related erectile function. Because the proximal penis is the most significant treatment-related predictor of brachytherapy-related ED, techniques to minimize the radiation dose to the proximal penis may result in improved rates of potency preservation.     

Safety of Prostate Stereotactic Body Radiation Therapy after Transurethral Resection of Prostate (TURP): A Propensity Score Matched Pair Analysis

PurposeTo determine the genitourinary (GU) toxicity outcomes in prostate cancer patients treated with stereotactic body radiation therapy (SBRT) who have undergone a prior transurethral resection of prostate (TURP) and compare it to a similar non-TURP cohort.Materials and MethodsFifty prostate cancer patients who had undergone a single TURP, had a good baseline urinary function, and had been subsequently treated with SBRT were chosen from a prospectively maintained database. These were propensity score matched to a similar non-TURP cohort treated during the same period. Matching was done for diabetes mellitus and volume of radiation therapy. Acute GU and late GU toxicity were scored using the Radiation Therapy Oncology Group (RTOG) criteria. Stricture and incontinence were scored using Common Terminology for Common Adverse Events version 4.0.ResultsMedian follow-up for the entire cohort was 26 months (non-TURP vs TURP, 30 months vs 22 months, P = .34). The median duration between TURP and start of SBRT was 10 months. There was no significant difference between non-TURP versus TURP cohort in terms of RTOG acute GU toxicities grade ≥2 (8% vs 6%, P = .45), RTOG late GU toxicities grade ≥2 (8% vs 12%, P = .10), stricture rates (4% vs 6%, P = .64), and incontinence rates (0% vs 4%, P = .15). The median duration of time to late toxicity was 16 months vs 10 months (P = .12) in non-TURP and TURP cohort, respectively.ConclusionsAlthough modestly increased as compared with non-TURP patients, GU toxicities remains low with SBRT in post-TURP patients. SBRT can be safely performed in carefully selected post-TURP prostate cancer patients.     

Predictive factors of urinary retention following prostate brachytherapy

PURPOSE: To evaluate the incidence and duration of urinary retention requiring catheterization and the factors predictive for these end points. METHODS AND MATERIALS: Two hundred eighty-two patients treated with prostate brachytherapy alone were evaluated. Clinical and treatment-related factors examined included: age, baseline International Prostate Symptom Score (IPSS), presence of comorbidity, planning ultrasound target volume (PUTV), postimplant prostate CT scan volume, the CT:PUTV ratio, number of seeds inserted, number of needles used, use of neoadjuvant hormones, procedural physician, clinical stage, Gleason score, and pretreatment PSA. Dosimetric quality indicators were also examined. RESULTS: Urinary obstruction after prostate brachytherapy developed in 43 (15%) patients. The median duration of catheter insertion was 21 days (mean 49, range 1-365). Univariate analysis demonstrated that presence of diabetes, preimplant volume, postimplant volume, CT:PUTV ratio, number of needles, and dosimetric parameters were predictive for catheterization. However, in multivariate analysis, only the baseline IPSS, CT:PUTV ratio, and presence of diabetes were significant independent predictive factors for catheterization. CONCLUSION: Baseline IPSS was the most important predictive factor for postimplantation catheterization. The extent of postimplant edema, as reflected by the CT:PUTV ratio, predicted for need and duration of catheterization. The presence of diabetes was predictive for catheterization, but may relate to the absence of prophylactic steroids, and therefore requires further evaluation.     

The effect of androgen deprivation on the early changes in prostate volume following transperineal ultrasound guided interstitial therapy for localized carcinoma of the prostate

Purpose: To determine the change in volume of the prostate as a result of neoadjuvant androgen deprivation prior to prostate implant and in the early postimplant period following transperineal ultrasound guided palladium-103 brachytherapy for early-stage prostate cancer.

Methods and Materials: Sixty-nine men received 3 to 6 months of androgen deprivation therapy followed by treatment planning ultrasound followed 4 to 8 weeks later by palladium-103 implant of the prostate. All patients had clinical and radiographic stage T1c–T2b adenocarcinoma of the prostate. A second ultrasound study was carried out 11 to 13 days following the implant to determine the change in volume of the prostate as a result of the implant. The prehormonal and preimplant volumes were compared to the postimplant volume to determine the effect of hormones and brachytherapy on prostate volume.

Results: The median decrease in prostate volume as a result of androgen deprivation was 33% among the 54 patients with prostate volume determinations prior to hormonal therapy. The reduction in volume was greatest in the quartile of men with the largest initial gland volume (59%) and least in the quartile of men with smallest glands (10%). The median reduction in prostate volume between the treatment planning ultrasound and the follow-up study after implant was 3%, but 23 (33%) patients had an increase in prostate volume, including 16 (23%) who had an increase in volume >20%; 11 of these patients (16%) had an increase in volume >30%. The time course of development and resolution of this edema is not known. The severity of the edema was not related to initial or preimplant prostate volume or duration of hormonal therapy.

Conclusions: Prostate edema may significantly affect the dose delivered to the prostate following transperineal ultrasound guided brachytherapy. The effect on the actual delivered dose will be greater when shorter lived isotopes are used. It remains to be observed whether this edema will affect outcome.