Effect of Time,Dose, and Fractionation on Temporal Lobe Necrosis Following Radiotherapy for Nasopharyngeal Carcinoma

Purpose: To study the relative effects of different radiation factors on temporal lobe necrosis (TLN) and predictive accuracy of different biological equivalent models.Methods and Materials: Consecutive patients (1008) treated radically with four different fractionation schedules during 1976–1985 for T1 nasopharyngeal carcinoma were retrospectively analyzed. All were irradiated by megavoltage photons using the same technique. Their age ranged from 18–84 years, and 92% of patients had complete follow-up. The fractional dose to inferomedial parts of both temporal lobes ranged from 2.5–4.2 Gy, total dose 45.6–60 Gy, and overall time 38–75 days.Results: Despite a lower total dose of 50.4 Gy, the 621 patients irradiated with 4.2 Gy per fraction had a significantly higher incidence of temporal lobe necrosis than the 320 patients treated to 60 Gy with 2.5 Gy per fraction: the 10-year actuarial incidence being 18.6% vs. 4.6%, p < 0.001. Multivariate survival analysis showed that fractional effect (product of total dose and fractional dose) was the most significant factor: p = 0.0022, hazard ratio (HR) = 1.044 per Gy². Overall time and age were both insignificant. The α/β ratio calculated from our data was 2.9 Gy (95% CI: −1.8, 7.6 Gy). Biological effective dose (BED_Gy3), neuret, and brain tolerance unit all showed strongly significant correlation with the necrotic rate (p < 0.001), and gave similar predictions. The hazard of TLN increased by 14% per Gy₃, and it was estimated that 64 Gy (at conventional fractionation of 2 Gy daily) would lead to a 5% necrotic rate at 10 years. Not only did the nominal standard dose (NSD) show the lowest value in terms of log likelihood and standardized HR, but its predictions on TLN deviated markedly from clinically observed rates.Conclusion: Fractional effect is the most significant factor affecting cerebral necrosis, and overall time has little protective effect. The BED formula, assuming an α/β ratio of 3 Gy, is an appropriate model for predicting late effects on the temporal lobe, and NSD could give seriously misleading predictions.     

Clinical radiobiology of stage T2-T3 bladder cancer

PURPOSE: To evaluate the relationship between total radiation dose and overall treatment time (OTT) with the treatment outcome, with adjustment for selected clinical factors, in patients with Stage T2-T3 bladder cancer treated with curative radiotherapy (RT). METHODS AND MATERIALS: The analysis was based on 480 patients with Stage T2-T3 bladder cancer who were treated at the Center of Oncology in Gliwice between 1975 and 1995. The mean total radiation dose was 65.5 Gy, and the mean OTT was 51 days. In 261 patients (54%), planned and unplanned gaps occurred during RT. Four fractionation schedules were used: (1) conventional fractionation (once daily, 1.8-2.5 Gy/fraction); (2) protracted fractionation (pelvic RT, once daily, 1.6-1.7 Gy/fraction, boost RT, once daily, 2.0 Gy/fraction); (3) accelerated hyperfractionated boost (pelvic RT, once daily, 2.0 Gy/fraction; boost RT, twice daily, 1.3-1.4 Gy/fraction); and (4) accelerated hyperfractionation (pelvic and boost RT, twice daily, 1.2-1.5 Gy/fraction). In all fractionation schedules, the total radiation dose was similar (average 65.5 Gy), but the OTT was different (mean 53 days for conventional fractionation, 62 days for protracted fractionation, 45 days for accelerated hyperfractionated boost, and 41 days for accelerated hyperfractionation). A Cox proportional hazard model and maximum likelihood logistic model were used to evaluate the relationship between the treatment-related parameters (total radiation dose, dose per fraction, and OTT) and clinical factors (clinical T stage, hemoglobin level and bladder capacity before RT) and treatment outcome. RESULTS: With a median follow-up of 76 months, the actuarial 5-year local control rate was 47%, and the overall survival rate was 40%. The logistic analysis, which included the total dose, OTT, and T stage, revealed that all of these factors were significantly related to tumor control probability (p = 0.021 for total radiation dose, p = 0.038 for OTT, and p = 0.00068 for T stage). A multivariate Cox model, which included the treatment-related parameters and other clinical factors, revealed that the hemoglobin level and bladder capacity before RT and T-stage were statistically significant factors determining local control and overall survival. The total radiation dose was of borderline statistical significance for overall survival (p = 0.087), and OTT did not reach statistical significance. CONCLUSION: The results of our study showed that the treatment outcome after RT for bladder cancer depends mainly on clinical factors: hemoglobin level and bladder capacity before RT, and clinical T stage. An increase in the total radiation dose seemed to be associated with a better treatment outcome. The effect of the OTT was difficult to define, because it was influenced by other prognostic factors.     

Different risks of symptomatic brain necrosis in NPC patients treated with different altered fractionated radiotherapy techniques

PURPOSE: To report our observation of excessive temporal lobe necrosis in nasopharyngeal carcinoma (NPC) patients treated with 160 cGy b.i.d. radiotherapy technique. During the same period, patients treated with 120 cGy b.i.d. have not shown a similar tendency. Our experience may be useful for designing unconventional radiotherapy regimens for NPC patients. METHODS AND MATERIALS: During the period from October 1991 to January 1998, 81 M0, previously untreated NPC patients completed altered fractionated radiotherapy. Seventy patients were treated with the hyperfractionated technique, and 11 were treated using the accelerated-hyperfractionated scheme. Hyperfractionated radiotherapy was delivered using 120 cGy b.i.d. separated by 6-h intervals throughout the course. A minimum tumor dose of 8000 cGy was the standard dose over an 8-week period. With the accelerated-hyperfractionated scheme, 160 cGy was given twice daily, also with an interval of 6 h. The minimum tumor dose ranged between 6840 and 7640 cGy, with 7 of the 11 patients receiving 7000 cGy. The arrangement of portals was the same for both regimens. The follow-up period for patients alive was from 32 to 102 months with a median of 61 months for the hyperfractionated patients. For the accelerated-hyperfractionated group, it ranged from 67 to 82 months with a median of 72 months. No patient was lost to follow-up. RESULTS: At the time of analysis, 49 of the 70 patients in the hyperfractionated group were alive. In the accelerated group, 8 of the 11 patients were alive. The estimated radiation dose to the temporal lobe for the hyperfractionated group was 6000-7440 cGy with a median of 7080 cGy. For the accelerated-hyperfractionated group, the dose range was 4480-6700 cGy with a median of 6400 cGy. Of the 70 patients treated with hyperfractionated radiotherapy, none developed symptomatic brain necrosis, despite the higher total dose to the temporal lobe in general. In contrast, 3 of the 11 (27%) patients irradiated using the accelerated-hyperfractionated regimen suffered from temporal lobe necrosis at 16, 19, and 40 months after completion of radiotherapy. CONCLUSION: An excessive incidence of temporal lobe necrosis was noted when an accelerated-hyperfractionated regimen with 160 cGy b.i.d. was used in NPC patients with a median brain dose of 6400 cGy. There has been no such event in patients treated using a hyperfractionated regimen with 120 cGy and a median brain dose of 7000 cGy. The real causes of this discrepancy are not known. However, a high sensitivity of the human brain to a change in fraction size may play a role.     

Cerebral radiation necrosis: incidence, outcomes, and risk factors with emphasis on radiation parameters and chemotherapy

PURPOSE: To investigate radiation necrosis in patients treated for glioma in terms of incidence, outcomes, predictive and prognostic factors. METHODS AND MATERIALS: Records were reviewed for 426 patients followed up until death or for at least 3 years. Logistic regression analysis was performed to identify predictive and prognostic factors. Multivariate survival analysis was conducted using Cox proportional hazards regression. Separate analyses were performed for the subset of 352 patients who received a biologically effective dose (BED) > or =85.5 Gy2 (> or =45 Gy/25 fractions) who were at highest risk for radionecrosis. RESULTS: Twenty-one patients developed radionecrosis (4.9%). Actuarial incidence plateaued at 13.3% after 3 years. In the high-risk subset, radiation parameters confirmed as risk factors included total dose (p < 0.001), BED (p < 0.005), neuret (p < 0.001), fraction size (p = 0.028), and the product of total dose and fraction size (p = 0.001). No patient receiving a BED <96 Gy2 developed radionecrosis. Subsequent chemotherapy significantly increased the risk of cerebral necrosis (p = 0.001) even when adjusted for BED (odds ratio [OR], 5.8; 95% confidence interval [CI], 1.6-20.3) or length of follow-up (OR, 5.4; 95% CI, 1.5-19.3). Concurrent use of valproate appeared to delay the onset of necrosis (p = 0.013). The development of radionecrosis did not affect survival (p = 0.09). CONCLUSIONS: Cerebral necrosis is unlikely at doses below 50 Gy in 25 fractions. The risk increases significantly with increasing radiation dose, fraction size, and the subsequent administration of chemotherapy.     

Radical radiotherapy for invasive bladder cancer: What dose and fractionation schedule to choose?

PURPOSE: To establish the alpha/beta ratio of bladder cancer from different radiotherapy schedules reported in the literature and provide guidelines for the design of new treatment schemes. METHODS AND MATERIALS: Ten external beam radiotherapy (EBRT) and five brachytherapy schedules were selected. The biologically effective dose (BED) of each schedule was calculated. Logistic modeling was used to describe the relationship between 3-year local control (LC3y) and BED. RESULTS: The estimated alpha/beta ratio was 13 Gy (95% confidence interval [CI], 2.5-69 Gy) for EBRT and 24 Gy (95% CI, 1.3-460 Gy) for EBRT and brachytherapy combined. There is evidence for an overall dose-response relationship. After an increase in total dose of 10 Gy, the odds of LC3y increase by a factor of 1.44 (95% CI, 1.23-1.70) for EBRT and 1.47 (95% CI, 1.25-1.72) for the data sets of EBRT and brachytherapy combined. CONCLUSION: With the clinical data currently available, a reliable estimation of the alpha/beta ratio for bladder cancer is not feasible. It seems reasonable to use a conventional alpha/beta ratio of 10-15 Gy. Dose escalation could significantly increase local control. There is no evidence to support short overall treatment times or large fraction sizes in radiotherapy for bladder cancer.     

Hyperfractionated radiation therapy for locoregionally advanced nasopharyngeal cancer

OBJECTIVE: The purpose of this study is to clarify the efficacy and toxicity of hyperfractionated radiation therapy (RT) for patients with nasopharyngeal cancer (NPC). METHODS: Twenty-two patients with NPC treated at our hospital between April 1994 and December 2002 were the subjects of this study. They received hyperfractionated RT with a fraction size of 1.2 Gy, with a median tumor dose of 72 Gy (range 64.8-80.4). During this study period, our institutional strategy for locoregionally advanced NPC included neoadjuvant or concurrent chemotherapy combined with hyperfractionated RT, and 17 patients received some forms of cisplatin-containing chemotherapy. RESULTS: With a median follow-up of 59 months, the estimated 5-year disease-free survival rate and overall survival rate were 72.7 and 85.2%, respectively. Acute hematological toxicities were acceptable and manageable. However, >50% of patients required nutritional support, and experienced severe pharyngitis, skin reaction and body weight loss. With regard to late sequelae, one patient developed grade 3 osteomyelitis, and one patient each developed grade 4 passage disturbance and laryngeal edema. No patients experienced any grades of optic nerve injury or temporal lobe necrosis. CONCLUSIONS: Hyperfractionated RT using 1.2 Gy per fraction, for a total dose of 72 Gy, produces a comparable treatment outcome. Although deleterious neurological sequelae were not observed in this study, caution should be exercised regarding other late sequelae, such as osteomyelitis and passage disturbance.     

Use of individual fraction size data from 3756 patients to directly determine the alpha/beta ratio of prostate cancer

PURPOSE: To examine the effect of fraction size and total dose of radiation on recurrence of localized prostate cancer. METHODS AND MATERIALS: A total of 3756 patients treated with radiation monotherapy at three institutions were analyzed, including 185 high-dose-rate brachytherapy (HDRB) boost patients. The 5th to 95th centiles of external beam radiotherapy (EBRT) fraction sizes and doses were 1.8 to 2.86 Gy, and 57.4 to 77.4 Gy, respectively, and HDRB fractional doses were between 5.5 and 12 Gy, totaling 147 unique fractionation schedules. Failure was defined by one biochemical (nadir + 2 ng/ml) and two advanced disease endpoints. The alpha/beta ratios were estimated via a proportional hazards model stratified by risk severity and institution. RESULTS: The alpha/beta ratio using biochemical recurrence was 3.7 Gy (95% confidence interval [95% CI], 1.1, infinity Gy) for EBRT-only cases and 2.6 Gy (95% CI, 0.9, 4.8 Gy) after the addition of HDRB data. This estimate was highly dependent on an HDRB homogeneity correction factor (120% HDRB dose increase; alpha/beta ratio 4.5 Gy, 95% CI 1.6, 8.7 Gy). A 5-Gy increase in total dose reduced the hazard of failure by 16% (95% CI 11, 21%, p < 0.0001), and had more impact as follow-up matured (p < 0.0003). The clinically advanced endpoints concurred with the biochemical failure results, albeit with less precision. CONCLUSIONS: This study supports the concept that the alpha/beta ratio of prostate cancer is low, although considerable uncertainty remains in the estimated value. Outcome data from EBRT studies using substantially higher doses per fraction are needed to show increased precision in these estimates.     

Locoregional irradiation for inflammatory breast cancer: effectiveness of dose escalation in decreasing recurrence

Purpose: To evaluate the effect of radiation dose escalation on locoregional control, overall survival, and long-term complication in patients with inflammatory breast cancer.

Patients and Methods: From September 1977 to December 1993, 115 patients with nonmetastatic inflammatory breast cancer were treated with curative intent at The University of Texas M. D. Anderson Cancer Center. The usual sequence of multimodal treatment consisted of induction FAC or FACVP chemotherapy, mastectomy (if the tumor was operable), further chemotherapy, and radiation therapy to the chest wall and draining lymphatics. Sixty-one patients treated from September 1977 to September 1985 received a maximal radiation dose of 60 Gy to the chest wall and 45–50 Gy to the regional lymph nodes, 22 treated once a day at 2 Gy per fraction, and 35 were treated b.i.d. (32 after mastectomy and all chemotherapy was completed, and 2 immediately after mastectomy; one patient had distant metastases discovered during b.i.d. irradiation, and treatment was stopped). Four additional patients received preoperative radiation with standard fractionation. Based on the analysis of the failure patterns of the patients, the dose was increased for the b.i.d. patients in the new series, with 51 Gy delivered to the chest wall and regional nodes, followed by a 15-Gy boost to the chest wall with electrons. From January 1986 to December 1993, 39 patients were treated b.i.d. to this higher dose after mastectomy and all the chemotherapy was completed; and 8 additional patients received preoperative irradiation with b.i.d. fractionation to 51 Gy. During this period, another 7 patients were treated using standard daily doses of 2 Gy per fraction to a total of 60 Gy, either because they had a complete response or minimal residual disease at mastectomy or because their work schedule did not permit the b.i.d. regimen. Comparison was made between the groups for locoregional control, disease-free and overall survival, and complication rates.

Results: The median follow-up time was 5.7 years (range, 1.8–17.6 years). For the entire patient group, the 5- and 10-year local control rates were 73.2% and 67.1%, respectively. The 5- and 10-year disease-free survival rates were 32.0% and 28.8%, respectively, and the overall survival rates for the entire group were 40.5% and 31.3%, respectively. To evaluate the effectiveness of dose escalation, a specific comparison of patients who received b.i.d. radiation after mastectomy and completion of adjuvant chemotherapy was performed. There were 32 patients treated b.i.d. to 60 Gy in the old series versus 39 patients treated b.i.d. to 66 Gy in the new series. There was an significant improvement in the rate of locoregional control for the b.i.d. patients for the old vs. new series, from 57.8% to 84.3% and from 57.8% to 77.0% (p = 0.028) at 5 and 10 years, respectively. Chemotherapy regimens did not change significantly during this time period.

Long-term complications of radiation, such as arm edema more than 3 cm (7 patients), rib fracture (10 patients), severe chest wall fibrosis (4 patients), and symptomatic pneumonitis (5 patients), were comparable in the two groups, indicating that the dose escalation did not result in increased morbidity. Significant differences in the rates of locoregional control (p = 0.03) and overall survival (p = 0.03), and a trend of better disease-free survival (p = 0.06) were also observed that favored the recently treated patients receiving the higher doses of irradiation.

Conclusion: Twice-daily postmastectomy radiation to a total of 66 Gy for patients with inflammatory breast cancer resulted in improved locoregional control, disease free survival, and overall survival, and was well tolerated.     

Association between pathologic response in metastatic lymph nodes after preoperative chemoradiotherapy and risk of distant metastases in rectal cancer: An analysis of outcomes in a randomized trial

PURPOSE: To compare 5 x 5 Gy preoperative radiotherapy with immediate surgery vs. preoperative chemoradiotherapy (50.4 Gy, 5-fluorouracil, leucovorin) with delayed surgery in a randomized trial for cT3-T4 low-lying rectal cancer. Despite the downstaging effect of chemoradiotherapy, similar long-term outcomes were observed in both groups. METHODS: The Cox model was used to evaluate the prognostic value of ypTN ("yp" denotes that pathologic classification was performed after initial multimodality therapy) categories and the surgical margin status in 291 patients. RESULTS: Disease-free survival (DFS) (hazard ratio [HR] 1.05, 95% confidence interval [CI], 0.73-1.51), distant metastases (HR, 1.17; 95% CI, 0.77-1.78), and local control (HR, 1.45; 95% CI, 0.74-2.84) were similar in both arms. The ypN status was the only independent prognostic factor for DFS (p < 0.001). An interaction (p = 0.016) between N stage and the assigned treatment was demonstrated. For ypN-negative patients, DFS was similar in both arms (HR, 0.83, 95% CI, 0.47-1.48); however, for ypN-positive patients, DFS was worse in the chemoradiotherapy arm (HR, 1.73; 95% CI, 1.07-2.77). The 4-year (median follow-up) DFS rate in N-positive patients was 51% in the 5 x 5-Gy arm vs. 25% in the chemoradiotherapy arm. The corresponding 4-year rates for the incidence of local recurrence and distant metastases were 14% vs. 27% (HR, 1.95; 95% CI, 0.78-4.86) and 38% vs. 68% (HR, 2.05; 95% CI, 1.21-3.48). CONCLUSION: N-positive disease after chemoradiotherapy indicates radiochemoresistance. N-positive disease after 5 x 5 Gy RT includes both radiosensitive and radioresistant tumors, because the interval between radiotherapy and surgery was too short for radiosensitive cancer to undergo necrosis. Thus, the greater risk of distant metastases recorded in the chemoradiotherapy arm suggests that radiochemoresistance of nodal metastases from rectal cancer is associated with a high potential for developing distant metastases.     

Effect of radiotherapy fraction size on tumour control in patients with early-stage breast cancer after local tumour excision: long-term results of a randomised trial

BACKGROUND: Standard curative schedules of radiotherapy to the breast deliver 25 fractions of 2.0 Gy over 5 weeks. In a randomised trial, we tested whether fewer, larger fractions were at least as safe and as effective as standard regimens. In this analysis, we assessed the long-term results of tumour control in the same population. METHODS: In 1986-98, we randomly assigned 1410 women with invasive breast cancer (tumour stage 1-3 with a maximum of one positive node and no metastasis) who had had local tumour excision of early stage breast cancer to receive 50 Gy radiotherapy given in 25 fractions, 39 Gy given in 13 fractions, or 42.9 Gy given in 13 fractions, all given over 5 weeks. The primary endpoint was late change in breast appearance, which has been reported elsewhere. Here, we report ipsilateral tumour relapse, one of the secondary endpoints. Relapse was defined as any appearance of cancer in the irradiated breast. Analysis was by intention to treat. FINDINGS: After a median follow-up of 9.7 years (IQR 7.8-11.8) for the 838 (95%) patients who survived, the risk of ipsilateral tumour relapse after 10 years was 12.1% (95% CI 8.8-15.5) in the 50 Gy group, 14.8% (11.2-18.3) in the 39 Gy group, and 9.6% (6.7-12.6) in the 42.9 Gy group (difference between 39 Gy and 42.9 Gy groups, chi2 test, p=0.027). The sensitivity of breast cancer to dose per fraction was estimated to be 4.0 Gy (95% CI 1.0-7.8), similar to that estimated for the late adverse effects in healthy tissue from breast radiotherapy. INTERPRETATION: Breast cancer tissue is probably just as sensitive to fraction size as dose-limiting healthy tissues. If this finding is confirmed, radiotherapy schedules can be greatly simplified by the delivery of fewer, larger fractions without compromising effectiveness or safety, and possibly improving both.     

Megavoltage external beam irradiation of craniopharyngiomas: analysis of tumor control and morbidity

From 1971 to 1985, 21 patients received megavoltage external beam radiation therapy at the University of Pittsburgh for control of craniopharyngioma. Minimum tumor doses prescribed to the 95% isodose volume ranged between 51.3 to 70.0 Gy. Median total dose was 60.00 Gy and median dose per fraction was 1.83 Gy. Three deaths occurred from intercurrent disease and no deaths from tumor progression. Actuarial overall survival was 89% and 82% at 5 and 10 years. Actuarial local control was 95% at 5 and 10 years. Radiation related complications included one patient with optic neuropathy, one with brain necrosis, and one that developed optic neuropathy followed by brain necrosis. The high dose group of patients who received a NSD or Neuret equivalent of greater than 60 Gy at 1.8 Gy per fraction had a significantly greater risk of radiation complications (p = .024). The actuarial risk at 5 years for optic neuropathy was 30% and brain necrosis was 12.5% in the high dose group. Tumor control in the high dose group was not shown to be significantly better. Any possible benefit in tumor control in treating patients with craniopharyngioma with doses above 60 Gy at 1.8 Gy per fraction appears to be offset by the increased risk of radiation injury.     

Effects of dosimetric inadequacy on local control and toxicities in the patients with T4 nasopharyngeal carcinoma extending into the intracranial space and treated with intensity-modulated radiotherapy plus chemotherapy

Background:To protect neurological tissues,underdosing occurs in most cases ofT4 nasopharyngeal carcinoma (NPC) with intracranial extension.In this study,we aimed to evaluate the effect of dosimetric inadequacy on local control and late neurological toxicities for patients treated with intensity-modulated radiotherapy (IMRT) plus chemotherapy.Methods:We prospectively enrolled patients who had non-metastatic T4 NPC with intracranial extension treated between January 2009 and November 2013.The prescribed dose was 66.0-70.4 Gy to the primary planning target volume (primary gross tumor volume [GTVp;i.e.,the nasopharyngeal tumor] + 5.0 mm).Dose-volume histogram parameters were calculated,including minimum point dose (Dmin) and dose to 95％ of the target volume (D9s).All patients received chemotherapy with the cisplatin,5-fluorouracil,and docetaxel regimen.Survivals were estimated using the Kaplan-Meier method and compared using the log-rank test.Results:In total,41 patients were enrolled.The local partial response rate was 87.8％ after induction chemotherapy.With a median follow-up of 51 months,7 patients experienced failure in the nasopharynx;the 3-year local failure-free survival and overall survival rates of the 41 patients were 87.4％ and 90.2％,respectively.The actual mean Dmin to the GTVp was 55.2 Gy (range 48.3-67.3 Gy),and D9s was 61.6 Gy (range 52.6-69.0 Gy).All doses received by neurological organs remained well within their dose constraints.No patients developed temporal lobe necrosis or other neurological dysfunctions.Conclusions:With relative underdosed IMRT plus effective chemotherapy,the patients achieved satisfactory local control with few late toxicities of the central nervous system.Determining the acceptable extent of dosimetric inadequacy requires further exploration.     

30例早期鼻咽癌调强放射治疗疗效分析

目的:探讨调强放射治疗(IMRT)对早期鼻咽癌的近期疗效和不良反应.方法:回顾分析30例早期鼻咽癌患者,鼻咽部和上颈部淋巴引流区采用IMRT技术照射,下颈部淋巴引流区采用颈前野常规照射.鼻咽大体肿瘤体积(GTVnx)处方剂量68Gy-74Gy,颈部淋巴结(GTVnd)处方剂量64Gy-70Gy,临床靶体积(CTV1)处方剂量 60Gy-64Gy,临床靶体积(CTV2)处方剂量 50Gy-54Gy,分30-34次进行照射.对于淋巴结分期为N1的患者,结合淋巴结的情况行诱导化疗和(或)同期化疗2-4周期,N0患者行单纯调强放射治疗.结果:鼻咽大体肿瘤体积(GTVnx)D95平均剂量为74.5Gy,GTVnx V95平均体积99.6%,脊髓D1cc平均剂量41.5Gy,脑干D3平均剂量50.3Gy,左腮腺D50平均剂量32.8Gy,右腮腺D50平均剂量31.4Gy,左颞叶D10平均剂量45.5Gy,右颞叶D10平均剂量45.2Gy,均低于限制剂量.中位随访时间33.5个月(4-45个月).1年、2年、3年的总生存率、无局部复发生存率和无远处转移生存率均为100%.最严重的急性反应是放射性黏膜炎,1-3级分别有 63.3%,30%,和6.7%,晚期不良反应主要表现为口干(Ⅰ度33.3%,Ⅱ度3.7%).结论:IMRT对初治早期鼻咽癌可获得理想的剂量分布,取得较好的近期疗效,正常组织得到很好的保护.     

Long-term results of a phase III trial comparing once-daily radiotherapy with twice-daily radiotherapy in limited-stage small-cell lung cancer

PURPOSE: This Phase III study was performed to determine whether twice-daily (b.i.d.) radiotherapy (RT) resulted in better survival than once-daily (q.d.) RT for patients with limited-stage small-cell lung cancer (LD-SCLC). METHODS AND MATERIALS: A total of 310 patients with LD-SCLC initially received three cycles of etoposide and cisplatin. Subsequently, the 261 patients without significant progression were randomized to two cycles of etoposide and cisplatin plus either q.d. RT (50.4 Gy in 28 fractions) or split-course b.i.d. RT (24 Gy in 16 fractions, a 2.5-week break, and 24 Gy in 16 fractions) to the chest. Patients then received a sixth cycle of etoposide and cisplatin followed by prophylactic cranial RT. RESULTS: Follow-up ranged from 4.6 to 11.9 years (median, 7.4 years). The median survival and 5-year survival rate from randomization was 20.6 months and 21% for patients who received q.d. RT compared with 20.6 months and 22% for those who received b.i.d. RT (p = 0.68), respectively. No statistically significant differences were found in the rates of progression (p = 0.68), intrathoracic failure (p = 0.45), in-field failure (p = 0.62), or distant failure (p = 0.82) between the two treatment arms. No statistically significant difference was found in the overall rate of Grade 3 or worse (p = 0.83) or Grade 4 or worse toxicity (p = 0.95). Grade 3 or worse esophagitis (p = 0.05) was more common in the b.i.d. arm. Grade 5 toxicity occurred in 4 (3%) of 130 patients who received b.i.d. RT compared with 0 (0%) of 131 who received q.d. RT (p = 0.04). CONCLUSION: Although this study did not demonstrate an advantage to split-course b.i.d. RT, the long-term survival was favorable, likely reflecting the positive influences of concurrent combined modality therapy and prophylactic cranial RT.     

Excellent local control with stereotactic radiotherapy boost after external beam radiotherapy in patients with nasopharyngeal carcinoma

PURPOSE: To determine long-term outcomes in patients receiving stereotactic radiotherapy (SRT) as a boost after external beam radiotherapy (EBRT) for locally advanced nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: Eight-two patients received an SRT boost after EBRT between September 1992 and July 2006. Nine patients had T1, 30 had T2, 12 had T3, and 31 had T4 tumors. Sixteen patients had Stage II, 19 had Stage III, and 47 had Stage IV disease. Patients received 66 Gy of EBRT followed by a single-fraction SRT boost of 7-15 Gy, delivered 2-6 weeks after EBRT. Seventy patients also received cisplatin-based chemotherapy delivered concurrently with and adjuvant to radiotherapy. RESULTS: At a median follow-up of 40.7 months (range, 6.5-144.2 months) for living patients, there was only 1 local failure in a patient with a T4 tumor. At 5 years, the freedom from local relapse rate was 98%, freedom from nodal relapse 83%, freedom from distant metastasis 68%, freedom from any relapse 67%, and overall survival 69%. Late toxicity included radiation-related retinopathy in 3, carotid aneurysm in 1, and radiographic temporal lobe necrosis in 10 patients, of whom 2 patients were symptomatic with seizures. Of 10 patients with temporal lobe necrosis, 9 had T4 tumors. CONCLUSION: Stereotactic radiotherapy boost after EBRT provides excellent local control for patients with NPC. Improved target delineation and dose homogeneity of radiation delivery for both EBRT and SRT is important to avoid long-term complications. Better systemic therapies for distant control are needed.     

High-dose thoracic radiation therapy at 3.0 Gy/fraction in inoperable stage I/II non-small cell lung cancer

OBJECTIVE: High-dose thoracic radiation therapy (HDTRT) alone has been an alternative to surgery in stage I/II non-small cell lung cancer patients with medical co-morbidities and/or poor performance status. Here, we report on the outcome and safety of HDTRT at 3.0 Gy per fraction for reduced treatment duration. METHODS: HDTRT alone at 3.0 Gy per fraction was given to 35 patients (22 at stage I and 13 at stage II). The median age was 73 years old and 14 patients had ECOG performance above 2. The median radiation dose to the primary lesion was 60 (54-66) Gy over 27 (23-38) days, and the dose to the mediastinum was individualized. RESULTS: After the median follow-up of 24 (3-72) months, local in-field progression developed in 11 patients (31.4%) and distant metastases in 14 (40.0%). The median survival period and the 3- and 5-year overall survival (OS) rates for all patients were 24.0 (95% CI: 13.57-34.43) months, 31.4 and 11.2%. Intercurrent deaths were observed in 11 patients. Treatment-related acute and subacute morbidities were observed in 20 patients (57.1%); however, there was neither treatment interruption nor long-term morbidity. CONCLUSIONS: On the basis of the above observations, we achieved treatment outcomes comparable with those of conventional protracted fractionation schedules at considerably shorter duration and lower cost by HDTRT at 3.0 Gy per fraction.     

Phase I/II study of S-1 combined with weekly docetaxel in patients with metastatic gastric carcinoma

We designed a phase I/II trial of S-1 combined with weekly docetaxel to determine the maximum tolerated dose (MTD) and recommended dose (RD) and to evaluate the efficacy and toxicity in metastatic gastric carcinoma (MGC). Patients with measurable disease received S-1 orally b.i.d. on days 1-14 and docetaxel intravenously on days 1 and 8 every 3 weeks. In phase I (n=30), each cohort received escalating doses of S-1 (30-45 mg m(-2) b.i.d.) and docetaxel (25-40 mg m(-2)); MTD was 45 mg m(-2) b.i.d. S-1/35 mg m(-2) docetaxel and RD was 40 mg m(-2) b.i.d. S-1/35 mg m(-2) docetaxel. Dose-limiting toxicities included grade 3 elevated liver enzymes, gastric perforation, grade 3 diarrhoea/fatigue, febrile neutropenia with grade 3 anorexia/fatigue, and neutropenic infection with grade 3 stomatitis/anorexia. In phase II (n=52), the overall response rate was 66.7% (95% confidence interval (CI): 53.8-79.6%) and the median time to progression and overall survival were 6.5 months (95% CI: 4.9-8.1) and 13.7 months (95% CI: 9.9-17.5), respectively. The most common grade 3/4 toxicity was neutropenia (29.4%), and febrile neutropenia/neutropenic infection occurred in 19.6% of patients. Non-haematological toxicities were generally mild. There was one treatment-related death due to pneumonitis. S-1 combined with weekly docetaxel is active in MGC with moderate toxicities.     

A Feasibility Study Using Three-dimensional Conformal Boost Technique in Locally Advanced Carcinoma of the Nasopharynx

To investigate the feasibility and efficacy of dose escalation using three-dimensional (3-D) conformal boost technique, 21 patients with stage III or IV nasopharyngeal cancer were enrolled in a prospective protocol. All patients with node metastases initially received external radiotherapy by conventional technique up to 70.2 Gy, followed by 3-D conformal radiotherapy (3-D CRT) to the boost part up to 79.2 Gy with 9 Gy increments (daily fraction of 1.8 Gy for 5 days). A modified technique with the same dose escalation of 9 Gy using 3-D CRT was applied to 7 patients without node metastases, who were treated by conventional technique up to 54 Gy, followed by 3-D CRT to boost up to a basic dose of 70.2 Gy, and then finally with dose escalation of 9 Gy. The protocol was relatively well tolerated by the majority of patients. Acute complications during the dose escalation schedule was low, with rare occurrences of grade 3 or 4 toxicity. Although late radiation-induced complications also appeared limited, 1 patient developed a temporal lobe necrosis and 2 patients suffered from sensory-neural hearing loss. There were no radiation-induced fatal complications. At a median follow-up of 48 months, only 3 patients experienced local failure and 2 patients developed distant metastases. The 5-year overall actuarial survival rate and recurrencefree survival rate for all patients were 68% and 85%, respectively. On the basis of acceptable morbidity and encouraging treatment results, we conclude that the dose escalation in 9 Gy increments using a 3-D conformal boost technique is relatively safe and efficacious, enough to be used routinely for locally advanced nasopharyngeal cancers.     

Local control of oropharyngeal carcinoma after two accelerated hyperfractionation radiation therapy schemes

In October 1979 we started an accelerated hyperfractionation program consisting of 1.6 Gy/fraction, 2 fractions/day for 12 days or 38.4 Gy. Due to acute toxicity, the patients were then given a 2-week break and resumed once daily radiation therapy with 1.8 Gy/fraction up to 65 Gy, designated as the b.i.d.-q.d. program. In August 1982, the program was changed and the latter part of the treatment was continued on the twice daily program with 1.6 Gy/fraction for a total of 64 Gy, designated as the b.i.d.-b.i.d. program. We evaluated the local control rates of 140 patients with squamous cell carcinomas arising from the oropharynx, that is faucial tonsil and base of tongue. After these treatment regimens, the 36 month actuarial local rates for the T1-4 lesions were 56% for b.i.d.-q.d. (52 patients) and 85% for b.i.d.-b.i.d. (88 patients) with a p value of 0.0013. For the T1-2 lesions the corresponding rates were 81% (13 patients) and 97% (44 patients) with a p value of 0.53. The difference was marked for the T3-4 lesions, that is 47% vs 77% respectively with a p value of 0.017, and those patients without nodal metastases, that is 46% vs 93% with a p value of 0.00043. The improvement was probably due to marked shortening of the overall treatment course following b.i.d.-b.i.d. accelerated program--in this case 1 1/2 weeks. Our preliminary data suggests that the b.i.d.-b.i.d. program is superior to the b.i.d.-q.d. program. The seemingly improved local control rates for the treatment of oropharyngeal carcinomas requires a clinical prospectively randomized trial for confirmation, that is b.i.d.-b.i.d. versus b.i.d.-q.d. versus standard fractionation (q.d.) program.