D.S. Brabbins

Comparison of dose-escalated, image-guided radiotherapy vs. dose-escalated, high-dose-rate brachytherapy boost in a modern cohort of intermediate-risk prostate cancer patients

PURPOSE We compared outcomes in intermediate-risk prostate cancer patients treated with dose-escalated adaptive image-guided radiation therapy (IGRT) or dose-escalated high-dose-rate brachytherapy boost (HDR-B). METHODS AND MATERIALS Patients with intermediate-risk prostate cancer by National Comprehensive Cancer Network criteria were treated with either CT-based off-line adaptive IGRT (n = 734) or HDR-B (n = 282). IGRT was delivered with 3D-conformal or intensity-modulated radiation therapy with a median dose of 77.4 Gy. For HDR-B, the whole pelvis received a median 46 Gy, and the prostate 2 implants of 9.5 Gy (n = 71), 10.5 Gy (n = 155), or 11.5 Gy (n = 56). RESULTS Median followup was 3.7 years for IGRT and 8.0 years for HDR-B (p < 0.001). Eight-year biochemical control was 86% for IGRT and 91% for HDR-B (p = 0.22), disease-free survival 67% for IGRT and 79% for HDR-B (p = 0.006), and overall survival 75% for IGRT and 86% for HDR-B (p = 0.009). Cause-specific survival (8-year, 100% vs. 99%), freedom from distant metastases (98% vs. 97%), and freedom from local recurrence (98% vs. 98%) did not differ (p > 0.50 each). A worse prognosis group was defined by percent positive prostate biopsy cores >50%, perineural invasion, or stage T2b-c, encompassing 260 (35%) IGRT and 171 (61%) HDR-B patients. These patients evidenced a 5-year biochemical control of 96% for HDR-B and 87% for IGRT (p = 0.002). CONCLUSIONS Dose-escalated IGRT and HDR-B both yield excellent clinical outcomes for patients with intermediate-risk prostate cancer. Improved biochemical control with HDR-B for patients with worse pretreatment characteristics suggests that a subgroup of intermediate-risk prostate cancer patients may benefit from dual-modality treatment.

Ten Year Outcome for Poor Histology or High Risk Endometrial Cancer Patients Treated by Whole Abdomino-pelvic Irradiation: 9:14 Am (13)

Purpose: Evaluate the long term results of adjuvant whole abdominopelvic irradiation with a vaginal boost (WAPI) in patients with stage I-III endometrial carcinoma including clear cell(CP) and serous-papillary(SP). Materials and Methods: In a prospective nonrandomized trial, 119 patients were treated with adjuvant WAPI between 11/81 and 4/00. Mean age 66 years (39–88). Thirty-eight patients (32%) were 1998 FIGO stage I-II, 81(68%) were stage III. Pathological features: 58% with high grade lesions, 54% had deep myometrial invasion, 40%with positive peritoneal cytology, 18% with positive lymph nodes, and 37% with SP/CC. Results: Mean follow up was 5.8 years (0.2–14.7). The 5 and 10 year cause specific survival(CSS) was 75% and 69% whereas disease-free survival(DFS) was 58% and 48%. When stratified by histology the 5 and 10 year CSS for adenocarcinoma was 76% and 71% while SP/CC was 74% and 63% p = 0.917. The 5 and 10 year DFS for adenocarcinoma was 60% and 50% whereas SP/CC was 54% and 37% p = 0.498. For surgical stages I-II the 5 year CSS was 82% for adenocarcinoma and 87% for SP/CC p = 0.48. For stage III, it was 75% and 66% p = 0.129. When stratified by histology, 32% of patients with adenocarcinoma and 30% with SP/CC developed recurrent disease. The majority of failures were in the abdominopelvic region. Multivariate analysis (age, surgical stage, grade, myometrial invasion, histologic type, lymph node and peritoneal cytology) demonstrated age P = 0.01 and surgical stage P = 0.03 to be significant for CSS while age P = 0.03 was the only significant prognostic factor for DFS. Chronic grade 3 GI toxicity 12% and grade 3 renal toxicity 2%. Conclusion: Adjuvant WAPI is very effective treatment with excellent 10 year results for stage I-III endometrial carcinoma with risk factors for intra-abdominopelvic recurrence, including SP/CC histology, deep myometrial invasion, high grade, nodal involvement, and positive peritoneal cytology. The low long term complication rate with high CSS makes WAPI the treatment of choice.