Evaluation of a 36 Gy elective node irradiation dose in anal cancer.

PURPOSE: To retrospectively analyze the efficacy of 36 Gy of elective node irradiation and report patterns of recurrence in patients with anal cancer treated by chemoradiation with the same radiotherapy (RT) treatment scheme. METHODS AND MATERIALS: Between January 1996 and December 2013, 142 patients with anal squamous cell cancer were scheduled to receive a dose of 36 Gy of elective node irradiation (ENI) to the inguinal area and whole pelvis over 4 weeks followed after a 2-week gap by a boost dose of 23.4 Gy over 17 days to the macroscopic disease. Mitomycin C combined with fluorouracil, capecitabin or cisplatin was given at day 1 of each sequence of RT. RESULTS: Disease stages were I: 3, II: 78, IIIA: 23, IIIB: 38. Compliance rates were 97.2% with RT and 87.9% with chemotherapy. After a median follow up of 48 months [3.6-192], estimated 5-year overall survival and colostomy-free survival were 75.4% and 85.3% respectively. Eleven patients (7.7%) never achieved a complete response, 15 had a local component of recurrence and 5 a regional one. One patient had failure in the common iliac node area outside the treatment fields. The inguinal control rate was 98.5%. The 5-year tumor and nodal control rates were 81.5% and 96.0%, respectively. CONCLUSION: Chemoradiation with a dose of 36 Gy ENI achieved excellent nodal control. However, it is necessary to improve the 5-year control rate of the primary tumor. Omitting the gap and using additional doses per fraction or hyper-fractionation are to be explored.

Mapping of failures after radiochemotherapy in patients with non-metastatic esophageal cancer: A posteriori analysis of the dose distribution in the sites of loco-regional relapse.

BACKGROUND AND PURPOSE: We aimed to evaluate the patterns of loco-regional failure (LRF) after exclusive chemoradiotherapy (eCRT) for esophageal cancer with respect to planned dose and/or the incidental (unplanned) dose outside target volumes. MATERIALS AND METHODS: Co-image registration of CT or (18)F-FDG PET-CT at the time of failure (tf) and at the time of CRT (t0) was performed in 34 patients with LRF. Dosimetric parameters with regard to local failure (LF), nodal failure (NF) and involved nodal stations (NS) were derived. RESULTS: Twenty-two patients (64.7%) had LF, the majority of which (95.5%) were located at the epicenter of the GTV of the primary tumor. The mean doses recalculated to the NS at tf were more likely to be lower than the planned dose delivered to the PTV at t0: Dmean=33.9 ± 20.8 Gy vs 52.2 ± 8.5 Gy (p=0.0009), D95%=27.5 ± 21 Gy vs 46.1 ± 4.8 Gy (p=0.004). Among the 12 patients with NF outside the elective nodal irradiation (ENI) volume, Dmean of NS outside the ENI was significantly lower (19.4 ± 21.4 Gy) than the Dmean of NS with failure within the ENI (45.1 ± 6.1 Gy, p=0.01). CONCLUSION: Loco-regional failure after exclusive chemoradiotherapy for esophageal cancer may be due to an inadequately low dose.