P-122 - Concurrent Chemotherapy and Volumetric Modulated Arc Therapy (VMAT) in carcinoma of the anal canal- Reduction of acute gastrointestinal and genitour...

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Anti-Cancer Agents & Biologic Therapy
Anal Cancer
Surgery and/or Radiotherapy of Cancer
Presenter K. Yordanov
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors K. Yordanov, M.C. Valli, G. Pesce, N.C. Azinwi, F. Martucci, J.J. Stelmes, A. Richetti
  • Oncology Institute of Southern Switzerland-IOSI, Bellinzona/CH

Abstract

Introduction

To investigate the acute GI and GU toxicity in anal cancer patients,treated with definitive chemoradiation using Volumetric Modulated Arc Therapy(VMAT Rapid Arc)

Methods

We retrospectively reviewed the records of 21 patients with anal cancer,treated in our institution with concurrent chemoradiation from January 2010 to July 2014. Median radiation dose was 57.6 Gy (range 55.8-59.4 Gy) with 1.8 Gy daily dose. Anal canal and mesorectal, external iliac, internal iliac, presacral and inguinal lymph nodes were irradiated to 39.6 Gy and after planned split -median gap was 11,3 days (range 2-23 days) the primary tumor and involved lymph nodes were boosted with 19.8 Gy/1.8 Gy. All patients were treated with VMAT Rapid Arc technique in supine position with full bladder. The bowel bag and the urinary bladder were contoured according to RTOG guidelines. Chemotherapy with 5-fluorouracil (200 mg/mq continuous infusion on days 1-4 and 29-32) and mitomycin C (10 mg/mq on days 1 and 29) was the standard regimen for 19 patients. Two patients were treated with capecitabine and mitomycin C. All patients were assessed weekly by clinical oncologist, using RTOG Acute Radiation Morbidity Scoring Criteria for GI and GU toxicity. The volume of bowel receiving 30Gy (V30) and the volume of bladder receiving 30Gy (V30) were considered as predictors for acute GI and GU toxicity.

Results

From 21 patients, 11 had G1 gastrointestinal toxicity, 3 patients had G2 and one patient had G3 toxicity. For this particular patient bowel bag V30 was 940 cc. Median V30 for bowel bag was 406 cc (range 48cc-940cc). According to genitourinary toxicity, 9 from 21 patients had G1 toxicity. No G2 or more GU toxicity was recorded. Median V30 for bladder was 47cc (range 3-182 cc).

Conclusion

VMAT Rapid Arc technique in combination with concurrent chemotherapy (5-fluorouracil and mitomycin C) for anal cancer patients is feasible option with significant sparing of Grade 2+ acute gastrointestinal and genitourinary toxicity. V30 for bowel bag and bladder are important predictors for severe acute GI and GU toxicity