Volumetric modulated arc therapy (VMAT) in the combined modality treatment of anal cancer patients

Objective:To report clinical and dosimetric outcomes of a consecutive series of patients with anal cancer treated with volumetric-modulated arc therapy (VMAT) concomitant to chemotherapy (CT).Methods:A cohort of 39 patients underwent VMAT employing a schedule consisting of 50.4 Gy/28 fractions to the gross tumour volume (GTV) and 42 Gy/28 fractions to the elective nodal volumes for patients with cT2N0 disease. Patients with cT3–T4/N0–N3 tumours were prescribed 54 Gy/30 fractions to the GTV and 50.4 Gy/30 fractions to the gross nodal volumes if sized ≤3 cm or 54 Gy/30 fractions if > 3 cm. Elective nodal regions were given 45 Gy/30 fractions. CT was administered concurrently following Nigro's regimen. The primary end point was acute toxicity. Secondary end points were colostomy-free survival (CFS), disease-free survival (DFS), cancer-specific survival (CSS) and overall survival (OS). Dosimetric data are also provided.Results:Median follow-up was 21 months. Maximum acute toxicities were: dermatologic—G3: 18%...