Basic assessments and randomisation Pre-radiotherapy

assessment included a detailed medical history, complete physical examination, peripheral blood count and biochemistry, electrocardiogram, chest X-ray, computed tomography or magnetic resonance imaging of the abdomen and pelvis, bone scintigraphy -when indicated- and flexible sigmoidoscopy with bowel biopsies from areas included within the radiation fields. All patients were randomised 1:1 to receive subcutaneous amifostine (Ethyol, Schering Plough S.A) immediately before each fraction of radiotherapy (Group A) or radiotherapy alone (Group R). Radiotherapy modifications All patients but one received radical or postoperative external beam radiotherapy by a linear accelerator (6 MV) and one patient was treated using a Compound Library Cobalt-60 unit. Four parallel opposed fields – anteroposterior, posteroanterior Inhibitor Library high throughput Neuronal Signaling inhibitor and two laterals- were applied (box technique). The median daily radiation dose was 1.9 Gy. All fields were treated every day (5 fractions/week) and the mean number of fractions per patient was 28 (range 23-36 fractions). Reasons for treatment discontinuation were disease progression

during treatment, severe or life threatening radiation toxicity, patient decision to stop treatment, poor patient compliance or systemic reactions due to amifostine use. All patients with any sign of severe toxicity not responding to standard measures discontinued radiotherapy. Amifostine administration Patients randomised to the A group (Amifostine plus Radiotherapy) were adequately hydrated and pre-treated with antiemetics 1-2 hours prior to the administration of amifostine. Amifostine was given subcutaneously at a flat dose of 500 mg. Amifostine injection was repeated daily (5 days/week), 20-30 minutes before radiotherapy. Endoscopic surveillance and follow-up All patients in both groups (A and R) were planned to undergo

three endoscopies (sigmoidoscopies, up to the splenic flexure). The first sigmoidoscopy would be performed before the initiation of radiotherapy, the second after the completion of radiotherapy (approximately 40 days after the first) and the third at least six months after the end of radiotherapy. Diagnosis of radiation colitis (RC) was based on patients’ symptoms, laboratory tests, endoscopic and histological L-gulonolactone oxidase findings. Biopsy specimens from each patient consisted of at least 3 samples of large bowel mucosa, taken blindly from the region included in the radiation field every 10 cm, or from areas that appeared to be affected (at least one sample), as well as from normal-appearing mucosa (at least one sample). The same gastroenterologist, who was blinded to the patient treatment arm, assessed in each endoscopy the extent and the degree of colonic mucosal damage. Radiation toxicity to the bowel was assessed using the RTOG/EORTC late radiation morbidity scale for large intestine as the only validated currently available scale [11].