Intrarectal amifostine during external beam radiation therapy for prostate cancer produces significant improvements in Quality of Life measured by EPIC score

Abstract

Purpose: To test whether intrarectal amifostine limits symptoms of radiation proctitis, measured by using the Radiation Therapy Oncology Group (RTOG) gastrointestinal (GI) toxicity score and the Expanded Prostate Cancer Index Composite (EPIC) score.

Methods and materials: Patients with localized prostate cancer received amifostine as a rectal suspension 30-45 minutes before daily three-dimensional conformal radiation therapy. The first 18 patients received 1 g of amifostine, and the next 12 patients received 2 g. Toxicity was assessed at baseline, during treatment, and at follow-up visits by using RTOG grading and the EPIC Quality of Life (QoL) 50-item questionnaire. The Bowel Function subset of the bowel domain (EPIC-BF), which targets symptom severity, and the Bowel Bother subset of the bowel domain (EPIC-BB), which assesses QoL, were evaluated and compared with the RTOG GI toxicity score.

Results: Median follow-up was 30 months (range, 18-36 months). Overall, EPIC-BF and EPIC-BB scores both tracked closely with the RTOG GI toxicity score. Seven weeks after the start of radiation therapy, the incidence of RTOG Grade 2 toxicity was 33% in the 1-g group (6/18 patients) compared with 0% (0/12 patients) in the 2-g group and tended toward statistical significance (p = 0.06). A significant difference between amifostine groups was observed using the EPIC-BF score at 7 weeks (p = 0.04). A difference in EPIC-BB scores between dose groups was evident at 7 weeks (p = 0.07) and was significant at 12 months (p = 0.04).

Conclusions: Higher doses of amifostine produced significant improvements in acute and late bowel QoL (up to 1 year after therapy), measured using the EPIC score.

Conflict of interest statement

Conflict of Interest Notification:

No authors had any conflict of interest to report.

Figures

Figure 1. RTOG GI Toxicity Score

RTOG toxicity was determined at each pre-determined time point for the patients in each group. Mean RTOG scores are presented by dose. Patients who received 1gm Amifostine (---△---) had slightly higher, but not significantly different RTOG scores than the patients who received a 2gm dose (—□—).

Figure 2. EPIC-Bowel Function Composite Score

EPIC-BF toxicity was determined at each pre-determined time point for the patients in each group. Mean RTOG scores are presented by dose. Patients who received 1gm Amifostine (---△---) had slightly higher, EPIC scores than the patients who received a 2gm dose (—□—). This difference was significant (p=0.04) at the 7-week time point (denoted by **).

Figure 3. EPIC-Bowel Bother Composite Score

EPIC-BB toxicity was determined at each pre-determined time point for the patients in each group. Mean RTOG scores are presented by dose. Patients who received 1gm Amifostine (---△---) had slightly higher, EPIC scores than the patients who received a 2gm dose (—□—). This difference was nearly significant (p=0.07) at the 7-week time point (denoted by *) and achieved statistical significance (p=0.04) at 12 months (denoted by **).