Limited cytoprotective effects of amifostine in high-dose radioactive iodine 131-treated well-differentiated thyroid cancer patients: analysis of quantitative salivary scan. Randomized phase III trial of postoperative radiochemotherapy +/- amifostine in head and neck cancer. Is there evidence for radioprotection?
The aim of present study was to investigate the cytoprotective effect of amifostine on salivary glands in 131I-treated differentiated thyroid cancer (DTC) patients using serial quantitative analysis of salivary gland scans.
                Serial quantitative salivary scintigraphies were performed in 80 newly diagnosed DTC patients (9 men, 71 women; mean age, 43.2 years old; range, 21-58 years old). Forty-two patients were assigned randomly to the amifostine treatment group, which received 300 mg/m2 amifostine intravenously before 131I administration.
                In both amifostine-treated and nontreated groups statistically significant declines of functional parameters after 131I treatment were revealed by quantitative salivary scintigraphy in DTC patients. Amifostine pretreatment did not prevent the parenchymal damage to major salivary gland function after 131I treatment (F = 1.37, p = 0.2461). However, the dose of 131I had significant effects on salivary gland function after 131I treatment (F = 9.72, p = 0.0002).
                The present study did not show cytoprotective effects of amifostine for DTC patients treated with 131I. Experimental and clinical data suggest a reduction of radiation-induced acute toxicity by amifostine (A). We investigated this issue in a randomized trial comparing radiochemotherapy (RT + CT) versus radiochemotherapy plus amifostine (RC + CT + A) in patients with head and neck cancer.
                56 patients with oro-/hypopharynx or larynx cancer (T1-2 N1-2 G3, T3-4 N0-2 G1-3) were randomized to receive RC + CT alone or RC + CT + A. Patients were irradiated up to 60 Gy (R0) or 70 Gy (R1/2) and received chemotherapy (70 mg/m(2) carboplatin, day 1-5 in week 1 and 5 of radiotherapy). 250 mg amifostine were applied daily before each radiotherapy session. Acute toxicity was evaluated according to the Common Toxicity Criteria (CTC). As for acute xerostomia, patients with laryngeal cancer were excluded from evaluation.
                50 patients were evaluable (25 patients in the RC + CT, 25 patients in the RC + CT + A group). Clinical characteristics were well balanced in both treatment groups. Amifostine provided reduction in acute xerostomia and mucositis but had no obvious influence on Karnofsky performance status, body weight, cutaneous side effects, and alopecia. The differences between both groups were statistically significant for acute xerostomia and nonsignificant, but with a trend for mucositis.
                According to our results, there is a radioprotective effect on salivary glands and a potential effect on oral mucosa by amifostine in postoperative radiotherapy combined with carboplatin. To improve the radio- and chemoprotective effects of amifostine in clinical practice, the application of a higher dose (> 250 mg) seems to be necessary.
Results from two randomised controlled clinical trials suggest that the amifostine has no significant radioprotective effects on salivary glands in high-dose radioactive iodine treated differentiated thyroid cancer patients. Moreover, no health-related quality of life and other patient-oriented outcomes were evaluated in the two included trials. Randomised controlled clinical trials with low risk of bias investigating patient-oriented outcomes are needed to guide treatment choice.