Serious adverse effects of amifostine during radiotherapy in head and neck cancer patients

Background and purpose: Amifostine has been shown to protect against xerostomia induced by radiotherapy for head and neck cancer, but its impact on the therapeutic index is unknown. This is the first report focusing on amifostine related adverse effects leading to discontinuation of amifostine treatment.

Patients and methods: Thirty-nine patients from two centers irradiated for head and neck cancer received i.v.-infusions of amifostine prior to each radiation fraction. In a phase III study, two daily amifostine doses, 200 mg/m² (n=21) and 340 mg/m² (n=18), were compared for protection against radiation induced toxicity. Total radiation dose was 60–70 Gy (2 Gy per fraction), nine patients received concurrent chemotherapy with cisplatin/5-FU. amifostine was usually discontinued after >1 episode of serious toxicity during subsequent treatment sessions.

Results: In 16/39 patients (41%) amifostine was discontinued due to severe adverse effects, which led to discontinuation of the phase III study. In four of 16 patients radiotherapy was delayed due to amifostine related adverse effects for 1–3 days. Discontinuation occurred more often in patients receiving chemotherapy. The results led to a literature review for amifostine treatment during radiotherapy in head and neck cancer patients. Regarding our series and published series using an amifostine schedule comparable to ours, total discontinuation rate was 27% (57/214). Discontinuation was significantly influenced by chemotherapy (P=0.007), but not by amifostine dose (P=0.156).

Conclusion: Daily i.v. administration of amifostine during radiotherapy in head and neck cancer is associated with a high rate of serious adverse effects leading to discontinuation of amifostine treatment and sometimes delay of radiotherapy.     

Radiotherapy alone, versus radiotherapy with amifostine 3 times weekly, versus radiotherapy with amifostine 5 times weekly: A prospective randomized study in squamous cell head and neck cancer

BACKGROUND: The main objective of this study was to investigate whether nondaily intravenous administration of amifostine was as effective as daily intravenous administration with regard to the reduction of the incidence of Grade 2 or greater xerostomia in patients with head and neck cancer. METHODS: Ninety-one patients who received bilateral irradiation for head and neck cancer were included. Thirty patients received no amifostine (AMI-0), 31 patients received amifostine at a dose of 200 mg/m2 3 times weekly (AMI-3), and 30 patients received amifostine at a dose of 200 mg/m2 daily (5 times weekly) (AMI-5). Acute and late xerostomia and quality of life (QOL) were assessed at baseline, 6 weeks later, and at 6-month intervals from 6 months to 24 months postradiotherapy. RESULTS: Grade 2 or greater late xerostomia differed significantly at 6 months (AMI-0 74% vs. AMI-3 67% vs. AMI-5 52%; P = .03), but not thereafter. During follow-up, patient-rated xerostomia deteriorated more in AMI-0 patients (mean difference score:, 52 for AMI-0 compared with 25 for AMI-3, and 29 for AMI-5; P = .01). Nausea and emesis were reported most frequently as side effect, but Grade 2 or greater toxicity was observed in only 4 patients. However, 28% of patients discontinued amifostine before the end of radiotherapy. CONCLUSIONS: Long-term, patient-rated xerostomia was less for the AMI-3 and AMI-5 groups through 2-year follow-up, but no difference was noted between the AMI-3 and AMI-5 groups. For late xerostomia according to the Radiation Therapy Oncology Group criteria, the same effect was observed at 6 months, but not thereafter.