Limited effects of selenium substitution in the prevention of radiation-associated toxicities. results of a randomized study in head and neck cancer patients.

OBJECTIVE: The substitution of selenium activates the selenium-dependent enzyme glutathione peroxidase, which is important for scavenging free radicals. To date, only limited data are available about the clinical impact of selenium regarding the toxicities due to free radical producing therapies, e.g. irradiation or chemotherapy, and therefore the objective of this study was to investigate the clinical impact of selenium in such therapies. PATIENTS AND METHODS: 39 patients (8 female, 31 male) with advanced head and neck cancer were included in a randomised phase II study. The mean age was 63.52+/-9.31 years. Tumour localizations: oral cavity 15 patients, oropharynx 19 patients, hypopharynx 5 patients, carcinoma of unknown primary 1 patient. Group A (n=22) received 500 microg sodium selenite on the days of radiotherapy and 300 microg sodium selenite on days without radiotherapy. Group B (17) was irradiated without any selenium substitution. Both groups were well balanced according to age, gender, localization and stage of the tumour. The RTOG grade of radiation-associated toxicities was evaluated once per week. RESULTS: The following serious toxicities were observed (group A vs. group B): dysphagia 22.7% vs. 35.3%, loss of taste 22.7% vs. 47.1%, dry mouth 22.7% vs. 23.5%, and stomatitis 36.4% vs. 23.5%. A statistical trend (Fisher's exact test) was only seen for the loss of taste (p=0.172). The weekly patient analysis (Student's t-test) showed a significant reduction of dysphagia in the selenium group (Group 1) at the last week of irradiation. CONCLUSION: This small randomised trial showed limited effects of selenium in the prevention of ageusia (loss of taste) and dysphagia due to radiotherapy of head and neck cancer.

A new administration schedule for amifostine as a radioprotector in cancer therapy.

Thus far, amifostine, a new radioprotective substance, had been given as short infusion 30 minutes before radiotherapy. In our investigation for the first time we have administered the substance as bolus injection (200 mg/m2 dissolved in 10 ml sodium chloride 0.9%). 42 patients with malignancies of the head and neck region, recurrences of rectal carcinomas and bronchial carcinomas had been treated with different solution volumes over different time periods. Using amifostine as a bolus injection had led to a statistically significant decrease in acute toxicity (p = 0.012). In comparison to short infusion (15 minutes) we have documented the same radioprotective impact. Hence, bolus injection of amifostine is feasible and can spare manpower and time in the department of radiotherapy.

Radiotherapy on adult patients with soft tissue sarcoma with fast neutrons or photons.

Through adjuvant photon radiotherapy, it is possible to improve tumor control as well as avoid ultra radical surgery in patients with soft tissue sarcoma. Similar results have been obtained in cases of incomplete resected G1/G2 sarcoma after applying neutron radiotherapy. We compared the results of a group of patients with soft tissue sarcoma treated with those having received photon therapy (100 patients) or neutron therapy (61 patients). The median dose in the photon treated group was 60 Gy (range 45 to 65 Gy). The neutron therapy group received a median dose of 14.1 Gy (range 5.0 to 18.57 Gy). Patients treated with mixed-beam irradiation received an average dose of 36.5 Gy photon and 8.5 Gy neutrons. The 5-year survival rate of the photon group rated 43.1%. In the neutron group we found 42.5%, respectively. In both groups the results of surgical resection and grading were of high significance according to survival. 4% of the patients belonging to the photon group developed grade III/IV WHO side effects. In the neutron group side effects grade III/IV WHO were observed in 11% of the cases. Comparing treatment results of neutron and photon therapy we demonstrated that incompletely resected G1 and G2 tumor patients show greater benefit in the case of neutron radiotherapy.