Sterotactic radiotherapy offers good results in recurrent head and neck cancer
medwireNews: For patients with recurring head and neck cancer, stereotactic body radiotherapy (SBRT) offers a feasible and tolerable salvage treatment, with median overall survival rates of more than 1 year, report researchers.
Almost half of patients with advanced head and neck cancer present with a local relapse or second primary tumor in previously irradiated tissues, explains the team, and re-irradiation is limited by the dose tolerance of nearby critical structures including the spinal cord.
SBRT is delivered with very high precision, with multiple small beams, and can be hypofractionated, remark Eric Lartigau (Centre Oscar Lambret, Lille, France) and colleagues. Keeping the overall treatment time short is a major clinical advantage to populations with poor clinical prognoses.
These factors "might significantly increase the therapeutic ratio (local control/morbidity) in this patient population," they write in the International Journal of Radiation Oncology Biology Physics.
The findings emerge from a study of 40 patients with recurrent head and neck tumors in the oral cavity (20%), oropharynx (10%), hypopharynx (8%), back of skull (18%), and other sites, who were treated at their center over a 3-year period.
Patients received a total SBRT dose of 36 Gy in six fractions of 6 Gy over 11 or 12 days, and those with squamous cell carcinoma (n=20) received additional cetuximab therapy.
After a median follow up of 25.6 months, 34 patients remained alive or available for evaluation, and the researchers observed a complete response (measured using Response Evaluation Criteria in Solid Tumors) in 15 (44%) patients, a partial response in 12 (35%), and stable disease in seven (21%) patients. The overall objective response rate was 79%.
Median overall survival of the cohort was 13.6 months, with a median relapse-free survival of 8.8 months. Among the 11 patients who died without disease progression, eight died from comorbidities and three from other unrelated tumors.
Almost half (n=17) the patients presented with no toxicities during SBRT treatment, and only four (10%) presented with grade 3 (National Cancer Institute Common Toxicity Criteria) toxicities, including mucositis, dysphagia, induration, and/or fibrosis. Three of these patients had received cetuximab.
The results demonstrate the feasibility of re-irradiating head and neck tumors with SBRT, conclude Lartigau et al, adding that the "number of beams per fraction (>150) is certainly one of the factors explaining the excellent early tolerance rate."
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By Sarah Guy, medwireNews Reporter