SBRT offers good 1-year survival for inoperable head and neck patients
MedWire News: Stereotactic body radiotherapy (SBRT) can achieve good local disease control in head and neck cancer patients who have already undergone radiotherapy, show Turkish study results.
Furthermore, overall survival in these patients after SBRT is almost 1 year, say the researchers, and just 13.3% of the patients in their cohort experienced Radiation Therapy Oncology Group (RTOG) Grade II long-term complications.
Mustafa Cengiz and colleagues from Hacettepe University in Ankara evaluated the outcomes of 46 patients with recurrent, unresectable, and previously irradiated head and neck cancer who were treated with CyberKnife (Accuray, Sunnyvale, California, USA).
CyberKnife is a novel SBRT device that enables the application of high doses of radiation precisely to tumors in this type of patient, explain the researchers in the International Journal of Radiation Oncology Biology Physics.
The study cohort comprised 22 women and 24 men aged a median of 53 years with primary tumors in the nasopharynx, oral cavity, paranasal sinus, larynx, hypopharynx, and other sites.
The median tumor dose with the CyberKnife was 30 Gy, which the majority of patients received in five fractions.
Of the 37 patients with follow-up data available, 10 had complete tumor regression, 11 had a partial response, and 10 had stable disease after SBRT. Of the patients with stable disease, four had relief from symptoms.
The median overall survival was 11.9 months, and median progression-free survival was 10.5 months; 1-year overall and progression-free survival rates were 47% and 41%, respectively.
Eight patients experienced acute side effects, according to RTOG definitions, and six (13.3%) patients had long-term complications including soft tissue necrosis, mandibula necrosis, and dysphagia.
A total of nine patients died during study follow-up, and eight deaths were due to carotid blow-out syndrome. Only one of these deaths was attributed to tumor progression, and the rest were related to treatment, notes the research team.
The high number of patients observed with carotid blow-out syndrome could be explained by the fact that the majority of patients had large tumor volumes that trapped the carotid arteries, remark Cengiz et al.
"When we analyzed our results, we observed that carotid blow-out syndrome occurred only in patients whose tumor surrounded half or more of the carotid artery wall, and when the carotid arteries received 100% of the prescribed dose," they write.
Therefore, they recommend more caution be given to carotid arteries during treatment planning to prevent the development of this "highly fatal complication."
By Sarah Guy