Preliminary report of pulsed dose rate brachytherapy in head-and-neck cancer.

PURPOSE: To assess the feasibility and acute/delayed toxicity of pulsed-dose-rate brachytherapy (PDR BT) in head-and-neck tumors. PATIENTS AND METHODS: 45 head and neck cancer patients underwent interstitial or contact PDR BT at a dose of 10.2-70 Gy (median, 70 Gy) and 0.6 or 1.0 Gy/pulse/h. 42 patients were administered BT as part of their curative treatment; 32 of them had sole BT. Three reirradiated patients with recurrent tumor had palliative BT.
RESULTS: PDR BT was well tolerated. Intense bleeding was the only complication associated with catheter removal from the tongue and bucca. 44 patients who completed BT experienced acute mucositis. Grade 3 toxicity of skin and oral mucosa occurred in three (6.8%) and six patients (13.6%), respectively. At a median follow-up of 22 months (range, 2-67 months), late serious toxicity (grade 4, for soft tissue and bone) was seen in seven patients (15.9%). Among the parameters analyzed, only dental care performed before BT had a significant impact on mucosal side effects. Acute severe mucositis was observed in 23% of patients without dental care compared to 0% of those with dental care (p=0.044). Late severe mucositis occurred in 17.7% and 26.9% of the respective patients (p=0.035), overall in 23%. The larger the volume encompassed by the reference isodose, the more late (p=0.004) mucosal reactions were observed.
CONCLUSION: PDR BT continued over a few days is a feasible and safe approach in head-and-neck tumors; however, it is accompanied by some toxicity. Dental care should precede isotope application.