Interstitial pulsed-dose-rate brachytherapy for head and neck cancer--Single-institution long-term results of 385 patients.

Purpose: To assess the long-term results of protocol-based pulsed-dose-rate (PDR) interstitial brachytherapy (iBT) in 385 patients with head and neck cancer who underwent PDR-iBT preferably after minimal, nonmutilating surgery.

Methods And Materials: From 1997 to 2009, a total of 385 patients received protocol-based PDR-iBT for head and neck cancer. Brachytherapy was preceded by surgery in most of our patients (326/385, 84.7%). Altogether, 246 of 385 patients (63.9%) received iBT alone and 135 of 385 patients (36.1%) in combination with external beam radiation therapy. The analysis was done after a median followup of 63 months.

Results: The 5-, 10-, and 15-year local relapse-free survival rates according to Kaplan-Meier test for all analyzed patients were 85.8%, 83.1%, and 80.2%, respectively. The 5-, 10-, and 15-year overall survival and disease-free survival rates were 68.9%, 52.2%, and 44.1%, and 81.3%, 79.3%, and 76.3%, respectively. For N0-/N1- vs. N2-patients, we observed significantly different 5-year local recurrence-free survival rates with values of 92.3% and 73.7%, respectively (p=0.007). No other patient or treatment-related parameters had a significant influence on treatment results. Serious late side effects, such as soft tissue or bone necrosis, were observed in 39 of 385 patients (10.2%) and 18 of 385 patients (4.9%), respectively.

Conclusions: The PDR-iBT with 0.4-0.7Gy each hour, 24h per day for patients with head and neck cancer is a proven, effective, and safe treatment method with excellent long-term data.