Interstitial brachytherapy as boost for locally advanced T4 head and neck cancer

Locally advanced squamous cell cancers of the head and neck (SCCHN) with bone and cartilage invasion (BCI) or those with soft-tissue invasion (STI) have been treated with resection followedup with chemoradiotherapy (CRT) or definitive CRT. However, locoregional recurrence remained a large component of treatment failure. High-dose-rate interstitial brachytherapy (BT) has been used for dose escalation to further prevent local relapse. This is a review of our experience.

T4N0-3M0 locally advanced oral cavity and oropharyngeal squamous cell carcinoma (SCCA) patients underwent definitive CRT or radiotherapy (RT) followedup with brachytherapy (BT). RT doses ranged from 45 to 50.4Gy. The patients were reassessed at this dose and if response was inadequate, patients underwent BT. BT doses ranged from 24 to 30Gy at 3-4Gy per fraction BID with 6h in between fractions. Concurrent chemotherapy was platinum based.

Twenty patients were treated with CRT or RT alone followed by BT. Thirteen patients had STI and 7 had BCI; 14 patients were treated with CRT followed by BT; and 6 patients were treated with RT alone followed by BT. Five-year locoregional control was 61%. Five-year overall survival was 29%. When we excluded the patients treated with RT alone, 5-year overall survival was 36%. Nodal status was the only prognostic factor.

This study suggests CRT followedup with BT for patients with T4 locally advanced SCCHN of the oral cavity, and oropharynx is a feasible treatment option. In patients with poor response to CRT, BT may be used for dose escalation to increase locoregional control.