Local regional relapse patterns following ipsilateral postoperative adjuvant radiotherapy for buccal cancer

To study the initial local regional relapse (iLRR) patterns following ipsilateral postoperative adjuvant radiotherapy (iPART) for primary buccal cancer as an aid in defining the clinical target volume (CTV) for buccal cancer. From June 1991 through April 1999, forty-six patients with localized primary squamous cell carcinoma of the buccal/gingival mucosa were treated with complete iPART with two dimensional (2D) planning technique (generally due to negative clinical/imaging exam of contralateral neck). The median age of these 43 men and 3 women was 58 years. Stage III/IV cases composed the majority of the study group (41/46). The median dose at tumor bed was 60 Gy with range of 50-70Gy. Eight patients received chemotherapy. After a median follow-up of 20 months (2-101 months), twenty-five patients had thirty-four iLRR (ipsilateral vs both side vs. contralateral only vs other = 19 vs. 3 vs. 2 vs. 1). Advanced stage (T4N2-3, 4/11 = 36%) was the most possible risk factor with statistical significance for contralateral iLRR. The risk of contralateral iLRR was 3% in non-T4N2-3 patients. It might be appropriate to perform iPART only for non high-risk buccal cancer patients.