Purpose/objective: To evaluate the feasibility, response rates, and toxicity of a Phase II study using targeted supradose cisplatin and concurrent radiation therapy in unresectable Stage III-IV head and neck squamous cell carcinoma.
Methods and materials: Sixty patients presenting between 6/93-9/94 were enrolled, 44 (73%) of whom had T4 and/or N2-N3 nodal disease. All patients were treated with rapid targeted superselective intraarterial infusions of cisplatin (150 mg/m2 weekly x 4) and simultaneous sodium thiosulfate intravenously (9 g/m2) for systemic neutralization of cisplatin. Concurrent (day 1) daily radiation therapy was delivered to the primary tumor and overt nodal disease to 66-74 Gy while the uninvolved lower neck received 50 Gy, at 2.0 Gy/fraction.
Results: Fifty-one (85%) patients completed the full RADPLAT protocol as planned. Fifty-seven of 60 patients were evaluable for response. Histological (n = 50) or clinical (n = 7) assessment of primary site revealed a complete response (CR) in 52 patients, partial response (PR) in 4, and stable disease (SD) in 1. Of the 40 patients presenting with nodal metastases, pathological (n = 31) or clinical (n = 6) assessment revealed a CR in 25, PR in 11, and SD in 1, while 3 were unevaluable. Overall, for both primary site and nodal disease, CR was attained in 44 (75%), PR in 12 (23%), and SD in 1 (2%) of the 57 evaluable patients. Only 2 (4%) of 57 evaluable patients have recurred above the clavicle, 1 in the primary site and 1 in the regional lymph nodes. Twelve patients (23%) have failed in distant sites. Grade III/VI toxicity has included gastrointestinal in 6, hematologic in 6, mucosal in 12, vascular in 4, and neurological in 4 patients.
Conclusion: Concurrent radiation therapy and targeted supradose cisplatin (i.e., RADPLAT) can be safely delivered with high response rates and excellent loco-regional control in advanced Stage III/IV head and neck squamous cell carcinoma.