Radiotherapy with concomitant continuous cisplatin infusion for unresectable tumors of the upper aerodigestive tract: results of a phase I study.

A phase I-II study was initiated in February 1991 of concomitant radiation and cisplatin (CDDP) in the treatment of unresectable head and neck squamous cell carcinomas (n = 12). The first patient was treated palliatively for a cervical recurrence of laryngeal cancer. The 11 other patients had locally advanced (stage IV) previously untreated carcinomas of the oropharynx (n = 9), hypopharynx (n = I), or cervical node with unknown primary site (n = 1). Standard external radiation was carried out up to a total dose of 60 Gy/6 weeks (7 MeV electron beam) for the first patient and 72 Gy/8 weeks (Co-60 beam) for the other 1 1 patients. CDDP was infused continuously during the entire radiation treatment, 5 days/week. The starting dose was 4 mg/m(2)/day and was escalated by increments of 1 mg/m(2)/day; dose-limiting toxicity was observed at 7 mg/m(2)/day. Neutropenia (grade 4, one patient; grade 3, three patients) and thrombocytopenia (grade 3, one patient; grade 2, one patient) were the limiting factors. Therefore, the recommended dose of CDDP is 6 mg/m(2)/day. All patients but one completed the scheduled radiation. For the entire group, mucositis was not more severe than that observed with radiotherapy alone. There was no nephro-, oto-, or neurotoxicity. A complete response was obtained in eight (66%) patients. Of these, four were free of disease 12-34 months after completion of treatment and one had a total glossectomy for a tongue necrosis. For the whole series, the mean overall survival was 16 months posttreatment. Pharmacokinetic analysis indicated the total cisplatin accumulation at the end of treatment to be 743-1551 ng/ml. Accumulation of ultrafilterable platin was noted in only one patient (137 ng/ml at the end of treatment).