Zweitbestrahlung von plattenepithelkarzinomen im HNO-Bereich in simultaner kombination mit paclitaxel zweimal wochentlich. Ergebnisse einer phase-I/II-studie

Purpose: To define the maximum tolerated dose (MTD) and the dose- limiting toxicity (DLT) of paclitaxel using a twice-a-week schedule concurrent with a reirradiation in the head and neck region. Patients and Methods: Nineteen patients with histologically proven relapsed squamous cell carcinoma of the head and neck were enrolled. Twelve of them were pretreated with surgery and adjuvant irradiation or radio-chemotherapy, 6 patients had undergone definitive radio-chemotherapy, 1 definitive irradiation alone. In 15 cases the recurrent carcinoma were unresectable and 4 patients had a R1 status after salvage-surgery. Radiotherapy doses in the first line treatment ranged between 56 and 96.9 Gy (mean 67 Gy). Paclitaxel was given concurrently to the reirradiation twice a week as a 2-h-infusion. The chemotherapy dose was escalated in cohorts of 3 patients in 6 steps (20/30/35/40/45/50 mg/m², each 8 single doses). Depending on prior radiotherapy the patients were irradiated after 3D-planning with a conventional fractionation regime (2.0 Gy to 30 to 46 Gy). Results: Eighteen patients completed the protocol. The MTD was reached at the dose level VI (50 mg/m²). The dose limiting toxicity was a mucositis III°CTC in the irradiated area for more than 7 days. All further side effects were below grade III CTC. The response rate of the 15 measurable tumors was 80% (1x CR, 9x PR, 2x NC). Conclusion: With the described schedule is in adequately monitored patients an outpatient setting possible. The results justify a phase-II study to evaluate the response rates.