Hyperthermia and radiotherapy for inoperable squamous cell carcinoma metastatic to cervical lymph nodes from an unknown primary site

Introduction: Neck node metastases from an unknown primary carcinoma repres ent an infrequent but challenging problem for oncologists. The management o f such patients is controversial, but radiotherapy alone or as part of a mu ltimodal approach is often indicated. Patients with inoperable lesions usua lly receive radiotherapy alone at palliative doses. In an attempt to increa se local control in patients with locally advanced neck disease from an unk nown primary carcinoma, local hyperthermia was combined with definitive rad iotherapy. Material and method's: Between 1982 and 1993, radiotherapy and local microw ave hyperthermia were used to treat 15 patients with metastatic neck nodes from an unknown primary site. The patients had previously undergone only bi opsy or fine needle biopsy, and showed no signs of metastases beyond the cl avicle. Radiation to the nodes and the potentially primary sites in the hea d and neck was delivered by a 6 MV linear accelerator or a Cobalt 60 unit, to a total dose of 57.50-74.40 Gy (median 70 Gy). Hyperthermia was added us ing a BSD 1000 unit at an operating frequency of 280-300MHz for 2-7 session s (mean 3.1; median 2) at a desired minimum temperature of 42.5 degrees C. Two patients also received i.v. cisplatin 20 mg/m2/week as a radiosensitize r. Results: Nine patients achieved a complete, and four a partial response for an overall response rate of 86.5%. Acute and late toxicity was mild: four patients experienced pain during hyperthermia, two moist cutaneous desquama tion, and one cutaneous necrosis. The actuarial probability of maintaining local control at 5 years is 64.5% and the actuarial overall survival 29%. F ive patients developed distant metastases and died of disease, two experien ced nodal recurrence and two died of other unrelated causes. Conclusion: The addition of local microwave hyperthermia to radiotherapy in the treatment of metastatic squamous cell carcinoma of the neck in patient s with an unknown primary site leads to good local control with moderate to xicity. No definite conclusions are possible because of the small number of patients involved in this phase II trial.