Indications and Results of Telecobalt Therapy in Epithelial Tumors of the Oral Cavity

A report of the results obtained in 194 cases of epithelial tumors of the oral cavity subjected to telecobalt therapy between June 1958 and December 1964 at the Institute of Radiology, University of Milan, and the Radiology Division of the National Cancer Institute. The criteria for establishing whether the treatment was indicated and the principles of selection of cases are specified. In the majority of cases the tumors were no longer circumscribed (T3-T4) and in over half the cases regional lymph node metastases were present when treatment commenced. Thirty-six patients had previously been subjected to radiotherapy or surgery. Telecobalt therapy was given almost exclusively to stationary fields using one or two portals of entry. Tumors of the floor of the mouth were often irradiated through wedges of lead. In 80% of the cases a tumor-dose of between 5000 and 6000 r was given over 6–8 weeks. At the end of treatment the tumor had completely disappeared in 22.7% of the patients, regressed to some extent in 40.6% and was unchanged or had deteriorated in 36.7%. The survival curves show that 2/3 of the patients died within two years of starting treatment; the five-year survival rate was 10.9%. This case-series confirmed that the prognosis is poorer in cases with regional lymph node metastases at the start of treatment and in patients subjected to telecobalt therapy for relapse after radiotherapy or surgery. The results obtained with telecobalt therapy proved to be considerably inferior to those obtained with curietherapy and so the latter is recommended in cancers of the oral cavity whenever it is feasible. Telecobalt therapy may be indicated, mainly as a symptomatic palliative, in very extensive infiltrating tumors adhering to the bone structures and in patients with inoperable lymph node metastases.