[Post-operative radiotherapy of supraglottic carcinoma: technique with three fields of 60Co (author's transl)].

Post-operative radiotherapy of supraglottic carcinoma, because of the high risk of lymph-nodal metastases, should include irradiation of the primary tumour as well as regional lymph-nodes (jugular chain, posterior cervical. supraclavicular, submental and submaxillary triangle nodes). Taking into account the anatomically complex region to be irradiated and the critical organs present within the areas involved, the authors present a treatment plan that provides the neck irradiation through three 60Co fields: Two posterior oblique and a posterior one with median lead block in correspondence to the spinal cord. The isodose curves (at jaw level, at the medium plane of the neck and at clavear level) show that the required dose distribution has been achieved by safeguarding of radiation tissue tolerance of medulla. The authors conclude that only the adoption of a "different" procedure, i.e. outwith of any reciprocal relation "portal-target", has permitted the overcoming of anatomo-clinical problems linked with the region to be irradiated. The authors believe that the adopted methodology, the only acceptable in case of irradiation of anatomically complex and articulate regions, can be also extended to simple cases where immediate and intuitive solution is not always the most appropriate, one.