USE OF MR-CONTROLLED LASER-INDUCED THERMO THERAPY (LITT) IN THE MANAGEMENT OF RECURRENT SQUAMOUS-CELL CARCINOMAS IN THE HEAD AND NECK

Background: The management of patients with recurrent carcinomas of th e head and neck that had been treated before by surgery, radiation, an d/or chemotherapy presents a considerable problem. The value of the MR -controlled laser-induced thermotherapy (LITT) was analysed as a new p alliative treatment modality. Method: LITT was used in five patients w ith recurrent head and neck squamous cell carcinomas, who had undergon e established methods of treatment. One patient with a primary larynge al carcinoma, who refused surgery, was treated by LITT in addition to radiation. A Nd:YAG laser was used to deliver laser light via an appli cator directly into the tissue and to produce tumor necrosis. Using tw o special MR thermosequences (Thermo-TurboFLASH-, modified FLASH-2 D-S equenfe) the laser process was controlled on line. The necroses were m easured by a static and dynamic area calculation program based on a pi xel evaluation. Results: The induced tumor necroses ranged from 4 cm(3 ) to 28 cm(3). In all cases the MR thermosequences showed a loss of th e signal up to 15 mm around the top of the applicator. In the post-int erventional T-1 sequences with intensified contrast, the coagulation n ecroses were represented as hypovascular areas. No side effects were s een and five of the patients felt an improvement of clinical symptoms. Conclusion: LITT as a minimal invasive, MR-controlled method may be a good alternative in palliative therapy of head and neck carcinomas.