Laserthermia on head and neck malignancies--experimental and clinical studies.

In recent years, remarkable progress has been made in thermotherapy. However, there is little information on localized laser hyperthermia (laserthermia) or on conventional hyperthermia technique applied to head and neck cancers. We have developed a ceramic probe to insert into tumor tissue and irradiate the Nd:YAG laser omnidirectionally. This probe can heat a spherical range of 1.5 cm to 43 degrees C. This paper concerns experimental and clinical studies on the effectiveness of laserthermia using our technique in the tumor of head and neck regions. The results obtained were as follows: histological findings and biochemical studies of arachidonic acid metabolites on normal rabbit tongue after laserthermia showed very slight effect and relatively short duration of the concomitant inflammation. The combination of laserthermia and CDDP chemotherapy was found to give a much better cytocidal effect on the tumor tissue in nude mice implanted with human thyroid cancer cells. In a clinical study on 21 cases with head and neck cancers, four cases showed complete and 13 cases showed partial remission after combined treatments of laserthermia and radiochemotherapy. Both basic experimental and clinical results have indicated a role for laserthermia in the treatment of head and neck cancer. Possible uses include the treatment of early cancer as well as advanced or recurrent cancer, where its therapeutic effect may be increased by combination with radiotherapy or chemotherapy.