[Problems of hyperthermia in deep-seated tumors]

Abstract

The results of the combined use of radiotherapy and hyperthermia for 27 cases of deep-seated tumors were evaluated, and the clinical efficacy of hyperthermia was summarized as follows: 1) Tissue image and size of tumor: Adenocarcinoma: 21 cases, 78%; and tumors 6 cm or larger: 22 cases, 83%. With radiotherapy alone, local control was impossible. 2) Effectiveness of treatment in terms of tumor size before and after treatment: CR 3 cases, PRa 7 cases, PRb and NA 8 cases each, and NE 1 case. Thus, the effectiveness of the combined use of hyperthermia is confirmed. 3) Treatment effectiveness was not correlated with temperature of tumor and thermal dose. Measurement of the deep-tissue temperature and its display must be fundamentally considered. 4) With deep-seated tumors, it is difficult to determine the effectiveness of the treatment accurately merely by the change in tumor size. In many cases, a large low-density area could be detected inside the tumor even though the size was not changed on the CT image. Standard judgement of treatment effectiveness must be determined on the basis of the change in CT image quality and histological findings of tumor. 5) Irradiation with 5000 to 7000 rads was performed in all CR and PRa cases. An adequate irradiation does is required, because it is applied to radioresistant cancer. Conformation radiotherapy is especially required, whereby X-rays are concentrated on the target region without irradiating important organs.