Local treatment of rabbit VX2 rectal carcinoma with combined hyperthermia and intratumoral CDDP injection

The efficacy of combined use of hyperthermia and intratumoral cisplatin (CDDP) injection was investigated in rabbit rectal carcinoma models produced by VX2 carcinoma injection. Local hyperthermia was administered with a 13.56 MHz radiofrequency generator at 42-43 degrees C for 30 min. CDDP (3 mg) was injected into two sites within tumours. Temperatures in the VX2 rectal carcinomas reached 42-43 degrees C within 3 min following initiation of heating and remained stable. Tumour growth was inhibited markedly in rabbit undergoing combined treatment with intratumoral CDDP and hyperthermia, when compared with rabbit treated with hyperthermia or intratumoral CDDP alone. Histological examination further revealed that combined treatment resulted in more extensive tumour necrosis, when compared with hyperthermia or CDDP alone. Therefore, combined hyperthermia and CDDP intratumoral injection may be useful for neoadjuvant preoperative treatment of advanced rectal carcinomas as well as patients with recurrent rectal carcinoma.