Yasuhiro Yuri

ULTRASOUND-GUIDED MICROWAVE THERMOTHERAPY ON A VX-2 CARCINOMA IMPLANTED IN RABBIT KIDNEY

A temperature greater than 60 degrees C was maintained for 60 s within a 5-mm radius of a microwave electrode implanted in a rabbit kidney using 2450 MHz at 100 W for 30 s. Histological examination revealed complete coagulation necrosis in that area. VX-2 cells were inoculated into the kidneys of 10 rabbits. One week later, five rabbits received ultrasound-guided microwave thermotherapy, and the remaining five rabbits received no treatment. All rabbits with microwave thermotherapy had a complete response to treatment while all rabbits without therapy died of cancer within 6 weeks of the VX-2 implantation. These results indicate that ultrasound-guided microwave thermotherapy has the potential of being a nephron-salvaging treatment for small renal tumors.

EXPERIMENTAL STUDY OF MICROWAVE COAGULATION OF A VX-2 CARCINOMA IMPLANTED IN RABBIT KIDNEY

This paper describes the results of an experimental study of the microwave coagulation of VX‐2 renal tumors implanted in rabbits. The rabbits undergoing microwave treatment exhibited a satisfactory survival rate and a complete response to treatment, as verified by histological examination. All the rabbits receiving no treatment died within 6 weeks of implantation of the VX‐2 carcinoma. These results indicate that microwave coagulation may be a curative method of treatment for a relatively small renal tumor. Intraoperative real‐time ultrasonic scanning permits the percutaneous microwave coagulation of renal cancer in a clinical situation.

A case of bladder cancer treated by transurethral microwave coagulation with the flexible cystoscope

We have performed transurethral microwave tissue coagulation (MTC) for urinary bladder cancer, and especially applied MTC to small tumors of outpatients without anesthesia. We have used a rigid cystoscope which is 7 mm in diameter. In this report, 93-year-old man was performed MTC with a flexible cystoscope. The flexible cystoscope, CYF-5A (OLYMPUS) was used. It is 5.5 mm in diameter and have a 2 mm working channel, and the microwave applicator is 1.8 mm in diameter. Reccurent tumors of bladder neck and posterior wall were treated. Both tumors were 2 mm, and coagulated once and twice for 5 seconds at the energy of 50 Watts. This procedure is less painful than that with a rigid cystoscope, and it can be performed immediately after cystoscopy.

A case of transurethral microwave coagulation therapy for urinary bladder diverticulum

We applied transurethral microwave coagulation therapy to urinary bladder diverticulum. The case is 71-year-old female who had two large diverticulums, 11 × 9 × 7 cm in size on the right lateral wall and 5 × 5 × 4 cm in size on the anterior wall. Electrode resection of diverticular neck was performed, and then all of the inside mucosa was coagulated with a microwave energy of 100 watts. This procedure was able to be performed safely to the end without any complications. After the operation, both diverticulums disappeared. It supposed that the transurethral microwave coagulation therapy was a useful procedure for the endoscopic treatment of urinary bladder diverticulum.