Teruaki Kigure

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.

Microwave Surgical Treatment of the Prostate: Clinical Application of Microwave Surgery as a Tool for Improved Prostatic Electroresection

Microwave surgery as a tool for improved prostatic electroresection is introduced. Prior to electroresection the prostate was coagulated with 2,450 MHz of microwave which was emitted from the bipolar electrode of a specially designed probe. We conducted a comparative study of 35 patients with bladder neck obstruction. There was a microwave coagulation group treated with subsequent transurethral resection (TUR) and a conventional TUR group. Both groups were analyzed for the amount of blood loss, irrigant absorption and the frequency of complications. Both during and following surgery, the former group had a significant reduction in blood loss and had no complications. We conclude that the combination procedure of microwave coagulation and TUR can minimize the disadvantage of formal TUR and may be of value in the treatment of patients with both prostatic obstruction and of hemorrhagic diathesis as well as in high risk patients.

Transcystoscopic Intracavitary Irradiation for Carcinoma of the Bladder: Technique and Preliminary Clinical Results

A remote controlled transcystoscopic intracavitary after-loading unit is introduced for irradiation therapy of bladder carcinoma. With intense radiation therapy a significant dose can be delivered to the tumor during a short interval. We treated 12 patients with transitional cell carcinoma of the bladder using transcystoscopic intracavitary irradiation. Of the patients 9 initially had a complete response, although within several months 3 subsequently had recurrence in a different part of the bladder. Technical difficulties and severe complications were not encountered. The preliminary results and technique of transcystoscopic intracavitary irradiation are reported.

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.

Microwave Coagulation Therapy for Urinary Bladder Tumors

A new device has been developed for microwave coagulation of urinary bladder tumors. Twenty-one patients with urinary bladder tumors were treated by irradiation with microwave energy of 2,450 MHz. Results were obtained as follows: (1) microwave coagulation was performed in 21 patients with transitional cell carcinoma of the urinary bladder. Excluding 4 patients who subsequently received radical cystectomy, 17 patients showed a complete response, although 2 patients subsequently developed recurrences in different parts of the bladder within the following several months. Histological examination of the excised specimen revealed complete eradication of the tumor in 2 patients. In the remaining 2 patients with high-stage tumor (T4), viable tumor cells were noted in the urethra or vaginal wall. (2) Although neither technical difficulties nor severe complications were encountered, transient urinary frequency and calcification of the bladder wall were noted. The results of this study indicate that microwave coagulation may be used in the treatment of both superficial and invasive tumors.

Intraoperative real-time ultrasonic scanning for microwave coagulation of the prostate

Nine patients with severe dysuria caused by prostatic cancer received prostatic microwave coagulation under intraoperative real-time ultrasonic scanning. During the procedure, the microwave applicator was clearly observed, and the coagulation region appeared as an hyperechoic area compared to the noncoagulated region. Intraoperative real-time ultrasonic scanning allowed safer and more efficacious application of prostatic microwave coagulation.

Remote Afterloading Transurethral Radiotherapy for Prostatic Cancer

We have developed a technique of transurethral radiotherapy for prostatic cancer using a remote after-loading system. The radioactive source is a cobalt-60 pellet with 3.7-Ci activity. Four patients with adenocarcinoma of the prostate were treated. In all patients, the local tumor response was rapid and satisfactory as judged by physical examination as well as ultrasonography. Serious complications were not seen. A new technique and preliminary clinical results are reported.

Urinary basic fetoprotein in the diagnosis and follow‐up of patients with urothelial carcinoma

Urothelial carcinoma is one of the most common malignant neoplasms of the urinary tract and is characterized by a high local recurrence rate. However, no specific and reliable tumor marker has been identified for the diagnosis and follow‐up of patients with urothelial carcinoma.

Microwave Coagulation Therapy on VX-2 Carcinoma Implanted in Rabbit Urinary Bladders

In order to evaluate the effectiveness of microwave coagulation therapy on urinary bladder carcinoma, we conducted a series of experiments using carcinoma VX-2 cells designed for the application on animal hosts. Three days after implantation of VX-2 cells into the bladder of the rabbits, microwave coagulation therapy was performed. The antitumor effect, i.e. the survival rate, the histological study and the immunological response of the microwave therapy was examined in comparison with the control group (no treatment), the partially cystectomized group and the sham-operated group (no tumor cell implantation). The results were obtained as follows. (1) The survival rate in the microwave group was greater than that in the control group. (2) The stimulation index value (SI), which represents humoral immunity, decreased postoperatively in all groups. In the microwave group, SI increased gradually beginning 21 days after the transient decrease. (3) Histological findings revealed severe degeneration, necrosis and complete eradication of the cancer cells of the bladder wall in the microwave group, however, perforation of the urinary bladder could not be detected. The results indicate that microwave coagulation therapy is an effective procedure for urinary bladder tumors. Furthermore, microwave therapy may also accelerate the inactivation of immunological suppressors in the carcinoma host, an additional benefit of the microwave procedure.

Combination Therapy with Microwave Coagulation and Intracavitary Irradiation for Bladder Cancer

Twenty-five patients with transitional cell carcinoma of the bladder have been treated with combined therapy consisting of microwave regional coagulation and intracavitary irradiation. A remote-controlled after-loading system was utilized for the radiation therapy. The follow-up period ranged from 6 to 19 months with an average of 11.4 months. Tumor stages were Tis (n = 2), Ta or T1 (n = 17), T2 (n = 2), T3 (n = 3) and T4 (n = 1), and grades were G1 (n = 10), G2 (n = 11) and G3 (n = 4). In 23 patients (92%), there was no endoscopic or histologic evidence of tumor after the initial treatment. Heterotopic recurrences were found after 2 or 3 months in 3 patients who received microwave regional coagulation or intracavitary regional irradiation. Additional intracavitary whole bladder mucosal irradiation was performed for 10 patients with multiple tumors and frequent recurrent tumors. Nine patients had no recurrence (average follow-up 11 months). Our preliminary findings indicate that combination therapy of microwave coagulation and intracavitary irradiation is a useful treatment for bladder cancer.