Takumi Kumazaki

Microwave surgical treatment of diseases of prostate

A new transurethral probe for microwave radiation of the prostate has been developed. As a preliminary experiment, sliced ham was radiated with microwaves using this probe in order to evaluate the extent of thermal effect. Using mongrel male dogs, microwave coagulation of the prostate was examined. These animal experiments showed marked destruction of the prostate gland. Furthermore, the safety of this method was confirmed on the basis of results from the experiments. Prostatic bladder neck obstruction also has been treated in 6 patients with benign prostatic hypertrophy or carcinoma of the prostate by this technique. There has been no mortality and also no complications. The results of this preliminary clinical trial have been excellent.

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.

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.

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.