ULTRASOUND-GUIDED PLACEMENT OF TRANSPERINEAL PROSTATIC AFTERLOADING CATHETERS

Purpose: A new method of performing temporary prostate brachytherapy w hich does not require an open laparotomy is described. Methods and Mat erials: This procedure allows dynamic visualization of the placement o f 13-gauge (I-125) or 17-gauge (Ir-192) afterloading catheters into th e prostate gland via saggital ultrasound imaging. The image enables vi sualization of the entire path of the catheter as well as cephalad gla nd movement. The prostate gland, seminal vesicles, bladder neck, ureth ra, and rectum are easily identified and implanted, if desired, during the procedure. This procedure has been used in 34 patients as an inte rstitial boost for locally advanced (T2b, T3) prostatic carcinoma foll owing external beam therapy as a means to safely deliver higher doses to the gland. Another eight patients have undergone this procedure as salvage following failure of prior radical prostatectomy or external b eam therapy. Results: Very customized dosimetry has been obtained usin g this technique as a result of the optimal catheter placement achieve d under ultrasound guidance, particularly with I-125. Although it is t oo early to evaluate efficacy, the procedure has been well tolerated a nd is associated with minimal morbidity to date. Conclusion: This new procedure seems to be an excellent means of safe delivery of higher do ses to the gland compared to conventional external beam therapy. Due t o the ability to cover the seminal vesicles as well as the afterloadin g nature of this procedure, a more customized implant is obtained rela tive to most permanent techniques, and open laparotomy is not required .