Purpose: Brachytherapy (BT) for prostate cancer can be performed with either preoperative (PO) or intraoperative (IO) planned dosimetry. Potential benefits of intraoperative include fewer procedures for the patient, cost savings and improved accuracy of seed implantation leading to improved tumor control and urinary side effect profile. We report our experience with transition to IO planned BT after performing more than 600 PO planned implants since 1997.
Materials and methods: From September 2001 to February 2003, 46 consecutive patients with T1-3N0M0 adenocarcinoma of the prostate underwent BT. IO dosimetry was performed in 23 patients, while PO dosimetry was used in 23 immediately before changing to IO. American Urological Association (AUA) symptom index questionnaires were administered preoperatively and postoperatively. All patients underwent postoperative dosimetry by computerized tomography. Total, irritative and obstructive AUA scores were compared in the 2 groups using analysis of covariance. Models were adjusted for pretreatment variables of symptom scores, type of procedure and time since procedure.
Results: Median followup was 47 and 45 days for PO and IO dosimetry, respectively. No differences were observed in seed, needle numbers or prostate size in the 2 groups. Average operative times were higher (47 vs 79 minutes, p <0.01) in the IO group but they decreased to nearly the same levels as PO implants in the first 23 cases so treated. Slopes of operative time over date of procedure differed significantly between methods (p <0.01). Comparing PO to IO dosimetry adjusted estimate of difference was -1.96 for total (95% CI -6.4, 2.5), -0.48 for obstructive (95% CI -3.3, 2.3) and -1.78 for irritative (95% CI -3.9, 0.31) AUA score. These differences were neither statistically nor clinically significant.
Conclusions: Our experience indicates that intraoperative planned BT is easily implemented in clinical practice as a result of a short learning curve. In addition, the approach is not associated with any changes in early postoperative voiding symptoms and, due to only marginally longer operative times, may have a cost advantage by eliminating the preplanning visit and ultrasound.