Brachytherapy Brachytherapy is the direct implantation of radioactive sources into the prostate. It is based on the principle that the deposition of radiation energy in tissues decreases as a function of the square of the distance from the source (Chap. 81). The goal is to deliver intensive irradiation to the prostate, minimizing the exposure of the surrounding tissues. The current standard technique achieves a more homogeneous dose distribution by placing seeds according to a customized template based on CT and ultrasonographic assessment of the tumor and computer-optimized dosimetry. The implantation is performed transperineally, without an open procedure, with real-time imaging. The. | Chapter 091. Benign and Malignant Diseases of the Prostate Part 7 Brachytherapy Brachytherapy is the direct implantation of radioactive sources into the prostate. It is based on the principle that the deposition of radiation energy in tissues decreases as a function of the square of the distance from the source Chap. 81 . The goal is to deliver intensive irradiation to the prostate minimizing the exposure of the surrounding tissues. The current standard technique achieves a more homogeneous dose distribution by placing seeds according to a customized template based on CT and ultrasonographic assessment of the tumor and computer-optimized dosimetry. The implantation is performed transperineally without an open procedure with real-time imaging. The improvements in brachytherapy techniques have resulted in fewer complications and a marked reduction in local failure rates. In a series of 197 patients followed for a median of 3 years 5-year actuarial PSA relapse-free survival for patients with pretherapy PSA levels of 0-4 4-10 and 10 ng mL were 98 90 and 89 respectively. In a separate report of 201 patients who underwent posttreatment biopsies 80 were negative 17 were indeterminate and 3 were positive. The results did not change with longer follow-up. Nevertheless many physicians feel that implantation is best reserved for patients with good or intermediate prognostic features. Brachytherapy is well tolerated although most patients experience urinary frequency and urgency that can persist for several months. Incontinence has been seen in 2-4 of cases. Higher complication rates are observed in patients who have undergone a prior TURP or who have obstructive symptoms at baseline. Proctitis has been reported in 2 of patients. Active Surveillance Active surveillance described previously as watchful waiting or deferred therapy is a policy of monitoring the illness at fixed intervals with DREs PSA measurements and repeat biopsies of the prostate as indicated but with no .
