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Purpose To report the toxicity outcome in patients with localized prostate cancer undergoing 125 I permanent-seed brachytherapy (BT) according to a urethra-sparing, intraoperative (IO), real-time planned conformal technique. Methods and Materials Data were analyzed on 250 patients treated consecutively for low- or intermediate-risk prostate cancer between 2005 and 2009. The planned goal was urethral V 150 = 0. Acute and late genitourinary (GU), gastrointestinal (GI), and erectile toxicities were scored with the International Prostate Symptom Score (IPSS) questionnaire and Common Terminology Criteria for Adverse Events (version 3.0). Median follow-up time for patients with at least 2 years of follow-up ( n = 130) was 34.4 months (range, 24–56.9 months). Results Mean IO urethra V 150 was 0.018% ± 0.08%. Mean prostate D 90 and V 100 on day-30 computed tomography scan were 158.0 ± 27.0 Gy and 92.1% ± 7.2%, respectively. Mean IPSS peak was 9.5 ± 6.3 1 month after BT (mean difference from baseline IPSS, 5.3). No acute GI toxicity was observed in 86.8% of patients. The 3-year probability of Grade ≥2 late GU toxicity-free survival was 77.4% ± 4.0%, with Grade 3 late GU toxicity encountered in only 3 patients. Three-year Grade 1 late GI toxicity-free survival was 86.1% ± 3.2%. No patient presented Grade ≥2 late GI toxicity. Of patients with normal sexual status at baseline, 20.7% manifested Grade ≥2 erectile dysfunction after BT. On multivariate analysis, elevated baseline IPSS ( p = 0.016) and high-activity sources (median 0.61 mCi) ( p = 0.033) predicted increased Grade ≥2 late GU toxicity. Conclusions Urethra-sparing IO BT results in low acute and late GU toxicity compared with the literature. High seed activity and elevated IPSS at baseline increased long-term GU toxicity.

Purpose : To validate the feasibility of a single-fraction high-dose-rate brachytherapy (HDRBT) boost for prostate cancer using real-time transrectal ultrasound (TRUS) based planning. Material and methods : From August 2012 to September 2015, 126 patients underwent a single-fraction HDRBT boost of 15 Gy using real-time TRUS based planning. External beam radiation therapy (EBRT) (37.5 Gy/15 fractions, 44 Gy/22 fractions, or 45 Gy/25 fractions) was performed before (31%) or after (69%) HDRBT boost. Genito-urinary (GU) and gastro-intestinal (GI) toxicity were assessed 4 and 12 months after the end of combined treatment using the international prostate symptom score scale (IPSS) and the common terminology criteria for adverse events (CTCAE) v3.0. Results : All dose-planning objectives were achieved in 90% of patients. Prostate D 90 ≥ 105% and ≤ 115% was achieved in 99% of patients, prostate V 150 ≤ 40% in 99%, prostate V 200 < 11% in 96%, urethra D 10 < 120% for 99%, urethra V 125 = 0% in 100%, and rectal V 75 < 1 cc in 93% of patients. Median IPSS score was 4 at baseline and did not change at 4 and 12 months after combined treatment. No patients developed ≥ grade 2 GI toxicity. With a median follow-up of 10 months, only two patients experienced biochemical failure. Among patients who didn’t receive ADT, cumulative percentage of patients with PSA ≤ 1 ng/ml at 4 and 18 months was respectively 23% and 66%. Conclusions : Single-fraction HDRBT boost of 15 Gy using real-time TRUS based planning achieves consistently high dosimetry quality. In combination with EBRT, toxicity outcomes appear promising. A longer follow-up is needed to assess long-term outcome and toxicities.

Purpose To analyze the difference in prostate coverage and dose to the rectum in men with prostate carcinoma treated with permanent seed brachytherapy with different seed activities. Methods Forty-nine patients treated with iodine-125 permanent seed prostate brachytherapy with low-activity seeds of 0.30–0.37 mCi were identified. For each of these patients, 2 patients with similar prostate volume (±2 cc) were paired: one treated with intermediate seed activity (0.44–0.46 mCi) and one with high seed activity (0.60–0.66 mCi). The doses to prostate and rectum were compared using CT on Day 30. Results A total of 147 patients divided into the three seed activity groups were analyzed. Mean prostate volume was 35.7 cc (standard deviation [SD], 11.70). Compared with low-activity seeds, implants with high-activity seeds consisted of an average of 22 seeds and 4.7 needles less. The dose to the prostate (prostate volume receiving 100% of the prescribed dose [ V 100 ], prostate volume receiving 150% of the prescribed dose, and minimal dose covering 90% of the prostate volume expressed in Gy) was not higher on Day 30 ( p = 0.58–0.97). The mean volume (in cubic centimeters) of rectal wall receiving 100% of the prescribed dose ( V 100 ) increased with activity: low activity, 0.34 cc (SD, 0.49), intermediate activity, 0.47 cc (SD, 0.48), and high activity, 0.72 cc (SD, 0.79) ( p = 0.009). There was a trend ( p = 0.073) toward a higher frequency of clinically unfavorable rectal dosimetry ( V 100 > 1.3 cc) in patients with high-activity seeds (16.7%) compared with low-activity (6.3%) or intermediate-activity (4.2%) seeds. Conclusion High-activity seeds do not result in a higher dose to the prostate but in a higher dose to the rectum.

Purpose To compare low (mean 0.44, SD ± 0.0163 mCi) with high source activity (0.61 ± 0.0178 mCi) in I 125 permanent seed brachytherapy regarding seed loss, dosimetric outcome, and toxicity. Methods and Materials The study included 199 patients with prostate cancer treated by permanent seed brachytherapy alone: the first 105 with seeds of lower activity (first cohort), the following 94 with higher seed activity (second cohort). The V100, V150, V200, and D90 were analyzed on the CT scan 30 days after implantation (CTD30). The V100, V150, and D2 of the rectum were also calculated on CTD30. Seed loss was determined 30 days after implantation. Urinary toxicity was measured with the International Prostate Symptom Score (IPSS) questionnaire. Results Lower seed activity was associated with lower V150 and V200 ( p = 0.01 and p ≤ 0.001, respectively) on CTD30. More patients had a V100 p = 0.098 for D90 and p = 0.029 for V100) on CTD30. There was no difference between cohorts in dose to the rectum ( p = 0.325–0.516) or difference in patients' IPSS score from baseline ( p = 0.0.117–0.618), although there was a trend toward more urinary toxicity at 4 and 8 months for high activity seeds. Seed loss as a percentage of implanted seeds was not different ( p = 0.324). Conclusions Higher seed activity (I 125 ≥ 0.6 mCi) results in at least equal V100 and D90 on CTD30. However, dose inhomogeneity and a trend toward more urinary toxicity at 4 and 8 months after treatment may lead to a higher long-term urinary complications.

Purpose To identify dosimetric parameters predictive of a good prostate seed I 125 quality implant. We analyzed preimplant and postimplant realtime dosimetry in patients treated with intraoperative (IO) inverse planning. Methods and Materials We analyzed 127 consecutively treated patients with primarily low-risk prostate carcinoma who underwent prostate permanent seed I 125 brachytherapy using an IO planning approach. The implant was done using the three-dimensional transrectal ultrasound (PRE-TRUS)-guided IO interactive inverse preplanning system. The TRUS was repeated in the operating room after the implant procedure was complete (POST-TRUS). The prostate was recontoured and postimplant dosimetry was calculated. Each patient underwent computed tomography scan on Day 28 (CT-D28) to evaluate implant quality. Area under the receiver operating characteristic curves (AUROC) was evaluated for models predictive of a V100 of ≥90% and a D90 of ≥140 Gy on the basis of CT-D28 values. Results On CT-D28, 72.4% of patients had a V100 of ≥90% and 74.8% had a D90 of ≥140 Gy. AUROC for a V100 of ≥90% was 0.665 ( p = 0.004) on PRE-TRUS and 0.619 ( p = 0.039) on POST-TRUS. AUROC for D90 of ≥140 Gy was 0.602 ( p = 0.086) on PRE-TRUS and 0.614 ( p = 0.054) on POST-TRUS. Using PRE-TRUS V100 cutoff of >97% gives sensitivity of 88% and a false-positive rate of 63%. A POST-TRUS D90 cutoff of >170 Gy resulted in a sensitivity of 62% and a false-positive rate of 34%. Conclusions Because of unacceptably high false-positive rates, IO preimplant and postimplant TRUS-based dosimetry are not accurate tools to predict for postimplant computed tomography–based dosimetry.