Patient-reported health-related quality of life for men treated with low-dose-rate prostate brachytherapy as monotherapy with 125-iodine, 103-palladium, or 131-cesium: Results of a prospective phase II study.

PURPOSE: To compare quality of life (QoL) after brachytherapy with one of the three approved radioactive isotopes. METHODS AND MATERIALS: Patients with mostly favorable intermediate-risk prostate cancer were treated on this prospective phase II trial with brachytherapy as monotherapy, without hormonal therapy. QoL was recorded at baseline and each follow-up by using the Expanded Prostate Cancer Index Composite instrument. The minimal clinically important difference was defined as half the standard deviation of the baseline score for each domain. Mixed effect models were used to compare the different isotopes, and time-driven activity-based costing was used to compute costs. RESULTS: From 2006 to 2013, 300 patients were treated with iodine-125 (I-125, n = 98, prescribed dose [PD] = 145 Gy), palladium-103 (Pd-103, n = 102, PD = 125 Gy), or cesium-131 (Cs-131, n = 100, PD = 115 Gy). Median age was 64.9 years. Median follow-up time was 5.1 years for the entire cohort, and 7.1, 4.8 and 3.3 years for I-125, Pd-103, and Cs-131 groups, respectively. All three isotope groups showed an initial drop in QoL at first follow-up, which gradually improved over the first 2 years for urinary and bowel domains. QoL profiles were similar between I-125 and Pd-103, whereas Cs-131 showed a statistically significant decrease in QoL regarding bowel and sexual function at 12 months compared with Pd-103. However, these differences did not reach the minimal clinically important difference. Compared with I-125, the use of Pd-103 or Cs-131 resulted in cost increases of 18% and 34% respectively. CONCLUSIONS: The three different isotopes produced a similar QoL profile. Statistically significant differences favored Pd-103/I-125 over Cs-131 for bowel and sexual QoL, but this did not reach clinical significance.

Prospective Phase 2 Trial of Permanent Seed Implantation Prostate Brachytherapy for Intermediate-Risk Localized Prostate Cancer: Efficacy, Toxicity, and Quality of Life Outcomes.

PURPOSE: To report the efficacy, physician-reported toxicity, and patient-reported outcomes of men with intermediate-risk prostate cancer after brachytherapy in a prospective phase 2 trial. METHODS AND MATERIALS: This prospective phase 2 trial involved 300 patients with previously untreated prostate cancer treated from 2006 through 2013. Eligible patients had ≤cT2b (T3 excluded according to magnetic resonance imaging), Gleason score (GS) 6 with prostate-specific antigen (PSA) level 10-15 ng/mL, or GS 7 with PSA <10 ng/mL, and were treated with prostate brachytherapy (without hormonal therapy). RESULTS: Median patient age was 64.9 years; 3.7% had GS 6, 78.7% had GS 7 (3+4), and 17.7% had GS 7 (4+3). Median follow-up time was 5.1 years. Median PSA at 5 years was 0.01 ng/mL (range, 0-6.0 ng/mL). Ten biochemical failures occurred, for a 5-year freedom from biochemical failure rate of 97.3% (95% confidence interval [CI], 95.1-99.5), and 16 patients died, only 1 from prostate cancer, for 5-year rates of overall and biochemical progression-free survival of 94.9% (95% CI, 92.1-97.9) and 92.7% (95% CI, 89.3-96.2%). Four patients had late grade 3 genitourinary toxicity, and 2 patients had late grade 3 rectal toxicity; no grade 4 or 5 toxicity was observed. Rates of "moderate or big problems" at 4 years were 7.4% for urinary (vs 0.4% at baseline), 2.9% bowel (vs 0.4%), and 29.7% sexual function (vs 19.7%). Most men were "satisfied or extremely satisfied" (91% at 2 years after treatment and 93% at 4 years). CONCLUSIONS: Brachytherapy monotherapy is safe and effective and leads to good quality of life for some men with localized intermediate-risk prostate cancer.

Defining the value framework for prostate brachytherapy using patient-centered outcome metrics and time-driven activity-based costing.

PURPOSE: Value, defined as outcomes over costs, has been proposed as a measure to evaluate prostate cancer (PCa) treatments. We analyzed standardized outcomes and time-driven activity-based costing (TDABC) for prostate brachytherapy (PBT) to define a value framework. METHODS AND MATERIALS: Patients with low-risk PCa treated with low-dose-rate PBT between 1998 and 2009 were included. Outcomes were recorded according to the International Consortium for Health Outcomes Measurement standard set, which includes acute toxicity, patient-reported outcomes, and recurrence and survival outcomes. Patient-level costs to 1 year after PBT were collected using TDABC. Process mapping and radar chart analyses were conducted to visualize this value framework. RESULTS: A total of 238 men were eligible for analysis. Median age was 64 (range, 46-81). Median followup was 5 years (0.5-12.1). There were no acute Grade 3-5 complications. Expanded Prostate Cancer Index Composite 50 scores were favorable, with no clinically significant changes from baseline to last followup at 48 months for urinary incontinence/bother, bowel bother, sexual function, and vitality. Ten-year outcomes were favorable, including biochemical failure-free survival of 84.1%, metastasis-free survival 99.6%, PCa-specific survival 100%, and overall survival 88.6%. TDABC analysis demonstrated low resource utilization for PBT, with 41% and 10% of costs occurring in the operating room and with the MRI scan, respectively. The radar chart allowed direct visualization of outcomes and costs. CONCLUSIONS: We successfully created a visual framework to define the value of PBT using the International Consortium for Health Outcomes Measurement standard set and TDABC costs. PBT is associated with excellent outcomes and low costs. Widespread adoption of this methodology will enable value comparisons across providers, institutions, and treatment modalities.

Sexual potency preservation and quality of life after prostate brachytherapy and low-dose tadalafil.

PURPOSE: To prospectively determine sexual function, bother, and potency preservation in men treated with prostate brachytherapy and twice-weekly tadalafil. METHODS AND MATERIALS: From 2005 to 2011, men treated with low-dose-rate prostate brachytherapy were treated on a prospective registration study. All patients were prescribed tadalafil 10mg twice weekly. The expanded prostate cancer index composite questionnaire was administered before treatment and at each followup. A subgroup analysis of men with sexual potency at baseline was performed. RESULTS: A total of 237 men were analyzed. Median age was 64 years (range, 44-86). Median followup was 24.8 months (range, 1-60). At baseline, 175 men (74%) reported erections firm enough for sexual activity and 148 (62%) were potent (erections firm enough for intercourse). Statistically significant changes in sexual function/bother were appreciated from baseline throughout the analysis period, although absolute changes were relatively small and did not meet criteria for clinical significance. At 24-months followup, 72% reported erections firm enough for sexual activity and 56% were potent. Of men with potency at baseline, 89% had erections firm enough for sexual activity and 76% remained potent 24 months after treatment. CONCLUSIONS: Peri-procedural tadalafil and prostate brachytherapy resulted in high rates of sexual potency preservation and no clinically significant effect on sexual quality of life.

Establishing high-quality prostate brachytherapy using a phantom simulator training program.

PURPOSE: To design and implement a unique training program that uses a phantom-based simulator to teach the process of prostate brachytherapy (PB) quality assurance and improve the quality of education. METHODS AND MATERIALS: Trainees in our simulator program were practicing radiation oncologists, radiation oncology residents, and fellows of the American Brachytherapy Society. The program emphasized 6 core areas of quality assurance: patient selection, simulation, treatment planning, implant technique, treatment evaluation, and outcome assessment. Using the Iodine 125 ((125)I) preoperative treatment planning technique, trainees implanted their ultrasound phantoms with dummy seeds (ie, seeds with no activity). Pre- and postimplant dosimetric parameters were compared and correlated using regression analysis. RESULTS: Thirty-one trainees successfully completed the simulator program during the period under study. The mean phantom prostate size, number of seeds used, and total activity were generally consistent between trainees. All trainees met the V100 >95% objective both before and after implantation. Regardless of the initial volume of the prostate phantom, trainees' ability to cover the target volume with at least 100% of the dose (V100) was not compromised (R=0.99 pre- and postimplant). However, the V150 had lower concordance (R=0.37) and may better reflect heterogeneity control of the implant process. CONCLUSIONS: Analysis of implants from this phantom-based simulator shows a high degree of consistency between trainees and uniformly high-quality implants with respect to parameters used in clinical practice. This training program provides a valuable educational opportunity that improves the quality of PB training and likely accelerates the learning curve inherent in PB. Prostate phantom implantation can be a valuable first step in the acquisition of the required skills to safely perform PB.

An MRI-based dose--reponse analysis of urinary sphincter dose and urinary morbidity after brachytherapy for prostate cancer in a phase II prospective trial.

PURPOSE: To compare dose-volume histogram variables for the internal and external urinary sphincters (IUS/EUS) with urinary quality of life after prostate brachytherapy. METHODS AND MATERIALS: Subjects were 42 consecutive men from a prospective study of brachytherapy as monotherapy with (125)I for intermediate-risk localized prostate cancer. No patient received hormonal therapy. Preplanning constraints included prostate V100 higher than 95%, V150 lower than 60%, and V200 lower than 20% and rectal R100 less than 1cm(3). Patients completed the Expanded Prostate Cancer Index Composite quality-of-life questionnaire before and at 1, 4, 8, and 12 months after implantation, and urinary domain scores were analyzed. All structures including the IUS and EUS were contoured on T2-weighted MRI at day 30, and doses received were calculated from identification of seeds on CT. Spearman's (nonparametric) rank correlation coefficient (ρ) was used for statistical analyses. RESULTS: Overall urinary morbidity was worst at 1 month after the implant. Urinary function declined when the IUS V285 was 0.4% (ρ=-0.32, p=0.04); bother worsened when the IUS V35 was 99% (ρ=-0.31, p=0.05) or the EUS V240 was 63% (ρ=-0.31, p=0.05); irritation increased when the IUS V35 was 95% (ρ=-0.37, p=0.02) and the EUS V265 was 24% (ρ=-0.32, p=0.04); and urgency worsened when the IUS V35 was 99.5% (ρ=-0.38, p=0.02). Incontinence did not correlate with EUS or IUS dose. CONCLUSIONS: Doses to the IUS and EUS on MRI/CT predicted worse urinary function, with greater bother, irritative symptoms, and urgency. Incorporating MRI-based dose-volume histogram analysis into the treatment planning process may reduce acute urinary morbidity after brachytherapy.

Improving prostate brachytherapy quality assurance with MRI-CT fusion-based sector analysis in a phase II prospective trial of men with intermediate-risk prostate cancer.

PURPOSE: We combined sector analysis with MRI-CT fusion to comprehensively assess postimplant dosimetry after prostate brachytherapy. METHODS AND MATERIALS: Subjects were 50 men with intermediate-risk prostate cancer treated with (125)I brachytherapy in a prospective phase II clinical trial. On Day 30 after the implantation, dosimetry was evaluated in the prostate base, midgland, and apex regions on fused MRI-CT scans and CT scans. Volumes of each sector receiving 100% of the prescribed dose (V100) and doses to 90% of each sector (D90) were also calculated on the ultrasonogram used for treatment planning and compared with values derived from CT and fused MRI-CT scans. RESULTS: Fused MRI-CT scans revealed lower-than-expected doses for the whole prostate (V100=91.3%, D90=152.9Gy) compared with CT scans (98.5% and 183.6Gy, p<0.0001) and lower doses to the prostate base (V100=79%, D90=130Gy) vs. CT (96% and 170Gy, p<0.0001). However, lower doses to the prostate base did not adversely affect biochemical outcomes in men with biopsy-proven disease at the base. At a median followup time of 42 months, the mean prostate-specific antigen level for all patients was 0.3ng/mL, and no patient had experienced biochemical or clinical progression or recurrence. CONCLUSIONS: MRI-CT fusion-based sector analysis was feasible and revealed significantly lower doses to the prostate base than doses estimated from CT alone, although this did not affect biochemical outcomes. MRI-CT fusion-based sector analysis may be useful for developing MRI-based dosimetric markers to predict disease outcomes and treatment-related morbidity.

Endorectal magnetic resonance imaging for predicting pathologic T3 disease in Gleason score 7 prostate cancer: implications for prostate brachytherapy.

PURPOSE: To determine the ability of endorectal magnetic resonance imaging (erMRI) and other pretreatment factors to predict the presence and extent of extraprostatic extension (EPE) in men with Gleason score (GS) 7 prostate cancer. METHODS AND MATERIALS: We included patients with clinical stage T1c-T2c, GS=7 (3+4 or 4+3), and prostate-specific antigen (PSA) <10ng/mL who underwent pre-prostatectomy erMRI. We compared pathologic EPE findings with pretreatment factors. RESULTS: One hundred seventy-one men were eligible for inclusion. Pretreatment characteristics were: median age=60 years (42-76); median PSA 4.9ng/mL (0.4-9.9); GS 3+4=61%; T1c=51%; T2a=25%; T2b=21%; T2c=3%; ≥50% positive cores=46%; EPE-positive (EPE+) erMRI=28%. Thirty-three percent had pathologic EPE. Increasing T-stage (p<0.0001) and EPE+ erMRI (p<0.0001) were significant predictors of pathologic EPE, whereas GS (4+3 vs. 3+4) (p=0.14), percentage of positive core biopsies (p=0.15), and pretreatment PSA (p=0.41) were not. Median EPE distance was 1.75mm (range, <1-15mm). The rates of EPE >5mm and EPE >3mm were 11% and 15%, respectively. The odds ratios for erMRI detection of any EPE and of EPE >5mm were 3.06 and 3.75, respectively. CONCLUSIONS: T-stage and EPE+ erMRI predict pathologic EPE in men with GS 7 prostate cancer. The ability of erMRI to detect EPE increases with increasing EPE distance. These findings may be useful in patient selection for prostate brachytherapy monotherapy.

Magnetic resonance imaging-based treatment planning for prostate brachytherapy.

PURPOSE: Transrectal ultrasound (TRUS) is the standard imaging modality for planning prostate brachytherapy. However, magnetic resonance imaging (MRI) provides greater anatomic detail than TRUS. We compared treatment plans generated using TRUS, endorectal coil MRI (erMRI), and standard body array coil MRI (sMRI). METHODS AND MATERIALS: Treatment plans were used from patients treated with permanent, stranded-seed (125)I brachytherapy in a prospective trial. All men underwent pretreatment planning based on TRUS, and all underwent erMRI before treatment and sMRI 30 days after the implant. Treatments for 20 consecutive patients were replanned on sMRI and erMRI images by investigators blinded to TRUS-based plans. Prostate volume/dimensions, radioactivity-to-prostate-volume ratio, and dosimetric parameters were compared. RESULTS: Compared with TRUS, mean prostate volume measured by erMRI was smaller, medial-lateral diameter was larger, and anterior-posterior diameter was smaller, suggesting that the endorectal coil produced anatomic distortions. Craniocaudal prostate length was smaller on both types of MRI than on TRUS, suggesting that TRUS overestimates prostate length. Activity per volume was 7.5% lower for plans based on sMRI than on TRUS (0.901 vs. 0.974mCi/cm(3), p<0.001). sMRI plans had similar coverage of the planning target volume (PTV) (dose to 90% of the prostate [D(90)] 116.6% sMRI vs. 117.5% TRUS, p=0.526) and improved dose homogeneity (percentage of PTV receiving 150% of the prescription dose [V(150)] 47.4% sMRI vs. 53.8% TRUS, p=0.001 and percentage of PTV receiving 200% of the prescription dose [V(200)] 16.6% sMRI vs. 19.2% TRUS, p<0.001). CONCLUSIONS: Staging erMRI should not be routinely used for treatment planning because it produces anatomic distortion. sMRI may have treatment planning advantages over TRUS because of superior soft-tissue delineation of the prostate and adjacent normal tissue structures.

Knife or needles? A cohort analysis of outcomes after radical prostatectomy or brachytherapy for men with low- or intermediate-risk adenocarcinoma of the prostate.

PURPOSE: The purpose of this study was to evaluate long-term outcomes for men with early stage prostate cancer treated with radical prostatectomy (RP) or brachytherapy (BT) at a single tertiary care center. METHODS AND MATERIALS: We retrospectively analyzed data from 371 men with clinical T1a-T2c disease with prostate-specific antigen level <20 ng/mL and Gleason score (GS) 6-7 who were treated with RP (n=279) or BT (n=92) at MD Anderson Cancer Center in 2000-2001. Biochemical recurrence-free survival (BRFS) and prostate cancer-specific survival rates were compared by treatment modality. RESULTS: The median followup time was 7.2 and 7.6 years for patients treated with RP and BT, respectively. Disease was upgraded from GS 6 to 7 after central review of the biopsy specimen for 36 men treated with RP (12.9%) and 15 men treated with BT (16.3%). After RP, GS was upgraded in 121 men (43.4%) between the centrally reviewed biopsy and the RP specimen. After RP, 5-year BRFS rates were 96.1% and 90.6% for low- and intermediate-risk disease, respectively (p=0.003). After BT, 5-year BRFS rates were 92.5% and 95.8% for low- and intermediate-risk disease, respectively (p=0.017). After RP or BT, 5-year BRFS rates were not significantly different with GS upgraded. Five-year prostate cancer-specific survival rates for patients with upgraded GS were 100% for both RP and BT. CONCLUSIONS: Excellent disease control outcomes can be achieved after either RP or BT as monotherapy for men with early stage prostate cancer. Upgrading of GS from 6 to 7, either (3+4) or (4+3), did not predict for worse outcomes.

Preoperative treatment planning with intraoperative optimization can achieve consistent high-quality implants in prostate brachytherapy.

Advances in brachytherapy treatment planning systems have allowed the opportunity for brachytherapy to be planned intraoperatively as well as preoperatively. The relative advantages and disadvantages of each approach have been the subject of extensive debate, and some contend that the intraoperative approach is vital to the delivery of optimal therapy. The purpose of this study was to determine whether high-quality permanent prostate implants can be achieved consistently using a preoperative planning approach that allows for, but does not necessitate, intraoperative optimization. To achieve this purpose, we reviewed the records of 100 men with intermediate-risk prostate cancer who had been prospectively treated with brachytherapy monotherapy between 2006 and 2009 at our institution. All patients were treated with iodine-125 stranded seeds; the planned target dose was 145 Gy. Only 8 patients required adjustments to the plan on the basis of intraoperative findings. Consistency and quality were assessed by calculating the correlation coefficient between the planned and implanted amounts of radioactivity and by examining the mean values of the dosimetric parameters obtained on preoperative and 30 days postoperative treatment planning. The amount of radioactivity implanted was essentially identical to that planned (mean planned radioactivity, 41.27 U vs. mean delivered radioactivity, 41.36 U; R(2) = 0.99). The mean planned and day 30 prostate V100 values were 99.9% and 98.6%, respectively. The mean planned and day 30 prostate D90 values were 186.3 and 185.1 Gy, respectively. Consistent, high-quality prostate brachytherapy treatment plans can be achieved using a preoperative planning approach, mostly without the need for intraoperative optimization. Good quality assurance measures during simulation, treatment planning, implantation, and postimplant evaluation are paramount for achieving a high level of quality and consistency.

Sexual function and the use of medical devices or drugs to optimize potency after prostate brachytherapy.

PURPOSE: Prospective evaluation of sexual outcomes after prostate brachytherapy with iodine-125 seeds as monotherapy at a tertiary cancer care center. METHODS AND MATERIALS: Subjects were 129 men with prostate cancer with I-125 seed implants (prescribed dose, 145 Gy) without supplemental hormonal or external beam radiation therapy. Sexual function, potency, and bother were prospectively assessed at baseline and at 1, 4, 8, and 12 months using validated quality-of-life self-assessment surveys. Postimplant dosimetry values, including dose to 10% of the penile bulb (D10), D20, D33, D50, D75, D90, and penile volume receiving 100% of the prescribed dose (V100) were calculated. RESULTS: At baseline, 56% of patients recorded having optimal erections; at 1 year, 62% of patients with baseline erectile function maintained optimal potency, 58% of whom with medically prescribed sexual aids or drugs. Variables associated with pretreatment-to-posttreatment decline in potency were time after implant (p = 0.04) and age (p = 0.01). Decline in urinary function may have been related to decline in potency. At 1 year, 69% of potent patients younger than 70 years maintained optimal potency, whereas 31% of patients older than 70 maintained optimal potency (p = 0.02). Diabetes was related to a decline in potency (p = 0.05), but neither smoking nor hypertension were. For patients with optimal potency at baseline, mean sexual bother scores had declined significantly at 1 year (p < 0.01). Sexual potency, sexual function, and sexual bother scores failed to correlate with any dosimetric variable tested. CONCLUSIONS: Erections firm enough for intercourse can be achieved at 1 year after treatment, but most men will require medical aids to optimize potency. Although younger men were better able to maintain erections firm enough for intercourse than older men, there was no correlation between potency, sexual function, or sexual bother and penile bulb dosimetry.

Outcomes after prostate brachytherapy are even better than predicted.

BACKGROUND: During the first 3 years after prostate cancer treatment with radiation therapy, benign prostate-specific antigen (PSA) bounces are difficult for clinicians to distinguish from a biochemical recurrence, which can result in unnecessary interventions and erroneous predictions of outcomes. The objective of this study was to evaluate a commonly used PSA failure definition in a multinational, multi-institutional study after monotherapy with prostate brachytherapy. METHODS: Participants were selected from 2919 men who underwent permanent prostate brachytherapy at the University Medical Center Utrecht, Princess Margaret Hospital, or Seattle Prostate Institute between 1998 and 2006. Inclusion required not having received androgen-deprivation therapy and having at least 30 months of follow-up. Failure was defined as any post-treatment use of hormone therapy, clinical relapse, or prostogram-defined biochemical (PSA) failure. Cases in which the nomogram predicted biochemical failure were evaluated at each institution to verify biochemical status over time and the actual clinical outcome at 5 years. RESULTS: The median follow-up for the 1816 patients was 5.2 years. Concordance between the prostogram-predicted and actual outcomes, as measured by the Harrell c statistic, was 0.655 (95% confidence interval [CI], 0.536-0.774; P = .010) for the Princess Margaret group, 0.493 (95% CI, 0.259-0.648; P = .955) for the Seattle group, and 0.696 (95% CI, 0.648-0.744, P < .001) for the Utrecht group. The overall mean difference in biochemical recurrence-free survival at 5 years between actual outcomes and prostogram-defined outcomes was 9.2% (95% CI, 7.7%-10.6%). The total numbers of prostogram-defined and actual biochemical failures were 312 and 157, respectively (P = .001). CONCLUSIONS: The widely used prostogram could not adequately distinguish a benign PSA bounce from a biochemical recurrence after prostate brachytherapy and could not be used to counsel patients about their predicted outcomes after treatment. The authors conclude that, to avoid unnecessary active interventions after treatment, clinicians should monitor PSA levels for at least 3 years and provide reassurance to patients that a PSA rise during this time is common and may not indicate a treatment failure.

Screening colonoscopy before prostate cancer treatment can detect colorectal cancers in asymptomatic patients and reduce the rate of complications after brachytherapy.

PURPOSE: To investigate the incidence of undiagnosed, asymptomatic synchronous colorectal cancer (CRC) by using screening colonoscopy before brachytherapy, and to compare the subsequent rates of CRC and rectal toxicity in this screened population with those rates in unscreened patients after brachytherapy. METHODS AND MATERIALS: Patient, disease, and treatment characteristics, including history of colonoscopy and CR malignancy, were extracted from the medical records of all men who had undergone brachytherapy as monotherapy for low- or intermediate-risk prostate cancer at a single tertiary cancer care center between January 2000 and December 2009. The frequency of biopsy or polypectomy at screening colonoscopy, incidence of CR malignancy before and after prostate cancer diagnosis, and rate of brachytherapy toxicity including rectal bleeding were compared between men who had had screening colonoscopy before brachytherapy and men who had not. RESULTS: Of the 451 men identified, 268 had undergone screening colonoscopy during the 36 months before brachytherapy and 183 had not. Of the 268 men who had had screening colonoscopy, 117 (44%) underwent biopsy or polypectomy, and 6 (3.2%) were found to have asymptomatic CRC. After brachytherapy, CRC was diagnosed in 3 (1.6%) of the 183 men who had not had screening colonoscopy before treatment versus 0 of the 268 men who had had screening colonoscopy (P = 0.035). Rectal toxicity was more common and more severe among men who had not undergone screening colonoscopy compared with those who had had screening colonoscopy before brachytherapy (14% vs 6%, P = 0.003). More unscreened patients (18% vs 5%) underwent postbrachytherapy colonoscopy (P < 0.001), with the potential of subjecting the irradiated rectum to biopsy. CONCLUSIONS: More than 3% of men with newly diagnosed prostate cancer in this study presented with undiagnosed, asymptomatic CRC, and the rate of postbrachytherapy rectal complications was higher among unscreened than among screened patients. We recommend screening colonoscopy for men who have not had CRC screening within the 3 years preceding prostate cancer diagnosis before radiation therapy to avoid unnecessary rectal biopsies and the associated risk of major complications.

Displacement of periurethral stranded seeds and its dosimetric consequences in prostate brachytherapy.

PURPOSE: The use of stranded seeds for prostate brachytherapy has raised concern that displacement of strands, particularly in the periurethral region, may result in inadequate coverage of the prostate. We sought here to evaluate the displacement of periurethral stranded seeds after a prostate brachytherapy implant (Day 0) and its dosimetric consequences 1 month later (Day 30). METHODS AND MATERIALS: Subjects were 10 consecutive patients who underwent implantation with (125)I stranded seeds via a peripheral-loading technique. Computed tomography scanning was done on Days 0 and 30. Seeds were located and dose distributions calculated with a Variseed 7.2 treatment planning system (Varian Medical Systems). Images were registered by two methods, one using the penile bulb as reference and the other using the pubic bones for verification. Only seeds within the periurethral strands were analyzed. RESULTS: The mean displacement of periurethral stranded seeds relative to the prostate did not exceed 1mm in any direction. Calculated displacements were not affected by the registration method used. The mean dose covering 90% of the prostate volume (D(90)) and prostate volume receiving 100% of the prescribed dose (V(100)) were 169Gy and 97% on Day 0 and 186.5Gy and 98.7% on Day 30 (p<0.001 for D(90)). CONCLUSIONS: Displacement of periurethral stranded seeds 30 days after implantation was minimal and did not compromise dosimetric coverage of the prostate.

Impact of urinary catheterization on dosimetry after prostate implant brachytherapy with palladium-103 or iodine-125.

PURPOSE: Postoperative dosimetry is integral to quality assurance for prostate brachytherapy. Images on Day 0 are typically obtained with a contrast-filled urinary catheter in place for urethral dose calculations. However, expansion of the urethra and perhaps the prostate by the catheter may affect target coverage. We assessed the effect of urinary catheterization on target dosimetry after implantation with palladium-103 ((103)Pd) or iodine-125 ((125)I) seeds. METHODS AND MATERIALS: Patients were 29 consecutive men with postimplant dosimetry calculated with and without a urinary catheter after brachytherapy seed implantation; 19 patients received (103)Pd seeds and 10 patients received (125)I seeds. In each case, 14-French caude tip urinary catheters were placed before implantation, and axial CT slices of the pelvis were obtained before and after catheter removal for postimplant dosimetry. Dosimetric parameters were measured and compared with paired Student's t tests. Trends were assessed by linear regression with the Pearson correlation coefficient. RESULTS: Removal of the urinary catheter significantly improved V(100) and D(90) for (103)Pd implants (mean±standard deviation (SD), 2.7%±4.2%; range, -0.4% to 15%; p=0.011 and mean±SD, 4.0%±3.4%; range, -0.1% to 13.8%; p<0.01, respectively). For (125)I implants, catheter removal improved D(90) (mean±SD, 1.5%±1.8%; range, -1.3% to 4.2%; p=0.027). For the (103)Pd group, the magnitude of change in V(100) correlated with prostate size (R(2)=0.16) and source number (R(2)=0.15). CONCLUSIONS: Urinary catheterization can artificially reduce target coverage after prostate implant brachytherapy. The patients undergoing (103)Pd implantation with smaller (<30cm(3)) prostates and fewer (<90) sources are particularly susceptible to reduced D(90) and V(100) when a urinary catheter is present.

Subacute penile numbness after brachytherapy for prostate cancer.

PURPOSE: Penile numbness is a rare complication of permanent prostate brachytherapy, and optimal clinical management remains unclear. We present such a case and discuss pathophysiology and clinical management strategies. METHODS AND MATERIALS: A 68-year-old male presented with a serum prostate-specific antigen level of 6.9 ng/mL, Gleason score of 7 (3+4), and clinical T1c adenocarcinoma of the prostate. After a permanent prostate brachytherapy implant with (125)I monotherapy to a dose of 145Gy, the patient developed complete penile numbness postoperatively on the third day. RESULTS: The patient experienced complete restoration of penile sensation and function by postoperative day 9 with conservative management. CONCLUSIONS: Subacute penile shaft numbness after brachytherapy is rare and is caused by dorsal penile nerve compression. Over the course of a week, the restoration of penile sensation is likely to occur with conservative management.

Anisotropy characterization of I-125 seed with attached encapsulated cobalt chloride complex contrast agent markers for MRI-based prostate brachytherapy.

We have developed a novel MRI marker for prostate brachytherapy. The purpose of this study was to evaluate the changes in anisotropy when cobalt chloride complex contrast agent encapsulated contrast agent markers (C4-ECAM) were placed adjacent to an iodine-125 (I-125) titanium seed, and to verify that the C4-ECAMs were visible on magnetic resonance imaging (MRI) after radiation exposure. Two C4-ECAMs were verified to be MRI visible in a phantom before radiation exposure. The C4-ECAMs were then attached to each end of a 12.7-U (10-mCi) I-125 titanium seed in a polymer tube. Anisotropy was measured and analyzed with the seed alone and with attached C4-ECAMs by suspending thermoluminescent dosimeters in a water phantom in 2 circles surrounding the radioactive source with radius of 1 or 2 cm. A T1-weighted MRI evaluation of C4-ECAMs was then performed after exposure to the amount of radiation typically delivered during 1 month of prostate brachytherapy. Measured values of the anisotropy function F(r, θ) for the I-125 seed with and without the C4-ECAMs were mutually statistically indistinguishable (standard error of the mean <4.2%) and agreed well with published TG-43 values for the bare seed. As expected, the anisotropy function ϕ(an)(r) for the 2 datasets (with and without C4-ECAMs) derived from the measured F(r, θ) did not exhibit statistically measurable difference. Both datasets showed agreement with the published TG-43 ϕ(an)(r) for the bare seed. The C4-ECAMs were well visualized by MRI after 1 month of radiation exposure. There were no changes in anisotropy when the C4-ECAMs were placed next to an I-125 radioactive seed, and the C4-ECAMs were visualized after radiation exposure.

Long-term tumor control after brachytherapy for base-of-prostate cancer.

PURPOSE: To evaluate the outcomes of patients presenting with cancer at the base of the prostate after brachytherapy as monotherapy. MATERIAL AND METHODS: We retrospectively reviewed the medical records of all patients who had undergone transperineal ultrasound-guided implantation with (125)I or (103)Pd seeds as monotherapy between March 1998 and December 2006, at our institution. A minimum follow-up interval of 2 years was required for inclusion in our analysis. Dosimetry was assessed using computed tomography 30 days after the implant. Treatment failure was defined as the appearance of biopsy-proved tumor after seed implantation, radiographic evidence of metastases, receipt of salvage therapy, or elevation of the prostate-specific antigen level beyond the nadir value plus 2 ng/mL. RESULTS: With a median follow-up interval of 89 months (range 25-128 months), all 52 of the identified patients had no evidence of disease progression or biochemical failure. The mean number of cores sampled at the prostate base was 2.84 (median 2); Gleason scores assigned at central review were 6-8 in all patients. Of the 30 patients (58%) for whom dosimetric data were available at day 30, the median V100 values of the right and left base were 92.0% and 93.5%, respectively, and the median D90 values of the right and left base were 148 Gy and 151 Gy, respectively. CONCLUSION: Permanent prostate brachytherapy as monotherapy results in a high probability of disease-free survival for men with cancer at the base of the prostate.