Brachytherapy For Prostate Cancer Research Articles

The oncologic and safety outcomes of low-dose-rate brachytherapy for the treatment of prostate cancer.

Around 40years have passed since a modern low-dose-rate (LDR) brachytherapy for prostate cancer was introduced. LDR brachytherapy has become one of the definitive treatment options besides radical prostatectomy (RP) and external beam radiation therapy (EBRT). LDR brachytherapy has several advantages over EBRT such as a higher prescribed dose to the prostate gland while avoiding unnecessary irradiation of organs at risk, a precipitous dose gradient, a brief treatment time, and a short hospital stay. Previous reports revealed that the long-term oncologic outcomes of LDR brachytherapy are superior to those of EBRT. The oncologic outcomes of low- to intermediate-risk patients are equivalent to those of RP using the recurrence definition of surgery of prostate specific antigen (PSA) >0.2ng/mL, while the oncologic outcomes of LDR brachytherapy as tri-modality (combined EBRT and androgen deprivation therapy) for high-risk patients is superior to that of RP using the recurrence definition of surgery. In respect of toxicity, urinary disorders such as urgency and frequency are often observed after the acute phase of treatment, but these events usually resolve, while the quality of life of urinary continence is well preserved for a long time. Erectile function decreases yearly, but is relatively preserved compared to RP. In conclusion, the most noteworthy strength of LDR brachytherapy for low- to intermediate-risk patients is the "brief treatment time" that provides long recurrence-free survival, while that for high-risk patients who received LDR brachytherapy (tri-modality) is "excellent disease control."

PSOR12 Presentation Time: 12:55 PM: Single Fraction High Dose Rate Prostate Brachytherapy in Intermediate-Risk Prostate Cancer

PSOR12 Presentation Time: 12:55 PM: Single Fraction High Dose Rate Prostate Brachytherapy in Intermediate-Risk Prostate Cancer

PO73: DIL-Concentrated PSA as a Predictor of Local Recurrence after HDR Brachytherapy in Primary Prostate Cancer

PO73: DIL-Concentrated PSA as a Predictor of Local Recurrence after HDR Brachytherapy in Primary Prostate Cancer

PO70: Combining External Beam Radiation, Brachytherapy, and Rectal Hydrogel Spacer for Prostate Cancer: A Study of Gastrointestinal Toxicity and Implant Quality

PO70: Combining External Beam Radiation, Brachytherapy, and Rectal Hydrogel Spacer for Prostate Cancer: A Study of Gastrointestinal Toxicity and Implant Quality

PP06 Presentation Time: 10:05 AM: Comparison of Perioperative & Subacute Postoperative Complications between LDR & HDR Brachytherapy for Prostate Cancer

PP06 Presentation Time: 10:05 AM: Comparison of Perioperative & Subacute Postoperative Complications between LDR & HDR Brachytherapy for Prostate Cancer

Long-term outcomes of ultra-hypofractionated 2 fractions single day HDR brachytherapy in localized prostate cancer

Introduction and objectivesWe previously published the toxicity and initial results of a prospective cohort of patients treated with 2 fractions HDR-BRT administered in a single day. In the present analysis we report the long-term cancer control results of our prospective trial and investigate the relationship between PSA nadir and biochemical control. Material and methodsA total of 120 patients were treated with HDR Brachytherapy monotherapy administered in two fractions in a single day. Between November 2010 and February 2016, 84 patients with low-risk and 36 patients with intermediate-risk prostate cancer in accordance with the NCCN practice guidelines. ResultsMedian age was 66 years (range 45–84) and median PSA was 7.5 ng/ml (range 0.01–16 ng/ml). Overall, 84.2% had Gleason score 6 and 15.8% Gleason 7. Thirty-one percent of patients received ADT.After a median follow-up of the cohort was 123 months. Actuarial rates of no biochemical evidence of disease (bNED), overall survival, local control and metastasis-free survival for all patients were 93.3%, 86.7%, 95.2% and 96.1%, respectively.The median time to achieve PSA nadir was 80.5 months. Patients who attained a PSA Nadir ≤ 0.20 ng/mL exhibited a 10-year bNED survival rate of 96.9%, whereas thosewho failed to reach this PSA level had a survival rate of only 40%. ConclusionsIn patients with favorable localized prostate cancer, 2 fractions HDR-BT monotherapy is a highly curative radiation technique that attains PSA nadir levels < 0.2 ng/mL in 95% of cases.

A novel direction modulated brachytherapy technique for urethra sparing in high-dose-rate brachytherapy of prostate cancer

PurposeImage-guided high-dose-rate (HDR) prostate brachytherapy is a safe and effective treatment option for prostate cancer patients; however, some patients still experience acute and late genitourinary (GU) toxicity. Studies have shown that urethral dose is associated with the incidence and severity of GU toxicity. Therefore, a technique that can further spare the urethra while ensuring adequate target coverage is highly desirable. Intensity modulated brachytherapy (IMBT) designs, such as rotating shield brachytherapy (RSBT), offer ideal dosimetry theoretically but are challenging to implement clinically due to the need for high precision in moving the treatment delivery mechanisms synchronized with the source loading. In this study, we propose a novel relatively easy-to-implement solution based on the direction modulated brachytherapy (DMBT) design concept, which does not involve moving parts and works effectively with the ubiquitous 192Ir source. Materials and MethodsThe popular Varian VS2000 (VS) and GammaMedPlus (GMP) 192Ir sources, with outer diameters of 0.6 mm and 0.9 mm, respectively, were simulated using the GEANT4 Monte Carlo (MC) simulation code. The novel DMBT needle concept consists of a 14-gauge nitinol needle, which houses a platinum shield inside. A single groove, consistent with the outer diameter of each source, was incorporated inside the platinum shield to accommodate the HDR source. The maximum thickness of the shield was 1.1 mm (0.8 mm) for the VS (GMP) source. To evaluate the effectiveness of the DMBT needle concept in reducing urethral dose, 6 patient cases were studied and DMBT plans were created by replacing two needles close to the urethra with the DMBT needles. The dosimetric comparisons between the DMBT and reference clinical plans were done by assessing the dose-volume histogram (DVH) planning criteria for the target coverage and organs-at-risk. ResultsThe MC results showed that the use of the novel DMBT needle design with the VS source (GMP source) could reduce the dose by 49.6% (39.2%) at 1 cm from the needle behind the platinum shield, as compared to the unshielded side. Additionally, when using the same DVH planning criteria as the original plan, the DMBT plan with the VS (GMP) source reduced the maximum urethral dose by 10.3% ± 5.6% (8.1% ± 5.0%) and 17.7% ± 14.2% (16.6% ± 13.3%) for 0 mm and 2 mm margins, respectively, while maintaining equivalent V90% and D100 target coverage. ConclusionThe novel DMBT technique offers a promising clinically implementable solution for sparing urethra, particularly in pre-apical region, without compromising the target coverage or increasing treatment time.

Low-dose-rate brachytherapy in low-risk prostate cancer- treatment results, radiation toxicity and quality of life-dissertation project with literature review

Low-dose-rate brachytherapy (LDR-BT) is a an internal radiation therapy method for the treatment of localized prostate cancer The treatment modality has been known for several decades. The choice of the treatment modality for prostate cancer patients depends mainly on the stage of the disease and the prognostic factors. Brachytherapy monotherapy is a well-tolerated procedure compared to alternative treatments. Based on a literature review, we have considered a prospective study on the treatment efficiency after LDR-BT with a permanent iodine-125 (I-125) implant, compared to that of hypo-fractionated external beam radiotherapy (EBRT) alone. The working thesis is to present the advantages and disadvantages of LDR-BT for low-risk prostate carcinoma, compared to a similar group of patients treated with definitive intensity-modulated hypo-fractionated radiotherapy (IMHRT)

Associations of Clinical and Dosimetric Parameters with Urinary Toxicities after Prostate Brachytherapy: A Long-Term Single-Institution Experience.

To examine the association of clinical, treatment, and dose parameters with late urinary toxicity after low-dose-rate brachytherapy (LDR-BT) for prostate cancer, we retrospectively studied patients with prostate cancer who underwent LDR-BT from January 2007 through December 2016. Urinary toxicity was assessed using the International Prostate Symptom Score (IPSS) and Overactive Bladder (OAB) Symptom Score (OABSS). Severe and moderate lower urinary tract symptoms (LUTS) were defined as IPSS ≥ 20 and ≥ 8, respectively; OAB was defined as a nocturnal frequency of ≥ 2 and a total OABSS of ≥ 3. In total, 203 patients (median age: 66 years) were included, with a mean follow-up of 8.4 years after treatment. The IPSS and OABSS worsened after 3 months of treatment; these scores improved to pretreatment levels after 18-36 months in most patients. Patients with a higher baseline IPSS and OABSS had a higher frequency of moderate and severe LUTS and OAB at 24 and 60 months, respectively. LUTS and OAB at 24 and 60 months were not correlated with the dosimetric factors of LDR-BT. Although the rate of long-term urinary toxicities assessed using IPSS and OABSS was low, the baseline scores were related to long-term function. Refining patient selection may further reduce long-term urinary toxicity.

Clinical and treatment characteristics of secondary bladder malignancies following low dose rate brachytherapy for prostate cancer.

To characterize the clinical course and prognosis of bladder malignancies associated with prior prostate brachytherapy SUBJECTS/PATIENTS AND METHODS: We queried our institutional database for patients with bladder cancer (BC) diagnosed between January 2005 and April 2019 who had previously undergone low dose rate (LDR) prostate brachytherapy. Patients diagnosed with BC at least 1 year following LDR prostate brachytherapy with or without external beam radiation therapy were included. Clinical and disease-specific characteristics were abstracted from chart review and survival outcomes were estimated using Kaplan-Meier estimates. We compared the pathologic characteristics and prognosis of secondary BCs in our study cohort to those of BCs diagnosed after prostate cancer managed without radiation reported by the Surveillance, Epidemiology, and End Results (SEER) populational database from 2005 to 2018. Three hundred seventy-five patients were identified with combined diagnosis of prostate cancer and BC, 51 of whom met inclusion criteria in the study cohort. Median times from brachytherapy to BC diagnosis for the study and SEER cohort were 9.5 ± 4.5 and 6.3 ± 4.1 years, respectively. Compared to the SEER cohort, significantly greater proportion of BC from the study cohort presented with high-grade (study: 78.4%, SEER: 52.3%, P = 0.0008) and with MIBC (Study BC 35.3%, SEER BC: 17.5%, P = 0.0009). The study and the SEER cohort had similar 5-year overall survival (study: 67.9%, SEER: 58.0%, P = 0.1099), and 5-year cancer-specific survival (study: 81.0%, SEER: 82.8%, P = 0.5559). The 5-year progression-free survival for the study cohort was 43.7% (95% CI: 28.8-57.7). Compared to bladder cancers following prostate cancer managed without radiation, bladder malignancies following prostate LDR brachytherapy present with higher grade and are more likely to be muscle invasive. Despite the aggressive presenting features of postprostate brachytherapy BC, there were no differences in overall and cancer-specific survival between the groups.

Long-term evaluation of low-dose-rate (LDR) brachytherapy in localized prostate cancer

As aresult of technical innovation, i.e., improvement of seed quality, implantation method, and dose calculation, it has been possible to continuously improve oncological results in the treatment of localized prostate cancer with low-dose-rate brachytherapy (LDR-BT). Randomized controlled trials have shown that there is no significant difference in oncological control between the use of radical prostatectomy and LDR-BT in patients with low-risk prostate cancer. The objective of this study was to investigate the oncological efficacy of LDR-BT. A retrospective multicenter analysis was conducted on 618patients treated with LDR-BT as monotherapy, who received adose of 145 Gy. We used iodine125 as the radioactive source. The analysis was conducted with follow-up data from two brachytherapy centers in Germany between 2004 and 2019. The primary endpoint was biochemical relapse-free survival (bRFS), whereby the Phoenix definition (PSA - nadir +2 ng/ml; PSA: prostate-specific antigen) was used to define biochemical relapse, i.e., therapeutic failure. Median follow-up was 52months (range 3-180months). The bRFS across all risk groups was 87.87%. Oncological efficacy was significantly higher in patients with aGleason score of 6 and 7a (p-value < 0.0001); however, there was no significant difference in bRFS between these two groups. Bilateral tumor infiltration or prostate volume had no significant influence on bRFS. Our results show no difference in bRFS between Gleason score6 and7a.

Factors Affecting Prostate Displacement During Volumetric Modulated Arc Therapy in Prone Position After High-Dose-Rate Brachytherapy for Prostate Cancer

In irradiating the prostate and pelvic lymph node regions, registration based on bony structures matches the pelvic lymph node regions but not necessarily the prostate position, and it is important to identify factors that influence prostate displacement. Therefore, we investigated factors influencing prostate displacement during volumetric modulated arc therapy after single-fraction high-dose-rate brachytherapy (HDR-BT) for prostate cancer and the trends in displacement for each fraction. Seventy patients who underwent pelvic volumetric modulated arc therapy of 46 Gy in the prone position 15 days after 13 Gy HDR-BT were included. Prostate displacement relative to bony structures was calculated using cone beam computed tomography. Systematic error (SE) and random error (RE) were evaluated in the right-left (RL), craniocaudal (CC), and anteroposterior (AP) directions. The association with clinical and anatomic factors on the planning computed tomography or magneticresonanceimaging was analyzed. Prostate volume change (PVC) was defined as the volume change at 2 days after HDR-BT. Displacement trends were individually examined from the first to 23rd fractions. The mean SE in the RL, CC, and AP directions was -0.01 mm, -2.34 mm, and -0.47 mm, respectively. The root mean square of the RE in the RL, CC, and AP directions was 0.44 mm, 1.14 mm, and 1.10 mm, respectively. SE in the CC direction was independently associated with bladder volume (P=.021, t statistic=2.352) and PVC (P < .001, t statistic=-8.526). SE in the AP direction was independently associated with bladder volume (P=.013, t statistic=-2.553), PVC (P < .001, t statistic=5.477), and rectal mean area (P=.008, t statistic=2.743). RE in the CC direction was independently associated with smoking (P=.035). RE in the AP direction was associated with PVC (P=.043). Gradual displacement caudally and posteriorly occurred during the irradiation period. Anatomic characteristics of the bladder, rectum, and prostate predict SE. Smoking and PVC predict RE. In particular, whether PVC is ≥140% affects setting internal margins.

PO-2192 Congruence between patient-reported outcomes and toxicity of LDR Brachytherapy for prostate cancer

PO-2192 Congruence between patient-reported outcomes and toxicity of LDR Brachytherapy for prostate cancer

Dosimetric evaluation in brachytherapy and teletherapy for prostate cancer using Monte Carlo simulation and anatomically realistic virtual anthropomorphic phantom

The benefits that radiotherapy provides to the patient are unquestionable. However, there is growing concern about the increased risk of radiation-induced secondary cancer and the late damage to organs and tissues associated with the treatment. In this sense, the main objective of this study was to determine the radiation doses in the organs and tissues of the prostate cancer patient for two radiotherapy options, using the Monte Carlo code MCNP×2.7.0. The patient was represented by the ICRP 110 reference virtual anthropomorphic phantom and underwent brachytherapy with a192Ir source, Nucletron Microselectron V2 model, and alternatively, conventional 3D-CRT radiotherapy with an 18 MV X-ray beam from a Varian 2100c medical linear accelerator with 4-field planning (anteroposterior, 0°; posteroanterior, 180°; left lateral, 90°; and right lateral, 270°). A set of conversion factors (CF) for equivalent and effective dose were determined. The obtained results showed that in the more distant organs related to the prostate, such as the lung, brain, and salivary glands, the contribution of scattered radiation decreases, especially when brachytherapy is used. Comparing the two treatment modalities, the CF for effective dose per therapeutic dose was 42% lower when 192Ir was chosen as the main form of treatment. The CF values for photon equivalent doses calculated in 3D-CRT 4-fields are among one and two orders of magnitude higher than 192Ir therapy. These differences are even higher when the neutron equivalent dose in 3D-CRT is considered. In this way, the tools and methodology presented significantly improve the previously used to accurately estimate the equivalent doses in organs and tissues, which is the best quantity to assess the risk of inducing secondary cancer of healthy organs and tissues of patients undergoing treatment with radiotherapy.

Salvage prostate brachytherapy in radiorecurrent prostate cancer: An international Delphi consensus study

Background and PurposeLocal recurrences after previous radiotherapy (RT) are increasingly being identified in biochemically recurrent prostate cancer. Salvage prostate brachytherapy (BT) is an effective and well tolerated treatment option. We sought to generate international consensus statements on the use and preferred technical considerations for salvage prostate BT. Materials and MethodsInternational experts in salvage prostate BT were invited (n = 34) to participate. A three-round modified Delphi technique was utilized, with questions focused on patient- and cancer-specific criteria, type and technique of BT, and follow-up. An a priori threshold for consensus of ≥ 75% was set, with a majority opinion being ≥ 50%. ResultsThirty international experts agreed to participate. Consensus was achieved for 56% (18/32) of statements. Consensus was achieved in several areas of patient selection: 1) A minimum of 2–3 years from initial RT to salvage BT; 2) MRI and PSMA PET should be obtained; and 3) Both targeted and systematic biopsies should be performed. Several areas did not reach consensus: 1) Maximum T stage/PSA at time of salvage; 2) Utilization/duration of ADT; 3) Appropriateness of combining local salvage with SABR for oligometastatic disease and 4) Repeating a second course of salvage BT. A majority opinion preferred High Dose-Rate salvage BT, and indicated that both focal and whole gland techniques could be appropriate. There was no single preferred dose/fractionation. ConclusionAreas of consensus within our Delphi study may serve as practical advice for salvage prostate BT. Future research in salvage BT should address areas of controversy identified in our study.

External beam radiotherapy combination is a risk factor for bladder cancer in patients with prostate cancer treated with brachytherapy

To investigate the risk of bladder cancer (BCa) in patients treated with brachytherapy for prostate cancer (PCa). We retrospectively analyzed 583 patients with PCa who underwent brachytherapy with or without external beam radiotherapy (EBRT). We analyzed the disease-free survival (DFS) of BCa in patients with PCa who underwent brachytherapy with or without EBRT. We performed multivariate Cox regression analyses of DFS using age, EBRT, and Brinkman index (BI) score (number of cigarettes smoked per day × number of years smoking) ≥ 200 as variables for BCa after brachytherapy. Fourteen patients (2.4%) developed BCa after brachytherapy with or without EBRT. The percentage of high-grade urothelial carcinoma (UC) was 63.6%. A total of 85.7% of patients had non-muscle invasive BCa, and 14.3% of patients had muscle invasive BCa. DFS was longer in brachytherapy monotherapy than in combination therapy (brachytherapy + EBRT). Multivariate Cox regression analysis showed that a BI score ≥ 200 (Hazard Ratio (HR 8.61; 95% Confidence Interval (CI) 1.12-65.98) and EBRT combination (HR 3.29; 95% CI 1.03-10.52) were significantly associated with BCa development in patients with PCa treated with brachytherapy. Furthermore, patients with BI score ≥ 200 and EBRT combination had a significantly higher risk of BCa compared with patients with BI score < 200 (HR Log-rank test P = 0.010). Most cases of BCa after brachytherapy with or without EBRT are high grade and invasive. We hypothesized that the EBRT combination might be a risk factor for BCa in patients with PCa who underwent brachytherapy.

Relationship between changes in quality of life and genitourinary toxicity grade after brachytherapy with I-125 alone for localised prostate cancer.

The relationship between the grading of toxicities based on toxicity criteria and longitudinal changes in quality of life (QOL) scores after permanent prostate brachytherapy (PPB) for localized prostate cancer remains unclear. This study aimed to evaluate these relationships. We assessed 107 patients treated with PPB using Iodine-125 alone from May 2007 to April 2010. Disease-specific QOL scores before PPB and at 1, 3, 6, 12, and 24 months after PPB were retrospectively evaluated with the Expanded Prostate Cancer Index Composite (EPIC), focusing on urinary domains. Toxicities were graded using the Radiation therapy oncology group and the European organization for research and treatment of cancer toxicity criteria. The median follow-up duration was 116 (range 18-148) months. Thirty-four patients (31.8%) developed grade ≥ 2 acute genitourinary (GU) toxicities; six (5.6%) developed grade ≥ 2 late GU toxicities. The general urinary domain score dropped significantly at 1 month (77.1 ± 14.1) post-PPB compared to the baseline score (92.2 ± 8.2), and then gradually returned to the baseline level by 12 months (93.7 ± 8.3) post-PPB. Reductions in the general urinary domain scores, including its subscale scores at 1, 3, and 6-months post-PPB were significantly greater among patients with grade ≥ 2 GU toxicity than among those with grade 0-1 GU toxicity. Changes in urinary domain scores demonstrated a close relationship with acute GU toxicity grades after PPB. Longitudinal assessments of the EPIC QOL scores provided additional information regarding time-course changes in GU toxicities after PPB.

Seed Density as a New Predictive Index of Seed Migration in Brachytherapy for Prostate Cancer Using Iodine-125 Loose Seed

This study aimed to examine the usefulness of seed density as a predictor of seed migration in patients with prostate cancer who received brachytherapy using Iodine-125 loose seed. From May 2006 to April 2016, 320 patients with localized prostate cancer underwent transperineal brachytherapy using iodine-125 loose seeds. Among them, 202 (63.1%) patients received brachytherapy monotherapy and 118 (36.9%) received combined brachytherapy and external beam radiotherapy. Seed density was calculated using the following formula: seed density = implanted seed number/prostate volume. All patients underwent radiography of the chest, abdomen and pelvis, and computed tomography at 1 day, 1 month, and 1 year after brachytherapy to evaluate the presence of seed migration. In total, the number of implanted seeds was 21,876. Seed migration was detected in 92 (28.8%) patients. Of a total of 21,876 seeds, 144 (0.66%) showed migration. The number of needles, number of seeds, and seed density were significantly higher in the group with migration than in the group without migration (p = 0.05). The ROC cutoff values for prostate volume, number of needles, number of seeds, and seed density were 20.9 cc, 21, 65, and 3.0, respectively. In the univariate analysis, prostate volume, number of needles, number of seeds, seed density, and treatment modality were all significant factors in predicting migration (p = 0.05). In the multivariate analysis, seed density and treatment modality were significant factors in predicting migration (p = 0.05). Seed density is useful for predicting seed migration. In cases with seed density > 3.0, it is necessary to take measures such as considering the use of stranded seeds.

PD15-07 PROSTATE BRACHYTHERAPY CASE VOLUME IN THE COMMUNITY SETTING DOES NOT AFFECT ONCOLOGIC OUTCOMES

You have accessJournal of UrologyCME1 Apr 2023PD15-07 PROSTATE BRACHYTHERAPY CASE VOLUME IN THE COMMUNITY SETTING DOES NOT AFFECT ONCOLOGIC OUTCOMES Kevin Chang, Lufan Wang, Janet Cowan, Osama Mohamad, Peter Carroll, and Matthew Cooperberg Kevin ChangKevin Chang More articles by this author , Lufan WangLufan Wang More articles by this author , Janet CowanJanet Cowan More articles by this author , Osama MohamadOsama Mohamad More articles by this author , Peter CarrollPeter Carroll More articles by this author , and Matthew CooperbergMatthew Cooperberg More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003262.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Prostate cancer brachytherapy (BT) is a treatment modality that has been declining in usage. The goal of this study is to describe the relationship between facility BT case volume and cancer-specific outcomes in patients with localized prostate cancer (PCa). METHODS: We identified patients in CaPSURE (Cancer of the Prostate Strategic Urologic Research Endeavor) diagnosed with localized PCa between 1999-2007 and treated with BT. Only community sites had sufficient recorded cases for inclusion. BT case volume of each facility was based on its number of BT-treated PCa patients, with those above the 75th percentile categorized as high-volume. Our primary outcome is the effect of case volume on biochemical failure based on the Phoenix definition or receipt of salvage treatment after primary BT to account for a large proportion of missing PSA follow-up values in our cohort. Secondary outcomes included patient-reported UCLA Prostate Cancer Index scores for urinary, sexual, and bowel function and bother. RESULTS: We identified 1,282 BT-treated patients with localized PCa with median follow-up of 9 years (3.8 years based on last PSA) across 18 community sites with a median of 210 BT cases. Overall, 92% of patients were National Comprehensive Cancer Network low- or intermediate-risk and 98% received low dose rate BT. 722 patients (56.3%) received BT at high-volume (>210 cases) community facilities and 560 patients (43.7%) at low-volume (10-210 cases) facilities. High-volume facilities predominantly used Pd-103 seeds while low-volume facilities predominantly used I-125 seeds (p<0.01). A greater proportion of patients at low-volume facilities had pre-BT hormone therapy (p<0.01). High-volume facility status was not associated with improved rates of biochemical failure (10-year cumulative incidence 10.3% vs 12.5%, log-rank p=0.27, Figure 1A) or prostate cancer specific mortality (10-year cumulative incidence 4.0% vs 4.5%, log-rank p=0.62). Patient-reported scores of urinary, sexual, and bowel bother at 6 months following BT were comparable (Figure 1B). CONCLUSIONS: BT-treated patients with localized PCa at high-volume community facilities have similar rates of biochemical failure, prostate cancer specific mortality, and trends in quality of life outcomes compared to those treated at low-volume community facilities. Source of Funding: UCSF Goldberg-Benioff Program in Translational Cancer Biology © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e421 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kevin Chang More articles by this author Lufan Wang More articles by this author Janet Cowan More articles by this author Osama Mohamad More articles by this author Peter Carroll More articles by this author Matthew Cooperberg More articles by this author Expand All Advertisement PDF downloadLoading ...

Outcomes after PD-103 versus I-125 for low dose rate prostate brachytherapy monotherapy: An international, multi-institutional study

Background and PurposePd-103 and I-125 are commonly used in low dose rate (LDR) brachytherapy for prostate cancer. Comparisons of outcomes by isotope type are limited, but Pd-103 has distinct radiobiologic advantages over I-125 despite its lesser availability outside the United States. We evaluated oncologic outcomes after Pd-103 vs I-125 LDR monotherapy for prostate cancer. Materials and MethodsWe retrospectively analyzed databases at 8 institutions for men who received definitive LDR monotherapy with Pd-103 (n = 1,597) or I-125 (n = 7,504) for prostate cancer. Freedom from clinical failure (FFCF) and freedom from biochemical failure (FFBF) stratified by isotope were analyzed by Kaplan-Meier univariate and Cox multivariate analyses. Biochemical cure rates (prostate-specific antigen level ≤ 0.2 ng/mL between 3.5 and 4.5 years of follow-up) by isotype were calculated for men with at least 3.5 years of follow-up and compared by univariate and multivariate logistic regression. ResultsCompared with I-125, Pd-103 led to higher 7-year rates of FFBF (96.2% vs 87.6%, P < 0.001) and FFCF (96.5% vs 94.3%, P < 0.001). This difference held after multivariate adjustment for baseline factors (FFBF hazard ratio [HR] = 0.31, FFCF HR = 0.49, both P < 0.001). Pd-103 was also associated with higher cure rates on univariate (odds ratio [OR] = 5.9, P < 0.001) and multivariate (OR = 6.0, P < 0.001) analyses. Results retained significance in sensitivity analyses of data from the 4 institutions that used both isotopes (n = 2,971). ConclusionsPd-103 monotherapy was associated with higher FFBF, FFCF, and biochemical cure rates, and suggests that Pd-103 LDR may lead to improved oncologic outcomes compared with I-125.