125I versus 103Pd for low-risk prostate cancer: preliminary PSA outcomes from a prospective randomized multicenter trial

Uncertainty in magnetic resonance imaging-based prostate postimplant dosimetry: Results of a 10-person human observer study, and comparisons with automatic postimplant dosimetry

PURPOSE

Uncertainties in postimplant quality assessment (QA) for low-dose-rate prostate brachytherapy (LDRPBT) are introduced at two steps: seed localization and contouring. We quantified how interobserver variability (IoV) introduced in both steps impacts dose-volume-histogram (DVH) parameters for MRI-based LDRPBT, and compared it with automatically derived DVH parameters.

METHODS AND MATERIALS

Twenty-five patients received MRI-based LDRPBT. Seven clinical observers contoured the prostate and four organs at risk, and 4 dosimetrists performed seed localization, on each MRI. Twenty-eight unique manual postimplant QAs were created for each patient from unique observer pairs. Reference QA and automatic QA were also performed for each patient. IoV of prostate, rectum, and external urinary sphincter (EUS) DVH parameters owing to seed localization and contouring was quantified with coefficients of variation. Automatically derived DVH parameters were compared with those of the reference plans.

RESULTS

Coefficients of variation (CoVs) owing to contouring variability (CoVcontours) were significantly higher than those due to seed localization variability (CoVseeds) (median CoVcontours vs. median CoVseeds: prostate D90-15.12% vs. 0.65%, p < 0.001; prostate V100-5.36% vs. 0.37%, p < 0.001; rectum V100-79.23% vs. 8.69%, p < 0.001; EUS V200-107.74% vs. 21.18%, p < 0.001). CoVcontours were lower when the contouring observers were restricted to the 3 radiation oncologists, but were still markedly higher than CoVseeds. Median differences in prostate D90, prostate V100, rectum V100, and EUS V200 between automatically computed and reference dosimetry parameters were 3.16%, 1.63%, -0.00 mL, and -0.00 mL, respectively.

CONCLUSIONS

Seed localization introduces substantially less variability in postimplant QA than does contouring for MRI-based LDRPBT. While automatic seed localization may potentially help improve workflow efficiency, it has limited potential for improving the consistency and quality of postimplant dosimetry.

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

BACKGROUND AND PURPOSE

Pd-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 METHODS

We 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.

RESULTS

Compared 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).

CONCLUSIONS

Pd-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.

Low dose rate brachytherapy for primary treatment of localized prostate cancer: A systemic review and executive summary of an evidence-based consensus statement

PURPOSE

The purpose of this guideline is to present evidence-based consensus recommendations for low dose rate (LDR) permanent seed brachytherapy for the primary treatment of prostate cancer.

METHODS AND MATERIALS

The American Brachytherapy Society convened a task force for addressing key questions concerning ultrasound-based LDR prostate brachytherapy for the primary treatment of prostate cancer. A comprehensive literature search was conducted to identify prospective and multi-institutional retrospective studies involving LDR brachytherapy as monotherapy or boost in combination with external beam radiation therapy with or without adjuvant androgen deprivation therapy. Outcomes included disease control, toxicity, and quality of life.

RESULTS

LDR prostate brachytherapy monotherapy is an appropriate treatment option for low risk and favorable intermediate risk disease. LDR brachytherapy boost in combination with external beam radiation therapy is appropriate for unfavorable intermediate risk and high-risk disease. Androgen deprivation therapy is recommended in unfavorable intermediate risk and high-risk disease. Acceptable radionuclides for LDR brachytherapy include iodine-125, palladium-103, and cesium-131. Although brachytherapy monotherapy is associated with increased urinary obstructive and irritative symptoms that peak within the first 3 months after treatment, the median time toward symptom resolution is approximately 1 year for iodine-125 and 6 months for palladium-103. Such symptoms can be mitigated with short-term use of alpha blockers. Combination therapy is associated with worse urinary, bowel, and sexual symptoms than monotherapy. A prostate specific antigen <= 0.2 ng/mL at 4 years after LDR brachytherapy may be considered a biochemical definition of cure.

CONCLUSIONS

LDR brachytherapy is a convenient, effective, and well-tolerated treatment for prostate cancer.

Peritricuspid annular prostate pellet

A 75-year-old was treated for prostate adenocarcinoma with brachytherapy in September 2018. A routine follow-up chest radiograph 3 months later revealed a metallic object of the same dimensions as a brachytherapy pellet located in the right ventricle. Further imaging showed the brachtherapy pellet was located in the anterobasal right ventricular endocardium close to the tricuspid valve. Frequent asymptomatic premature ventricular contractions were observed with likely origin from the left ventricular outflow tract, an area remote from the site of the pellet. The patient remains asymptomatic and subsequent imaging shows that the position of the pellet has not changed.

I-125 or Pd-103 for brachytherapy boost in men with high-risk prostate cancer: A comparison of survival and morbidity outcomes

PURPOSE

Brachytherapy boost improves biochemical recurrence rates in men with high-risk prostate cancer (HRPC). Few data are available on whether one isotope is superior to another. We compared the oncologic and morbidity outcomes of I-125 and Pd-103 in men with HRPC receiving brachytherapy.

METHODS AND MATERIALS

Of 797 patients with HRPC, 190 (23.8%) received I-125 or 607 received Pd-103 with a median of 45 Gy of external beam irradiation. Freedom from biochemical failure (FFBF), freedom from metastases (FFMs), cause-specific survival (CSS), and morbidity were compared for the two isotopes by the ANOVA and the χ² test with survival determined by the Kaplan-Meier method and Cox regression.

RESULTS

Men treated with I-125 had a higher stage (p < 0.001), biological equivalent dose (BED) (p < 0.001), and longer hormone therapy (neoadjuvant hormone therapy, p < 0.001), where men treated with Pd-103 had a higher Gleason score (GS, p < 0.001) and longer followup (median 8.3 vs. 5.3 years, p < 0.001). Ten-year FFBF, FFM, and CSS for I-125 vs. Pd-103 were 77.5 vs. 80.2% (p = 0.897), 94.7 vs. 91.9% (p = 0.017), and 95.4 vs. 91.8% (p = 0.346), respectively. Men with T3 had superior CSS (94.1 vs. 79.5%, p = 0.001) with I-125. Significant covariates by Cox regression for FFBF were prostate specific antigen (PSA), the GS, and the BED (p < 0.001), for FFM PSA (p < 0.001) and GS (p = 0.029), and for CSS PSA, the GS (p < 0.001) and the BED (p = 0.022). Prostate cancer mortality was 7/62 (15.6%) for BED ≤ 150 Gy, 18/229 (7.9%) for BED >150-200 Gy, and 20/470 (5.9%) for BED >200 Gy (p = 0.029). Long-term morbidity was not different for the two isotopes.

CONCLUSIONS

Brachytherapy boost with I-125 and Pd-103 appears equally effective yielding 10-year CSS of over 90%. I-125 may have an advantage in T3 disease. Higher doses yield the most favorable survival.

The 100 most cited articles in prostate cancer brachytherapy: systematic review and bibliometric analysis

Purpose

The aim of this study was to identify the 100 most cited research articles in prostate cancer brachytherapy (PCB) and to review the characteristics of these citation.

Material and methods

The Web of Science Core Collection was used to identify the 100 most cited articles in PCB as of December 31^st, 2019. The following important information was extracted: year and month of publication, title, journal, country of origin, authors, type of article, treatment modality, and topics.

Results

The 100 most cited articles in PCB were published between 1999 and 2018, and the number of citations ranged from 455 to 54; these articles had collectively been cited 10,331 times at the time of search. These articles were from 11 countries, with most publications being from the United States (n = 61), followed by Canada (n = 10), the United Kingdom (n = 8), and Germany (n = 5). The “International Journal of Radiation Oncology, Biology, Physics” published the most articles (n = 47), followed by the “Journal of Urology” (n = 11), “Radiotherapy and Oncology” (n = 10), “Cancer” (n = 7), and “Urology” (n = 6). Permanent interstitial brachytherapy (n = 52) was the most widely used treatment modality, followed by temporary brachytherapy (n = 45). Disease control (n = 51) was the most common topic, followed by side effects (n = 44) and quality of life (n = 27).

Conclusions

The bibliometric analysis presents a detailed list of the 100 most cited articles in prostate cancer brachytherapy. There are clear recommendations for treatment with prostate cancer brachytherapy. The goal of prostate cancer brachytherapy is to improve long-term outcomes and quality of life.

The current state of randomized clinical trial evidence for prostate brachytherapy

Interstitial brachytherapy is one of several curative therapeutic options for the treatment of localized prostate cancer. In this review, we summarize all available randomized data to support the optimal use of prostate brachytherapy. Evidence from completed randomized controlled trials is the focus of this review with a presentation also of important ongoing trials. Gaps in knowledge are identified where future investigation may be fruitful with intent to inspire well-designed prospective studies with standardized treatment that focuses on improving oncological outcomes, reducing morbidity, or maintaining quality of life.

Reducing seed migration to near zero with stranded-seed implants: Comparison of seed migration rates to the chest in 1000 permanent prostate brachytherapy patients undergoing implants with loose or stranded seeds

PURPOSE

Pulmonary seed emboli to the chest may occur after permanent prostate brachytherapy (PPB). The purpose of this study is to analyze factors associated with seed migration to the chest in a large series of PPB patients from a single institution undergoing implant with either loose seeds (LS), mixed loose and stranded seeds (MS), or exclusively stranded seeds in an absorbable vicryl suture (VS).

METHODS AND MATERIALS

Between May 1998 and July 2015, a total of 1000 consecutive PPB patients with postoperative diagnostic chest x-rays at 4 months after implant were analyzed for seed migration. Patients were grouped based on seed implant technique: LS = 391 (39.1%), MS = 43 (4.3%), or VS = 566 (56.6%). Univariate and multivariate analysis were performed using Cox proportional hazards regression models to determine predictors of seed migration.

RESULTS

Overall, 18.8% of patients experienced seed migration to the chest. The incidence of seed migration per patient was 45.5%, 11.6%, and 0.9% (p < 0.0001), for patients receiving LS, MS, or VS PPB, respectively. The right and left lower lobes were the most frequent sites of pulmonary seed migration. On multivariable analysis, planimetry volume (p = 0.0002; HR = 0.7 per 10 cc [0.6-0.8]), number of seeds implanted (p < 0.0001, HR = 2.4 per 25 seeds [1.7-3.4]), LS implant (p < 0.0001, HR = 15.9 [5.9-42.1]), and MS implant (p = 0.001, HR = 7.9 [2.3-28.1]) were associated with seed migration to the chest.

CONCLUSIONS

In this large series, significantly higher rates of seed migration to the chest are observed in implants using any LS with observed hazard ratios of 15.9 and 7.9 for LS and MS respectively, as compared with implants using solely stranded seeds.

Low dose rate prostate brachytherapy

Low dose rate (LDR) prostate brachytherapy is an evidence based radiation technique with excellent oncologic outcomes. By utilizing direct image guidance for radioactive source placement, LDR brachytherapy provides superior radiation dose escalation and conformality compared to external beam radiation therapy (EBRT). With this level of precision, late grade 3 or 4 genitourinary or gastrointestinal toxicity rates are typically between 1% and 4%. Furthermore, when performed as a same day surgical procedure, this technique provides a cost effective and convenient strategy. A large body of literature with robust follow-up has led multiple expert consensus groups to endorse the use of LDR brachytherapy as an appropriate management option for all risk groups of non-metastatic prostate cancer. LDR brachytherapy is often effective when delivered as a monotherapy, although for some patients with intermediate or high-risk disease, optimal outcome are achieved in combination with supplemental EBRT and/or androgen deprivation therapy (ADT). In addition to reviewing technical aspects and reported clinical outcomes of LDR prostate brachytherapy, this article will focus on the considerations related to appropriate patient selection and other aspects of its use in the treatment of prostate cancer.

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.

Evaluation of intraoperative magnetic resonance imaging/ultrasound fusion optimization for low-dose-rate prostate brachytherapy

Purpose

Intraoperative planning with transrectal ultrasound (US) is used for accurate seed placement and optimal dosimetry in prostate brachytherapy. However, prostate magnetic resonance imaging (MRI) has shown superiority in delineation of prostate anatomy. Accordingly, MRI/US fusion may be useful for accurate intraoperative planning. We analyzed planning with MRI/US fusion to compare differences in dosimetry and volume to that derived from the postoperative computed tomography (CT).

Material and methods

Twenty patients underwent preoperative prostate MRI, which was fused intraoperatively with US during prostate brachytherapy. Intraoperative ¹²⁵I or ¹⁰³Pd seed placement was modified by the use of MRI fusion when indicated. Following implantation, dose comparisons were made between data derived from MRI/US and that from post-operative CT scans. Plan parameters analyzed included the D₉₀ (dose to 90% of the prostate), rectal D₃₀, V₃₀ (volume of the rectum receiving 30 percent of dose), and prostate V₁₀₀.

Results

The median number of seeds implanted per patient was seventy-six. The MRI measured prostate volume, which was on average 4.47 cc larger than the CT measured prostate volume. In 9 patients, the apex of the prostate was better identified under MRI with the fusion protocol, and an average of 4 fewer seeds were required to be placed in the apex/urinary sphincter region. Both MRI and US individually showed a reduced intraoperative prostate D₉₀ in comparison to the postoperative CT, with a larger mean difference for MRI in comparison with US (9.71 vs. 4.31 Gy, p = 0.007). This was also true for the prostate V₁₀₀ (5.18 vs. 2.73 cc, p = 0.009). Post-operative CT underestimated rectal D₃₀ and V₃₀ in comparison to both MRI and US with MRI showing a larger mean difference than US for D₃₀ (40.64 vs. 35.92 Gy, p = 0.04) and V₃₀ (50.20 vs. 44.38 cc, p = 0.009).

Conclusions

The MRI/US fusion demonstrated greater prostate volume compared to standard CT/US based planning likely due to the better resolution of the prostate apex. Furthermore, rectal dose was underestimated with CT vs. MRI based planning. Additional study is required to assess long-term clinical implications of disease control and effects on long-term toxicity, especially as related to the rectum and urinary sphincter. MRI/US intraoperative fusion may improve prostate dosimetry while sparing the rectum and urethra, potentially impacting disease control and late toxicity.

The evolution of brachytherapy for prostate cancer

Brachytherapy (BT), using low-dose-rate (LDR) permanent seed implantation or high-dose-rate (HDR) temporary source implantation, is an acceptable treatment option for select patients with prostate cancer of any risk group. The benefits of HDR-BT over LDR-BT include the ability to use the same source for other cancers, lower operator dependence, and - typically - fewer acute irritative symptoms. By contrast, the benefits of LDR-BT include more favourable scheduling logistics, lower initial capital equipment costs, no need for a shielded room, completion in a single implant, and more robust data from clinical trials. Prospective reports comparing HDR-BT and LDR-BT to each other or to other treatment options (such as external beam radiotherapy (EBRT) or surgery) suggest similar outcomes. The 5-year freedom from biochemical failure rates for patients with low-risk, intermediate-risk, and high-risk disease are >85%, 69-97%, and 63-80%, respectively. Brachytherapy with EBRT (versus brachytherapy alone) is an appropriate approach in select patients with intermediate-risk and high-risk disease. The 10-year rates of overall survival, distant metastasis, and cancer-specific mortality are >85%, <10%, and <5%, respectively. Grade 3-4 toxicities associated with HDR-BT and LDR-BT are rare, at <4% in most series, and quality of life is improved in patients who receive brachytherapy compared with those who undergo surgery.

Cone-beam CT-based adaptive planning improves permanent prostate brachytherapy dosimetry: An analysis of 1266 patients

PURPOSE

To evaluate adaptive planning for permanent prostate brachytherapy and to identify the prostate regions that needed adaptation.

METHODS AND MATERIALS

After the implantation of stranded seeds, using real-time intraoperative planning, a transrectal ultrasound (TRUS)-scan was obtained and contoured. The positions of seeds were determined on a C-arm cone-beam computed tomography (CBCT)-scan. The CBCT-scan was registered to the TRUS-scan using fiducial gold markers. If dose coverage on the combined image-dataset was inadequate, an intraoperative adaptation was performed by placing remedial seeds. CBCT-based intraoperative dosimetry was analyzed for the prostate (D90, V100, and V150) and the urethra (D30). The effects of the adaptive dosimetry procedure for Day 30 were separately assessed.

RESULTS

We analyzed 1266 patients. In 17.4% of the procedures, an adaptation was performed. Without the dose contribution of the adaptation Day 30 V100 would be < 95% for half of this group. On Day 0, the increase due to the adaptation was 11.8 ± 7.2% (1SD) for D90 and 9.0 ± 6.4% for V100. On Day 30, we observed an increase in D90 of 12.3 ± 6.0% and in V100 of 4.2 ± 4.3%. For the total group, a D90 of 119.6 ± 9.1% and V100 of 97.7 ± 2.5% was achieved. Most remedial seeds were placed anteriorly near the base of the prostate.

CONCLUSION

CBCT-based adaptive planning enables identification of implants needing adaptation and improves prostate dose coverage. Adaptations were predominantly performed near the anterior base of the prostate.

Is it necessary to perform week three dosimetric analysis in low-dose-rate brachytherapy for prostate cancer when day 0 dosimetry is done? A quality assurance assessment

PURPOSE

To determine whether computed tomography/magnetic resonance imaging-based day 0 (d0) dosimetry is a meaningful predictor of day 21 (d21) dosimetry in low-dose-rate brachytherapy for localized prostate cancer.

METHODS AND MATERIALS

The study population consisted of 277 men with localized (T1-2 N0 M0), low-/intermediate-risk prostate cancer treated with low-dose-rate brachytherapy. Computed tomography/magnetic resonance imaging fusion was used for postimplant dosimetry at d0 and d21. Logistic regression was used to construct receiver operating characteristic curves for achieving each constraint at d21, based on d0 D90 and V100, and Youden's index was used to evaluate cutpoints. Freedom from biochemical failure (FBCF) was estimated with the Kaplan-Meier method.

RESULTS

The median d0 D90 increased from 133 to 150 Gy at d21, and median d0 V100 increased from 87% to 91%. For achieving the D90 constraint at d21, the optimal cut-point for d0 D90 was 135 Gy, with 84% of these patients maintaining a d21 D90 > 145 Gy. For achieving the D90 constraint at d21, the optimal cut-point for d0 V100 was 87%, with 83% of these patients maintained a d21 V100 > 90%. There was no improvement in FBCF in patients with a d0 D90 > 135 Gy or D90 > 145 Gy. Similarly, there was no improvement in FBCF in patients with a d0 V100 > 87% or V100 > 90%.

CONCLUSIONS

Meeting dosimetric constraints on d0 does not obviate d21 dosimetric analysis. Constraints used for dose prescriptions on d0 are not the ideal predictors of d21 dosimetry.

A dose-response analysis of biochemical control outcomes after (125)I monotherapy for patients with favorable-risk prostate cancer

PURPOSE

To define the optimal dose for (125)I prostate implants by correlating postimplantation dosimetry findings with biochemical failure and toxicity.

METHODS AND MATERIALS

Between 2003 and 2009, 683 patients with prostate cancer were treated with (125)I prostate brachytherapy without supplemental external beam radiation therapy and were followed up for a median time of 80 months. Implant dose was defined as the D90 (the minimal dose received by 90% of the prostate) on postoperative day 1 and 1 month after implantation. Therefore, 2 dosimetric variables (day 1 D90 and day 30 D90) were analyzed for each patient. We investigated the dose effects on biochemical control and toxicity.

RESULTS

The 7-year biochemical failure-free survival (BFFS) rate for the group overall was 96.4% according to the Phoenix definition. A multivariate analysis found day 1 D90 and day 30 D90 to be the most significant factors affecting BFFS. The cutoff points for day 1 D90 and day 30 D90, calculated from ROC curves, were 163 Gy and 175 Gy, respectively. By use of univariate analysis, various dosimetric cutoff points for day 30 D90 were tested. We found that day 30 D90 cutoff points from 130 to 180 Gy appeared to be good for the entire cohort. Greater D90s were associated with an increase in late genitourinary or gastrointestinal toxicity ≥ grade 2, but the increase was not statistically significant.

CONCLUSIONS

Improvements in BFFS rates were seen with increasing D90 levels. Day 30 D90 doses of 130 to 180 Gy were found to serve as cutoff levels. For low-risk and low-tier intermediate-risk prostate cancer patients, high prostate D90s, even with doses exceeding 180 Gy, achieve better treatment results and are feasible.

Low-dose rate brachytherapy for patients with low- or intermediate-risk prostate cancer: A systematic review

INTRODUCTION

We review the current evidence for the role of low-dose rate brachytherapy (PB) in patients with low- or intermediate-risk prostate cancer using a systematic review of the literature.

METHODS

We searched MEDLINE and EMBASE (from January 1996 to October 2011), the Cochrane Library, relevant guideline web-sites, and websites for meetings specific for genitourinary diseases.

RESULTS

Ten systematic reviews and 55 single-study papers met the pre-planned study selection criteria. In the end, 36 articles were abstracted and analyzed for this systematic review. There is no evidence for a difference in efficacy between PB and external beam radiation therapy (EBRT), or between PB and radical prostatectomy (RP). During the 6 months to 3 years after treatment, PB was associated with less urinary incontinence and sexual impotency than RP, and RP was associated with less urinary irritation and rectal morbidity than PB. However, these differences diminished over time. PB conferred less risk of impotency and rectal morbidity in the three years after treatment than EBRT. Iodine-125 and alladium-103 did not differ with respect to biochemical relapse-free survival and patient-reported outcomes.

CONCLUSIONS

PB alone is a treatment option with equal efficacy to EBRT or RP alone in patients with newly diagnosed low- or intermediate-risk prostate cancer who require or choose active treatment.

Time to failure after definitive therapy for prostate cancer: implications for importance of aggressive local treatment

Purpose

To explore patterns of time to failure in men receiving high doses of permanent seed brachytherapy with or without external beam radiation therapy as a function of risk status.

Material and methods

Two thousand two hundred and thirty four patients were treated with prostate brachytherapy with median follow up of 8.0 years. The population was 35% low risk, 49% intermediate risk, and 16% high risk (NCCN). Median day 0 implant D₉₀ was 119% and V₁₀₀ was 98%. Treatment failure was defined as PSA > 0.40 ng/mL after nadir. Rates of biochemical failure, distant metastases, and prostate cancer death were determined with non-prostate death as a competing risk.

Results

For all patients, the 10-year biochemical failure, distant metastases, and cause-specific mortality were 4.4%, 1.4%, and 1.3%, respectively. The biochemical failure rates were 1.3%, 4.8%, and 10.0% for men with low, intermediate, and high risk disease, respectively. Median time to failure was 2.8 years. In men who died from prostate cancer, the median time from treatment failure to death was 4.2 years. Overall, 83% of biochemical failures and 97% of metastases occurred within the first 4 years after treatment.

Conclusions

With the dose escalation achieved by high quality brachytherapy dosimetry, even high-risk prostate cancer patients have excellent long term biochemical outcomes. Treatment failures occur early, and one third become metastatic and progress rapidly to prostate cancer death. The low frequency and pattern of failures suggest the presence of micrometastatic disease prior to treatment is rare, even in high risk patients.

Evidence-based guideline recommendations on low-dose rate brachytherapy in patients with low- or intermediate-risk prostate cancer

OBJECTIVE

The Genitourinary Cancer Disease Site Group (GU DSG) and Cancer Care Ontario's Program in Evidence-Based Care (PEBC) in Ontario, Canada developed a guideline on low-dose rate brachytherapy (LDR-BT) in patients with early-stage low-grade prostate cancer in 2001. The current updated guideline focuses on the research questions regarding the effect of LDR-BT alone, the effect of LDR-BT with external beam radiation therapy (EBRT) and the selection of an isotope.

METHODS

This guideline was developed by using the methods of the Practice Guidelines Development Cycle and the core methodology was a systematic review. MEDLINE and EMBASE (from January 1996 to October 2011), the Cochrane Library, main guideline websites, and main annual meeting abstract websites specific for genitourinary diseases were searched. Internal and external reviews of the draft guideline were conducted.

RESULTS

The draft guideline was developed according to a total of 10 systematic reviews and 55 full text articles that met the pre-planned study selection criteria. The quality of evidence was low to moderate. The final report reflects integration of the feedback obtained through the internal review (two oncologists and a methodologist) and external review (five target reviewers and 48 professional consultation reviewers) process, with final approval given by the GU DSG and the PEBC.

CONCLUSION

THE MAIN RECOMMENDATIONS ARE: (1) For patients with newly diagnosed low-risk or intermediate-risk prostate cancer who require or choose active treatment, LDR-BT alone is a treatment option as an alternative to EBRT alone or RP alone; and (2) I-125 and Pd-103 are each reasonable isotope options.

Overview of randomized controlled treatment trials for clinically localized prostate cancer: implications for active surveillance and the United States preventative task force report on screening?

Prostate cancer and its management have been intensely debated for years. Recommendations range from ardent support for active screening and immediate treatment to resolute avoidance of screening and active surveillance. There is a growing body of level I evidence establishing a clear survival advantage for treatment of subsets of patients with clinically localized prostate cancer. This chapter presents a review of these randomized controlled trials. We argue that an understanding of this literature is relevant not only to those considering active surveillance but also to those evaluating the merits of screening. In addition, a number of important evidence-based conclusions concerning what should and should not be done can be gleaned from these trials.

The dosimetric impact of supplementing pre-planned prostate implants with discretionary 125I seeds

Introduction

Prostate implants at the British Columbia Cancer Agency are performed using a pre-planned technique. Physicians can augment the dose distribution using one to five non-planned ‘extra’ seeds and this option is determined without intraoperative feedback. The purpose of this research is to quantify the dosimetric impact of extra seeds and to assess the circumstances under which they are considered necessary.

Materials and methods

Implanting physicians used a questionnaire to record the three-dimensional location and their rationale for using extra seeds. A plan reconstruction algorithm was used to distinguish the extra seeds from the planned seeds. Distributions with and without extra seeds were calculated to quantify the dosimetric impact to the prostate, urethra and rectum.

Results

Extra seeds resulted in mean relative increases to V100, V150 and V200 of 3·7%, 13% and 19·1%, respectively. Mean prostate D90 increased from 147 to 156 Gy. Improvements in post-implant quality assurance codes were recorded in 30% of the implants with minimal dose increase to the rectum and urethra. Extra seeds were mainly deposited in the prostate anterior–superior quadrant.

Conclusions

The use of two to five extra seeds can result in improvements to pre-planned prostate implants, whereas the costs in terms of increased rectal and prostatic urethral dose are relatively minor.

Dosimetric characteristics of three new design 125I brachytherapy sources

For roughly 25 years, 125I sources have been used in the treatment of various malignant diseases such as prostate cancer. Three new brachytherapy sources, IR01-125I, IR02-125I and IR03-125I, have been developed and are designed for permanent implant application. The Monte Carlo radiation transport code version MCNP 5 was used to calculate the dosimetry parameters around the sources in accordance with the updated report of the American Association of Physicists in Medicine (AAPM), Task Group No. 43. For each source, the dose rate constant Λ, the radial dose function gL(r), and the anisotropy function F(r, θ), were obtained. The results indicated a dose rate constant of 0.932 ± 0.01, 0.934 ± 0.01 and 0.939 ± 0.01 Gy h−1 U−1 for the IR01-125I, IR02-125I and IR03-125I sources respectively. With the goal of determining an optimal design for a 125I source, each seed's parameters were compared with other seeds. In this study, the optimal source IR03-125I provides the most isotropic dose distribution in water. Finally, the results for optimal source were compared with published results for those of other commercial sources.

Brachytherapy in Men with Prostate Cancer: Update on Indications and Outcomes

Brachytherapy (BT), using either a low-dose-rate (LDR) or mostly high-dose-rate (HDR) technique, is the device able to deliver the highest dose-rate in the most conformal way It is used as monotherapy or in combination with external beam radiotherapy (EBRT). LDR-BT is mostly used as monotherapy; HDR-BT is combined with EBRT +/– adjuvant hormone therapy In patients with low-risk disease and in selected intermediate-risk patients, LDR-BT ensures long-term good disease control rates and HDR-BT shows similar results, even if with shorter follow-up. In patients with intermediate/high risk disease the combination therapy (EBRT + HDR-BT) provides better oncological outcomes compared to EBRT monotherapy, even if the role of adjuvant hormone therapy is still unclear. Literature shows variable efficacy of BT in case of local recurrence after EBRT and radical prostatectomy even if few cases have been reported with short follow-up. Side effects are acceptable (urogenital toxicity, urinary incontinence, sexual function) and comparable with the other treatment modalities. So far, randomized controlled trials comparing the different treatment modalities are necessary to clarify indications and real efficacy.

Management of Localized Prostate Cancer by Focal Transurethral Resection of Prostate Cancer: An Application of Radical TUR-PCa to Focal Therapy

Background. We analyzed radical TUR-PCa against localized prostate cancer. Patients and Methods. Seventy-nine out of 209 patients with prostate cancer in one lobe were studied. Patients' age ranged from 58 to 91 years and preoperative PSA, 0.70 to 17.30 ng/mL. In other 16 additional patients we performed focal TUR-PCa. Patients' age ranged from 51 to 87 years and preoperative PSA, 1.51 to 25.74 ng/mL. Results. PSA failure in radical TUR-PCa was 5.1% during the mean follow-up period of 58.9 months. The actuarial biochemical non-recurrence rate was 98.2% for pT2a and 90.5% for pT2b. Bladder neck contracture occurred in 28 patients (35.4%). In 209 patients, pathological study revealed prostate cancer of the peripheral zone near the neurovascular bundle bilaterally in 25%, unilaterally in 39% and no cancer bilaterally in 35%, suggesting the possibility of focal TUR-PCa. Postoperative PSA of 16 patients treated by focal TUR-PCa was stable between 0.007 and 0.406 ng/mL at 24.2 months' follow-up. No patients suffered from urinary incontinence. Bladder neck contracture developed in only 1 patient and all 5 patients underwent nerve-preserving TUR-PCa did not show erectile dysfunction. Conclusion. Focal TUR-PCa was considered to be a promising option among focal therapies against localized prostate cancer.

A comparison of the impact of isotope ((125)I vs. (103)Pd) on toxicity and biochemical outcome after interstitial brachytherapy and external beam radiation therapy for clinically localized prostate cancer

PURPOSE

To compare biochemical outcomes and morbidity associated with iodine-125 ((125)I) and palladium-103 ((103)Pd) brachytherapy as part of combined modality therapy for clinically localized prostate cancer.

METHODS AND MATERIALS

Between October 2002 and December 2008, 259 patients underwent prostate brachytherapy ((125)I prescription dose, 110Gy: n=199; (103)Pd prescription dose, 100Gy: n=60) followed by external beam radiotherapy (median dose, 50.4Gy). Eighty-seven patients also received neoadjuvant androgen deprivation therapy. Toxicities were recorded with CTCAE v 3.0, International Prostate Symptoms Score (IPSS), and International Index of Erectile Function questionnaires.

RESULTS

Overall, acute Grade ≥2 genitourinary toxicity occurred in 21% and 30% of patients treated with (125)I and (103)Pd, respectively (p=0.16). There were no significant differences in IPSS change or urinary quality-of-life scores between the isotopes at 4, 6, or 12 months (p=0.20, 0.21, and 1.0, respectively). IPSS resolution occurred at a median of 11 and 6 months for (125)I and (103)Pd patients, respectively (p=0.03). On multivariate analysis, only the use of neoadjuvant androgen deprivation therapy was predictive of time to IPSS resolution (p=0.046). Late Grade ≥2 gastrointestinal toxicity occurred in 7% of (125)I patients and 6% of patients treated with (103)Pd. Of 129 potent patients at baseline, there was better erectile function in patients who received (103)Pd (p=0.02); however, the followup was shorter for these patients. The 5-year prostate-specific antigen relapse-free survival for (125)I and (103)Pd patients was 95.2% and 98.2% (p=0.73), respectively.

CONCLUSION

There were no differences in acute or long-term genitourinary or gastrointestinal toxicity between (125)I and (103)Pd in combined modality therapy for prostate cancer. There may be less erectile toxicity with the use of (103)Pd; however, additional followup of these patients is needed. There was no significant difference in 5-year prostate-specific antigen relapse-free survival between (103)Pd and (125)I.

Low-dose rate brachytherapy for men with localized prostate cancer

BACKGROUND

Localized prostate cancer is a slow growing tumor for many years for the majority of affected men. Low-dose rate brachytherapy (LDR-BT) is short-distance radiotherapy using low-energy radioactive sources. LDR-BT has been recommended for men with low risk localized prostate cancer.

OBJECTIVES

To assess the benefit and harm of LDR-BT compared to radical prostatectomy (RP), external beam radiotherapy (EBRT), and no primary therapy (NPT) in men with localized prostatic cancer.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1950), and EMBASE (from 1980) were searched in June 2010 as well as online trials registers and reference lists of reviews.

SELECTION CRITERIA

Randomized, controlled trials comparing LDR-BT versus RP, EBRT, and NPT in men with clinically localized prostate cancer.

DATA COLLECTION AND ANALYSIS

Data on study methods, participants, treatment regimens, observation period and outcomes were recorded by two reviewers independently.

MAIN RESULTS

We identified only one RCT (N = 200; mean follow up 68 months). This trial compared LDR-BT and RP. The risk of bias was deemed high. Primary outcomes (overall survival, cause-specific mortality, or metastatic-free survival) were not reported. Biochemical recurrence-free survival at 5 years follow up was not significantly different between LDR-BT (78/85 (91.8%)) and RP (81/89 (91.0%)); P = 0.875; relative risk 0.92 (95% CI: 0.35 to 2.42).For severe adverse events reported at 6 months follow up, results favored LDR-BT for urinary incontinence (LDR-BT 0/85 (0.0%) versus RP 16/89 (18.0%); P < 0.001; relative risk 0) and favored RP for urinary irritation (LDR-BT 68/85 (80.0%) versus RP 4/89 (4.5%); P < 0.001; relative risk 17.80, 95% CI 6.79 to 46.66). The occurrence of urinary stricture did not significantly differ between the treatment groups (LDR-BT 2/85 (2.4%) versus RP 6/89 (6.7%); P = 0.221; relative risk 0.35, 95% CI: 0.07 to 1.68). Long-term information was not available.We did not identify significant differences of mean scores between treatment groups for patient-reported outcomes function and bother as well as generic health-related quality of life.

AUTHORS' CONCLUSIONS

Low-dose rate brachytherapy did not reduce biochemical recurrence-free survival versus radical prostatectomy at 5 years. For short-term severe adverse events, low-dose rate brachytherapy was significantly more favorable for urinary incontinence, but radical prostatectomy was significantly more favorable for urinary irritation. Evidence is based on one RCT with high risk of bias.

Comparison of high-dose proton radiotherapy and brachytherapy in localized prostate cancer: a case-matched analysis

PURPOSE

To report a case-matched analysis comparing high-dose external-beam radiation (EBRT) for prostate cancer delivered on Proton Radiation Oncology Group (PROG) 95-09, a randomized trial, with permanent prostate brachytherapy over the same era.

METHODS

From 1996 to 1999, 196 patients were accrued to the high-dose arm (79.2 Gray equivalent (GyE) using photons and protons) of PROG 95-09 at the Massachusetts General Hospital and Loma Linda University Medical Center. Entry criteria specified T1-2 and prostate-specific antigen ≤ 15 ng/mL. When Gleason score >7 was excluded, 177 men were left for case matching. At Massachusetts General Hospital, 203 similar patients were treated by a single brachytherapist from 1997 to 2002. Minimum follow-up was 3 years. Case matching, based on T stage, Gleason score, prostate-specific antigen, and age resulted in 141 matches (282 patients). Median follow-up was 8.6 and 7.4 years for EBRT and brachytherapy, respectively. The primary endpoint was biochemical failure (BF).

RESULTS

Using the Phoenix definition, the 8-year BF rates were 7.7% and 16.1% for EBRT and brachytherapy, respectively (p = 0.42). A stratified analysis was performed by risk group. In the EBRT group, 113 and 28 patients were low and intermediate risk, respectively. In the brachytherapy group, 118 and 23 were. When stratified by risk group, the BF rates were similar by either technique.

CONCLUSIONS

High-dose EBRT and brachytherapy result in similar BF rates for men with localized prostate cancer. Comparative quality-of-life and cost-effectiveness studies are warranted.

The effect of pro-qura case volume on post-implant prostate dosimetry

PURPOSE

To evaluate the effect of prostate brachytherapy case volume on postimplant dosimetric quality in Pro-Qura proctored programs.

METHODS AND MATERIALS

From August 1999 to December 2008, the computed tomography datasets for 6,600 prostate implants performed by 129 brachytherapists were submitted to Pro-Qura for dosimetric analysis. Brachytherapists were divided into three roughly equal-sized terciles based on total case volume. Postimplant computed tomography scans were obtained at a median of 30 days. Excellent target coverage was defined by a V100≥90% and D90≥100% minimum prescribed peripheral dose. To determine if the number of excellent implants improved with increasing case numbers, each brachytherapist's series of implants was bisected into early and late experience by a moveable critical point.

RESULTS

For the entire cohort, the mean V100 and D90 were 89.2% and 102.8%, respectively, with 47.7% of the implants scored as excellent. Brachytherapists in the highest-case tercile had a significantly greater fraction of excellent target coverage (57.9%) than did those in the two lower terciles (39.5% and 45.7%, p=0.015). Twenty-one (25.6%) of the 82 brachytherapists with sufficient case volume for dosimetric improvement analyses demonstrated quality improvement over time. Although there was no significant difference between prostate volume and seed strength, the number of seeds used was significantly greater in adequate implants.

CONCLUSIONS

The highest-volume brachytherapists were most likely to obtain excellent target coverage. We are encouraged that in general practice, nearly 48% of all implants were scored excellent. It is conceivable that with greater expert third-party involvement, an even greater percentage of cases with excellent target coverage will become reality.

A review of low-dose-rate prostate brachytherapy--techniques and outcomes

Prostate cancer is the most common male cancer in the United States and the second leading cause of male cancer death. The main therapeutic modalities for the treatment of prostate cancer are surgery, external beam radiation therapy, hormonal therapy, and brachytherapy. In recent years, brachytherapy has been increasingly utilized for the treatment of early-stage prostate cancer. Technological advances, including improvements in imaging, planning, and postimplant quality assessment by dosimetry have led to widespread use of brachytherapy. Outcomes for prostate brachytherapy have been shown to be equivalent, in selected patients, to those of other treatment modalities for prostate cancer, including radical prostatectomy and external beam radiation therapy. Further, prostate brachytherapy has quality-of-life benefits in comparison to these other treatment modalities, particularly in the domain of sexual function. This paper describes the history of low-dose rate brachytherapy; current techniques for brachytherapy implantation and postoperative dosimetric evaluation; recent outcomes studies; recent quality-of-life analyses; and current and future prostate brachytherapy developments, including open clinical trials. As research in prostate brachytherapy continues, it is likely that this modality will play an increasingly important role in the treatment of early-stage prostate cancer patients in the future.

Permanent prostate brachytherapy in prostate glands <20 cm(3)

PURPOSE

To investigate the dosimetry, treatment-related morbidity, and biochemical outcomes for brachytherapy in patients with prostate glands <20 cm(3).

METHODS AND MATERIALS

From November 1996 to October 2006, 104 patients with prostate glands <20 cm(3) underwent brachytherapy. Multiple prostate, urethral, and rectal dosimetric parameters were evaluated. Treatment-related urinary and rectal morbidity were assessed from patient questionnaires. Cause-specific survival, biochemical progression-free survival, and overall survival were recorded.

RESULTS

The median patient age, follow up, and pre-treatment ultrasound volume was 64 years, 5.0 years and 17.6cm(3), respectively. Median day 0 dosimetry was significant for the following: V100 98.5%, D90 126.1% and R100 <0.5% of prescription dose. The mean urethral and maximum urethral doses were 119.6% and 133.8% of prescription. The median time to International Prostate Symptom Score resolution was 4 months. There were no RTOG grade III or IV rectal complications. The cause-specific survival, biochemical progression-free survival, and overall survival rates were 100%, 92.5%, and 77.8% at 9 years. For biochemically disease-free patients, the median most recent postbrachytherapy PSA value was 0.02 ng/mL.

CONCLUSION

Our results demonstrate that brachytherapy for small prostate glands is highly effective, with an acceptable morbidity profile, excellent postimplant dosimetry, acceptable treatment-related morbidity, and favorable biochemical outcomes.

Postimplant rectal dosimetry is not dependent on 103Pd or 125I seed activity

PURPOSE

In this study, the effect of prostate brachytherapy seed activity on postimplant rectal dosimetry was evaluated in Pro-Qura (Prostate Brachytherapy Quality Assurance; Seattle, WA) proctored, community-based programs.

METHODS AND MATERIALS

Twenty-three hundred patients (1563 iodine-125 [(125)I] and 737 palladium-103 [(103)Pd]) from 78 brachytherapists with postimplant rectal dosimetry were identified. Seed activity was stratified into three tertiles for each isotope (≤0.300, 0.301-0.326, and >0.326 mCi/seed for (125)I and ≤1.330, 1.331-1.547, and >1.547 mCi/seed for (103)Pd). Postimplant dosimetry was performed in a standardized fashion. The rectum was contoured by outlining the outer rectal wall. The volume of the rectum receiving 100% of the prescription dose (R(100)) was calculated in cubic centimeters. The prostate V(100) and D(90) volumes were also calculated.

RESULTS

The mean prostate volume was 35.8 and 32.3 cm(3) for (125)I and (103)Pd. The median time to postimplant CT was 30 days. For (125)I, the V(100) increased from 91.0% to 93.7% (p=0.012) and the D(90) increased from 105.9% to 108.7% (p<0.001) for the lowest to the highest (125)I seed activities. In contrast, no significant changes in V(100) (p=0.751) or D(90) (p=0.200) were discerned when stratified by seed activity. For both isotopes, there was no correlation between seed activity and R(100), and R(100) was highest for the intermediate seed activities. Overall, the R(100) was lower for (103)Pd vs. (125)I (0.63 vs. 0.82 cm(3), p<0.001).

CONCLUSIONS

Within the confines of seed activities used in this study, higher activity seeds did not result in a deleterious effect on rectal dose. Higher activity seeds were associated with improved prostate dosimetry for (125)I, whereas (103)Pd dosimetry was not dependent on seed activity.

Dosimetric study of Cs-131, I-125, and Pd-103 seeds for permanent prostate brachytherapy

As a well-established single-modality approach for early-stage prostate cancer, transperineal interstitial permanent prostate brachytherapy (TIPPB) has gained increasing popularity due to its favorable clinical results. Currently, three isotopes, namely Cs-131, I-125, and Pd-103, are commercially available for TIPPB. This is the first study to systematically explore the dosimetric difference of these three isotopes for TIPPB. In total, 25 patients with T1-T2c prostate cancer previously implanted with I-125 seeds were randomly selected and replanned with Cs-131, I-125, and Pd-103 seeds to the prescription doses of 115, 145, and 125 Gy, respectively. The planning goals attempted were prostate V(p)100 approximately 95%, D(p)90 >or= 100%, and prostatic urethra D(u)10 <or= 150%. The dosimetric parameters, as well as the number of seeds and needles required, were analyzed and compared. The mean homogeneity index (HI) was 0.59, 0.56, and 0.46 for Cs-131, I-125, and Pd-103 plans, respectively. The average D(u)10 was 124.6%, 125.7%, and 129.7%, respectively. The average rectum V(r)100 was 0.19, 0.22, and 0.31 cc, respectively. In addition, the average number of seeds was 57.9, 63.0, and 63.7, and the average number of needles required was 31.6, 32.9, and 33.6 for Cs-131, I-125, and Pd-103 seeds, respectively. This study demonstrates that TIPPB, utilizing Cs-131 seeds, allows for better dose homogeneity, while providing comparable prostate coverage and sparing of the urethra and rectum, with a comparable number of, or fewer, seeds and needles required, compared to I-125 or Pd-103 seeds. Further biological and clinical studies associated with Cs-131 are warranted.

Relationship between Day 0 dosimetric parameters and biochemical relapse-free survival in patients treated with transperineal permanent prostate interstitial brachytherapy with (125)I seeds

OBJECTIVES

To determine the relationship between dosimetric parameters obtained on postimplantation Day 0 and biochemical relapse-free survival (bRFS) in patients treated with (125)I transperineal interstitial permanent prostate brachytherapy (TIPPB).

METHODS

Two-hundred twenty men with low-risk (n=155, 70.4%), low-volume intermediate-risk (n=63, 28.7%), or high-risk (n=2, 0.9%) prostate cancer were treated with TIPPB between December 2000 and June 2006. Seventy-four (33.6%) patients received short-term (3-6 months) androgen suppression therapy before TIPPB. The median followup for patients free of biochemical failure was of 37.9 months (range, 24.0-84.5 months).

RESULTS

The receiver operating characteristic (ROC) analysis established a best-fit cutoff value for the quantifiers D(90) and V(100) of 147Gy and 92%, respectively. The Kaplan-Meier analysis of bRFS at the cutoff value of D(90)=147Gy using the ASTRO, nadir+2, and combined (ASTRO and nadir+2) definitions showed a trend toward statistical significance for the ASTRO (p=0.076) and nadir+2 (p=0.064) definitions and a statistically significant correlation for the combined definition (p=0.033). The corresponding 7-year bRFS for the D(90) >147Gy and D(90) </=147Gy subsets using the ASTRO, nadir+2, and combined definitions were 96.5% vs. 89.7% (ASTRO, p=0.076); 93.7% vs. 70.5% (nadir+2, p=0.064); and 94.4 vs. 75.5% (combined, p=0.033). The V(100) (%) cutoff value of 92% predicted by the ROC analysis was not significant. Among other cutoff values, only D(90)=140Gy (p=0.050) and D(90)=160Gy (p=0.098) showed a trend toward statistical significance when the nadir+2 and the ASTRO definitions were used. The rest of dosimetric, tumor, and patient parameters did not show statistical correlation with bRFS in the Kaplan-Meier analysis.

CONCLUSIONS

The cutoff value of D(90)=147Gy obtained on postimplantation Day 0 showed a trend toward significant correlation with bRFS when the standard ASTRO and nadir+2 definitions were used and a weak but statistically significant correlation with bRFS as per the nonstandard combined definition in a series of patients with predominantly low-risk disease (70.4%) treated at high radiation doses (median D(90)=152.9Gy, median V(100)=92.5%).

Brachytherapy for prostate cancer: a systematic review

Low-dose rate brachytherapy has become a mainstream treatment option for men diagnosed with prostate cancer because of excellent long-term treatment outcomes in low-, intermediate-, and high-risk patients. To a great extend due to patient lead advocacy for minimally invasive treatment options, high-quality prostate implants have become widely available in the US, Europe, and Japan. High-dose-rate (HDR) afterloading brachytherapy in the management of localised prostate cancer has practical, physical, and biological advantages over low-dose-rate seed brachytherapy. There are no free live sources used, no risk of source loss, and since the implant is a temporary procedure following discharge no issues with regard to radioprotection use of existing facilities exist. Patients with localized prostate cancer may benefit from high-dose-rate brachytherapy, which may be used alone in certain circumstances or in combination with external-beam radiotherapy in other settings. The purpose of this paper is to present the essentials of brachytherapies techniques along with the most important studies that support their effectiveness in the treatment of prostate cancer.

Risk of Death From Prostate Cancer After Brachytherapy Alone or With Radiation, Androgen Suppression Therapy, or Both in Men With High-Risk Disease

Purpose

We estimated the risk of prostate cancer (PC) –specific mortality (PCSM) after brachytherapy alone or in conjunction with androgen suppression therapy (AST), external-beam radiation therapy (EBRT), or both in men with high-risk PC.

Patients and Methods

The study cohort comprised 1,342 men with a prostate-specific antigen level more than 20 ng/mL and clinical T3 or 4 and/or Gleason score 8 to 10 disease. Competing risks multivariable regression was performed to estimate the risk of PCSM in men treated with brachytherapy alone or with supplemental AST, EBRT, or both, adjusting for age, year of treatment, and known PC prognostic factors.

Results

Despite higher baseline probabilities of PCSM after a median follow-up of 5.1 years, there was a significant reduction in the risk of PCSM (adjusted hazard ratio [AHR], 0.32; 95% CI, 0.14 to 0.73; P = .006) in men treated with brachytherapy and both AST and EBRT as compared with neither. When compared with brachytherapy alone, a significant decrease in the risk of PCSM was not observed in men treated with either supplemental AST (AHR, 0.63; 95% CI, 0.27 to 1.47; P = .28) or EBRT (AHR, 0.57; 95% CI, 0.21 to 1.52; P = .26). There was a near-significant reduction (AHR, 0.53; 95% CI, 0.27 to 1.07; P = .079) in the risk of PCSM in men treated with tri- as compared with bimodality therapy.

Conclusion

Supplemental AST and EBRT but not either supplement compared with brachytherapy alone was associated with a decreased risk of PCSM in men with high-risk PC.