Biochemical relapse-free survival in 400 patients treated with I-125 prostate brachytherapy: the Guildford experience

Defining Biochemical Cure After Low Dose Rate Prostate Brachytherapy: External Validation of 4-year Prostate-specific Antigen Nadir as a Predictor of 10- and 15-year Disease-free Survival

AIMS

To externally validate a proposed biochemical definition of cure following low dose rate (LDR) brachytherapy for prostate cancer - 4-year post-implant prostate-specific antigen (PSA) ≤0.2 ng/ml - in a UK population, and report the long-term (10- and 15-year) outcomes for patients stratified by National Comprehensive Cancer Network (NCCN) risk groups, through analysis of a large, prospectively collected, single-centre database.

MATERIALS AND METHODS

All patients treated with LDR brachytherapy for prostate cancer at a single UK centre between 2001 and November 2020 (n = 1142) were eligible; 632 patients met the inclusion criteria for the analysis. The primary end point was disease-free survival (DFS), defined as freedom from clinical, radiological or PSA progression requiring androgen deprivation therapy. Four-year PSA was categorised as ≤0.2, >0.2 to ≤0.5, >0.5 to ≤1.0 and >1.0 ng/ml. Kaplan-Meier analysis to 15 years was undertaken for each group, and sensitivity and specificity of 4-year PSA as a surrogate for long-term cure were calculated. Kaplan-Meier analysis to 15 years was repeated, stratifying patients by NCCN risk groups.

RESULTS

The median cohort age was 63 years; the median follow-up was 9.1 years (range 3.5-18.7). In total, 248 patients were available for analysis at year 10, 46 at year 15. Sixty-four patients (10.1%) relapsed during the study period. The 10-year DFS for 4-year PSA categories ≤0.2, >0.2 to ≤0.5, >0.5 to ≤1.0 and >1.0 ng/ml (95% confidence intervals) were 97.5% (95.4-99.6), 89.0% (82.4-96.1), 81.5% (70.5-94.2) and 41.8% (29.7-58.9), respectively. The 10-year DFS results for NCCN low, favourable-intermediate and unfavourable-intermediate risk disease were 93.1% (89.6-96.7), 92.1% (87.6-96.9) and 75.9% (67.8-84.9), respectively.

CONCLUSIONS

Patients with 4-year PSA ≤0.2 ng/ml may be considered cured, and could be discharged to general practitioner follow-up. LDR brachytherapy is an excellent treatment option for patients with low and favourable-intermediate risk prostate cancer, but those with unfavourable-intermediate risk disease should be considered for treatment intensification strategies.

A retrospective analysis after low-dose-rate prostate brachytherapy with permanent 125I seed implant: clinical and dosimetric results in 70 patients

Aims and background

To evaluate the biochemical disease-free survival (bDFS) rate after 125I permanent-implant prostate brachytherapy.

Methods

Patients with a diagnosis of prostate adenocarcinoma and adequate PSA follow-up were selected for this retrospective study. Brachytherapy with permanent 125I seeds was performed as monotherapy, with a prescribed dose of 145 Gy to the prostate. Patients were stratified into recurrence risk groups according to the National Comprehensive Cancer Network (NCCN) guidelines. Biochemical failure was defined using the American Society of Therapeutic Radiology and Oncology (ASTRO) guidelines. The post-implant D90 (defined as the minimum dose covering 90% of the prostate) was obtained for each patient. Two cutoff points were used to test the correlation between D90 and bDFS results: 130 Gy and 140 Gy. bDFS was calculated from the implant date to the date of biochemical recurrence. Univariate and multivariate analysis were performed using the SPSS software and included clinical stage, pretreatment PSA, Gleason score (GS), androgen deprivation therapy, D90, and risk groups. In the univariate analysis we used a cutoff point of 5.89 ng/mL for PSA and 5 for GS.

Results

From June 2003 to April 2007, 70 patients were analyzed. The patients' distribution into recurrence risk groups was as follows: 39 patients (56%) in the low-risk group, 23 patients (33%) in the intermediate-risk group, and 8 patients (11%) in the high-risk group. At a median follow-up of 47 months (range, 19–70 months) bDFS was 88.4%, with a global actuarial 5-year bDFS of 86%. Disease-related factors including initial PSA level, GS and risk group were significant predictors of biochemical failure (P = 0.01, P = 0.01, P = 0.006, respectively). In multivariate analysis, risk group (P = 0.005) and GS (P = 0.03) were statistically significant.

Conclusion

Our data are in agreement with those in the literature and, despite the short follow-up, confirm the advantage of brachytherapy for patients at low and intermediate risk of recurrence.

Prostate brachytherapy in Ghana: our initial experience

Purpose

This study presents the experience of a brachytherapy team in Ghana with a focus on technology transfer and outcome. The team was initially proctored by experienced physicians from Europe and South Africa.

Material and methods

A total of 90 consecutive patients underwent either brachytherapy alone or brachytherapy in combination with external beam radiotherapy for prostate carcinoma between July 2008 and February 2014 at Korle Bu Teaching Hospital, Accra, Ghana. Patients were classified as low-risk, intermediate, and high-risk according to the National Comprehensive Cancer Network (NCCN) criteria. All low-risk and some intermediate risk group patients were treated with seed implantation alone. Some intermediate and all high-risk group patients received brachytherapy combined with external beam radiotherapy.

Results

The median patient age was 64.0 years (range 46-78 years). The median follow-up was 58 months (range 18-74 months). Twelve patients experienced biochemical failure including one patient who had evidence of metastatic disease and died of prostate cancer. Freedom from biochemical failure rates for low, intermediate, and high-risk cases were 95.4%, 90.9%, and 70.8%, respectively. Clinical parameters predictive of biochemical outcome included: clinical stage, Gleason score, and risk group. Pre-treatment prostate specific antigen (PSA) was not a statistically significant predictor of biochemical failure. Sixty-nine patients (76.6%) experienced grade 1 urinary symptoms in the form of frequency, urgency, and poor stream. These symptoms were mostly self-limiting. Four patients needed catheterization for urinary retention (grade 2). One patient developed a recto urethral fistula (grade 3) following banding for hemorrhoids.

Conclusions

Our results compare favorably with those reported by other institutions with more extensive experience. We believe therefore that, interstitial permanent brachytherapy can be safely and effectively performed in a resource challenged environment if adequate training and proctoring is provided.

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.

A prospective, randomized pilot study evaluating the effects of metformin and lifestyle intervention on patients with prostate cancer receiving androgen deprivation therapy

Study Type - Therapy (RCT) Level of Evidence 1b What's known on the subject? and What does the study add? Men with prostate cancer have higher rates of non-cancer mortality and CV morbidity and some of that excess risk has been attributed to the treatment they receive. ADT is an established treatment option for men with locally-advanced and metastatic prostate cancer and, although it has been shown to confer a disease-free survival advantage, it has also been associated with an increased incidence of CV disease and the metabolic syndrome (characterized by a cluster of CV risk factors, including insulin resistance). The benefits of the insulin sensitizer metformin and lifestyle intervention for reducing the incidence of metabolic syndrome have been shown in patients with impaired glucose tolerance. At the time of writing, the present study is the first to use metformin and lifestyle intervention in men with prostate cancer with the aim of reducing the risk of developing ADT-related CV morbidity and the metabolic syndrome. The study shows that lifestyle changes and metformin may indeed reduce the complications of androgen suppression in these men. Although further investigations are needed to establish which of the two interventions may be most beneficial, the favourable effects of a combination of these interventions on patients' quality of life and the potential for improved overall survival are of clinical significance.

OBJECTIVE

To investigate the effects of metformin and lifestyle changes on the development of androgen deprivation therapy (ADT)-related metabolic syndrome.

PATIENTS AND METHODS

Men with prostate cancer due to receive ADT were recruited and randomized. Controls received ADT alone. Men in the intervention arm received ADT with 6 months of metformin, a low glycaemic index diet and an exercise programme. All patients were investigated pretreatment and at 6 months for the metabolic syndrome, as well as for related biochemical and physical parameters.

RESULTS

In total, 40 men were recruited and randomized (20 to each arm). After 6 months, significant improvements in abdominal girth (P= 0.05), weight (P < 0.001), body mass index (P < 0.001) and systolic blood pressure (P= 0.01) were seen in the intervention arm compared to controls. Biochemical markers of insulin resistance did not differ significantly.

CONCLUSIONS

The present study shows the potential benefits of metformin and lifestyle changes in ADT-treated men. Further studies will aim to determine which intervention is most important, and may show that overall survival can be improved.

Does the outcome of prostate cancer patients with large prostates differ from small prostate size in permanent seed, low dose-rate brachytherapy?

OBJECTIVE

Brachytherapy has good results in the treatment of early prostate cancer (PC). The procedure is challenging in large prostates, and the optimal prostate volume for brachytherapy was previously defined as ≤40 ml. This study analysed the outcome of PC patients with small (group A) and large (group B) prostate volume in prospective data.

MATERIAL AND METHODS

The material consisted of 535 consecutive patients treated with brachytherapy in Kuopio University Hospital. The mean follow-up time was nearly 6 years. Prostate-specific antigen (PSA) failure was defined as PSA rising ≥2.0 μg/l above nadir. A PSA bounce was defined as a rise in PSA of ≥0.2 μg/l. The causes of death were recorded.

RESULTS

A bounce was recorded more frequently in group A (30%) than in group B (18%) (p = 0.006). A bounce correlated with young age predicted a favourable outcome in both groups. PSA failure rate was similar in both groups: 13% and 12% in groups A and B, respectively. Post-treatment PSA ≤0.5 μg/l was the only independent prognostic factor associated with PSA failure in both groups (p < 0.0001, both groups). PC survival was 98.4% in both groups. Overall survival was 91% and 94% in groups A and B, respectively (p = not significant).

CONCLUSIONS

There were no differences between the PC patients with small and large prostate volumes treated with brachytherapy with respect to PSA failure rate, PC survival or overall survival. All patients, independent of prostate size, are potential candidates for brachytherapy.

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.

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.

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.