Median 5 Year Follow-up of 125Iodine Brachytherapy as Monotherapy in Men Aged ≤ 55 Years With Favorable Prostate Cancer

Brachytherapy for favorable prognostic prostate cancer in men up to 60 years of age: Long term follow-up

PURPOSE

Brachytherapy (BT) is a standard treatment for low- and favorable intermediate-risk prostate adenocarcinoma. Few studies have focused on young patients. We therefore evaluated long-term efficacy and toxicity of BT in patients aged ≤ 60 years with low- and favorable intermediate-risk prostate cancer.

MATERIALS AND METHODS

This retrospective study included patients aged ≤60 years with low- or favorable intermediate-risk prostate adenocarcinoma treated with iodine BT alone between 1999 and 2014 at the Institut de Cancérologie de Lorraine. Follow-up assessment included incidence of biochemical failure (BF) at 10 and 15 years after BT, as well as survival data and late toxicities.

RESULTS

A total of 177 patients of median age 56 years (54-58) were analyzed, with a median follow-up of 126 months (97-172). Incidence of BF at 10 and 15 years after BT was 5.4% and 11.7% respectively. PSA nadir (HR = 51.8 [95% CI 6.69-277], p < 0.001), age at treatment (HR = 1.78 [95% CI 1.19-2.65], p = 0.005) and prostate D90% (HR = 1.08 [95% CI 1.01-1.15], p < 0.021) were identified as predictive factors of BF. Overall survival at 10 and 15 years after BT was 92.8% and 84.4% respectively. Cancer-specific survival at 10 and 15 years after BT was 99.3% and 97.7% respectively. No major toxicity was recorded.

CONCLUSIONS

Exclusive BT is a long-term effective treatment for patients aged ≤ 60 years with low- or favorable intermediate-risk prostate adenocarcinoma.

Biochemical outcomes and toxicities in young men with prostate cancer after permanent iodine-125 seed implantation: Prospective cohort study in 6662 patients

PURPOSE

We evaluated the effect of age, <60 and ≥60 years, on biochemical outcomes and toxicities in patients with prostate cancer who underwent permanent seed implantation (PI) ± external beam radiation therapy ± hormone therapy in a national Japanese prospective cohort study (J-POPS).

METHODS AND MATERIALS

The safety and efficacy analyses included 6721 and 6662 patients, respectively. We categorized patients into two age groups: <60 (n = 716) and ≥60 (n = 6,005) years. We used propensity score matching (PSM) to estimate the marginal effect of age on biochemical freedom from failure (bFFF) using a Phoenix definition and Cox proportional hazard models.

RESULTS

The median followup period was 60.0 months. Without PSM, men <60 years demonstrated similar 5-year bFFF (96.3%) compared with men ≥60 years (95.6%; p = 0.576); percent positive biopsies, biologically effective dose, Gleason score, risk classification, and supplemental external beam radiation therapy (p <0.001, <0.001, <0.001, 0.008, and <0.001) were significantly associated with bFFF while age was not (p = 0.576). With PSM, bFFF was not significantly different between age groups (p = 0.664); however, men <60 years showed a significantly lower incidence of declining erectile function, grade ≥2 all urinary toxicities, urinary frequency/urgency, and rectal bleeding (p <0.001, 0.024, 0.031, and 0.010) than men ≥60 years.

CONCLUSIONS

After PI, men <60 years achieved a comparable 5-year biochemical control rate and showed a lower incidence of several toxicities compared to men ≥60 years. This suggests that PI should be an excellent treatment option for men <60 years with prostate cancer.

Case Report: Role of an Iodinated Rectal Hydrogel Spacer, SpaceOAR Vue™, in the Context of Low-Dose-Rate Prostate Brachytherapy, for Enhanced Post-Operative Contouring to Aid in Accurate Implant Evaluation and Dosimetry

We present a case series of 13 consecutive patients with prostate cancer treated with low-dose-rate (LDR) brachytherapy, utilizing SpaceOAR Vue™, the recent iodinated iteration of the SpaceOAR™ hydrogel rectal spacer. Low- and favorable intermediate-risk patients receiving monotherapy and unfavorable intermediate- and high-risk patients undergoing a brachytherapy boost were included. Permanent brachytherapy can result in subacute and late rectal toxicity, and precise contouring of the anterior rectal wall and posterior aspect of the prostate is essential for accurate dosimetry to confirm a safe implant. Clearly visible on non-contrast CT imaging, SpaceOAR Vue™ can substantially aid in post-implant contouring and analysis. Not previously described in the literature in the context of LDR brachytherapy, we demonstrate the added clinical benefit of placing a well-visualized rectal spacer.

Acute and late side-effects after low dose-rate brachytherapy for prostate cancer; incidence, management and technical considerations

PURPOSE

To review common reported side effects and complications after primary LDR-BT (monotherapy) and discuss some of the technical aspects that could impact the treatment outcomes.

METHODS AND MATERIALS

A literature search was undertaken using medical subject headings (MeSH) complemented by the authors' personal and institutional expertise.

RESULTS

The reported incidence of acute and late grade 2 or above urinary, bowel and sexual side effects is very variable across the literature. The learning curve and the implant quality have a clear impact on the toxicity outcomes. Being aware of some of the technical challenges encountered during the procedure and ways to mitigate them could decrease the incidence of side effects. Careful planning of seed placement and seed deposition allow sparing of the organs at risk and a lower incidence of urinary and gastro-intestinal toxicity.

CONCLUSIONS

Low dose-rate brachytherapy remains a standard monotherapy treatment in the setting of favorable-risk prostate cancer. High disease control and low long-term toxicities are achievable in expert hands with a good technique.

Long-term oncological and functional follow-up in low-dose-rate brachytherapy for prostate cancer: results from the prospective nationwide Swiss registry

OBJECTIVE

To evaluate the long-term oncological, functional and toxicity outcomes of low-dose-rate brachytherapy (LDR-BT) in relation to risk factors and radiation dose in a prospective multicentre cohort.

PATIENTS AND METHODS

Data of patients from 12 Swiss centres undergoing LDR-BT from September 2004 to March 2018 were prospectively collected. Patients with a follow-up of ≥3 months were analysed. Functional and oncological outcomes were assessed at ~6 weeks, 6 and 12 months after implantation and annually thereafter. LDR-BT was performed with ¹²⁵ I seeds. Dosimetry was done 6 weeks after implantation based on the European Society for Radiotherapy and Oncology recommendations. The Kaplan-Meier method was used for biochemical recurrence-free survival (BRFS). A prostate-specific antigen (PSA) rise above the PSA nadir + 2 was defined as biochemical failure. Functional outcomes were assessed by urodynamic measurement parameters and questionnaires.

RESULTS

Of 1580 patients in the database, 1291 (81.7%) were evaluable for therapy outcome. The median (range) follow-up was 37.1 (3.0-141.6) months. Better BRFS was found for Gleason score ≤3+4 (P = 0.03, log-rank test) and initial PSA level of <10 ng/mL (P < 0.001). D'Amico Risk groups were significantly associated with BRFS (P < 0.001), with a hazard ratio of 2.38 for intermediate- and high-risk patients vs low-risk patients. The radiation dose covering 90% of the prostate volume (D90) after 6 weeks was significantly lower in patients with recurrence. Functional outcomes returned close to baseline levels after 2-3 years. A major limitation of these findings is a substantial loss to follow-up.

CONCLUSION

Our results are in line with other studies showing that LDR-BT is associated with good oncological outcomes together with good functional results.

Long-term oncological outcomes and toxicity in 597 men aged ≤60 years at time of low-dose-rate brachytherapy for localised prostate cancer

OBJECTIVES

To report oncological and functional outcomes of men treated with low-dose-rate (LDR) prostate brachytherapy aged ≤60 years at time of treatment.

PATIENTS AND METHODS

Of 3262 patients treated with LDR brachytherapy at our centre up to June 2016, we retrospectively identified 597 patients aged ≤60 years at treatment with ≥3-years post-implantation follow-up and four prostate-specific antigen (PSA) measurements, of which one was at baseline. Overall survival (OS), prostate cancer-specific survival (PCSS) and relapse free survival (RFS) were analysed together with prospectively collected physician-reported adverse events and patient-reported symptom scores.

RESULTS

The median (range) age was 57 (44-60) years, follow-up was 8.9 (1.5-17.2) years, and PSA follow-up 5.9 (0.8-15) years. Low-, intermediate- and high-risk disease represented 53%, 37% and 10% of the patients, respectively. At 10 years after implantation OS and PCSS were 98% and 99% for low-risk, 99% and 100% for intermediate-risk, and 93% and 95% for high-risk disease, respectively. At 10 years after implantation RFS, using the PSA level nadir plus 2 ng/mL definition, was 95%, 90% and 87% for low-, intermediate-, and high-risk disease, respectively. Urinary stricture was the most common genitourinary adverse event occurring in 19 patients (3.2%). At 5 years after implantation erectile function was preserved in 75% of the patients who were potent before treatment.

CONCLUSION

LDR brachytherapy is an effective treatment with long-term control of prostate cancer in men aged ≤60 years at time of treatment. It was associated with low rates of treatment-related toxicity and can be considered a first-line treatment for prostate cancer in this patient group.

125I brachytherapy in younger prostate cancer patients : Outcomes in low- and intermediate-risk disease

PURPOSE

To evaluate local recurrence in younger men treated with low-dose-rate (LDR) ¹²⁵I brachytherapy (BT) for localized prostate cancer.

PATIENTS AND METHODS

A total of 192 patients (≤65-years-old) were treated with LDR ¹²⁵I-BT ± hormone therapy. Local failure was defined as any prostate-specific antigen (PSA) rise leading to salvage treatment or biochemical failure according to the Phoenix definition. A bounce was defined as a rise in the nadir of ≥0.2 ng/mL followed by spontaneous return. Proportions were compared using Fisher's exact tests; continuous variables using the unpaired t-test or its non-parametric equivalent. Cox proportional hazards models were applied for multivariable survival analysis.

RESULTS

Median follow-up was 66 months. The 5‑year local recurrence-free survival was 96.1%. Biopsy-proven local recurrence developed in 13 patients, 4 had a Phoenix-defined recurrence at the last follow-up. Androgen deprivation therapy was started in 1 patient without proven recurrence. Univariable risk factors for local recurrence were: at least 50% positive biopsies, intermediate risk, treatment with neoadjuvant hormone therapy, low preimplantation volume receiving 100% of the prescribed dose, and no bounce development. Hormone-naïve patients not attaining a PSA value <0.5 ng/mL during follow-up also had a higher risk of local recurrences. Cox regression demonstrated that the variables "at least 50% positive biopsies" and "bounce" significantly impacted local failure (hazard ratio, HR 1.02 and 11.59, respectively). A bounce developed in 70 patients (36%). Younger patients and those treated with a lower activity per volume had a higher chance of developing a bounce in the Cox model (HR 0.99 and 0.04, respectively).

CONCLUSION

For younger men, LDR BT is a valid primary curative treatment option in low-risk and is to consider in intermediate-risk localized prostate cancer.

ACR appropriateness criteria: Permanent source brachytherapy for prostate cancer

PURPOSE

To provide updated American College of Radiology (ACR) appropriateness criteria for transrectal ultrasound-guided transperineal interstitial permanent source brachytherapy.

METHODS AND MATERIALS

The ACR appropriateness criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

RESULTS

Permanent prostate brachytherapy (PPB) is a treatment option for appropriately selected patients with localized prostate cancer with low to very high risk disease. PPB monotherapy remains an appropriate and effective curative treatment for low-risk prostate cancer patients demonstrating excellent long-term cancer control and acceptable morbidity. PPB monotherapy can be considered for select intermediate-risk patients with multiparametric MRI useful in evaluation of such patients. High-risk patients treated with PPB should receive supplemental external beam radiotherapy (EBRT) along with androgen deprivation. Similarly, patients with involved pelvic lymph nodes may also be considered for such combined treatment but reported long-term outcomes are limited. Computed tomography-based postimplant dosimetry completed within 60 days of PPB is essential for quality assurance. PPB may be considered for treatment of local recurrence after EBRT but is associated with an increased risk of toxicity.

CONCLUSIONS

Updated appropriateness criteria for patient evaluation, selection, treatment, and postimplant dosimetry are given. These criteria are intended to be advisory only with the final responsibility for patient care residing with the treating clinicians.

Urethral Strictures and Stenoses Caused by Prostate Therapy

The number of patients with prostate cancer and benign prostatic hyperplasia is on the rise. As a result, the volume of prostate treatment and treatment-related complications is also increasing. Urethral strictures and stenoses are relatively common complications that require individualized management based on the length and location of the obstruction, and the patient's overall health, and goals of care. In general, less invasive options such as dilation and urethrotomy are preferred as first-line therapy, followed by more invasive substitution, flap, and anastomotic urethroplasty.

Comparative study of late rectal toxicity in prostate cancer patients treated with low-dose-rate brachytherapy: With or without supplemental external beam radiotherapy

PURPOSE

Supplemental external beam radiation therapy (sEBRT) is often prescribed in men undergoing low-dose-rate (LDR) brachytherapy. A population of patients was analyzed to assess the effect of sEBRT on late rectal toxicity. It was hypothesized that sEBRT + LDR would be associated with a higher risk of late rectal toxicity.

METHODS AND MATERIALS

This retrospective cohort study examined LDR brachytherapy patients, treated with or without sEBRT, with a minimum of 5-year followup. Longitudinal assessments were evaluated using the computerized patient record system. The Kaplan-Meier method was used for analysis.

RESULTS

Median followup was 7.5 years for 245 patients from 2004 to 2007. sEBRT was administered to 33.5%. Followup beyond 5 years was available for 89%. Overall rates of Grade ≥2 and ≥3 rectal toxicities were 6.9% and 2.9%, respectively. The risk of Grade ≥2 rectal toxicity was 2.8-fold higher for patients receiving sEBRT (95% confidence interval: 1.1-7.2; p = 0.02). The risk of Grade ≥3 rectal toxicity was 11.9-fold higher for patients who received sEBRT (1.5-97.4, 95% confidence interval; p = 0.003). Six of seven patients with a Grade ≥3 rectal toxicity received sEBRT, including one who required an abdominoperineal resection. Median post-LDR D90, V150, V200, and R100 values were 103.3%, 59.4%, 30.1%, and 0.5 cc.

CONCLUSIONS

In a cohort of LDR brachytherapy patients with high rates of followup, sEBRT + LDR was associated with significantly higher risk of Grade ≥2 and ≥3 late rectal toxicity. This analysis supports previous findings and maintains concern about the supplemental use of external beam radiation therapy with LDR brachytherapy while its benefit for tumor control has yet to be prospectively validated.

Time Course and Accumulated Risk of Severe Urinary Adverse Events After High- Versus Low-Dose-Rate Prostate Brachytherapy With or Without External Beam Radiation Therapy

PURPOSE

Severe urinary adverse events (UAEs) include surgical treatment of urethral stricture, urinary incontinence, and radiation cystitis. We compared the incidence of grade 3 UAEs, according to the Common Terminology Criteria for Adverse Events, after low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy, as well as after LDR plus external beam radiation therapy (EBRT) and HDR plus EBRT.

METHODS AND MATERIALS

Men aged >65 years with nonmetastatic prostate cancer were identified from the Surveillance, Epidemiology, and End Results-Medicare database who were treated with LDR (n=12,801), HDR (n=685), LDR plus EBRT (n=8518), or HDR plus EBRT (n=2392). The populations were balanced by propensity weighting, and the Kaplan-Meier incidence of severe UAEs was compared. Propensity-weighted Cox proportional hazards models were used to compare the adjusted hazard of UAEs. These UAEs were compared with those in a cohort of men not treated for prostate cancer.

RESULTS

Median follow-up was 4.3 years. At 8 years, the propensity-weighted cumulative UAE incidence was highest after HDR plus EBRT (26.6% [95% confidence interval, 23.8%-29.7%]) and lowest after LDR (15.7% [95% confidence interval, 14.8%-16.6%]). The absolute excess risk over nontreated controls at 8 years was 1.9%, 3.8%, 8.4%, and 12.9% for LDR, HDR, LDR plus EBRT, and HDR plus EBRT, respectively. These represent numbers needed to harm of 53, 26, 12, and 8 persons, respectively. The additional risk of development of a UAE related to treatment for LDR, LDR plus EBRT, and HDR plus EBRT was greatest within the 2 years after treatment and then continued to decline over time. Beyond 4 years, the risk of development of a new severe UAE matched the baseline risk of the control population for all treatments.

CONCLUSIONS

Toxicity differences were observed between LDR and HDR, but the differences did not meet statistical significance. However, combination radiation therapy (either HDR plus EBRT or LDR plus EBRT) increases the risk of severe UAEs compared with HDR alone or LDR alone. The highest increased risk of urinary toxicity occurs within the 2 years after therapy and then declines to an approximately 1% increase in incidence per year.

The Patient Burden of Bladder Outlet Obstruction after Prostate Cancer Treatment

PURPOSE

Bladder outlet obstruction after prostate cancer therapy imposes a significant burden on health and quality of life in men. Our objective was to describe the burden of bladder outlet obstruction after prostate cancer therapy by detailing the type of procedures performed and how often those procedures were repeated in men with recurrent bladder outlet obstruction.

MATERIALS AND METHODS

Using SEER (Surveillance, Epidemiology and End Results)-Medicare linked data from 1992 to 2007 with followup through 2009 we identified 12,676 men who underwent at least 1 bladder outlet obstruction procedure after prostate cancer therapy, including external beam radiotherapy in 3,994, brachytherapy in 1,485, brachytherapy plus external beam radiotherapy in 1,847, radical prostatectomy in 4,736, radical prostatectomy plus external beam radiotherapy in 369 and cryotherapy in 245. Histogram, incidence rates and Cox proportional hazards models with repeat events analysis were done to describe the burden of repeat bladder outlet obstruction treatments stratified by prostate cancer therapy type. We describe the type of bladder outlet obstruction surgery grouped by level of invasiveness.

RESULTS

At a median followup of 8.8 years 44.6% of men underwent 2 or more bladder outlet obstruction procedures. Compared to men who underwent radical prostatectomy those treated with brachytherapy and brachytherapy plus external beam radiotherapy were at increased adjusted risk for repeat bladder outlet obstruction treatment (HR 1.2 and 1.32, respectively, each p <0.05). After stricture incision the men treated with radical prostatectomy or radical prostatectomy plus external beam radiotherapy were most likely to undergo dilation at a rate of 34.7% to 35.0%. Stricture resection/ablation was more common after brachytherapy, external beam radiotherapy or brachytherapy plus external beam radiotherapy at a rate of 28.9% to 41.2%.

CONCLUSIONS

Almost half of the men with bladder outlet obstruction after prostate cancer therapy undergo more than 1 procedure. Furthermore men with bladder outlet obstruction after radiotherapy undergo more invasive endoscopic therapies and are at higher risk for multiple treatments than men with bladder outlet obstruction after radical prostatectomy.

Comparison of permanent (125)I seeds implants with two different techniques in 500 cases of prostate cancer

Purpose

To perform a comparative study of 500 consecutive ¹²⁵I seeds implants for intracapsular prostate carcinoma with two techniques differing in terms of both strand implantation and planning.

Material and methods

From 2002 to 2007 we performed 250 implants with fixed stranded seeds (RapidStrand™) and a preplanning system and from 2007 to 2010, 250 with real-time and ProLink™ system. Mean age was 68 and 66, respectively, median PSA (prostate-specific antigen) 7.3 and 7.2, stage T1-T2a in 98% and 94%, and Gleason ≤ 6 in 96% and 86%. Low risk cases were 81% and 71%. The prescribed dose was 145 Gy to the prostate volume, or 108 Gy plus EBRT 46 Gy in some intermediate risk cases. Hormonal treatment was given to 42% and 28%.

Results

Median follow-up was 48 and 47 months, respectively, 14 patients in the first group and 7 patients in the second developed biochemical failure (BF). Actuarial biochemical relapse-free survival (bRFS) at 5 years increased from 90.2% to 97.2% (low risk from 91.3% to 97.2%, intermediate risk from 84.2% to 97.1%). Biochemical failure was independent of hormone treatment. Rectal complications were G1-2 in 1.2% and 5.2%, respectively. A urinary catheter was necessary in 6.9% and 9.6%, and urethral resection in 1.9% and 4.4%. Genitourinary toxicity was G1-2 in 4.6% and 12%, G3-4 in 1.9% and 4.8%. An assessment of mean D₉₀ in a sample of patients showed that the dosimetry in postoperative planning based on CT improved from a mean D₉₀ of 143 Gy to 157 Gy.

Conclusions

The outcome of patients with low risk prostate carcinoma treated with ¹²⁵I seed is very good with low complications rate. The real-time approach in our hands achieved a more precise seed implantation, better dosimetry, and a statistically non-significant better biochemical control. We have made this our standard technique.

A review of rectal toxicity following permanent low dose-rate prostate brachytherapy and the potential value of biodegradable rectal spacers

Permanent radioactive seed implantation provides highly effective treatment for prostate cancer that typically includes multidisciplinary collaboration between urologists and radiation oncologists. Low dose-rate (LDR) prostate brachytherapy offers excellent tumor control rates and has equivalent rates of rectal toxicity when compared with external beam radiotherapy. Owing to its proximity to the anterior rectal wall, a small portion of the rectum is often exposed to high doses of ionizing radiation from this procedure. Although rare, some patients develop transfusion-dependent rectal bleeding, ulcers or fistulas. These complications occasionally require permanent colostomy and thus can significantly impact a patient's quality of life. Aside from proper technique, a promising strategy has emerged that can help avoid these complications. By injecting biodegradable materials behind Denonviller's fascia, brachytherpists can increase the distance between the rectum and the radioactive sources to significantly decrease the rectal dose. This review summarizes the progress in this area and its applicability for use in combination with permanent LDR brachytherapy.

Effect of aging and long-term erectile function after iodine-125 prostate brachytherapy

PURPOSE

To evaluate long-term erectile function (EF) in men treated with iodine-125 prostate brachytherapy (PB) and to determine factors predictive for erectile dysfunction (ED), including natural decline because of aging.

METHODS

Two thousand nine hundred twenty-nine patients (implanted July 1989-June 2012) with baseline EF and greater than 10-month followup (FU) are included. About 78.9% had full and 7.9% had partial EF at baseline. EF was assessed on a physician-reported three-point scale. Poisson regression with generalized estimating equations was used to assess predictors of ED and Kaplan-Meier curves time to ED. The effect of aging was calculated from the declining rate of baseline EF seen in sequential 5-year age cohorts and from the Massachusetts Male Aging Study.

RESULTS

The median age was 66 years and median FU 3.5 years (maximum 14 years). About 1142 patients had more than 5 years of FU, and 43% had received 6 months of androgen deprivation therapy (ADT). Significant drop in EF was seen at 6 weeks after PB, with gradual decline thereafter. EF preservation at 5 years for age younger than 55, 56-59, 60-64, 65-69, and 70 year and older was 82%, 73%, 58%, 39%, and 23%, respectively. Comparisons of the 5-year age-related and treatment-related EF decline show that 50% of the long-term EF decline is related to aging. On univariate and multivariate analyses, age at implant, length of FU, hypertension, diabetes, and use of ADT (all p < 0.01) were significant predictors of ED.

CONCLUSION

More than 80% of young men have EF preserved 5 years after PB. Age, ADT, history of hypertension, and the natural decline in EF have negative impact on long-term EF after PB.

SIU/ICUD Consultation on Urethral Strictures: Posterior urethral stenosis after treatment of prostate cancer

Posterior urethral stenosis can result from radical prostatectomy in approximately 5%-10% of patients (range 1.4%-29%). Similarly, 4%-9% of men after brachytherapy and 1%-13% after external beam radiotherapy will develop stenosis. The rate will be greater after combination therapy and can exceed 40% after salvage radical prostatectomy. Although postradical prostatectomy stenoses mostly develop within 2 years, postradiotherapy stenoses take longer to appear. Many result in storage and voiding symptoms and can be associated with incontinence. The evaluation consists of a workup similar to that for lower urinary tract symptoms, with additional testing to rule out recurrent or persistent prostate cancer. Treatment is usually initiated with an endoscopic approach commonly involving dilation, visual urethrotomy with or without laser treatment, and, possibly, UroLume stent placement. Open surgical urethroplasty has been reported, as well as urinary diversion for recalcitrant stenosis. A proposed algorithm illustrating a graded approach has been provided.

Favourable long-term outcomes with brachytherapy-based regimens in men ≤60 years with clinically localized prostate cancer

OBJECTIVE

To report long-term outcomes of men ≤60 years treated with brachytherapy (BT) for low- and intermediate-risk prostate cancer.

PATIENTS AND METHODS

Of 1655 patients treated with BT for clinically localized prostate cancer between January 1998 and May 2008 at Memorial Sloan-Kettering Cancer Center, 236 patients with National Comprehensive Cancer Network low- (n = 178) or intermediate-risk (n = 58) prostate cancer were ≤60 years old with a 3-year minimum follow-up, and represent the subjects of this report. Brachytherapy was given either as monotherapy (n = 169) or with external beam radiation therapy (EBRT; n = 67). Forty-four patients (19%) received neoadjuvant cytoreductive hormone therapy. The 'nadir+2' definition was used for prostate-specific antigen (PSA) recurrence. Common Terminology Criteria for Acute Events (CTCAE) v 3.0 was used to grade genitourinary (GU) and gastrointestinal (GI) toxicity. Potency was defined as the ability to obtain an erection suitable for intercourse or an International Index of Erectile Function score ≥ 22. The Kaplan-Meier method and Cox regression were used for statistical analysis. The median follow-up was 83 months.

RESULTS

The 8-year PSA relapse-free survival (RFS), cancer-specific and overall survival rates for the entire cohort were 96, 99 and 96%, respectively. For patients with low-risk disease, the 8-year PSA RFS rate was 97% and for intermediate-risk patients it was 94% (P = 0.34). There was no difference in PSA RFS between BT alone and combined therapy (P = 0.17). Late grade ≥ 2 GU and GI toxicity was 14 and 3%, respectively. Of 150 patients potent before treatment, 76 (51%) were potent at last follow-up, with 50/76 (66%) using no medication. There was no significant difference in post-treatment potency between BT alone and BT with EBRT (P = 0.74).

CONCLUSIONS

Brachytherapy provides patients aged ≤ 60 years with low- and intermediate-risk prostate cancer with excellent outcomes and has a low risk of significant long-term GU or GI morbidity. Erectile function is preserved in >50% of patients and the majority do not require erectile dysfunction medication.

Canadian prostate brachytherapy in 2012

Prostate brachytherapy can be used as a monotherapy for low- and intermediate-risk patients or in combination with external beam radiation therapy (EBRT) as a form of dose escalation for selected intermediate- and high-risk patients. Prostate brachytherapy with either permanent implants (low dose rate [LDR]) or temporary implants (high dose rate [HDR]) is emerging as the most effective radiation treatment for prostate cancer. Several large Canadian brachytherapy programs were established in the mid- to late-1990s. Prostate brachytherapy is offered in British Columbia, Alberta, Manitoba, Ontario, Quebec and New Brunswick. We anticipate the need for brachytherapy services in Canada will significantly increase in the near future. In this review, we summarize brachytherapy programs across Canada, contemporary eligibility criteria for the procedure, toxicity and prostate-specific antigen recurrence free survival (PRFS), as published from Canadian institutions for both LDR and HDR brachytherapy.

Interpreting a rising prostate-specific antigen after brachytherapy for prostate cancer

The aim of the present study was to review the English language literature on the topic of prostate-specific antigen bounce after brachytherapy and present a summary of the current knowledge. Although ultimately prostate-specific antigen is a reliable measure of success after prostate brachytherapy, it can be very misleading in the first 3 years because of the frequency with which temporary benign rises in prostate-specific antigen occur. We have reviewed the English language literature on the topic of prostate-specific antigen bounce under the following headings: prostate neoplasms, brachytherapy, biochemical definition of prostate-specific antigen failure, "benign prostate-specific antigen bounce" and "prostate-specific antigen spike". We included brachytherapy delivered as either low dose rate or high dose rate, and either as monotherapy or as a boost combined with external beam radiotherapy. A benign self-limited rise in prostate-specific antigen after prostate brachytherapy is seen in an average of 35% of patients, but increases in frequency with younger age. In patients aged less than 55 years, it is observed in up to 68%. Other factors, such as sexual activity, dose, prostate volume and the use of high dose rate versus low dose rate have been implicated in affecting the frequency of the benign bounce. Benign increases in prostate-specific antigen are frequent after prostate brachytherapy. It is important to recognize and correctly diagnose this phenomenon in order to avoid unnecessary salvage treatment.