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

Erectile function preservation after radiotherapy using a dose-optimization approach on sexual structures for localized prostate cancer

PURPOSE

Erectile function preservation is an important quality of life factor in patients treated for prostate cancer. A dose-optimization approach on sexual structures was developed and evaluated to limit erectile dysfunction after radiotherapy.

MATERIALS AND METHODS

Twenty-three men with localized prostate cancer and no erectile dysfunction were enrolled in the study. All patients received a prescription dose between 76 and 78Gy. Computed tomography/magnetic resonance image registration was used to delineate the prostatic volume and the sexual structures: internal pudendal arteries (IPA), penile bulb and corpus cavernosum. Erectile function was evaluated using the 5-items International Index of Erectile Function (IIEF-5) score every 6 months during the 2 years after radiotherapy and once a year afterwards. No erectile dysfunction, mild erectile dysfunction and severe erectile dysfunction were defined if the IIEF-5 scores were 20-25, 17-19 and < 17, respectively.

RESULTS

The mean follow-up was 4.5 years. The mean age of the patients was 66.3 years. At 2 years, 67% of the patients had no erectile dysfunction, 11% had mild erectile dysfunction and 22% had severe erectile dysfunction. No significant difference was found between the patients with and without erectile dysfunction (IIEF-5≥20 and IIEF-5<20, respectively) for any of the parameters: dosimetric values (internal pudendal arteries, penile bulb, corpus cavernosum), age, comorbidity and smoking status. The biochemical-relapse free survival was 100% at 2 years.

CONCLUSION

This approach with dose-optimization on sexual structures for localized prostate cancer found excellent results on erectile function preservation after radiotherapy, with 78% of the patients with no or mild erectile dysfunction at 2 years.

Comparative Effectiveness Research in Localized Prostate Cancer: A 10-Year Follow-up Cohort Study

PURPOSE

Long-term comparative effectiveness research on localized prostate cancer treatments is scarce, and evidence is lacking especially for brachytherapy. The aim of this study was to assess the long-term impact of the side effects of radical prostatectomy, brachytherapy, and external radiation therapy on patients with localized prostate cancer at 10 years, using propensity score analyses.

METHODS AND MATERIALS

This was a prospective observational study of a cohort of men who received a diagnosis of clinically localized prostate cancer (clinical stage T1 or T2, low and intermediate risk group) and were treated with radical prostatectomy (n = 139), brachytherapy (n = 317), or external radiation therapy (n = 194). Treatment decisions were jointly made by patients and physicians. Patient-reported outcome (PRO) evaluation included the Expanded Prostate Cancer Index Composite and Short Form-36, administered centrally by telephone interviews before and annually after treatment. The Expanded Prostate Cancer Index Composite covers urinary, bowel, sexual, and hormonal domains. To assess PRO changes over time, while accounting for correlation among repeated measures, generalized estimating equation models adjusted by propensity scores were constructed.

RESULTS

The PRO completion rate at 10 years was 85.8%. Generalized estimating equation models showed that the pattern of radical prostatectomy side effects, with substantial urinary incontinence and sexual dysfunction, remained until 10 years after treatment (standard deviation [SD], -1.1 and -1.3, respectively). Brachytherapy produced late deterioration in urinary continence (SD, -0.4) and sexual function (SD, -0.9) that appeared midterm, but the differences from radical prostatectomy remained statistically significant at 10 years (P < .001 after adjusting by propensity score). External radiation therapy showed similar results to brachytherapy, but with bowel bother (SD, -0.3).

CONCLUSIONS

Although late deterioration in radiation therapy groups attenuated differences from radical prostatectomy, relevant PRO differences still remained after 10 years. Our findings support that brachytherapy is the treatment option that causes the least impact on PROs; it is therefore an alternative to be considered when making evidence-based decisions on localized prostate cancer treatment.

Prostate Cancer From a Sex and Gender Perspective: A Review

INTRODUCTION

Factors influencing patient behavior regarding risk of prostate cancer (PCa) and outcomes of PCa treatments are poorly understood. Similarly, how PCa treatments affect patient sexual function and sense of their masculinity has not been fully investigated. A better understanding of the relationship between sex and gender for patients with PCa could significantly improve their care and quality of life.

OBJECTIVES

To review how concerns about sex and gender influence men's attitudes toward PCa screening, diagnosis, and treatment. To explore how PCa influences sexual function and self-perceived masculine identity. To examine contexts for PSA screening for transgender individuals.

METHODS

We reviewed biomedical and sociological literature exploring the impact of PCa on patient sexual function and self-perceived masculinity using OVID, PubMed, and other databases. We similarly reviewed how masculine gender norms influence patient willingness to engage with PCa screening, diagnoses, and treatment.

RESULTS

Gender norms and sexual function concerns influence patient engagement in all aspects of PCa care. This includes PSA screening, digital rectal examinations, active surveillance, and androgen deprivation therapy (ADT) amongst others. ADT is particularly challenging to sexual function, self-esteem, and masculine identity. Our research suggests that sex and gender are not separate concepts, but rather tightly intertwined, particularly when dealing with the realities experienced by patients with PCa.

CONCLUSION

Interventions to help patients deal with the challenges of PCa and its treatment are likely to be most effective if they concurrently address patients' sexual needs and understanding of gender norms. PSA screening should be considered for transgender individuals who are at greater risk of cancer and on long-term hormone therapy. More research is needed on how concerns over sex and gender influence PCa screening, diagnosis, and treatment. There is also a need for long term data on the oncological outcomes of prolonged exposure to hormone therapy for patients who are transgender. Muermann MM, Wassersug RJ. Prostate Cancer From a Sex and Gender Perspective: A Review. Sex Med Rev 2021;XX:XXX-XXX.

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.

Toxicity in patients treated with permanent prostate brachytherapy using intraoperatively built custom-linked seeds versus loose seeds

Purpose

Low-dose-rate brachytherapy (BT) with permanent iodine-125 radioactive seeds is a highly effective treatment option for low- and favorable intermediate-risk prostate cancer. However, optimal implantation is not always achieved due to edema or seeds loss. One way to improve seed placement is the use of stranded seeds called "intraoperatively built custom-linked seeds (IBCLS)" in an opposition to loose seeds (LS). To date, there are few data comparing toxicity rates between these two techniques. The aim of this study was to compare dosimetric parameters and toxicity rates at 2 years between both procedures in a matched-paired population.

Material and methods

Patients were considered for BT according to European guidelines. Among 548 patients treated at our institution, 105 patients in the loose seeds cohort were individually matched to 105 patients in the IBCLS group according to age, prostate volume, pre-operative international prostate symptom score (IPSS), clinical stage, and Gleason score. Erectile function was scored using the five-item international index of erectile function (IIEF-5) score. A multivariable linear mixed-effects model was applied to examine the association between total and individual scores (repeated measures) and covariates.

Results

Overall, 61 (29%) patients presented with a favorable intermediate-risk prostate cancer. There were no significant changes in IPSS over time (p = 0.57). During follow-up, the IIEF-5 was similar in the two groups, except at one month, where it was lower in the IBCLS group (10.9 vs. 6.9, p = 0.029). Also, there was no difference in grade ≥ 2 rectal toxicity. At 1 month, D_90Gy, V_150%, and V_100% were higher in the LS group compared to the IBCLS group.

Conclusions

Low-dose-rate prostate brachytherapy using IBCLS is a safe technique, with comparable toxicity profiles at 2 years compared to LS brachytherapy.

Radiation protection and dosimetry issues for patients with prostate cancer after I-125 low-dose-rate brachytherapy permanent implant

PURPOSE

The aim of this work was to analyze the exposure rates measured in the proximity of patients who underwent prostate low-dose-rate brachytherapy with I-125 implant. Effective doses to relatives and to population were computed to estimate the time to reach radioprotection dose constraints.

METHODS AND MATERIALS

Measurements were obtained from 180 patients, whereas the body mass index was calculated and reported for 77 patients. The day after the implant, K˙ measurements were conducted at various skin distances and positions and converted to effective doses. A theoretical model was developed to estimate effective doses from total implanted activity. The latter was approximated with a 10-mL vial inside the patient.

RESULTS

The K˙ measurements showed a low correlation with the total implanted activity, albeit an increasing trend of K˙ was observed on increasing the activity. A stronger correlation was found between body mass index and K˙ measurements. The effective dose to population is in general lower than dose constraints as well as the effective doses to relatives, with the exception of children and pregnant women, who command special precautions. We report differences between the experimental model- and theoretical model-based dose evaluation together with their comparison with previous studies found in literature.

CONCLUSIONS

Based on the K˙ measurements and the results of the present analysis, it is possible to provide the patient with radiation safety instructions specifically tailored to his relatives' habits and working environment.

Dose to the penile bulb and individual patient anatomy are predictive of erectile dysfunction in men treated with 125I low dose rate brachytherapy for localized prostate cancer

Background: To evaluate the occurrence of erectile dysfunction at 3 years (3yED) after prostate brachytherapy (BT) and to predict 3yED after treatment based on patients and treatments characteristics. Material and methods: From September 2007 to July 2015, 117 men with mild or no ED [International Index of Erectile Function (IIEF-5) > 16] underwent ¹²⁵Iodine real-time ultrasound-guided low-dose rate BT to a total dose of 160 Gy for low-risk or favorable intermediate-risk prostate adenocarcinoma, and were followed prospectively during 3 years. Median age was 63 years (51-79). The post-implant dosimetric parameters on the postoperative computer tomography were derived from the dose-volume histogram of the prostate and the penile bulb (PB), crura, neurovascular bundles (NVBs) and internal pudendal arteries (IPAs). Potential clinical confounding factors were collected. Additionally, anatomical indexes reflecting the prostate anatomical location within the pelvis were studied. These variables were compared between patients with and without 3yED. 3yED was defined as an IIEF-5 score change to the lower category between baseline, with or without medication. Results: The 3yED rate was 59% (62% maintained an IIEF-5 > 16). On multivariate analysis, prostate D90% (p > .5) and pretreatment characteristics including age (p > .5), pre-implant potency (p > .5), diabetes (p = .08) and high cardiovascular risk rates (p = .1) did not influence the occurrence of 3yED. Only the PB dose especially the D10% > 51 Gy was associated with 3yED (p = .005). Conversely, dose to the crura, IPAs or NVBs did not seem to impact the erectile function. The prostate position, especially the apex location varied significantly between potent and impotent patients and 3yED was significantly associated with close position of the prostate apex to PB (p = .008). Conclusion: The most predictive factor of 3yED was the dose to the PB. This may be explained by variation in individual patients' anatomy and this could allow for the development of better strategies to prevent ED.

Low-dose-rate brachytherapy as a minimally invasive curative treatment for localised prostate cancer has excellent oncological and functional outcomes: a retrospective analysis from a single centre

Introduction

Low-dose-rate (LDR) brachytherapy is a widely used therapeutic option for localised prostate cancer. The aim of this study was to analyse the oncological and functional outcomes after 10 years of experience with brachytherapy for localised prostate cancer.

Material and methods

All patients who underwent brachytherapy between April 2006 and September 2017 were included for analysis. Initial prostate-specific antigen (PSA) levels, tumour stages, Gleason scores, positive biopsies, prostate volumes, dosimetric parameters, and urinary symptoms were noted.

Results

A total of 201 patients underwent brachytherapy between April 2006 and September 2017. Of these patients, 159 had >3 years of oncological and functional follow-up. Only these relevant patients were included in the statistical analysis. This showed a significant, persistent decline in PSA levels (p <0.0001): the mean PSA was 1.2 ng/ml after 6 months, 1.1 ng/ml after 1 year, and 0.49 ng/ml after 3 years. Only 9 patients had tumour recurrence (3 patients with Gleason score 6 and 6 patients with Gleason score 7). After receiving adequate treatment, the patients underwent oncological follow-up.

Important obstructive and irritative complaints were most pronounced during the first 9 months and decreased strongly after 18 months of follow-up.

Conclusions

LDR brachytherapy has excellent oncological outcomes with limited functional inconveniences that are adequately treatable. Our 10 years' experience shows that brachytherapy is a safe and effective method for the treatment of low-risk localised prostate cancer.

Reporting Erectile Function Outcomes After Radiation Therapy for Prostate Cancer: Challenges in Data Interpretation

BACKGROUND

Choice of prostate cancer treatment is frequently influenced by the expected chance of treatment-induced side effects such as erectile dysfunction (ED). However, great discrepancy in cited ED rates exists in the contemporary radiation therapy literature.

AIM

To analyze the reported ED rates and cause of discrepancies and explore the strengths and limitations in the literature on radiation-induced ED.

METHODS

We performed a PubMed literature search and reviewed the literature on ED rates associated with external-beam radiotherapy and brachytherapy from the past 10 years. Eighteen studies were eligible for inclusion and subsequently reviewed.

OUTCOMES

Variables required for interpretation of erectile function outcomes, including patient demographics, treatment characteristics, and sexual function outcomes.

RESULTS

A large variety in the reported incidence of ED was found among studies. In part, these differences resulted from large variations in (i) study populations, (ii) patient characteristics, (iii) treatment characteristics, (iv) prescription of androgen deprivation therapy, (v) means of data acquisition, (vi) definitions of ED, (vii) temporal considerations, and (viii) erectile aid use. Relevant data required for adequate appraisal of sexual function outcomes were not always reported.

CLINICAL IMPLICATIONS

Based on the present findings, we present general recommendations for reporting of erectile function outcomes after radiotherapy for prostate cancer. These should improve future reports.

STRENGTHS AND LIMITATIONS

This is the first report that presents general requirements on reporting erectile function outcomes in the setting of radiotherapy for prostate cancer. We did not conduct a formal meta-analysis because we focused on concepts of research design; this might be considered a limitation.

CONCLUSION

In this review, we have highlighted the strengths and deficiencies of the current literature on ED after external-beam radiotherapy and brachytherapy for prostate cancer. We have made general recommendations to achieve some degree of standardization among reports and improve clinical interpretability. Wortel RC, Incrocci L, Muhall JP. Reporting Erectile Function Outcomes After Radiation Therapy for Prostate Cancer: Challenges in Data Interpretation. J Sex Med 2017;14:1260-1269.

[Evaluation and results of ablative therapies in prostate cancer]

OBJECTIVE

To perform a state of the art about methods of evaluation and present results in ablative therapies for localized prostate cancer.

METHODS

A review of the scientific literature was performed in Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of keywords. Publications obtained were selected based on methodology, language and relevance. After selection, 102 articles were analysed.

RESULTS

Analyse the results of ablative therapies is presently difficult considering the heterogeneity of indications, techniques and follow-up. However, results from the most recent and homogeneous studies are encouraging. Oncologically, postoperative biopsies (the most important criteria) are negative (without any tumor cells in the treated area) in 75 to 95%. Functionally, urinary and sexual pre-operative status is spared (or recovered early) in more than 90% of the patients treated. More and more studies underline also the correlation between the results and the technique used considering the volume of the gland and, moreover, the "index lesion" localization.

CONCLUSION

The post-treatment pathological evaluation by biopsies (targeted with MRI or, perhaps in a near future, with innovative ultrasonography) is the corner stone of oncological evaluation of ablative therapies. Ongoing trials will allow to standardize the follow-up and determine the best indication and the best techniques in order to optimize oncological and functional results for each patient treated.

[Toxicity and quality of life comparison of iodine 125 brachytherapy and stereotactic radiotherapy for prostate cancers]

Quality of life is a major issue for good prognostic prostate cancer, for which brachytherapy is one of the reference treatments. Stereotactic Body Radiotherapy (SBRT) is a recent alternative however not yet validated as a standard treatment. This review of the literature reports and compares the toxicities and the quality of life, either after exclusive brachytherapy with iodine 125 or after SBRT. The comparison is made with the limitations of the absence of randomized trial comparing the two treatment techniques. Acute toxicity appears to be lower after SBRT compared to brachytherapy (from 10 to 40 % versus 30 to 40 %, respectively). Conversely, acute and late gastrointestinal toxicity (from 0 to 21 % and from 0 to 10 % of grade 2, respectively) appears more frequent with SBRT. Late urinary toxicity seems identical between both techniques (from 20 to 30 % of grade 2), with a possible urinary flare syndrome. Both treatments have an impact on erectile dysfunction, although it is not possible to conclude that a technique is superior because of the limited data on SBRT. SBRT has better bowel and urinary (irritation or obstruction) quality of life scores than brachytherapy; while sexual and urinary incontinence remain the same. The absence of randomized trial comparing SBRT with brachytherapy for prostate cancers does not allow to conclude on the superiority of one technique over another, thus justifying a phase III medicoeconomic evaluation.

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.

Institutional long-term outcomes at the first Canadian center performing intraoperatively planned low-dose-rate brachytherapy alone in low- and intermediate-risk prostate cancer

PURPOSE

The aim of this study is to report the long-term outcomes and toxicities from a large cohort of patients with localized prostate cancer treated with low-dose-rate intraoperatively planned brachytherapy.

METHODS AND MATERIALS

Prostate-specific antigen levels, urinary symptoms, and erectile function were recorded at baseline, and each followup visit was then entered into a prospective database. Urinary toxicity requiring procedural intervention was retrospectively verified using an integrated electronic medical system. A separate cross-sectional survey was performed to measure postimplant sexual function.

RESULTS

A total of 822 patients with low and favorable intermediate-risk prostate cancer were treated at our institution between 2003 and 2013. The Kaplan-Meier estimates for biochemical recurrence for our cohort were 95% and 87% at 5 and 10 years, respectively. Cystoscopy, transurethral resection of prostate, or dilatation was required for 7.1% of 720 patients with more than 2 years of followup. At a median followup of 3.7 years, 64.4% of patients retained adequate erectile function for intercourse, with 54% of patients who were no longer sexually active postimplant reporting social factors as the primary reason.

CONCLUSIONS

Our institutional experience with intraoperative low-dose-rate prostate brachytherapy yielded excellent long-term results with a low incidence of urinary and sexual toxicity.

Radiation-induced erectile dysfunction: Recent advances and future directions

Prostate cancer is one of the most prevalent cancers and the second leading cause of cancer-related deaths in men in the United States. A large number of patients undergo radiation therapy (RT) as a standard care of treatment; however, RT causes erectile dysfunction (radiation-induced erectile dysfunction; RiED) because of late side effects after RT that significantly affects quality of life of prostate cancer patients. Within 5 years of RT, approximately 50% of patients could develop RiED. Based on the past and current research findings and number of publications from our group, the precise mechanism of RiED is under exploration in detail. Recent investigations have shown prostate RT induces significant morphologic arterial damage with aberrant alterations in internal pudendal arterial tone. Prostatic RT also reduces motor function in the cavernous nerve which may attribute to axonal degeneration may contributing to RiED. Furthermore, the advances in radiogenomics such as radiation induced somatic mutation identification, copy number variation and genome-wide association studies has significantly facilitated identification of biomarkers that could be used to monitoring radiation-induced late toxicity and damage to the nerves; thus, genomic- and proteomic-based biomarkers could greatly improve treatment and minimize arterial tissue and nerve damage. Further, advanced technologies such as proton beam therapy that precisely target tumor and significantly reduce off-target damage to vital organs and healthy tissues. In this review, we summarize recent advances in RiED research and novel treatment modalities for RiED. We also discuss the possible molecular mechanism involved in the development of RiED in prostate cancer patients. Further, we discuss various readily available methods as well as novel strategies such as stem cell therapies, shockwave therapy, nerve grafting with tissue engineering, and nutritional supplementations might be used to mitigate or cure sexual dysfunction following radiation treatment.