ESTRO/EAU/EORTC recommendations on permanent seed implantation for localized prostate cancer

Real‑world retrospective study of early‑stage prostate cancer at a Portuguese Comprehensive Cancer Centre: The PEarlC study

Despite the high prevalence of localised prostate cancer (LPC) and locally advanced prostate cancer (LAPC), evidence on the characteristics of patients, treatments and clinical outcomes stratified by disease risk is limited. The PEarlC study was conducted to characterise a cohort of patients with early-stage prostate cancer that included real-world clinical outcomes. Retrospective data from a cohort of patients diagnosed with LPC/LAPC between 2015 and 2017 and followed up until December 2020 at a Portuguese comprehensive cancer centre (IPO Porto) was analysed. Patients were classified as LPC (high- or non-high-risk) or LAPC according to European Association of Urology guidelines, were eligible if diagnosed at stage I-III and followed up in Urology, Medical Oncology or Radiation Oncology outpatient clinics of IPO Porto. Data was collected from the medical/administrative records database. Clinical outcomes included prostate-specific antigen (PSA) progression-free survival, metastasis-free survival, disease-free survival, progression-free survival, overall survival (OS), PSA response (palliative) and no evidence of residual tumour (prostatectomy). Time-to-event outcomes were compared between subgroups using the log-rank test. A total of 790 patients were included (54.8% non-high-risk LPC, 30.9% high-risk LPC, 14.3% LAPC) and the median follow-up was 46.7 months. Patients had a median age of 68.0 years. The majority of patients were stage II (52.9%) and Eastern Cooperative Oncology Group 0-1 (99.9%) and received treatment with curative intent (85.4%). The median was only achieved in progression-free survival (29.9 months; 95% CI, 26.5-41.0 months), as evaluated in palliative patients. At year 5, 82.9% were free of PSA progression (curative), 87.5% were metastasis-free, 83.7% were disease-free, all patients in palliative treatment progressed and the 5-year OS rate was 92.9% (CI 95%, 90.2-95.7%). Among patients with LPC, OS was worse in high-risk vs. non-high-risk patients (5-year OS rate, 88.8% vs. 96.8%; hazard ratio=3.34, CI 95%, 1.64-7.05; P=0.001). PSA response rate was 81.4% in the palliative setting. There was no evidence of residual tumour in 61.6% of patients who underwent prostatectomy. Although most patients with early-stage prostate cancer treated at IPO Porto showed positive 5-year real-world outcomes, patients with high-risk LPC showed worse OS compared with patients with non-high-risk LPC and therefore a poorer prognosis. The present large-sample real-world study is an important contribution to reducing the evidence gap on prostate cancer.

Impact of Prostate Size on the Functional and Oncological Outcomes of Robot-assisted Radical Prostatectomy

BACKGROUND AND OBJECTIVE

Robot-assisted radical prostatectomy (RARP) is the main surgical approach for treatment of prostate cancer in the USA. Prostate size is always depicted as a factor affecting the outcomes of RARP as shown by many studies, but these studies are limited to a small number of patients. Our aim was to evaluate functional and oncologic outcomes of RARP across varying prostate size measured as prostate specimen weight.

METHODS

A cohort of 14 481 patients who underwent RARP in a single center was divided into four groups according to prostate specimen weight: group 1, <50 g; group 2, 50-100 g; group 3, 100-150 g; and group 4, >150 g. Perioperative and postoperative variables and pathological and functional outcomes were compared among the four groups. Cumulative incidence functions were plotted to visualize the distribution of event-time variables among the groups, and differences were evaluated using the log-rank test.

KEY FINDINGS AND LIMITATIONS

Patients with larger prostates (groups 3 and 4) were more likely to have higher prostate-specific antigen (PSA), lower biopsy grade group, and worse baseline urinary and sexual characteristics. Group 4 had lower rates of full nerve-sparing surgery (13.7% vs 38.3%) and lymph node dissection (51.3% vs 71.4%), more pT2 disease (69.8% vs 60.3%), less pT3 disease (30.2% vs 39.7%), and lower rates of positive surgical margins (12.8% vs 19.3%) and biochemical recurrence (5.9% vs 7.5%) than group 1. Finally, we observed differences in functional outcomes among the groups for greater prostate size, and patients in group 4 had worse rates of urinary continence (77.8% vs 89.5%) and recovery of sexual function (70.0% vs 84.1%) than group 1. Our study is limited by its retrospective design.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The results demonstrate that in this large cohort of patients, greater prostate size affects multiple outcomes, including the rate of nerve-sparing surgery, potency and continence recovery, and oncological and pathological outcomes. These data will be valuable when counseling patients regarding possible RARP outcomes and the timeline for recovery.

PATIENT SUMMARY

Our study shows that prostate size can affect the outcomes of robot-assisted removal of the prostate for patients with prostate cancer. Larger prostate size can be associated with worse functional outcomes after surgery.

Toward a deep learning-based magnetic resonance imaging only workflow for postimplant dosimetry in I-125 seed brachytherapy for prostate cancer

BACKGROUND AND PURPOSE

The current standard imaging-technique for creating postplans in seed prostate brachytherapy is computed tomography (CT), that is associated with additional radiation exposure and poor soft tissue contrast. To establish a magnetic resonance imaging (MRI) only workflow combining improved tissue contrast and high seed detectability, a deep learning-approach for automatic seed segmentation on MRI-scans was developed.

MATERIAL AND METHODS

Patients treated with I-125 seed brachytherapy received a postplan-CT and a 1.5 T MRI-scan on nominal day 30 after implantation. For MRI-based seed visualization, DIXON-sequences were acquired and deep learning-based quantitative susceptibility maps (QSM) were generated from 3D-gradient-echo-sequences from 20 patients. Seed segmentations created on CT served as ground truth. For automatic seed segmentation on MRI, a 3D nnU-net model was trained using QSM and DIXON, both solely and combined.

RESULTS

Of the implanted seeds 94.8 ± 2.4% were detected with deep learning automatic segmentation entrained on both QSM and DIXON data. Models trained on the individual sequence data-sets performed worse with detection rates of 87.5 ± 2.6% or 88.6 ± 7.5% for QSM and DIXON respectively. The seed centers identified on CT versus QSM and DIXON were on average 1.8 ± 1.3 mm apart. Postimplant dosimetry for evaluation of positioning inaccuracies revealed only small variations of up to 0.4 ± 4.26 Gy in D90 (dose 90% of the prostate receives) between the standard CT-approach and our MRI-only workflow.

CONCLUSION

The proposed deep learning-based MRI-only workflow provided a promisingly accurate and robust seed localization and thus has the potential to compete with current state-of-the-art CT-based postimplant dosimetry in the future.

Artificial intelligence applications in brachytherapy: A literature review

PURPOSE

Artificial intelligence (AI) has the potential to simplify and optimize various steps of the brachytherapy workflow, and this literature review aims to provide an overview of the work done in this field.

METHODS AND MATERIALS

We conducted a literature search in June 2022 on PubMed, Embase, and Cochrane for papers that proposed AI applications in brachytherapy.

RESULTS

A total of 80 papers satisfied inclusion/exclusion criteria. These papers were categorized as follows: segmentation (24), registration and image processing (6), preplanning (13), dose prediction and treatment planning (11), applicator/catheter/needle reconstruction (16), and quality assurance (10). AI techniques ranged from classical models such as support vector machines and decision tree-based learning to newer techniques such as U-Net and deep reinforcement learning, and were applied to facilitate small steps of a process (e.g., optimizing applicator selection) or even automate the entire step of the workflow (e.g., end-to-end preplanning). Many of these algorithms demonstrated human-level performance and offer significant improvements in speed.

CONCLUSIONS

AI has potential to augment, automate, and/or accelerate many steps of the brachytherapy workflow. We recommend that future studies adhere to standard reporting guidelines. We also stress the importance of using larger sample sizes and reporting results using clinically interpretable measures.

Direct Comparison of Two Different Definitions with Biochemical Recurrence after Low-Dose-Rate Brachytherapy for Prostate Cancer

We aimed to determine whether biochemical recurrence-free survival (BRFS) of patients with prostate cancer (PCa) who received low-dose-rate brachytherapy (LDR-BT) differed according to the definition of biochemical recurrence (BCR) after radical prostatectomy (RP) and the definition given by the Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS). We reviewed the clinical records of 476 consecutive patients with PCa who received LDR-BT at the Gifu University Hospital. The primary endpoint of this study was the difference in BRFS between the two aforementioned definitions. When the follow-up period ended, 74 (15.5%) and 20 (4.2%) patients had BCR according to the RP and J-POPS definitions, respectively. The 5-year BRFS rates were 85.0% and 96.9% for the RP and J-POPS definitions, respectively (p < 0.005). According to the RP definition, the 5-year BRFS rates were 80.6% in the group aged <63 years and 86.6% in those aged ≥63 years (p = 0.050). According to the J-POPS definition, the 5-year BRFS rates were 94.1% and 97.8% in the groups aged <63 years and ≥63 years, respectively (p = 0.005). The definition of recurrence in LDR-BT may need to be reconsidered.

Surgical Treatments of Benign Prostatic Hyperplasia and Prostate Cancer Stereotactic Radiotherapy: Impact on Long-Term Genitourinary Toxicity

AIMS

Although the results on acute and late toxicity of ultrahypofractionation are encouraging, data on safety in prostate cancer patients with a medical history of transurethral resection of the prostate (TURP) or adenomectomy remain scarce, especially in cases of repeated procedures. The aim of the present study was to report on long-term toxicities after stereotactic body radiotherapy (SBRT) of prostate cancer patients with previous surgical treatment of benign prostatic hyperplasia.

MATERIALS AND METHODS

Among 150 patients treated with SBRT (median dose 36.25 Gy in five fractions) realised from 2014 to 2019 in a single-centre institution, data of 24 men with a history of TURP (n = 19) or adenomectomy (n = 5) were analysed. Repeated TURP was carried out in three patients, with a median time between surgery and SBRT of 54 months. Genitourinary toxicity was assessed using the Common Terminology Criteria for Adverse Events v4.0 grading scale.

RESULTS

With a median follow-up of 45 months, 10 of 24 (42%) patients experienced at least one episode of transient haematuria. One patient (4%) with three previous TURP presented a grade 3 acute non-infective cystitis. Late grade 2 and 3 genitourinary toxicities were observed in eight (33%) and four patients (17%) (two treated with adenomectomy, one with multiple TURP and one with a 140 cm³ prostate size), respectively, with no grade ≥4 adverse events. A complete recovery of grade 3 genitourinary toxicities was observed for all patients after hyperbaric oxygen therapy.

CONCLUSION

Prostate SBRT is feasible and well-tolerated in patients with a medical history of surgical treatments of benign hyperplasia. Patients with prior adenomectomy or multiple TURP are at higher risk of developing severe genitourinary toxicity and should be carefully evaluated before SBRT treatments.

Implications and effects of COVID-19 on diagnosis and management of prostate cancer

PURPOSE OF REVIEW

The Coronavirus disease 2019 (COVID-19) pandemic has led to uncertainty on the optimal management for prostate cancer (PCa). This narrative review aims to shed light on the optimal diagnosis and management of patients with or suspected to have PCa.

RECENT FINDINGS

Faecal-oral or aerosol transmission is possible during prostate procedures; caution must be in place when performing digital rectal examinations, transrectal ultrasound-guided prostate biopsies and prostate surgeries requiring general anaesthesia. Patients must also be triaged using preoperative polymerase chain reaction tests for COVID-19. COVID-19 has accelerated the adoption of multiparametric Magnetic Resonance Imaging (MRI), reducing the need for prostate biopsy unless when absolutely indicated, and the risk of COVID-19 spread can be reduced. Combined with prostate-specific antigen (PSA) density, amongst other factors, multiparametric MRI could reduce unnecessary biopsies in patients with little chance of clinically significant PCa. Treatment of PCa should be stratified by the risk level and preferences of the patient. COVID-19 has accelerated the development of telemedicine and clinicians should utilise safe and effective teleconsultations to protect themselves and their patients.

SUMMARY

COVID-19 transmission during prostate procedures is possible. Patients with a Prostate Imaging-Reporting and Data System (PI-RADS) of <3 and PSA density <0.15 ng/ml/ml are deemed low-risk and are safe to undergo surveillance without MRI-targeted biopsy. Intermediate- or high-risk patients should be offered definitive treatment within four months or 30days of diagnosis to avoid compromising treatment outcomes; three-month courses of neoadjuvant androgen deprivation therapy can be considered when a delay of surgery is anticipated.

Stereotactic Radiation Therapy versus Brachytherapy: Relative Strengths of Two Highly Efficient Options for the Treatment of Localized Prostate Cancer

Stereotactic body radiation therapy (SBRT) has become a valid option for the treatment of low- and intermediate-risk prostate cancer. In randomized trials, it was found not inferior to conventionally fractionated external beam radiation therapy (EBRT). It also compares favorably to brachytherapy (BT) even if level 1 evidence is lacking. However, BT remains a strong competitor, especially for young patients, as series with 10-15 years of median follow-up have proven its efficacy over time. SBRT will thus have to confirm its effectiveness over the long-term as well. SBRT has the advantage over BT of less acute urinary toxicity and, more hypothetically, less sexual impairment. Data are limited regarding SBRT for high-risk disease while BT, as a boost after EBRT, has demonstrated superiority against EBRT alone in randomized trials. However, patients should be informed of significant urinary toxicity. SBRT is under investigation in strategies of treatment intensification such as combination of EBRT plus SBRT boost or focal dose escalation to the tumor site within the prostate. Our goal was to examine respective levels of evidence of SBRT and BT for the treatment of localized prostate cancer in terms of oncologic outcomes, toxicity and quality of life, and to discuss strategies of treatment intensification.

GEC-ESTRO ACROP prostate brachytherapy guidelines

This is an evidence-based guideline for prostate brachytherapy. Throughout levels of evidence quoted are those from the Oxford Centre for Evidence based Medicine (https://www.cebm.ox.ac.uk/resources/levels-of-evidence/oxford-centre-for-evidence-based-medicine-levels-of-evidence-march-2009). Prostate interstitial brachytherapy using either permanent or temporary implantation is an established and evolving treatment technique for non-metastatic prostate cancer. Permanent brachytherapy uses Low Dose Rate (LDR) sources, most commonly I-125, emitting photon radiation over months. Temporary brachytherapy involves first placing catheters within the prostate and, on confirmation of accurate positioning, temporarily introducing the radioactive source, generally High Dose Rate (HDR) radioactive sources of Ir-192 or less commonly Co-60. Pulsed dose rate (PDR) brachytherapy has also been used for prostate cancer [1] but few centres have adopted this approach. Previous GEC ESTRO recommendations have considered LDR and HDR separately [2-4] but as there is considerable overlap, this paper provides updated guidance for both treatment techniques. Prostate brachytherapy allows safe radiation dose escalation beyond that achieved using external beam radiotherapy alone as it has greater conformity around the prostate, sparing surrounding rectum, bladder, and penile bulb. In addition there are fewer issues with changes in prostate position during treatment delivery. Systematic review and randomised trials using both techniques as boost treatments demonstrate improved PSA control when compared to external beam radiotherapy alone [5-7].

Urethral and bladder dose-effect relations for late genitourinary toxicity following external beam radiotherapy for prostate cancer in the FLAME trial

PURPOSE

or objectives The FLAME trial (NCT01168479) showed that by adding a focal boost to conventional fractionated EBRT in the treatment of localized prostate cancer, the five-year biochemical disease-free survival increased, without significantly increasing toxicity. The aim of the present study was to investigate the association between radiation dose to the bladder and urethra and genitourinary (GU) toxicity grade ≥2 in the entire cohort.

MATERIAL AND METHODS

The dose-effect relations of the urethra and bladder dose, separately, and GU toxicity grade ≥2 (CTCAE 3.0) up to five years after treatment were assessed. A mixed model analysis for repeated measurements was used, adjusting for age, diabetes mellitus, T-stage, baseline GU toxicity grade ≥1 and institute. Additionally, the association between the dose and separate GU toxicity subdomains were investigated.

RESULTS

Dose-effect relations were observed for the dose (Gy) to the bladder D2cm³ and urethra D0.1cm³, with adjusted odds ratios of 1.14 (95% CI 1.12-1.16, p<0.0001) and 1.12 (95% CI 1.11-1.14, p<0.0001), respectively. Additionally, associations between the dose to the urethra and bladder and the subdomains urinary frequency, urinary retention and urinary incontinence were observed.

CONCLUSION

Further increasing the dose to the bladder and urethra will result in a significant increase in GU toxicity following EBRT. Focal boost treatment plans should incorporate a urethral dose-constraint. Further treatment optimization to increase the focal boost dose without increasing the dose to the urethra and other organs at risk should be a focus for future research, as we have shown that a focal boost is beneficial in the treatment of prostate cancer.

Prostate cancer brachytherapy: SFRO guidelines 2021

Prostate brachytherapy techniques are described, concerning both permanent seed implant and high dose rate brachytherapy. The following guidelines are presented: brachytherapy indications, implant procedure for permanent low dose rate implants and high dose rate with source projector, as well as dose and dose-constraints objectives, immediate postoperative management, post-treatment evaluation, and long-term follow-up.

Patterns of Failure Following External Beam Radiotherapy With or Without an Additional Focal Boost in the Randomized Controlled FLAME Trial for Localized Prostate Cancer

BACKGROUND

Focal dose escalation in external beam radiotherapy (EBRT) showed an increase in 5-yr biochemical disease-free survival in the Focal Lesion Ablative Microboost in Prostate Cancer (FLAME) trial.

OBJECTIVE

To analyze the effect of a focal boost to intraprostatic lesions on local failure-free survival (LFS) and regional + distant metastasis-free survival (rdMFS).

DESIGN, SETTING, AND PARTICIPANTS

Patients with intermediate- or high-risk localized prostate cancer were included in FLAME, a phase 3, multicenter, randomized controlled trial.

INTERVENTION

Standard treatment of 77 Gy to the entire prostate in 35 fractions was compared to an additional boost to the macroscopic tumor of up to 95 Gy during EBRT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

LFS and rdMFS, measured via any type of imaging, were compared between the treatment arms using Kaplan-Meier and Cox regression analyses. Dose-response curves were created for local failure (LF) and regional + distant metastatic failure (rdMF) using logistic regression.

RESULTS AND LIMITATIONS

A total of 571 patients were included in the FLAME trial. Over median follow-up of 72 mo (interquartile range 58-86), focal boosting decreased LF (hazard ratio [HR] 0.33, 95% confidence interval [CI] 0.14-0.78) and rdMF (HR 0.58, 95% CI 0.35-0.93). Dose-response curves showed that a greater dose to the tumor resulted in lower LF and rdMF rates.

CONCLUSIONS

A clear dose-response relation for LF and rdMF was observed, suggesting that adequate focal dose escalation to intraprostatic lesions prevents undertreatment of the primary tumor, resulting in an improvement rdMF.

PATIENT SUMMARY

Radiotherapy is a treatment option for high-risk prostate cancer. The FLAME trial has shown that a high dose specifically targeted at the tumor within the prostate will result in better disease outcome, with less likelihood of regional and distant disease spread. The FLAME trial is registered on ClinicalTrials.gov as NCT01168479.

Differences in treatment choices between prostate cancer patients using a decision aid and patients receiving care as usual: results from a randomized controlled trial

Objective

To determine whether or not decision aid (DA) use influences treatment decisions in patients with low and intermediate risk prostate cancer (PC).

Patients and methods

In a cluster randomized controlled trial, patients were randomized to either DA use (DA group) or no DA use (control group). Between 2014 and 2016, newly diagnosed patients with low or intermediate risk PC were recruited in 18 hospitals in the Netherlands. DA users had access to a web-based DA that provided general PC information, PC-treatment information, and values clarification exercises to elicit personal preferences towards the treatment options. Control group patients received care as usual. Differences in treatment choice were analysed using multilevel logistic regressions. Differences in eligible treatment options between groups were compared using Pearson Chi-square tests.

Results

Informed consent was given by 382 patients (DA group N = 273, control group N = 109). Questionnaire response rate was 88% (N = 336). Active surveillance (AS) was an option for 38%, radical prostatectomy (RP) for 98%, external beam radiotherapy (EBRT) for 88%, and brachytherapy (BT) for 79% of patients. DA users received AS significantly more often than control group. Patients (29 vs 16%, p = 0.01), whereas the latter more often chose BT (29 vs 18%, p < 0.01). No differences were found between groups regarding RP and EBRT. DA users who were not eligible for AS, received surgery more often compared to the control group (53 vs 35%, p = 0.01). Patient and disease characteristics were evenly distributed between groups.

Conclusion

DA-using PC patients chose the AS treatment option more often than non-DA-using patients did.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-021-03782-7.

Radiation dose rate variations in different measurement scenarios after prostate 125I brachytherapy

PURPOSE

This study aimed to directly compare different measurement scenarios using a supplemental radiation exposure measurement data set.

MATERIALS AND METHODS

Two sets of measurement scenarios comparing different body postures, such as standing and chair sitting positions, and different measurement directions, such as anterior and posterior directions, were assessed for radiation dose rate variations in this study at the Tokyo Medical Center, Japan. The estimated precaution time for holding children in the spoon position while sitting was also calculated.

RESULTS

Different radiation dose rate measurement scenarios showed different variation tendencies. Radiation dose rate measurement showed higher mean values of measured radiation dose tendency in the standing position than in the sitting positions. The measurement from the anterior direction showed a slightly lower tendency than that from the posterior direction. Assuming a dose limit of 1 mSv, the precaution time calculated for children being held in the spoon position for a certain duration every day was 51.5 (range, 12.5-152.2) minutes.

CONCLUSIONS

Our study presented a supplemental radiation exposure measurement data set and directly compared different measurement scenarios. Several trends in radiation exposure variations were found in the measurement scenarios at different body postures and different measurement directions. Our study data set could be a useful source of concrete information regarding radiation safety and contribute to the review and revision of public guidance in the future.

Anorectal dose-effect relations for late gastrointestinal toxicity following external beam radiotherapy for prostate cancer in the FLAME trial

BACKGROUND AND PURPOSE

The phase III FLAME trial (NCT01168479) showed an increase in five-year biochemical disease-free survival, with no significant increase in toxicity when adding a focal boost to external beam radiotherapy (EBRT) for localized prostate cancer [Kerkmeijer et al. JCO 2021]. The aim of this study was to investigate the association between delivered radiation dose to the anorectum and gastrointestinal (GI) toxicity (grade ≥2).

MATERIAL AND METHODS

All patients in the FLAME trial were analyzed, irrespective of treatment arm. The dose-effect relation of the anorectal dose parameters (D2cm³ and D50%) and GI toxicity grade ≥2 in four years of follow-up was assessed using a mixed model analysis for repeated measurements, adjusted for age, cardiovascular disease, diabetes mellitus, T-stage, baseline toxicity grade ≥1, hormonal therapy and institute.

RESULTS

A dose-effect relation for D2cm³ and D50% was observed with adjusted odds ratios of 1.17 (95% CI 1.13-1.21, p < 0.0001) and 1.20 (95% CI 1.14-1.25, p < 0.0001) for GI toxicity, respectively.

CONCLUSION

Although there was no difference in toxicity between study arms, a higher radiation dose to the anorectum was associated with a statistically significant increase in GI toxicity following EBRT for prostate cancer. This dose-effect relation was present for both large and small anorectal volumes. Therefore, further increase in dose to the anorectum should be weighed against the benefit of focal dose escalation for prostate cancer.

Prognostic value of PSA bounce in prostate cancer following definitive radiation therapy: a systematic review and meta-analysis

BACKGROUND

The prognostic significance of PSA bounce following definitive radiation therapy remains controversial. To develop a sense of current opinion in this area, we performed a systematic search of the literature based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

METHODS

In January 2021, we systematically searched PubMed, the Cochrane library, and Scopus for studies that compared patients who had localized prostate cancer with or without PSA bounce after definitive radiation therapy. Our objective was to evaluate the association of PSA bounce with biochemical recurrence-free survival, metastatic-free survival, cancer-specific survival, and overall survival, using multivariate Cox regression analysis.

RESULTS

A total of 8881 patients in 10 studies matched the selection criteria for the systematic review and meta-analysis. The number of patients with PSA bounce accounted for 2706 of all 8881 patients (30.5%). PSA bounce was associated with better biochemical recurrence-free survival after definitive radiation therapy (pooled HR: 0.62, 95% CI: 0.54-0.71). Subgroup analyses also showed that PSA bounce was independently associated with decreased risk for biochemical recurrence-free survival in prostate cancer patients treated with low dose rate brachytherapy alone (pooled HR: 0.38, 95% CI: 0.27-0.55) and external beam radiotherapy alone (pooled HR: 0.71, 95% CI: 0.57-0.87).

CONCLUSIONS

This meta-analysis indicated that PSA bounce after definitive radiation therapy is related to improved outcome in terms of biochemical failure in prostate cancer patients.

Low-/high-dose-rate brachytherapy boost in patients with intermediate-risk prostate cancer treated with radiotherapy: long-term results from a single institution team experience

Purpose

To compare brachytherapy (BT) boost of low-dose-rate (LDR) and high-dose-rate (HDR) techniques in patients diagnosed with intermediate-risk prostate cancer.

Material and methods

Between January 2005 and February 2018, 142 patients (50 LDR and 92 HDR) with intermediate-risk prostate cancer were treated with a BT boost, and retrospectively analyzed. Prescribed dose was 45 Gy with external beam radiotherapy (EBRT) plus 100-108 Gy with LDR-BT, and 60 Gy with EBRT plus one fraction of 10 Gy with HDR-BT. 99% of patients received androgen deprivation therapy (ADT) for 6 months. Primary endpoint was to compare LDR and HDR boosts in terms of biochemical progression-free survival (bPFS). Secondary endpoint, after re-classifying patients into "favorable" and "unfavorable" sub-groups, was to analyze differences with a similar treatment intensity.

Results

Median overall follow-up for the total cohort was 66.5 months (range, 16-185 months). There were no significant differences in bPFS, overall survival, cause specific survival, local failure, lymph node failure, or distant failure when LDR or HDR was employed. bPFS at 90 months was 100% for favorable, and 89% and 85% for unfavorable patients at 60 months and 90 months, respectively (log-rank test, p = 0.017). The crude incidence of genitourinary acute and chronic toxicity grade 3 was 0.7% and 4%, respectively. Twelve patients (8%) had chronic rectal hemorrhage grade 2, in whom argon was applied (4 LDR and 8 HDR).

Conclusions

Combined treatment is an excellent therapeutic option in patients with intermediate-risk prostate carcinoma, with similar results in both LDR and HDR approaches and very low toxicities. Importantly, the current literature has indicated that unfavorable-risk patients belong to a different category, and should be treated as patients with high-risk factors. Therefore, the stratification and identification of both risk groups is extremely relevant.

The one hundred most cited publications in prostate brachytherapy

PURPOSE

The aim of this study is to identify the leaders in research on prostate brachytherapy through a bibliometric analysis of the top 100 most cited publications in the field.

METHODS AND MATERIALS

A broad search was performed with the term "prostate brachytherapy" using the Web of Science database to generate wide-ranging results that were reviewed by reading the abstracts and, if necessary, the articles to select the top 100 most cited publications.

RESULTS

The median of the total citation count was 187 (range 132-1464). The median citation per year index (citations/year since publication) was 13.5 (range 6.3-379.0). In all publications, the first author was also the corresponding author. The top publishing countries of the first author included the United States (n = 78), Canada (n = 6), the UK (n = 5), and Germany (n = 4). The journal with the most publications was the International Journal of Radiation Oncology Biology Physics (n = 38). There were 27 more publications on low-dose-rate (LDR) than on high-dose-rate (HDR) (43 vs 16) among the top 100. HDR publications had only one first author that had three articles in comparison to LDR publications, which had four first authors, each with three articles on LDR. The United States was the leading country in 43.8% of HDR publications (n = 7) and 88.4% of LDR publications (n = 38).

CONCLUSIONS

Our bibliometric analysis of the top 100 most cited publications clearly demonstrates the North American dominance in the publications of prostate brachytherapy, especially in LDR. However, European first authors were more frequent in HDR publications.

Statistical methods to assess the prognostic value of risk prediction rules in clinical research

Prognosis aims at estimating the future course of a given disease in probabilistic terms. As in diagnosis, where clinicians are interested in knowing the accuracy of a new test to identify patients affected by a given disease, in prognosis they wish to accurately identify patients at risk of a future event conditional to one or more prognostic factors. Thus, accurate risk predictions play a primary role in all fields of clinical medicine and in geriatrics as well because they can help clinicians to tailor the intensity of a treatment and to schedule clinical surveillance according to the risk of the concerned patient. Statistical methods able to evaluate the prognostic accuracy of a risk score demand the assessment of discrimination (the Harrell's C-index), calibration (Hosmer-May test) and risk reclassification abilities (IDI, an index of risk reclassification) of the same risk prediction rule whereas, in spite of the popular belief that traditional statistical techniques providing relative measures of effect (such as the hazard ratio derived by Cox regression analysis or the odds ratio obtained by logistic regression analysis) could be per se enough to assess the prognostic value of a biomarker or of a risk score. In this paper we provide a brief theoretical background of each statistical test and a practical approach to the issue. For didactic purposes, in the paper we also provide a dataset (n = 40) to allow the reader to train in the application of the proposed statistical methods.

Treatment of low-risk prostate cancer: a retrospective study with 477 patients comparing external beam radiotherapy and I-125 seeds brachytherapy in terms of biochemical control and late side effects

PURPOSE

The goal of our study was comparison of external beam radiotherapy (EBRT) and I‑125 seeds brachytherapy in terms of biochemical control and development of late gastrointestinal and genitourinary side effects.

PATIENTS AND METHODS

477 low-risk prostate cancer patients treated between 2000 and 2019 at our department using either I‑125 seeds brachytherapy or EBRT with a dose of 74 or 78 Gy were reviewed for our analysis. 213 patients were treated with EBRT and 264 with seeds.

RESULTS

Patients were followed up yearly with a median follow-up of 70 (3-192) months. The biochemical no evidence of disease (bNED) rates after 5 years were 95% for both EBRT and seeds, and after 10 years 87% for EBRT and 94% for seeds using the Phoenix criteria, although no significant difference was observed. Concerning gastrointestinal side effects, EBRT showed significantly higher rates of RTOG grade ≥2 toxicity compared to seeds, but at no point in follow-up more than 15% of all patients. On the other hand, genitourinary side effects were significantly more prevalent in patients treated with seeds, with 40% RTOG grade ≥2 toxicity 12 months after treatment. Nevertheless, both types of side effects decreased over time.

CONCLUSION

Both EBRT and seeds provide excellent biochemical control with bNED rates after 10 years of about 90%. In terms of side effects, patients treated with seeds show higher grades of genitourinary side effects, while patients treated with EBRT show higher grades of gastrointestinal side effects.

Focal Boost to the Intraprostatic Tumor in External Beam Radiotherapy for Patients With Localized Prostate Cancer: Results From the FLAME Randomized Phase III Trial

PURPOSE

This study investigates whether focal boosting of the macroscopic visible tumor with external beam radiotherapy increases biochemical disease-free survival (bDFS) in patients with localized prostate cancer.

PATIENTS AND METHODS

In the phase III, multicenter, randomized controlled Focal Lesion Ablative Microboost in Prostate Cancer trial, 571 patients with intermediate- and high-risk prostate cancer were enrolled between 2009 and 2015. Patients assigned to standard treatment received 77 Gy (fractions of 2.2 Gy) to the entire prostate. The focal boost arm received an additional simultaneous integrated focal boost up to 95 Gy (fractions up to 2.7 Gy) to the intraprostatic lesion visible on multiparametric magnetic resonance imaging. Organ at risk constraints were prioritized over the focal boost dose. The primary end point was 5-year bDFS. Secondary end points were disease-free survival (DFS), distant metastases-free survival, prostate cancer-specific survival, overall survival, toxicity, and health-related quality of life.

RESULTS

Median follow-up was 72 months. Biochemical DFS was significantly higher in the focal boost compared with the standard arm (hazard ratio 0.45, 95% CI, 0.28 to 0.71, P < .001). At 5-year follow-up bDFS was 92% and 85%, respectively. We did not observe differences in prostate cancer-specific survival (P = .49) and overall survival (P = .50). The cumulative incidence of late genitourinary and GI toxicity grade ≥ 2 was 23% and 12% in the standard arm versus 28% and 13% in the focal boost arm, respectively. Both for late toxicity as health-related quality of life, differences were small and not statistically significant.

CONCLUSION

The addition of a focal boost to the intraprostatic lesion improved bDFS for patients with localized intermediate- and high-risk prostate cancer without impacting toxicity and quality of life. The Focal Lesion Ablative Microboost in Prostate Cancer study shows that a high focal boost strategy to improve tumor control while respecting organ at risk dose constraints is effective and safe.

Ten-year longitudinal health-related quality of life following iodine-125 brachytherapy monotherapy for localized prostate cancer

Purpose

This prospective longitudinal study quantifies health-related quality of life (HRQoL) up to 10 years following permanent iodine-125 (¹²⁵I) prostate brachytherapy alone for localized prostate cancer.

Material and methods

In total, 120 patients completed a validated expanded prostate cancer index composite (EPIC) questionnaire pre-treatment and at 8 time points after treatment (6 weeks, 6, 10, 18 months, and 2, 3, 5, 10 years). At each time point, clinically relevant small, moderate, and severe declines in HRQoL were defined as 0.2-0.5 SD, 0.5-0.8 SD, and > 0.8 SD of baseline function for each of urinary, bowel, and sexual domains, respectively.

Results

Response rates in the first two years were > 90%, but thereafter dropped to 75% and 48% at 5 and 10 years, respectively. 50 patients (41.6%) responded at all stages. Maximal deterioration in mean urinary and sexual summary scores was noted 6 weeks after implant, with severe urinary symptoms and moderate bowel/sexual symptoms. At 6 months, urinary and bowel quality of life (QoL) had improved to mild impairment, which then fully resolved at 10 months. Sexual QoL remained mildly impaired throughout the 10 years of follow-up. At 10 years, new mild impairment of urinary and bowel QoL was found.

Conclusions

Clinically mild changes in urinary, bowel, and sexual QoL are found 10 years after ¹²⁵I monotherapy. The impairment in sexual function persists from treatment, but urinary and bowel symptoms are new at 10 years.

EAU-EANM-ESTRO-ESUR-SIOG Guidelines on Prostate Cancer-2020 Update. Part 1: Screening, Diagnosis, and Local Treatment with Curative Intent

OBJECTIVE

To present a summary of the 2020 version of the European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Society of Urogenital Radiology (ESUR)-International Society of Geriatric Oncology (SIOG) guidelines on screening, diagnosis, and local treatment of clinically localised prostate cancer (PCa).

EVIDENCE ACQUISITION

The panel performed a literature review of new data, covering the time frame between 2016 and 2020. The guidelines were updated and a strength rating for each recommendation was added based on a systematic review of the evidence.

EVIDENCE SYNTHESIS

A risk-adapted strategy for identifying men who may develop PCa is advised, generally commencing at 50 yr of age and based on individualised life expectancy. Risk-adapted screening should be offered to men at increased risk from the age of 45 yr and to breast cancer susceptibility gene (BRCA) mutation carriers, who have been confirmed to be at risk of early and aggressive disease (mainly BRAC2), from around 40 yr of age. The use of multiparametric magnetic resonance imaging in order to avoid unnecessary biopsies is recommended. When a biopsy is performed, a combination of targeted and systematic biopsies must be offered. There is currently no place for the routine use of tissue-based biomarkers. Whilst prostate-specific membrane antigen positron emission tomography computed tomography is the most sensitive staging procedure, the lack of outcome benefit remains a major limitation. Active surveillance (AS) should always be discussed with low-risk patients, as well as with selected intermediate-risk patients with favourable International Society of Urological Pathology (ISUP) 2 lesions. Local therapies are addressed, as well as the AS journey and the management of persistent prostate-specific antigen after surgery. A strong recommendation to consider moderate hypofractionation in intermediate-risk patients is provided. Patients with cN1 PCa should be offered a local treatment combined with long-term hormonal treatment.

CONCLUSIONS

The evidence in the field of diagnosis, staging, and treatment of localised PCa is evolving rapidly. The 2020 EAU-EANM-ESTRO-ESUR-SIOG guidelines on PCa summarise the most recent findings and advice for their use in clinical practice. These PCa guidelines reflect the multidisciplinary nature of PCa management.

PATIENT SUMMARY

Updated prostate cancer guidelines are presented, addressing screening, diagnosis, and local treatment with curative intent. These guidelines rely on the available scientific evidence, and new insights will need to be considered and included on a regular basis. In some cases, the supporting evidence for new treatment options is not yet strong enough to provide a recommendation, which is why continuous updating is important. Patients must be fully informed of all relevant options and, together with their treating physicians, decide on the most optimal management for them.

Knowledge-Based Assessment of Focal Dose Escalation Treatment Plans in Prostate Cancer

PURPOSE

In a randomized focal dose escalation radiation therapy trial for prostate cancer (FLAME), up to 95 Gy was prescribed to the tumor in the dose-escalated arm, with 77 Gy to the entire prostate in both arms. As dose constraints to organs at risk had priority over dose escalation and suboptimal planning could occur, we investigated how well the dose to the tumor was boosted. We developed an anatomy-based prediction model to identify plans with suboptimal tumor dose and performed replanning to validate our model.

METHODS AND MATERIALS

We derived dose-volume parameters from planned dose distributions of 539 FLAME trial patients in 4 institutions and compared them between both arms. In the dose-escalated arm, we determined overlap volume histograms and derived features representing patient anatomy. We predicted tumor D98% with a linear regression on anatomic features and performed replanning on 21 plans.

RESULTS

In the dose-escalated arm, the median tumor D50% and D98% were 93.0 and 84.7 Gy, and 99% of the tumors had a dose escalation greater than 82.4 Gy (107% of 77 Gy). In both arms organs at risk constraints were met. Five out of 73 anatomic features were found to be predictive for tumor D98%. Median predicted tumor D98% was 4.4 Gy higher than planned D98%. Upon replanning, median tumor D98% increased by 3.0 Gy. A strong correlation between predicted increase in D98% and realized increase upon replanning was found (ρ = 0.86).

CONCLUSIONS

Focal dose escalation in prostate cancer was feasible with a dose escalation to 99% of the tumors. Replanning resulted in an increased tumor dose that correlated well with the prediction model. The model was able to identify tumors on which a higher boost dose could be planned. The model has potential as a quality assessment tool in focal dose escalated treatment plans.

Diagnostic performance of imaging techniques for detecting of local recurrence after prostate brachytherapy

PURPOSE

The purpose of this study was to evaluate MRI and fluorocholine PET/CT diagnostic performances for the detection of local recurrence following prostate brachytherapy for localised prostate cancer.

MATERIAL AND METHODS

In this single-centre study, we retrospectively reviewed data from 21 patients treated by brachytherapy for localised prostate cancer and diagnosed with biochemical recurrence according to Phoenix Criteria, who underwent MRI and fluorocholine PET/CT. We included patients with local relapse suspicion according to imaging exams, with biopsy for the final assessment of local recurrence. Patient analysis data were supplemented by segment analysis using an 8-segment model.

RESULTS

The fluorocholine PET/CT was positive for 81% and negative for 19% of patients. The sensitivity and specificity were 92% and 33% with diagnosis accuracy of 67%. The MRI was positive for 57% and negative for 43% of patients. The sensitivity and specificity were 67% and 56% with diagnosis accuracy of 62%. There was no statistically significant difference between fluorocholine PET/CT and MRI accuracy (P=0.63). On a segment-based analysis, the sensitivity and specificity were 44% and 82% for fluorocholine PET/CT with diagnosis accuracy of 78%. For MRI, specificity was 91% diagnosis accuracy was 82%.

CONCLUSION

Both MRI and fluorocholine PET/CT permit to highlight local recurrence sites after prostate brachytherapy. Confirmation biopsies are, however, necessary since this accuracy is insufficient.

Incidence of subsequent primary cancers and radiation-induced subsequent primary cancers after low dose-rate brachytherapy monotherapy for prostate cancer in long-term follow-up

BACKGROUND

As aging is the most significant risk factor for cancer development, long-term prostate cancer (PCa) survivors have an evident risk of developing subsequent primary cancers (SPCs). Radiotherapy itself is an additional risk factor for cancer development and the SPCs appearing beyond 5 years after radiotherapy in the original treatment field can be considered as radiation-induced subsequent primary cancers (RISPCs).

METHODS

During the years 1999-2008, 241 patients with localized PCa who underwent low dose-rate brachytherapy (LDR-BT) with I125 and were followed-up in Kuopio University Hospital, were included in this study. In this study the incidences and types of SPCs and RISPCs with a very long follow-up time after LDR-BT were evaluated.

RESULTS

During the median follow-up time of 11.4 years, a total of 34 (14.1%) patients developed a metachronous SPC. The most abundant SPCs were lung and colorectal cancers, each diagnosed in six patients (16.7% out of all SPCs). The crude incidence rate of RISPC was 1.7% (n = 4). Half of the SPC cases (50%) were diagnosed during the latter half of the follow-up time as the risk to develop an SPC continued throughout the whole follow-up time with the actuarial 10-year SPC rate of 7.0%. The crude death rates due to metachronous out-of-field SPCs and RISPCs were 50 and 50%, respectively.

CONCLUSION

The crude rate of SPC was in line with previously published data and the incidence of RISPC was very low. These results support the role of LDR-BT as a safe treatment option for patients with localized PCa.

Impact of real-time, dose-escalated permanent seed implant brachytherapy in intermediate-risk prostate cancer

Purpose

To retrospectively evaluate biochemical control and toxicity in patients who underwent 125I seed brachytherapy (BT) for intermediate-risk prostate cancer (PCa).

Materials and Methods

Between January 2004-December 2014, 395 patients with intermediate-risk PCa underwent 125I BT. Of these, 117 underwent preoperative planning (PP; 145 Gy) and 278 real-time intraoperative preplanning (IoP; 160 Gy). All patients were followed for ≥ 6 months (> 5 years in 48% of patients and > 7 years in 13%). Median follow-up was 59 months.

Results

Biochemical relapse-free survival (BRFS) rates at 5 and 8 years were, respectively, 91.7% and 82.1%. By treatment group, the corresponding BRFS rates were 93.5% and 90% for IoP and 89% and 76.8% for PP. The maximum dose to the urethra remained unchanged (217 Gy) despite the dose escalation (from 145 to 160 Gy), without any significant increase in treatment-related toxicity (p = 0.13). Overall toxicity outcomes in the series were excellent, with only 3 cases (0.76%) of grade 3 genitourinary toxicity.

Conclusion

The real-time intraoperative planning technique at 160 Gy yields better biochemical controls than the preoperative planning technique at 145 Gy. Dose escalation did not increase urinary toxicity. The excellent results obtained with the IoP BT technique support its use as the first treatment option in this patient population.

Prostate-specific antigen bounce after 125I-brachytherapy for prostate cancer is a favorable prognosticator in patients who are biochemical recurrence-free at 4 years and correlates with testosterone

BACKGROUND

Because patients with prostate-specific antigen (PSA) bounce do not experience biochemical recurrence (BCR) until PSA bounce occurs, the period until PSA bounce ends can be considered the so-called lead-time bias. Therefore, we evaluated differences in BCR-free rate in prostate cancer patients who were BCR-free 4 years after 125I-brachytherapy alone. Furthermore, we evaluated predictors for PSA bounce and the correlation between testosterone and PSA bounce.

METHODS

From 2004 to 2012, 256 patients with prostate adenocarcinoma underwent 125I-brachytherapy alone. PSA and testosterone levels were monitored prior to 125I-brachytherapy, at 1, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54 and 60 months after 125I-brachytherapy and yearly after 5-year follow-up. PSA bounce was defined as ≥0.2 ng/ml increase above the interval PSA nadir, followed by a decrease to nadir or below.

RESULTS

BCR-free rate in patients with PSA bounce (100% 7-year BCR-free rate) was significantly better (P < 0.044) than that in patients without PSA bounce (95.7% 7-year BCR-free rate) in patients who were BCR-free 4 years after 125I-brachytherapy alone (n = 223). Age was the only predictor (odds ratio: 0.93, 95% confidence interval: 0.88-0.98, P = 0.004) for PSA bounce (n = 177). The testosterone level at PSA bounce was significantly higher (P = 0.036) than that at nadir before PSA bounce (87 cases).

CONCLUSIONS

Patients with PSA bounce had good BCR-free rate even in patients who were BCR-free 4 years after 125I-brachytherapy alone. Testosterone levels were higher at PSA bounce; increased testosterone levels may be a cause of PSA bounce.

A history of transurethral resection of the prostate should not be a contra-indication for low-dose-rate 125I prostate brachytherapy: results of a prospective Uro-GEC phase-II trial

Purpose

Early reports suggested that transurethral resection (TURP) prior to permanent seed brachytherapy (BT) results in high incontinence rates. Guidelines consider prior TURP as a contra-indication to treatment, but improvements in imaging and treatment planning may reduce this risk, and are investigated in this prospective study.

Material and methods

99 men with histologically proven low- to intermediate-risk, localized prostate cancer, with a history of TURP performed at least 3 months before BT procedure were enrolled. All patients received a permanent seed implant between March 2009 and June 2015. Intra-operative interactive planning was recommended to ensure optimal accuracy of seed placement during the procedure. No supplemental external beam was allowed. Target and organ at risk contouring, definition of clinical target volume (CTV), and dosimetric parameters followed the modified GEC-ESTRO guidelines for permanent seed implants, as described an earlier report of our group. Follow-up was scheduled every 3 months for the first year, and every 6 months afterwards, with minimum follow-up of 2 years.

Study endpoints

The primary endpoint was the incidence of post-implant urinary incontinence. Secondary endpoints were the incidence of urinary and gastro-intestinal toxicity, the eventual impact on the sexual function, and the freedom from biochemical failure.

Results

The median follow-up time for these 99 patients was 49 months (min. 24, max. 96). In this series, the incontinence rate was 2% after TURP + BT and 2% in case of TURP + BT + re-TURP, ending up with a total urinary incontinence rate of 4%. Acute and late urinary toxicities were extremely low. No significant late gastro-intestinal toxicity was seen, and the 5-year biochemical non-evidence of disease (bNED) was 93%.

Conclusions

The excellent long-term results and low morbidity presented as well as many advantages of prostate brachytherapy over other treatments demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and organ-confined prostate cancer.

Prostate cancer in sexual minorities and the influence of HIV status

Prostate cancer is the second most common cause of cancer-related death in men in the USA, but the effect of prostate cancer diagnosis and treatment on men in a sexual minority group, including men who have sex with men and transgender women, is poorly understood. Efforts to study this population are complicated, as cancer registries do not routinely collect information on sexual orientation. As a result, epidemiological data regarding this population have come from small studies that have included disparate rates of prostate cancer screening, diagnosis and treatment. Qualitative studies indicate that prostate cancer is experienced differently by sexual minorities, with distinct health-care needs that arise owing to differences in sexual practices, social support systems and relationships with the medical community. Notably, sexual minorities have been reported to experience poorer health-related quality of life outcomes than heterosexual men, and tend to have less robust social support systems, experience increased psychological distress caused by sexual dysfunction (areas of which are unmeasured after treatment), experience isolation within the health-care system and express increased levels of dissatisfaction with treatment. The incidence of prostate cancer actually seems to be decreased in men from sexual minorities living with HIV, despite there being no differences in screening and treatment, with poor cancer-specific mortality. Although the literature on patients with prostate cancer in men from sexual minority groups has historically been sparse, peer-reviewed research in this area has grown considerably during the past decade and has become an important field of study.

Detection of individual prostate cancer via multiparametric magnetic resonance imaging in own material - initial experience

Purpose

Multiparametric magnetic resonance imaging (mpMRI) is an evolving non-invasive imaging modality that increases the accurate localization of prostate cancer (PCa) at the time of MRI targeted biopsy, enhancing clinical risk assessment, and improving the ability to appropriately counsel patients regarding therapy.

Material and methods

A total of forty patients with prostate-specific antigen (PSA), mpMRI and Gleason score (based on MRI template-guided cognitive biopsy) results were analyzed in this study, with eight patients (20%) diagnosed with PCa. The mpMRI was performed to facilitate the decision to perform prostate biopsy. Spearman’s coefficient analysis was used to evaluate the relationships between characteristics. Diagnostic performance was assessed measuring the area under the curve (AUC) of the receiver operating characteristic (ROC) analysis. Diagnostic accuracy, sensitivity, and specificity were determined using the best cut-off on each ROC.

Results

Out of all the study group, 55% of patients were subjected to primary biopsy and 45% were directed to repeated TRUS-Bx with the suspicion of prostate cancer. Forty suspected lesions on MRI images were identified with 5% of PI-RADS 1, 17.5% of PI-RADS 2, 32.5% of PI-RADS 3, 27.5% of PI-RADS 4 (27.5%) and 17.5% of PI-RADS 5. The highest correlation was observed for mpMRI results and Gleason score with Spearman’s coefficient equal to 0.41 (95% CI: 0.104-0.646). ROC analysis revealed that mpMRI discriminates between directing the patients for prostate biopsy or active surveillance with AUC = 0.771 (0.117, 95% CI: 0.542-1.001).

Conclusions

Introducing pre-biopsy mpMRI into our contemporary PCa diagnosis pathway increased the diagnostic yield of transrectal biopsy by increasing the prostate cancer detection. This enabled the introduction of clinically significant prostate cancer (csPCa) treatment. mpMRI application also allowed biopsy to be avoided among patients with no csPCa.

Quantitative MRI Changes During Weekly Ultra-Hypofractionated Prostate Cancer Radiotherapy With Integrated Boost

Purpose: Quantitative MRI reflects tissue characteristics. As possible changes during radiotherapy may lead to treatment adaptation based on response, we here assessed if such changes during treatment can be detected.

Methods and Materials: In the hypoFLAME trial patients received ultra-hypofractionated prostate radiotherapy with an integrated boost to the tumor in 5 weekly fractions. We analyzed T2 and ADC maps of 47 patients that were acquired in MRI exams prior to and during radiotherapy, and performed rigid registrations based on the prostate contour on anatomical T2-weighted images. We analyzed median T2 and ADC values in three regions of interest (ROIs): the central gland (CG), peripheral zone (PZ), and tumor. We analyzed T2 and ADC changes during treatment and compared patients with and without hormonal therapy. We tested changes during treatment for statistical significance with Wilcoxon signed rank tests. Using confidence intervals as recommended from test-retest measurements, we identified persistent T2 and ADC changes during treatment.

Results: In the CG, median T2 and ADC values significantly decreased 12 and 8%, respectively, in patients that received hormonal therapy, while in the PZ these values decreased 17 and 18%. In the tumor no statistically significant change was observed. In patients that did not receive hormonal therapy, median ADC values in the tumor increased with 20%, while in the CG and PZ no changes were observed. Persistent T2 changes in the tumor were found in 2 out of 24 patients, while none of the 47 patients had persistent ADC changes.

Conclusions: Weekly quantitative MRI could identify statistically significant ADC changes in the tumor in patients without hormonal therapy. On a patient level few persistent T2 changes in the tumor were observed. Long-term follow-up is required to relate the persistent T2 and ADC changes to outcome and evaluate the applicability of quantitative MRI for response based treatment adaptation.

Brachytherapy for the urologist: A multidisciplinary team update for 2019

Brachytherapy is a well-established treatment for localised prostate cancer. Urologists are often tasked with discussing all available treatment options with the newly diagnosed patient. Unlike radical prostatectomy and external beam radiotherapy, knowledge of brachytherapy may be limited. The aim of this article is to provide an up-to-date guide on patient selection, modern brachytherapy techniques and the management of side effects, such that the core urologist can be more confident in both discussing initial treatment options and the long-term management of brachytherapy patients.

Level of Evidence: Level 5 - review article

Prostate Brachytherapy with Iodine-125 Seeds: Radiation Protection Issues

Aims and background

Brachytherapy for prostate cancer by means of permanently implanted 125 I sources is a well established procedure. An increasing number of patients all over the world are treated with this modality. When the technique was introduced at our institution, radiation protection issues relative to this technique were investigated in order to comply with international recommendations and national regulations. Particular attention was paid to the need for patient shielding after discharge from hospital.

Methods

The effective and equivalent doses to personnel related to implantation, the effective dose to patient relatives as computed by a developed algorithm, the air kerma strength values for the radioactive sources certified by the manufacturer compared with those measured by a well chamber, and the effectiveness of lead gloves in shielding the hands were evaluated.

Results

The effective dose to the bodies of personnel protected by a lead apron proved to be negligible. The mean equivalent doses to the physician's hands was 420 μSv for one implant; the technician's hands received 65 μSv. The mean air kerma rate measured at the anterior skin surface of the patient who had received an implant was 55 μGy/h (range, 10–115) and was negligible with lead protection. The measured and certified air kerma strength for 125I seeds in RAPID Strand corresponded within a margin of ± 5%. The measured attenuation by lead gloves in operative conditions was about 80%. We also defined the recommendations to be given to the patient at discharge.

Conclusions

The exposure risks related to brachytherapy with 125I to operators and public are limited. However, alternation of operators should be considered to minimize exposure. Patient-related measurements should verify the dose rate around the patient to evaluate the need for shielding and to define appropriate radiation protection recommendations.

Long-term efficacy and urological toxicity of low-dose-rate brachytherapy (LDR-BT) as monotherapy in localized prostate cancer

PURPOSE

The purpose of this study was to evaluate the incidence of late severe (≥Grade 3) urinary toxicity and the long-term efficacy after low-dose-rate brachytherapy (LDR-BT) in patients with localized prostate cancer (PCa).

METHODS AND MATERIALS

During the years 1999-2008, 241 patients with PCa who underwent LDR-BT with I¹²⁵ and were followed up in Kuopio University Hospital were included to this analysis. The incidence of late severe (Grade 3) urinary toxicity and the long-term efficacy results were analyzed.

RESULTS

All D'Amico risk groups were represented, as 58.9%, 35.3%, and 5.8% of the patients were classified as low-, intermediate-, and high-risk patients, respectively. With a median followup of 11.4 years after implantation, the incidence of severe urinary toxicity increased throughout the followup period. The risk of Grade 3 urinary toxicity was highest among patients with higher Gleason scores (p = 0.016) and higher initial urine residual volumes (p = 0.017) and the cumulative incidence of severe urinary toxicity was 10.0%. The crude rate for transurethral prostatic resection was 5.8%. The relapse-free survival, the cause-specific survival, and the overall survival were 79.3%, 95.0%, and 66.4%, respectively.

CONCLUSIONS

The treatment was well tolerated as 90% of patients avoided any Grade 3 urinary toxicity. LDR-BT for localized PCa achieved high and durable efficacy. These results support the role of LDR-BT monotherapy as one of the valid primary treatment options for low-risk and favorable intermediate-risk patients.

Correlation between real-time intraoperative and postoperative dosimetry and its implications on intraoperative planning

PURPOSE

The purpose of this study was to study the correlation between intraoperative and postimplant dosimetry. We investigated the correlation between prostate (V₁₅₀) and urethra (D₃₀, D₅) dose limits, and whether it is possible to increase prostate D₉₀ and V₁₀₀ in intraoperative planning without violating postimplant urethra and rectum dose limits.

METHODS AND MATERIALS

Seventy-nine patients who underwent real-time ultrasound-guided prostate implants using intraoperative planning from 2013 to 2017 were analyzed. Forty-one of the 79 implants were ¹²⁵I as monotherapy and the remainder was ¹⁰³Pd as boost to external beam radiation therapy or external beam radiation therapy plus androgen deprivation therapy. Prescriptions followed the guidelines of AAPM TG-137. The urethra was catheterized during intraoperative implantation and postimplant imaging to facilitate the urethra identification. T2-cubed MRI and CT were acquired on the same day and about 1 month after the low-dose-rate procedure, and MRI was later fused with the CT scan for accurate delineation of the prostate and postimplant dosimetry evaluation. An institutionally based peer-review process and document procedure were established based on national recommendations. Correlation of dose parameters: D₉₀, V₁₅₀, V₁₀₀ of prostate, D₃₀, D₅ of urethra, and V₁₀₀ of rectum between intraoperative and postimplant plans were evaluated.

RESULTS

D₉₀ and V₁₀₀ declined for all implants between intraoperative and postimplant dosimetry. On average, D₉₀ declined by 17.5% and 21.7% for ¹²⁵I and ¹⁰³Pb implants, respectively. V₁₀₀ declined for all implants between intraoperative and postimplant dosimetry but less pronounced. Prostate V₁₅₀ and urethra D₃₀ and D₅ also showed different tendency of decline. Of the 79 implants, 60 did not meet the postimplant dosimetry target for prostate (V₁₅₀ ≤ 50%), and 46 of the 60 implants met the optimal dosimetry targets for both D₃₀ (<125%) and D₅ (<150%), and the other 14 of the 60 implants failed to meet either the D₃₀ or the D₅ limits. All the implants met the postimplant target dose for rectum: V₁₀₀≤ 1.3 cc.

CONCLUSION

Intraoperative implant dosimetry could not accurately predict postimplant dosimetry; however, to avoid underdosage of prostate, intraoperative D₉₀ should be close to 120% of prescribed dose and V₁₀₀ needs to be close to 100% of prescribed dose. Prostate V₁₅₀> 50% does not necessarily indicate the violation of urethra D₃₀ and D₅ dose limits. For most of the implants, target intraoperative D₉₀ and V₁₀₀ could be raised without violating urethra D₃₀ and D₅ limits recommended by American Brachytherapy Society in postimplant evaluation.

Permanent seed implant brachytherapy in low-risk prostate cancer: Preoperative planning with 145 Gy versus real-time intraoperative planning with 160 Gy

Aim

The present retrospective study was to compare toxicity and survival outcomes in a group of low-risk PCa patients treated with either the preoperative planning technique (145 Gy) or the real-time IoP technique (160 Gy).

Background

The two most common permanent seed implantation techniques are preoperative planning (PP) with 145 Gy and real-time intraoperative planning (IoP) with 160 Gy. Although IoP has largely replaced PP at many centres in recent years, few studies have directly compared these two techniques.

Materials and methods

Retrospective study of 408 patients with low-risk PCa treated with permanent seed implant brachytherapy at our institution between October 2003 and December 2014. Of these, 187 patients were treated with PP at a dose of 145 Gy while 221 received real-time IoP with 160 Gy.

Results

At a median follow up of 90 months, 5- and 8-year rates of biochemical relapse-free survival (BRFS) were 94.8% and 86% with the IoP technique versus 90.8% and 83.9%, respectively, with PP. The maximum dose to the urethra was <217 Gy with both techniques. Despite the higher dose, IoP did not cause any significant increase in toxicity (p = 0.11).

Conclusions

The present study shows that real-time intraoperative brachytherapy at a dose of 160 Gy yield better biochemical control than preoperative planning at 145 Gy. In addition, urinary toxicity did not increase, despite the dose escalation, probably because the dose constraints to the urethra were met despite the increased dose escalation. These findings support the use of real-time IoP.

Five-year effectiveness of low-dose-rate brachytherapy: comparisons with nomogram predictions in patients with non-metastatic prostate cancer presenting significant control of intra- and periprostatic disease

PURPOSE

To assess the effectiveness of low-dose-rate (LDR) brachytherapy in patients with localized prostate cancer and to compare the outcome with predictions from Kattan and Partin nomograms at 60 months after seed implantation.

MATERIAL AND METHODS

One thousand, one hundred and eighty-seven patients with localized prostate cancer at low-, intermediate-, or high-risk of progression received LDR brachytherapy using iodine-125 seeds with curative intent, applied as monotherapy or in combination with external beam radiation therapy (EBRT), and/or androgen deprivation therapy (ADT). At 60 months after seed implantation, data of 1,064 patients (1,058 alive + 6 who died of prostate cancer) were analyzed for biochemical progression-free survival (bPFS) based on prostate-specific antigen (PSA) levels using the Phoenix definition. Five-year bPFS probabilities were determined for various risk group classifications (d'Amico, Mt. Sinai, MSKCC/Seattle, NCCN). Outcomes were also compared to patient-individualized nomogram predictions of 5-year bPFS (Kattan 2002) and probability of organ-confined disease (Kattan 2002, Partin 2007).

RESULTS

Overall, 93.3% (993/1,064) of the patients were free of biochemical progression within 5 years, while the average 5-year bPFS probability according to the Kattan nomogram was significantly lower (85%, p < 0.001). Outcomes were significantly better than Kattan nomogram predictions in the subgroup of patients with monotherapy as well as in patients additionally treated with EBRT. Comparison of the overall outcome with nomogram predictions for organ-confined disease (Kattan nomogram: 50%; Partin nomogram: 65%) revealed a significant probability of LDR brachytherapy to destroy periprostatic tumor spread (p < 0.001) in all risk group constellations, even in high-risk patients.

CONCLUSIONS

The results indicate high effectiveness of LDR brachytherapy in all risk groups, significantly better than predicted with the Kattan nomogram in most subgroups. The significant superiority of LDR brachytherapy compared to nomogram predictions of organ-confined disease suggests that LDR brachytherapy effectively controls both intra- and periprostatic disease.

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.

A process to describe radiation damage at the molecular level. Application to the 125I seeds in water

The correlation between the absorbed energy and the induced biological damage still has unclear aspects, especially in the low energy and low dose rate irradiation regimes. From the knowledge of the molecular-induced effects (dissociations), it would be possible to better understand the side effects of radiation, such as induced cancers or damage to healthy tissue. With this in view, this paper presents results of a simulation of a ¹²⁵I-seed treatment with an event-by-event MC code (LEPTS) specifically designed to account for the low energy secondary particle interactions, such as electron attachment, vibro-rotational and neutral dissociation interactions. This calculation allowed us to analyze the potential radiation damage not only in connection with the energy deposition, but also in terms of induced molecular dissociations by taking into account ionizing and non-ionizing dissociative processes. We propose that this description of the molecular level damage be the basis for nanodosimetric evaluations.