Radiotherapy For Prostate Cancer Research Articles

Incidence of acute and delayed rectal toxicities following hydrogel spacer insertion in men receiving dose-escalated radiotherapy for prostate cancer

Objectives: The objective of this study was to evaluate the effectiveness of a hydrogel spacer in reducing acute and delayed rectal toxicities. Materials and Methods: Patients undergoing definitive radiotherapy between January 2015 and March 2018 were retrospectively identified from our institutional cancer registry. Planning data were collected on dose-volume histograms (DVH) for V65, V70 and V75 Gy. All patients underwent definitive volumetric modulated arc therapy (VMAT) of 78 Gy over 39 fractions in a single centre. Toxicity reporting and definitions were in accordance with Common Terminology Criteria for Adverse Events (CTCAE) guidelines. Results: A total of 162 patients received radiotherapy during the study period (spacer n = 80; no spacer n = 82). Baseline characteristics between groups were comparable. Acute rectal toxicity was documented in 19 men (24%) with spacer versus 36 men (44%) without spacer devices ( p = 0.007). Over a median post-treatment follow-up period of 17 months (range = 3–38 months), there was a significant reduction in delayed toxicity in men with spacers compared to men without (17 men 21% vs. 31 men 39%, p = 0.021). Conclusion: Hydrogel spacer devices reduce rectal radiation exposure in prostate cancer patients undergoing radiotherapy. This translates into a clinical benefit in terms of acute and delayed rectal toxicities. Level of evidence: cohort study

Variation in Access to Palliative Radiotherapy in Prostate Cancer: A Population-Based Study in Canada.

As a result of improvements in cancer therapies, patients with metastatic malignancies are living longer, and the role of palliative radiotherapy has become increasingly recognized. However, access to adequate palliative radiotherapy may continue to be a challenge, as is evident from the high proportion of patients dying of prostate cancer who never receive palliative radiotherapy. The main objective of this investigation is to identify and describe the factors associated with the receipt of palliative radiation treatment in a decedent cohort of prostate cancer patients in Ontario. Population-based administrative databases from Ontario, Canada, were used to identify prostate cancer decedents, 65 years or older who received androgen deprivation therapy between January 1, 2013, and December 31, 2018. Baseline and treatment characteristics were analyzed using univariate and multivariate logistic regression models for association with receipt of radiotherapy in a two-year observation period before death. We identified 3,788 prostate cancer decedents between 2013 and 2018; among these, 49.9% received radiotherapy in the two years preceding death. There were statistically significant positive associations between receipt of radiotherapy and younger age at diagnosis (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.1-2.3); higher stage at diagnosis (OR 1.3, 95% CI 1.1-1.7); receipt of care at a regional cancer center (OR 1.8, 95% CI 1.3-2.4); and involvement of radiation oncologists (OR 155.1, 95% CI 83.3-288.7)or medical oncologists (OR 1.4, 95% CI 1.1-1.8). However, there were no associations between receipt of radiotherapy and income, distance to the nearest cancer center, involvement of urologists in cancer care, healthcare administrative region, home-care involvement, or number of hospitalizations in the observation period. We found the utilization of palliative radiotherapy for prostate cancer patients in Ontario varies depending on age, stage at diagnosis, number of comorbidities, registration at regional cancer centers, and involvement of oncologists. There were no differences detected based on incomeor distance from a cancer center. The findings of this study represent an important opportunity to facilitate better access to palliative radiotherapy and referrals to multidisciplinary regional cancer centers, to improve the quality of life of this patient population.

Image-guided moderately hypofractionated radiotherapy for localized prostate cancer: a multicentric retrospective study (IPOPROMISE)

BackgroundModerate hypofractionated radiotherapy is a treatment option for the cure of localized prostate cancer (PCa) patients based on the results of randomized prospective trials, but there is a clinical concern about the relatively short length of follow-up, and real-world results on outcome and toxicity based on cutting-edge techniques are lacking. The objective of this study is to present the long-term results of a large multicentric series.Materials and methodsWe retrospectively evaluated 1325 PCa patients treated with daily volumetric image-guided hypofractionated radiotherapy between 2007 and 2020 in 16 Centers. For survival endpoints, we used Kaplan–Meier survival curves and fitted univariate and multivariable Cox’s proportional hazards regression models to study the association between the clinical variables and each survival type.ResultsAt the end of the follow-up, 11 patients died from PCa. The 15-year values of cancer-specific survival (CSS) and biochemical relapse-free survival (b-RFS) were 98.5% (95%CI 97.3–99.6%) and 85.5% (95%CI 81.9–89.4%), respectively. The multivariate analysis showed that baseline PSA, Gleason score, and the use of androgen deprivation therapy were significant variables for all the outcomes. Acute gastrointestinal (GI) and genitourinary (GU) toxicities of grade ≥ 2 were 7.0% and 16.98%, respectively. The 15-year late grade ≥ 2 GI and GU toxicities were 5% (95%CI 4–6%) and 6% (95%CI 4–8%), respectively.ConclusionReal-world long-term results of this multicentric study on cutting-edge techniques for the cure of localized PCa demonstrated an excellent biochemical-free survival rate of 85.5% at 15 years, and very low rates of ≥ G3 late GU and GI toxicity (1.6% and 0.9% respectively), strengthening the results of the available published trials.

Stereotactic ablative radiation therapy in metastatic prostate cancer.

The evolving role of stereotactic ablative radiation therapy (SABR) as metastasis-directed therapy (MDT) for oligometastatic prostate cancer (omPCa) will be discussed. Oligometastatic disease (OMD) is an intermediate state between localized and wide-spread malignant disease. OMD has recently been spotlighted given the increasing demonstration of clinical benefit from local therapies despite presence of metastatic disease and allure of the curative potential of MDT in select cases. Among the different forms of MDT, SABR has rapidly become a widely adopted treatment modality. Significant efforts in this space have focused on omPCa, owing to its relatively indolent biology, presence of a sensitive and specific serum biomarker and recent advances in molecular imaging. While most studies have evaluated the role of SABR MDT in hormone sensitive omPCa, new emerging clinical data also suggests benefits of SABR MDT for even castration-resistant disease. Treating omPCa with SABR MDT appears to generate an efficacy signal with minimal morbidity across both hormone-sensitive and castration-resistant disease. However, additional definitive omPCa trial data are needed. Future research efforts should investigate biomarkers for this heterogeneous disease space and the role of SABR MDT in combination with systemic agents to improve upon standard of care treatments.

Dosimetric benefit of online treatment plan adaptation in stereotactic ultrahypofractionated MR-guided radiotherapy for localized prostate cancer.

Apart from superior soft tissue contrast, MR-guided stereotactic body radiation therapy (SBRT) offers the chance for daily online plan adaptation. This study reports on the comparison of dose parameters before and after online plan adaptation in MR-guided SBRT of localized prostate cancer. 32 consecutive patients treated with ultrahypofractionated SBRT for localized prostate cancer within the prospective SMILE trial underwent a planning process for MR-guided radiotherapy with 37.5 Gy applied in 5 fractions. A base plan, derived from MRI simulation at an MRIdian Linac, was registered to daily MRI scans (predicted plan). Following target and OAR recontouring, the plan was reoptimized based on the daily anatomy (adapted plan). CTV and PTV coverage and doses at OAR were compared between predicted and adapted plans using linear mixed regression models. In 152 out of 160 fractions (95%), an adapted radiation plan was delivered. Mean CTV and PTV coverage increased by 1.4% and 4.5% after adaptation. 18% vs. 95% of the plans had a PTV coverage ≥95% before and after online adaptation, respectively. 78% vs. 100% of the plans had a CTV coverage ≥98% before and after online adaptation, respectively. The D0.2cc for both bladder and rectum were <38.5 Gy in 93% vs. 100% before and after online adaptation. The constraint at the urethra with a dose of <37.5 Gy was achieved in 59% vs. 93% before and after online adaptation. Online adaptive plan adaptation improves target volume coverage and reduces doses to OAR in MR-guided SBRT of localized prostate cancer. Online plan adaptation could potentially further reduce acute and long-term side effects and improve local failure rates in MR-guided SBRT of localized prostate cancer.

Relationship between hydrogel spacer distribution and dosimetric parameters in linear-accelerator-based stereotactic body radiotherapy for prostate cancer.

To explore the potential of quantitative parameters of the hydrogel spacer distribution as predictors for separating the rectum from the planning target volume (PTV) in linear-accelerator-based stereotactic body radiotherapy (SBRT) for prostate cancer. Fifty-five patients underwent insertion of a hydrogel spacer and were divided into groups 1 and 2 of the PTV separated from and overlapping with the rectum, respectively. Prescribed doses of 36.25-45Gy in five fractions were delivered to the PTV. The spacer cover ratio (SCR) and hydrogel-implant quality score (HIQS) were calculated. Dosimetric and quantitative parameters of the hydrogel spacer distribution were compared between the two groups. For PTV, D99% in group 1 (n=29) was significantly higher than that in group 2 (n=26), and Dmax, D0.03cc, D1cc, and D10% for the rectum were significantly lower in group 1 than in group 2. The SCR for prostate (89.5±12.2%) in group 1 was significantly higher (p<0.05) than that in group 2 (74.7±10.3%). In contrast, the HIQS values did not show a significant difference between the groups. An area under the curve of 0.822 (95% confidence interval, 0.708-0.936) for the SCR was obtained with a cutoff of 93.6%, sensitivity of 62.1%, and specificity of 100%. The SCR seems promising to predict the separation of the rectum from the PTV in linear-accelerator-based SBRT for prostate cancer.

(016) Sexual Health Toxicity Following MRI-Guided versus CT-guided Prostate SBRT

Abstract Introduction Sexual health toxicities remain an under-reported but important health outcome for patients undergoing radiotherapy for localized prostate cancer. With the increasing adoption of higher daily doses of radiation over shorter timeframes delivered using stereotactic body radiotherapy (SBRT), the precision of radiation delivery remains an important factor that can reduce patient toxicity. MRI-guided SBRT (MRgRT) allows for improved image quality, treatment gating, and planning target volume margin reduction, offering improved radiation precision, which may translate to reduced treatment-related toxicity as compared to traditional CT-guided SBRT (CTgRT). Objective We sought to evaluate the effect of MRI-guidance on sexual health toxicity in patients following prostate SBRT for the treatment of localized prostate cancer. Methods We conducted a post-hoc analysis of patients enrolled on a phase III single-center randomized trial (MIRAGE: NCT04384770). The trial overall seeks to study the relative benefit of MRI vs CT guided SBRT (40 Gy/5 fractions) in patients with localized prostate cancer. Right and left neurovascular bundles (NVBs) and internal pudendal arteries (IPAs) were contoured on treatment planning images. Dosimetric parameters for these structures (Dmax, Dmin, Dmean, and V20Gy) were collected. Patient-reported sexual function outcomes (SHIM and EPIC-26 surveys) were also collected prior to treatment and at 1, 3, and 12 months following treatment. A clinically relevant decrement was defined as a ≥24 point decrease in the EPIC-26 sexual domain scores and a ≥9 point decrease on SHIM surveys. Unpaired t-tests and chi-square tests were used to evaluate for statistical significance. Results 152 patients received either MRgRT (n = 77) or CTgRT (n = 75). MRgRT resulted in a significant improvement in the volume receiving 20 Gy or less of radiation (V20Gy) in the left NVB (7.3cc vs 10.9cc, p = 4.4x10-8), right NVB (7.0cc vs 10.7cc, p = 2.8x10-7), and right IPA (0.42cc vs 1.35cc, p = 0.049), and trended towards significance for the left IPA (0.3cc vs 1.1cc, p = 0.066). Only 48 patients were not given hormonal therapy with radiotherapy. No statistically significant differences in clinically relevant decrements in patient-reported SHIM or EPIC scores were seen between MRgRT and CTgRT in these patients. No clear association between acute or chronic (12-months post-RT) sexual health toxicity and radiation exposure to the NVBs or IPAs was identified. Conclusions Patients treated with MRgRT had decreased radiation exposure to the bilateral NVBs and IPAs compared to patients treated with CTgRT. These data highlight the dosimetric benefits of MRgRT with regard to sexually relevant organs at risk. Power to detect associations between dosimetry and patient-reported sexual health outcomes will increase as the data matures and more patients have recovered testosterone after use of hormonal therapy. Future work will assess the impact on MRI-guided vs CT-guided radiation on sexual health outcomes at later time points. Disclosure No.

Converting between the International Prostate Symptom Score (IPSS) and the Expanded Prostate Cancer Index Composite (EPIC) urinary subscales: modeling and external validation

BackgroundProstate-related quality of life can be assessed with a variety of different questionnaires. The 50-item Expanded Prostate Cancer Index Composite (EPIC) and the International Prostate Symptom Score (IPSS) are two widely used options. The goal of this study was, therefore, to develop and validate a model that is able to convert between the EPIC and the IPSS to enable comparisons across different studies.MethodsThree hundred forty-seven consecutive patients who had previously received radiotherapy and surgery for prostate cancer at two institutions in Switzerland and Germany were contacted via mail and instructed to complete both questionnaires. The Swiss cohort was used to train and internally validate different machine learning models using fourfold cross-validation. The German cohort was used for external validation.ResultsConverting between the EPIC Urinary Irritative/Obstructive subscale and the IPSS using linear regressions resulted in mean absolute errors (MAEs) of 3.88 and 6.12, which is below the respective previously published minimal important differences (MIDs) of 5.2 and 10 points. Converting between the EPIC Urinary Summary and the IPSS was less accurate with MAEs of 5.13 and 10.45, similar to the MIDs. More complex model architectures did not result in improved performance in this study. The study was limited to the German versions of the respective questionnaires.ConclusionsLinear regressions can be used to convert between the IPSS and the EPIC Urinary subscales. While the equations obtained in this study can be used to compare results across clinical trials, they should not be used to inform clinical decision-making in individual patients.Trial registrationThis study was retrospectively registered on clinicaltrials.gov on January 14th, 2022, under the registration number NCT05192876.

Hypofractionated versus conventional fractionation external beam radiotherapy in intermediate and high risk localized prostate cancer

BackgroundProstate cancer is the second most common malignancy in men, and its incidence is increasing which is attributed to increased screening programs. The treatment options of intermediate and high risk prostate cancer include radical prostatectomy, radiotherapy and androgen deprivation therapy. Hypofractionated radiotherapy is becoming more popular lately due to better understanding of the radiobiology of prostate cancer and favorable logistics.ObjectiveTo compare the toxicity and efficacy of hypofractionated versus conventional fractionation external beam radiotherapy in patients with intermediate and high risk localized prostate cancer treated in Shaukat Khanum Memorial Hospital and Research Center, Lahore (SKMCH & RC).MethodologyWe retrospectively conducted this study on histopathologically confirmed 114 patients with prostate adenocarcinoma who underwent treatment from January 2013 till December 2018. These patients were treated with radical radiotherapy along with hormonal therapy as per indication. Data was collected from electronic hospital system and analyzed by SPSS version 23.Results114 patients were selected according to the inclusion criteria. Mean age was 68 years (61–75). 88% of patients had stage III-IVA disease at the time of diagnosis. Mean PSA and GS was 33 ± 39 SD and 7 ± 0.9 SD respectively. 89% (n = 102) received radiotherapy with 69% of patients receiving dose of 60 Gy in 20 fractions. Among patients who received hypofractionated dose, 86% (n = 61) of them were categorized as high risk and 14% (n = 10) were intermediate risk, whereas among conventional group 90% (n = 28) were high risk patients and 10% (n = 3) were of intermediate risk. In hypofractionated dose group, 14% (n = 10) developed grade 2 proctitis and 8% (n = 6) developed grade 2 cystitis, in contrast to conventional dose group in which only 3 patients (5%) developed grade 2 GI toxicity and 2 patients (2.9%) had grade 2 GU toxicity. However, these toxicities and their grade were clinically insignificant when compared with the dose groups (p = 0.11). 5 year overall survival for hypofractionated radiotherapy versus conventional dose was 100% and 90% respectively with 95% Cl and p value of 0.3 (clinically insignificant), whereas 5 year disease free survival was 100% and 75% for hypofractionation versus conventional EBRT respectively with 95% CI and p value of 0.04 (clinically significant).ConclusionHypofractionated radiotherapy in patients with intermediate and high risk localized prostate cancer has better disease free survival at the expense of higher risk for proctitis and cystitis but no difference in overall survival as compared to conventional dose of radiation.

Retrospective study on the toxicity induced by stereotactic body radiotherapy: overview of the reunion experience on prostate cancer in elderly patients.

Prostate cancer is the fourth most commonly diagnosed cancer among men worldwide. Various tools are used to manage disease such as conventional radiotherapy. However, it has been demonstrated that large prostate volumes were often associated with higher rates of genitourinary and gastrointestinal toxicities. Currently, the improvements in radiotherapy technology have led to the development of stereotactic body radiotherapy, which delivers higher and much more accurate radiation doses. In order to complete literature data about short-term outcome and short-term toxic effects of stereotactic body radiotherapy, we aimed to share our experience about gastrointestinal and genitourinary toxicities associated with stereotactic body radiotherapy in prostate cancer in patients over 70 years old. We retrospectively reviewed the medical records of elderly patients with prostate cancer treated between 2021 and 2022. The elderly patients were treated with a non-coplanar robotic stereotactic body radiotherapy platform using real-time tracking of implanted fiducials. The prostate, with or without part of the seminal vesicles, was treated with a total dose of 36.25 Gy delivered in five fractions, each fraction being administered every other day. We analyzed a total of 80 elderly patients, comprising 38 low-, 37 intermediate- and 5 high-risk patients. The median follow-up duration was 12 months. We did not observe biochemical/clinical recurrence, distant metastasis, or death. Grade 2 acute genitourinary toxicity was observed in 9 patients (11.25%) and Grade 2 acute gastrointestinal toxicity in 4 patients (5.0%). We did not observe any grade 3 or more acute or late toxicities. Over the follow-up period, we noted a low frequency of gastrointestinal and genitourinary toxicities induced by stereotactic body radiotherapy in the context of prostate cancer in elderly patients. Therefore, stereotactic body radiotherapy seems to represent a promising treatment option for elderly patients, with acceptable acute toxicity.

Time to next systemic therapy after stereotactic body radiation therapy for oligoprogressive metastatic castrate-resistant prostate cancer.

62 Background: Patients with castrate-resistant prostate cancer (CRPC) with progressive disease are generally require a change/escalation in systemic therapy. For patients with limited ( ≤3) sites of progressive disease (oligoprogression), metastasis-directed therapy with stereotactic body radiation therapy (SBRT) may allow a longer interval before next line systemic therapy, but there is limited data describing this approach. Methods: This is a retrospective study of patients with oligoprogressive metastatic CRPC (omCRPC) treated with SBRT at a single center between 2011-2022. The primary endpoint was time to next systemic therapy (TTNST) after SBRT. Secondary endpoints included overall survival (OS) after SBRT and TTNST stratified by presence of untreated non-progressing metastases. Results: Thirty-two patients with omCRPC received SBRT to 38 metastases. Patients had a median age of 72.5 years (range 50.6-84.3) and median PSA 6.85 ng/mL (range 0.39-922.0) at time of SBRT. The majority had an ECOG of 1-2 (29 patients, 90.6%) and metastases detected on conventional CT and/or bone scans (26 patients, 81.3%). The most commonly utilized SBRT regimen was 3000 cGy in 5 fractions (18 metastases, 47.4%) (Table). Sixteen patients were treated to all known sites of disease, whereas 16 patients received SBRT to oligoprogressive metastases but had at least one untreated non-progressing metastasis at the time of SBRT. Of 32 patients, 23 (65.7%) received SBRT to bone only, 3 (9.4%) to lymph node (LN) only, and 6 (18.8%) to other sites (pelvic tumor, n=2; pelvic tumor + LN, n =1; LN + bone, n=1; dura + bone, n=1; liver, n=1). Patients had received a median of 1.0 prior line of androgen receptor signaling inhibitors and were predominantly (26 patients, 81.3%) chemotherapy naïve. Following SBRT, the median TTNST was 10.1 months and median OS was 41.3 months. For patients with 0 versus ≥1 untreated non-progressing metastasis, TTNST was 11.3 versus 8.7 months, respectively (HR 0.67, 95% CI 0.33-1.36, logrank p=0.24). There were no grade ≥3 toxicities due to SBRT. Conclusions: In this cohort, patients with omCRPC treated with SBRT delayed the next line of systemic therapy for a median of 10.1 months. SBRT in patients with omCRPC may delay initiation of next line systemic therapy in well selected patients, including those with ≥1 untreated non-progressing metastases. [Table: see text]

Update from the PSMA-dRT trial: A randomized phase III trial of PSMA-PET prior to definitive radiation therapy for unfavorable intermediate-risk or high-risk prostate cancer.

291 Background: Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has superior diagnostic accuracy for detecting regional and distant metastases compared to conventional imaging (CT, bone scan, and MRI) in men with prostate cancer. This has the potential to guide definitive radiation therapy (dRT) patient selection and planning. Whether the use of improved diagnostic accuracy imaging improves patient outcomes remains to be demonstrated in clinical trials. Methods: This multi-institutional phase III randomized clinical trial (PSMA-dRT, NCT04457245) was designed to randomize 312 men with unfavorable intermediate-risk or high-risk prostate cancer 1.08:1 between receiving (n=162) and not receiving (n=150) a PSMA PET/CT prior to starting dRT. Treating radiation oncologists incorporated the PSMA PET/CT into radiotherapy planning. All other imaging modalities were allowed in the control arm. There were no prespecified androgen deprivation therapy (ADT) or dRT dose and volumes protocols. The primary endpoint was 5-year progression-free survival (PFS). Results: 54 patients were randomized between November 2020 and December 2021 (25 to PSMA PET/CT and 29 to control). The trial closed early following FDA approval and insurance coverage of PSMA PET/CT, since treatment without PSMA PET/CT in the control group was no longer acceptable for many patients and physicians. Among patients staged with PSMA PET/CT in the intervention group, 14 patients (58.3%) had localized miT2b-cN0M0 disease, 6 (25.0%) had locally advanced disease (miT3a-bN0M0), 3 (12.5%) had regional disease (miN1M0), and 1 (4.2%) had nodal and distant disease (miN1M1b). Four patients (16.7%) were upstaged relative to their staging at time of randomization. All three patients with miN1M0 disease received pelvic lymph node irradiation as part of their dRT course. The patient with miN1M1b disease received upfront ADT with abiraterone acetate and prednisone followed by consolidative radiotherapy to the prostate and pelvic lymph nodes. With a median follow-up of 21 months (interquartile range: 17.6-26.3 months), there were no cases of biochemical failure (PSA &gt;2 ng/mL above nadir), radiographic or biopsy-proven recurrence, salvage therapy, or prostate cancer death in either arm. Two-year PFS was 93.8% in the PSMA PET/CT arm (due to 2 non prostate cancer deaths) and 100% in the control arm. There was no significant difference in PFS between the PSMA PET/CT and control arms ( P=0.13). Conclusions: PSMA PET/CT upstaged 17% of patients compared to prior baseline staging, which allowed for more accurate treatment planning. Due to early termination, this trial was underpowered to assess the effect of PSMA PET/CT on PFS. PSMA-dRT is currently under submission for complete enrollment and data pooling at German sites. Clinical trial information: NCT04457245 .

Pretreatment colonoscopy impact on acute gastrointestinal (GI) toxicity following curative stereotactic body radiation therapy (SBRT) for localized prostate cancer.

Pretreatment colonoscopy impact on acute gastrointestinal (GI) toxicity following curative stereotactic body radiation therapy (SBRT) for localized prostate cancer.

PSMA PET imaging for evaluation of recurrent or persistent prostate cancer after primary prostate radiation.

35 Background: PSMA PET is increasingly utilized for the evaluation of disease stage at biochemical recurrence. Here we evaluate the association of clinico-pathologic features with PSMA findings in biochemically recurrent patients after primary prostate radiation therapy (RT). Methods: We queried the Northwestern Medical System Electronic Data Warehouse between July 2021 and March 2023 to identify 122 men treated with primary RT for presumptive localized prostate cancer who subsequently underwent Gallium-68 or F-18 piflufolastat (DCFPyL) PSMA PET/CT for staging. Patient characteristics, including demographic, clinical, pathological, and imaging variables were obtained. PSMA positivity for suspicious nodal or metastatic disease was determined based on radiology interpretation, with equivocal or likely benign lesions considered as negative findings. Patients with incomplete clinical history (n=3) were excluded. Clinical variables were compared using a Wilcoxon rank-sum and Fisher’s exact tests. Regression analysis was performed to determine variables associated with PSMA positivity in biochemically recurrent patients. Statistical significance was determined if the p-value was less than 0.05. Results: Among the 119 men staged with PET PSMA after RT, median PSA was 3.18 (IQR 1.35, 5.55 ng/mL). 78% (93/119) were found to have suspicious PSMA positive disease. 39% had PSMA positivity in the prostate only (46/119), 6.7% had pelvic nodal disease (8/119), and 33% had extrapelvic disease (39/119). On univariable regression analysis, PSA at the time of PSMA was the only factor associated with PSMA positivity (OR 1.32 per 1 point increase, 95% CI 1.10, 1.67, p=0.01; Table). Higher PSAs at the time of scan were additionally associated with distant recurrence (73.3% of men with distant recurrence if scanned at PSA &gt;10ng/mL versus 31.9% if scanned at PSA &lt;4ng/mL p=0.029). 20% (9/46) of men with PSMA positivity within the prostate were biopsied identifying 78% (7/9) positivity, of which 67% (4/6) receiving treatment selected management with salvage treatments. Conclusions: Patients with prostate cancer initially treated with RT showed significant rates of PSMA positive disease even when scanned at low PSAs (including many below the nadir+2ng/mL definition). Evaluation at low PSAs favors the identification of localized disease only which can be cured by salvage therapy if confirmed by biopsy (i.e. prostatectomy, cryoablation, HIFU). [Table: see text]

Does use of apalutamide enhance outcomes in combination with radiotherapy in metastatic hormone-sensitive prostate cancer? A real-world experience from the UK.

73 Background: Management of metastatic prostate cancer has undergone a significant change over the past decade, with the introduction of several novel agents and repurposing of others. Latest update from STAMPEDE trials shown prostate radiotherapy (RT) improves OS, without detriment in QoL in metastatic home sensitive prostate cancer mHSPC along with Docetaxel in those with low volume metastatic disease. There is no published data on impact of radiotherapy to prostate on Apalutamide treated mHSPC patients. Here we report our real-world experience of Apalutamide in mHSPC with radiotherapy. Methods: Patients with mHSPC (N = 266) from 5 UK centres, were treated with Apalutamide (240 mg) and ADT along with radiotherapy to prostate as per treating clinician’s discretion. The primary endpoint was objective rate (ORR) as determined by patients achieving a PSA decline of ≥90% (PSA90) and ≥50% (PSA50) and secondary endpoints included biochemical progression free survival (bPFS) and safety. Results: The median age for the whole cohort was 73.4 years (interquartile range 52 - 91), A total of 11.6% had received prior radical treatment (prostatectomy or radiotherapy for localised disease) and 88.4% had de novo metastatic disease. Median baseline PSA was 47 ng/ml (range 0.4-17100). The proportion of patients PSA90 and PSA50 at 3, 6 and 12 months is shown in the Table. Median PSA nadir was 0.1 ng/ml(rage 0.01- 48.2) and median time to reach nadir was 6 months (range 3-24 months). 13.5% (35) patients were treated with radiotherapy (RT) after at least 3 months (range 3 -6 months) of starting apalutamide. Patients received either a daily (55 Gy in 20 fractions over 4 weeks) or weekly (36 Gy in six fractions over 6 weeks) of radiotherapy (68 % vs 32%). Higher number of patients in RT group had achieved PSA90 compared to no radiotherapy cohort (97.14 % vs 87.3%, p =0.15). Patients treated with RT had median post treatment of PSA 0.01 ng/ml compared to 0.1 ng/ml in non RT group (p=0.0062). After median follow up of 8.4 months, proportion of patients shown biochemical progression in RT vs non RT group were 5.7 % vs 15 % respectively (p= 0.04). Patients with de novo metastatic disease have shown poor PSA response and higher chance of progression compared to patients who had initial radical treatment. Radiotherapy was well tolerated, with 17 % adverse events (Radiation Therapy Oncology Group grade 3–4) reported in radiotherapy group. Conclusions: Early experience of using apalutamide and radiotherapy in mHSPC showed improved PSA response and delayed progression. Treatment was well tolerated. Further follow up and clinical trials are needed to understand the impact on overall survival. [Table: see text]

Relugolix versus leuprolide in combination with radiotherapy for localized prostate cancer (REVELUTION trial): An initial analysis of patient treatment preferences and quality of life.

301 Background: Relugolix, an oral gonadotropin releasing hormone (GnRH) antagonist, has superior testosterone suppression and may lower cardiovascular (CV) toxicity compared with more commonly used injectable GnRH agonists, such as leuprolide. The Relugolix Versus Leuprolide Trial (REVELUTION, NCT 05320406) is an ongoing, investigator-initiated, randomized trial comparing radiotherapy (XRT) plus relugolix versus XRT plus leuprolide for men with localized prostate cancer (PCa). Primary endpoint is change in coronary plaque on cardiac computed tomography from baseline to 12 months following treatment. Secondary endpoints include patient-reported outcomes (PRO). Herein, we report patient-specific treatment preferences prior to randomization and acute treatment-associated toxicity. Methods: Men with non-metastatic intact or biochemically recurrent PCa pursuing pelvic XRT (1.8-2.5 Gy per fraction) with ≥ 6 months of androgen deprivation therapy (ADT) were enrolled and randomized 1:1 to leuprolide (IM/SC 45 mg q6mo) or relugolix (PO 360 mg day 1, 120 mg daily thereafter). Prior to randomization, each patient completed an ADT preference questionnaire after reviewing an education brochure describing both drugs’ administration, testosterone kinetics, and common toxicities. PROs were assessed by International Prostate Symptom Score (IPSS) and Expanded Prostate Index Composite (EPIC-CP) at baseline and 3-/6-months after XRT initiation, with higher scores indicating more severe toxicity. Scores were compared using linear mixed-effects models accounting for within-subject correlations. Results: Between 06/2022 and 07/2023, 65 men were randomized (34 leuprolide, 31 relugolix). Median follow-up was 5 months (IQR 4-8). Prior to randomization, 61 (94%) preferred relugolix over leuprolide, due to faster testosterone recovery (n=36, 59%), lower CV risk (n=23, 38%), or oral administration (n=2, 3%); the four patients who preferred leuprolide all had compliance concerns with a daily oral pill. Compared with XRT+leuprolide, XRT+relugolix was associated with less impact on IPSS urinary score (mean difference [MD] -3.68, p=0.04). There was no difference in EPIC-CP incontinence (MD +0.07, p=0.91), bowel (MD +0.39, p=0.44), sexual (MD -0.74, p=0.43), or vitality (MD +0.17, p=0.80). Conclusions: In this trial of men with localized PCa treated with XRT plus ADT, most preferred relugolix over leuprolide. Relugolix, compared with leuprolide, mitigated acute urinary toxicity from XRT, perhaps due to superior castration resulting in greater prostate gland downsizing and less obstructive uropathy. Longer-term follow up is ongoing, and primary CV toxicity endpoint is expected to be complete in 2024. Clinical trial information: NCT05320406 .

Multi-Institutional Outcomes of Dorsal Onlay Buccal Mucosal Graft Urethroplasty in Patients With Postprostatectomy, Postradiation Anastomotic Stenosis.

The treatment of urethral stenosis after a combination of prostatectomy and radiation therapy for prostate cancer is understudied. We evaluate the clinical and patient-related outcomes after dorsal onlay buccal mucosal graft urethroplasty (D-BMGU) in men who underwent prostatectomy and radiation therapy. A multi-institutional, retrospective review of men with vesicourethral anastomotic stenosis or bulbomembranous urethral stricture disease after radical prostatectomy and radiation therapy from 8 institutions between 2013 to 2021 was performed. The primary outcomes were stenosis recurrence and development of de novo stress urinary incontinence. Secondary outcomes were surgical complications, changes in voiding, and patient-reported satisfaction. Forty-five men were treated with D-BMGU for stenosis following prostatectomy and radiation. There was a total of 7 recurrences. Median follow-up in patients without recurrence was 21 months (IQR 12-24). There were no incidents of de novo incontinence, 28 patients were incontinent pre- and postoperatively, and of the 6 patients managed with suprapubic catheter preoperatively, 4 were continent after repair. Following repair, men had significant improvement in postvoid residual, uroflow, International Prostate Symptom Score, and International Prostate Symptom Score quality-of-life domain. Overall satisfaction was +2 or better in 86.6% of men on the Global Response Assessment. D-BMGU is a safe, feasible, and effective technique in patients with urethral stenosis after a combination of prostatectomy and radiation therapy. Although our findings suggest this technique may result in lower rates of de novo urinary incontinence compared to conventional urethral transection and excision techniques, head-to-head comparisons are needed.

Prostate cancer and elective nodal radiation therapy for cN0 and pN0-anever ending story? : Recommendations from the prostate cancer expert panel of the German Society of Radiation Oncology (DEGRO).

For prostate cancer, the role of elective nodal irradiation (ENI) for cN0 or pN0 patients has been under discussion for years. Considering the recent publications of randomized controlled trials, the prostate cancer expert panel of the German Society of Radiation Oncology (DEGRO) aimed to discuss and summarize the current literature. Modern trials have been recently published for both treatment-naïve patients (POP-RT trial) and patients after surgery (SPPORT trial). Although there are more reliable data to date, we identified several limitations currently complicating the definitions of general recommendations. For patients with cN0 (conventional or PSMA-PET staging) undergoing definitive radiotherapy, only men with high-risk factors for nodal involvement (e.g., cT3a, GS ≥ 8, PSA ≥ 20 ng/ml) seem to benefit from ENI. For biochemical relapse in the postoperative situation (pN0) and no PSMA imaging, ENI may be added to patients with risk factors according to the SPPORT trial (e.g., GS ≥ 8; PSA > 0.7 ng/ml). If PSMA-PET/CT is negative, ENI may be offered for selected men with high-risk factors as an individual treatment approach.

Rectal ulceration and rectourethral fistula as rare complications of radiotherapy for prostate cancer—a case report and literature review

Rectal ulceration and rectourethral fistula as rare complications of radiotherapy for prostate cancer—a case report and literature review

Patient-reported Side Effects 1 Year After Radical Prostatectomy or Radiotherapy for Prostate Cancer: A Register-based Nationwide Study

BackgroundData on functional and psychological side effects following curative treatment for prostate cancer are lacking from large, contemporary, unselected, population-based cohorts. ObjectiveTo assess urinary symptoms, bowel disturbances, erectile dysfunction (ED), and quality of life (QoL) 12 mo after robot-assisted radical prostatectomy (RARP) and radiotherapy (RT) using patient-reported outcome measures in the Swedish prostate cancer database. Design, setting, and participantsThis was a nationwide, population-based, cohort study in Sweden of men who underwent primary RARP or RT between January 1, 2018 and December 31, 2020. Outcome measurements and statistical analysisAbsolute proportions and odds ratios (ORs) were calculated using multivariable logistic regression, with adjustment for clinical characteristics. Results and limitationsA total of 2557 men underwent RARP and 1741 received RT. Men who underwent RT were older (69 vs 65 yr) and had more comorbidities at baseline. After RARP, 13% of men experienced incontinence, compared to 6% after RT. The frequency of urinary bother was similar, at 18% after RARP and 18% after RT. Urgency to defecate was reported by 14% of men after RARP and 34% after RT. At 1 yr, 73% of men had ED after RARP, and 77% after RT. High QoL was reported by 85% of men after RARP and 78% of men after RT. On multivariable regression analysis, RT was associated with lower risks of urinary incontinence (OR 0.25, 95% confidence interval [CI] 0.19–0.33), urinary bother (OR 0.79, 95% CI 0.66–0.95), and ED (OR 0.54, 95% CI 0.46–0.65), but higher risk of bowel symptoms (OR 2.86, 95% CI 2.42–3.39). QoL was higher after RARP than after RT (OR 1.34, 95% CI 1.12–1.61). ConclusionsShort-term specific side effects after curative treatment for prostate cancer significantly differed between RARP and RT in this large and unselected cohort. Nevertheless, the risk of urinary bother was lower after RT, while higher QoL was common after RARP. Patient summaryIn our study of patients treated for prostate cancer, urinary bother and overall quality of life are comparable at 1 year after surgical removal of the prostate in comparison to radiotherapy, despite substantial differences in other side effects.