Radiotherapy For Prostate Cancer Research Articles

MDT perspective: innovative applications of stereotactic body radiation therapy in metastatic castration-resistant prostate cancer

MDT perspective: innovative applications of stereotactic body radiation therapy in metastatic castration-resistant prostate cancer

P055 Dosimetric benefits of CT-based online adaptive radiotherapy in stereotactic body radiation therapy for prostate cancer

P055 Dosimetric benefits of CT-based online adaptive radiotherapy in stereotactic body radiation therapy for prostate cancer

Neurostimulators and radiation therapy: is there any risk?

The use of neurostimulators has increased in recent decades. However, safety guidelines in patients undergoing radiotherapy are lacking. We report two cases of pelvic radiation therapy for prostate cancer in patients with spinal cord neurostimulators. The implantable pulse generator was placed close to the irradiated volume in the gluteal region and received a median and maximal dose of 2.8 Gy and 5.68Gy respectively for patient 1; and 3.65Gy and 5.15Gy respectively for patient 2. During and after radiation therapy, No dysfunction of the device was recorded. Based on the similarity with the cardiac implantable electric devices, we recommend similar safety procedures, this include: (i)a cumulative dose <5 Gy, (II)avoiding neutron-producing RT, (iii)ensuring the IPG positioning outside the direct beams, (iv)switching the device to 'off-mode' during treatment delivery, and (v) in vivo verification in case of IPG close to irradiation volume . The final decision should involve neurology specialist.

Simulation-free magnetic resonance-guided radiation therapy of prostate cancer

Background and purposeDespite recent advances of online image-guided high-precision patient positioning and adaptation using magnetic resonance imaging (MRI) or cone-beam computed tomography (CT), standard radiation therapy pathway still involves a dedicated simulation scan. The aim of this study was to evaluate the feasibility and planning quality of integrating a simulation-free treatment planning workflow for adaptive online MRI-guided radiation therapy on a 1.5 T MRI linear accelerator (MRI-Linac) in prostate cancer using diagnostic CT (dCT) scans. Materials and methodsFor ten patients with prostate cancer previously treated at the MRI-Linac with adaptive radiation therapy (42.7 Gy in 7 fractions), simulation-free reference plans based on dCT were retrospectively created, and adaptive plans were simulated for the first treatment fraction. Reference and adapted plans derived from both standard and simulation-free workflows were compared with regard to institutional dose volume criteria, followed by statistical assessment using the paired Wilcoxon signed-rank test with a Bonferroni-corrected significance level of α = 0.025. ResultsSimulation-free reference and adapted plans consistently met dose volume criteria. Statistical analysis revealed no significant differences between both workflows, except median values for near-maximum dose (D2%) in the planning target volume: 44.2 Gy (standard) vs. 44.5 Gy (simulation-free) in reference plans (p = 0.014), and 44.5 Gy vs. 44.6 Gy in adapted plans (p = 0.009). ConclusionThis study demonstrated the feasibility of simulation-free radiation therapy planning using dCT. Comparable treatment plan quality was observed for both reference and adapted radiation therapy plans in a curative setting for patients with prostate cancer.

P070 Clinical and treatment factors associated with PSA bounce or recurrence: Decoding a rising PSA after radiation therapy for prostate cancer

P070 Clinical and treatment factors associated with PSA bounce or recurrence: Decoding a rising PSA after radiation therapy for prostate cancer

P062 Hypofractionated postoperative radiotherapy in prostate cancer: Long-term experience

P062 Hypofractionated postoperative radiotherapy in prostate cancer: Long-term experience

Comparative Cardiovascular Risks of Radical Prostatectomy and External Beam Radiation Therapy in Early-Stage Prostate Cancer: A Comprehensive Retrospective Analysis.

The risk of cardiac disease mortality has recently become a focal point of concern within the medical community for patients with prostate cancer (PCa). Given that radical prostatectomy (RP) and external beam radiation therapy (EBRT) are the main treatment modalities for localized PCa, their specific impact on cardiovascular-specific mortality (CSM) remains unclear. This study explored the specific effects of RP and EBRT on CSM risk to guide clinical treatment decisions. Data from patients aged 45-74years, who were diagnosed with T1-2N0M0 stage PCa from the SEER database (2010-2015), were used. Multivariate statistical methods, including propensity score matching (PSM), competing risk regression, COX regression analysis, and Fine-Gray testing, were applied to assess the impact of RP and EBRT on CSM risk. Among 146,082 T1-2 stage PCa patients, cardiac disease emerged as the primary cause of death, surpassing PCa itself. Multifactorial COX regression and competing risk regression analyses indicated that local treatments do not increase CSM risk. Further analysis revealed a significant increase in CSM risk for patients undergoing only EBRT compared with those undergoing only RP (hazard ratio [HR] = 2.71, 95% confidence interval [CI] 1.96-3.74, P < 0.001), with subsequent PSM adjustment, further confirming a significantly reduced risk in the RP treatment group (HR 0.23, 95% CI 0.13-0.40, P < 0.001). T1-2 stage PCa patients face a significant risk of CSM, with RP offering a potential advantage over EBRT in reducing this risk. These findings encourage clinicians to comprehensively consider the potential impact on cardiac health when formulating treatment plans, providing crucial guidance for optimizing treatment strategies.

P050 Real-world risk of death from cardiovascular disease, prostate cancer, and other causes in patients treated with radical prostatectomy or definitive radiation therapy for high-risk prostate cancer

P050 Real-world risk of death from cardiovascular disease, prostate cancer, and other causes in patients treated with radical prostatectomy or definitive radiation therapy for high-risk prostate cancer

Prostate-specific antigen kinetics after stereotactic body radiotherapy for localized prostate cancer: A scoping review and meta-analysis

Prostate-specific antigen kinetics after stereotactic body radiotherapy for localized prostate cancer: A scoping review and meta-analysis

Is Centralisation of Cancer Services Associated With Under-Treatment of Patients With High-Risk Prostate Cancer?-A National Population-Based Study.

Centralising prostate cancer surgical and radiotherapy services, requires some patients to travel longer to access treatment, but its impact on actual treatment utilisation and outcomes is unknown. Using national cancer registry records linked to administrative hospital data, we identified all patients with high risk and locally advanced prostate cancer diagnosed between 1 April 2019 and 31 March 2020 in the English National Health Service (n = 15,971). Estimated travel times from the patient residential areas to the nearest hospital providing surgery or radiotherapy were estimated for journeys by car and by public transport. Multivariable logistic regression was used to model relationships between travel time and receipt of care with adjustment for patient characteristics. 10,693 (67%) men received radical surgery or radiotherapy (RT) within 12 months of diagnosis. Average travel time to the nearest hospital providing prostatectomy or RT was 23.2 min by private car and 58.2 min by public transport. We found no association between travel time, either by car or public transport and the likelihood of receiving curative treatment. Patients living in the most socially deprived areas, those aged over 70, those with two or more comorbidities, and those of black ethnic origin, were less likely to receive curative treatment (p& =& 0.001 for all associations). The current configuration of national prostate cancer services is not associated with the likelihood of receiving curative treatment. Further increases in capacity will unlikely improve utilisation rates beyond addressing sociodemographic barriers.

Defining the potential for sexual structures-sparing for prostate cancer external beam radiotherapy: A dosimetric study

PurposeThe purpose of the study was to evaluate the dosimetric impact of sexual-sparing radiotherapy for prostate cancer, with magnetic resonance-only treatment planning. Material and methodsFifteen consecutive patients receiving prostate cancer radiotherapy were selected. A synthetic CT was generated with a deep learning method from each T2-weighted MRI performed at the time of treatment planning. For each patient, two plans were performed: standard treatment planning and sexual-structures sparing treatment planning. The treatment plan was designed to deliver a dose of 78Gy to the prostate and 50Gy to the seminal vesicles in 2Gy daily fractions, using volumetric arc therapy. Dose–volume histograms were computed to compare treatment plans. ResultsAll plans fulfilled dosimetric objectives and were equivalent regarding planning target volume coverage. The doses delivered to both rectum, bladder, and femoral heads were similar between plans (P=0.20). Sexual-sparing plans enabled to decrease all dosimetric parameters on sexual organs-at-risk. The mean penile bulb dose in sexual-sparing plans was significantly reduced (21.1Gy±20.7 versus 13.4Gy±14.0, P<0.01), however with large variability observed between individuals. The mean dose delivered to the corpora cavernosa was also significantly reduced within sexual-sparing plans (13.1Gy±16.7 versus 8.6Gy±10.4, P<0.01). A significant reduction was also observed in the highest doses delivered to internal pudendal arteries (D10%: 48.4Gy±8.3 versus 33.1Gy±4.6, P<0.05; D5%: 52.0Gy±8.7 versus 36.8Gy±5.5, P<0.05). ConclusionSparing of sexual structures appears feasible, without compromising neither planning target volume coverage nor doses delivered to non-sexual organs at risk. The clinical significance of this dose-reduction requires prospective evaluation.

Elective pelvic nodal irradiation in the setting of ultrahypofractionated versus moderately hypofractionated and conventionally fractionated radiotherapy for prostate cancer: Outcomes from 3 prospective clinical trials

Background and purposeData is needed regarding the use of ultrahypofractionated radiotherapy (UHRT) in the context of prostate cancer elective nodal irradiation (ENI), and how this compares to conventionally fractionated radiotherapy (CFRT) ENI with CFRT or moderately hypofractionated radiotherapy (MHRT) to the prostate. Materials and methodsBetween 2011–2019, 3 prospective clinical trials of unfavourable intermediate or high-risk prostate cancer receiving CFRT (78 Gy in 39 fractions to prostate; 46 Gy in 23 fractions to pelvis), MHRT (68 Gy in 25 fractions to prostate; 48 Gy to pelvis), or UHRT (35–40 Gy in 5 fractions to prostate +/- boost to 50 Gy to intraprostatic lesion; 25 Gy to pelvis) were conducted. Primary endpoints included biochemical failure (Phoenix definition), and acute and late toxicities (CTCAE v3.0/4.0). ResultsTwo-hundred-forty patients were enrolled: 90 (37.5 %) had CFRT, 90 (37.5 %) MHRT, and 60 (25 %) UHRT. Median follow-up time was 71.6 months (IQR 53.6–94.8). Cumulative incidence of biochemical failure (95 % CI) at 5-years was 11.7 % (3.5–19.8 %) for CFRT, 6.5 % (0.8–12.2 %) MHRT, and 1.8 % (0–5.2 %) UHRT, which was not significantly different between treatments (p = 0.38). Acute grade ≥ 2 genitourinary toxicity was significantly worse for UHRT versus CFRT and MHRT, but not for acute grade ≥ 3 genitourinary, or acute gastrointestinal toxicities. UHRT was not associated with worse late toxicities. ConclusionENI with UHRT resulted in similar oncologic outcomes to CFRT ENI with prostate CFRT/MHRT, with worse acute grade ≥ 2 GU toxicity but no differences in late toxicity. Randomized phase 3 trials of ENI using UHRT techniques are much anticipated.

Normal tissue complication probability modeling for late rectal bleeding after conventional or hypofractionated radiotherapy for prostate cancer

PurposeTo develop a single NTCP model for grade ≥ 2 late rectal bleeding (G2 LRB) after conventional or hypofractionated radiotherapy for prostate cancer. Methods and MaterialsThe development dataset consisted of prostate cancer patients (n = 656) previously randomized to conventional (39 x 2 Gy) or hypofractionated (19 x 3.4 Gy) external beam radiotherapy with N = 89 G2 LRB cases. Candidate predictors were obtained from literature. We fitted five separate logistic regression models to the data, each with one of the following dose parameters as candidate predictors in biological effective dose (BED), assuming α/β = 3 Gy: Equivalent uniform dose (EUD) with n = 0.1, EUD with n = 0.2, the relative volume receiving ≥ 111.9 Gy in BED (V111.9, the equivalent of physical V70 for a conventional schedule), minimum BED to the hottest 0.1 cm3 (D0.1cm3) or 2 cm3 (D2cm3). Previous abdominal surgery was included in every model and fractionation schedule was tested as predictor in each model. A sensitivity analysis was performed by varying the α/β-ratio, n and dose-volume cutoff. ResultsThe pre-selected candidate dosimetric predictor and previous abdominal surgery were significantly associated with the outcome in all five models. Fractionation schedule was eliminated by the backward scheme in only the EUD (n = 0.1), D0.1cm3 and D2cm3-based models. In internal validation these models showed AUC’s of 0.64, 0.60 & 0.62, respectively. The sensitivity analyses showed that EUD models with n ≥ 0.15 and / or α/β ≥ 4 Gy failed, and EUD models based on α/β = 2 Gy with n = 0.05–0.2 showed good fits as well. ConclusionsOur trial data set with different fractionation schedules offered the unique possibility to generate unbiased BED-based models. EUD (n = 0.1), D0.1cm3 and D2cm3 performed overall best in predicting G2 LRB; with α/β = 2 Gy equally good models were obtained. External validation is required to confirm our results.

P077 Updated results of patient-reported outcomes to assess quality of life in PSMA-PET and mpMRI-based focal dose escalation in definitive radiotherapy for prostate cancer (HypoFocal Phase II study)

P077 Updated results of patient-reported outcomes to assess quality of life in PSMA-PET and mpMRI-based focal dose escalation in definitive radiotherapy for prostate cancer (HypoFocal Phase II study)

P063 MR-guided online adaptive ultra-hypofractionated radiotherapy for prostate cancer

P063 MR-guided online adaptive ultra-hypofractionated radiotherapy for prostate cancer

Hypofractionated radiotherapy with simultaneous integrated boost for localized prostate cancer patients: effects on immune system and prediction of toxicity.

The other side of radiotherapy (RT), in addition to the cytotoxic effect, is the ability to modulate the immune system in terms of activation or suppression, also depending on the dose and fractionation delivered. This immune RT effect can be detected both locally in the irradiated tumor site and in the peripheral blood. The aim of this study was to assess the consequence of pelvic irradiation on peripheral immune cells and cytokine secretions in localized prostate cancer (PC) patients undergoing pelvic irradiation with a simultaneous moderately hypofractionated prostate/prostate bed boost by Volumetric Modulated Arc Therapy (VMAT). Furthermore, we analyzed whether there was a correlation between these peripheral immune parameters and acute and late genitourinary (GU) and gastrointestinal (GI) toxicity. Thirty-eight PC patients were treated with pelvis irradiation (dose per fraction 1.8 Gy) and simultaneous hypofractionated (median dose per fraction: 2.7 Gy) prostate/prostate bed boost. A longitudinal analysis was performed for 12 months on peripheral blood to assess changes in 9 different lymphocyte subpopulations by flow cytometry and 10 circulating cytokines by Multiplex Luminex assay and ELISA. Our analysis revealed that basal IFN-γ serum values were significantly lower in the definitive (curative intent for patients with prostate) patient group respect to the post-operative one. All the lymphocyte subsets and IFN-α, IFN-β and Il-2 peripheral concentrations displayed significant variations between the different time points considered. The immune cell population that suffers the greatest RT toxicity in the blood was B lymphocyte. We found an interesting correlation between basal TGF-β1 and late GU toxicity. In particular, TGF-β1 concentrations before RT were significantly higher in patients that experienced grade 2-3 of late GU toxicity, respect to grade 0-1. Exploring possible correlations between some clinical/biological findings and radiation planning parameters, we found no statistical significance. Our study analyzed, in the context of hypofractionated radiotherapy in prostate cancer, different parameters of the peripheral immune system. We have highlighted longitudinally the peripheral behavior of the different lymphocyte subpopulations and of a group of 10 cytokines during the first year after RT. One of the analyzed cytokines, such as TGF-β1, has proven to be promising predictive factor of severe late GU toxicity.

Mortality rates in radical cystectomy patients with bladder cancer after radiation therapy for prostate cancer.

To conduct a population-based study examining cancer-specific mortality (CSM) and other-cause mortality (OCM) differences in patients with radiation-induced secondary bladder cancer (RT-BCa) vs those with primary bladder cancer (pBCa) undergoing radical cystectomy (RC). Within the Surveillance, Epidemiology, and End Results database (2004-2020), we identified patients with T2-4N0-3M0 bladder cancer treated with RC, who had previously been treated with external beam radiation therapy (EBRT) or brachytherapy for prostate cancer, as well as patients with T2-4N0-3M0 pBCa treated with RC. Cumulative incidence plots and multivariable competing risks regression (CRR) models were used to assess CSM after additional adjustment for OCM. The same methodology was then repeated based on organ-confined (OC: T2N0M0) and non-organ-confined (NOC: T3-4 and/or N1-3) disease. Of 9957 RC patients, RT-BCa was identified in 347 (3%) compared with 9610 (97%) who had pBCa. In multivariable CRR models, no CSM differences were recorded in the overall comparison (P = 0.8), nor in sub-groups based on OC and NOC disease (P = 0.8 and 0.7, respectively). Conversely, multivariable CRR models identified RT-BCa as an independent predictor of 1.3-fold higher OCM in the overall cohort and of 1.5-fold higher OCM in those with NOC disease. In a sensitivity analysis of patients with NOC disease, EBRT was associated with higher OCM rates (hazard ratio 1.5). By contrast, OCM rates were not different in those with OC disease (P = 0.8). Our study showed that RC for RT-BCa was associated with similar CSM rates as RC for pBCa, regardless of disease stage. However, patients who had undergone EBRT exhibited significantly higher OCM in the NOC sub-group.

Assessing the Impact of the Prostate Cancer Patient Empowerment Program (PC-PEP) on Relationship Satisfaction, Quality of Life, and Support Group Participation: A Randomized Clinical Trial.

Background/Objectives: The Prostate Cancer Patient Empowerment Program (PC-PEP) is a 6-month, home-based intervention aimed at enhancing mental health in men undergoing curative prostate cancer treatment. This exploratory secondary analysis evaluates PC-PEP's impact on relationship satisfaction, quality of life, and support group attendance among partnered participants. Methods: In a crossover randomized clinical trial ClinicalTrials.gov identifier: NCT03660085) of 128 men aged 50-82 scheduled for curative prostate cancer surgery or radiotherapy, 119 participants in relationships were included. Of these, 59 received the 6-month PC-PEP intervention, while 60 were randomized to a waitlist-control arm, receiving standard care for 6 months before starting PC-PEP. The intervention included daily emails with video instructions on mental and physical health, diet, social support, fitness, stress reduction, and intimacy. Outcomes were assessed using the Dyadic Adjustment Scale (DAS) and the Functional Assessment of Cancer Therapy-Prostate (FACT-P). Results: While relationship satisfaction remained stable, a significant improvement in emotional well-being was observed at 12 months in participants undergoing radiation therapy (p = 0.045). The PC-PEP intervention also led to significantly higher support group attendance at both 6 months (p = 0.001) and 12 months (p = 0.003), emphasizing its role in fostering social support and community engagement. Conclusions: The PC-PEP program effectively maintains relationship satisfaction and enhances emotional well-being, particularly in patients with fewer physical side effects. Its design promotes comprehensive care by integrating physical, psychological, and social support, making it a valuable resource for improving the quality of life in prostate cancer patients and potentially applicable to other cancer types.

Radiotherapy for Oligometastatic Prostate Cancer

Radiotherapy for Oligometastatic Prostate Cancer

Prediction of prostate cancer recurrence after radiotherapy using a fused machine learning approach: utilizing radiomics from pretreatment T2W MRI images with clinical and pathological information

The risk of biochemical recurrence (BCR) after radiotherapy for localized prostate cancer (PCa) varies widely within standard risk groups. There is a need for low-cost tools to more robustly predict recurrence and personalize therapy. Radiomic features from pretreatment MRI show potential as noninvasive biomarkers for BCR prediction. However, previous research has not fully combined radiomics with clinical and pathological data to predict BCR in PCa patients following radiotherapy.&#xD;Purpose: This study aims to predict 5-year BCR using radiomics from pretreatment T2W MRI and clinical-pathological data in PCa patients treated with radiation therapy, and to develop a unified model compatible with both 1.5T and 3T MRI scanners.&#xD;Methods: A total of 150 T2W scans and clinical parameters were preprocessed. Of these, 120 cases were used for training and validation, and 30 for testing. Four distinct machine learning models were developed: Model 1 used radiomics, Model 2 used clinical and pathological data, and Model 3 combined these using late fusion. Model 4 integrated radiomic and clinical-pathological data using early fusion.&#xD;Results: Model 1 achieved an AUC of 0.73, while Model 2 had an AUC of 0.64 for predicting outcomes in 30 new test cases. Model 3, using late fusion, had an AUC of 0.69. Early fusion models showed strong potential, with Model 4 reaching an AUC of 0.84, highlighting the effectiveness of the early fusion model.&#xD;Conclusions: This study is the first to use a fusion technique for predicting BCR in PCa patients following radiotherapy, utilizing pre-treatment T2W MRI images and clinical-pathological data. The methodology improves predictive accuracy by fusing radiomics with clinical-pathological information, even with a relatively small dataset, and introduces the first unified model for both 1.5T and 3T MRI images.