Rectal Toxicity Research Articles

SpaceOAR Persistence on MRI at 59 Weeks Postplacement in a Patient With Stage IV CKD

External beam radiation therapy is commonly used to treat prostate cancer, and gel spacers such as SpaceOAR Hydrogel (Boston Scientific, Marlborough, MA) are approved to limit local rectal radiation toxicity. SpaceOAR is usually reabsorbed in 12 to 24 weeks and excreted renally. It has a known low rate of rectourethral fistula that is usually associated with ectopic placement into the rectal wall. We present a case of a SpaceOAR Hydrogel insert persisting in a patient with chronic kidney disease on serial MRI scans for 59 weeks after placement with colovesical fistula development 81 weeks after placement of unclear association.

Depth of Hydrogel Spacer Rectal Wall Infiltration Was Not Associated With Rectal Toxicity: Results From a Randomized Prospective Trial

Depth of Hydrogel Spacer Rectal Wall Infiltration Was Not Associated With Rectal Toxicity: Results From a Randomized Prospective Trial

Image-guided brachytherapy for pediatric bladder and/or prostate rhabdomyosarcoma: toward an increased personalization of treatment.: Brachytherapy in uro-pediatric rhabdomyosarcoma

IntroductionRhabdomyosarcoma (RMS) is the most common soft tissue cancer in children. Around 15% of RMS involve the bladder and/or prostate (BP). Overall survival is around 85%. After chemotherapy, patients receive local treatment based on surgery and/or radiotherapy. In recent decades, image guidance and pulsed dose-rate (PDR) brachytherapy have made it possible to personalize treatment, reduce radiation-related toxicity, while maintaining a good tumor control. We report one of the largest series of image-guided brachytherapy for pediatric RMS BP. Material and methodsThe clinical and dosimetric parameters of children treated with brachytherapy for BP RMS between July 2014 and September 2020 were retrospectively reviewed. Patients were treated with a multimodal conservative approach, combining partial conservative surgery (preservation of the bladder neck and urethra), followed by an interstitial brachytherapy procedure. Iridium-192 PDR treatment was administered on the basis of CT and MRI planning. Toxicities were reported according to version 4.0 of the Common Terminology Criteria for Adverse Events. ResultsA total of 75 patients were identified, with a median age of 29 months (range 2–84) at diagnosis. The median brachytherapy dose was 60.06 Gy (143 pulses, 0.42 Gy/pulse). With a median follow-up of 44.1 months (range 0.7–90), the 5-year OS and PFS rates were 97.3% and 92% respectively. Median D50% for the bladder and D1cc for the rectum were 38.6 Gy and 49 Gy respectively. The 5-year probability of survival without severe late urinary toxicity (grade 3 or higher) was estimated at 78.8% (CI95%: 68.1–91.1). A total of 9.3% of children experienced grade 2 or 3 late rectal toxicity. ConclusionsImage-guided PDR brachytherapy offers a personalized treatment for pediatric BP RMS, with a favorable therapeutic index. No prognostic factors for urinary toxicity have been identified. Multicenter studies with larger numbers of patients are needed to clarify these data.

Impact of neoadjuvant androgen deprivation therapy on toxicity in intensity-modulated radiation therapy for prostate cancer.

This study aimed to compare toxicities, prostate volume and dosimetry, between patients who underwent intensity-modulated radiation therapy (IMRT) combined with ≥3months of neoadjuvant androgen deprivation therapy (NADT) and those without NADT for prostate cancer. In total, 449 patients with intermediate- and high-risk prostate cancer received 78Gy IMRT in 39 fractions, of which 129 were treated without any ADT (non-ADT group) and 320 with NADT ≥3months (NADT group). Adverse events and dose-volume indices were compared between the two groups retrospectively. The NADT group had a lower rate of acute grade 2 gastrointestinal (GI) toxicities (17% vs 25%, P = 0.063) and late grade 2 GI toxicities (P = 0.055), including a significantly lower rate of late grade 2 rectal hemorrhage (P = 0.033), compared with the non-ADT group. There were no cases of late grade 3 or higher GI toxicities. The average volume of the prostate in the NADT group was 38% smaller than that in the non-ADT group (43.7 vs 27.0cm3, P < 0.001). Bladder V40Gy and V50Gy, and rectum V40Gy, V50Gy, V60Gy and V70Gy were significantly smaller in the NADT group. In the NADT group, no significant difference was observed in adverse events or dosimetry between the subgroups with NADT ≥12 and <12months. Acute and late rectal toxicities were reduced by NADT within ≥3months in accordance with reduced prostate volume and improved rectal dosimetry. This suggests a merit of administering neoadjuvant ADT ≥3months for reducing rectal toxicities.

Long-term evaluation of the safety of a rectal-prostate spacer, the ProSpace® balloon, in patients treated with radiotherapy for prostate cancer

BackgroundDue to the close proximity of the prostate and rectum, rectal toxicity remains a major problem in patient treated by radiotherapy for prostate adenocarcinoma. One method of increasing the distance between the prostate and the rectum is to use a spacer implanted into the rectoprostatic space. This report describes the long-term outcomes obtained with a new ballon spacer.MethodsPatients treated with curative radiotherapy for low- or intermediate-risk prostate adenocarcinoma, who underwent insertion of the ProSpace® (BioProtect Ltd, Tzur Yigal, Israel) rectal-prostate balloon spacer, were included. The main objective was to evaluate the dosimetric benefit of the spacer for OARs. The secondary objectives were to evaluate the feasibility and tolerability of ProSpace® balloon placement and to evaluate its long-term therapeutic efficacy and tolerance.ResultsBetween October 2013 and March 2015, 16 patients were enrolled in the Pasteur Clinic, Toulouse, France. The median follow-up was 85.5 months. From top to bottom, the space created was a mean of 16.3 mm (range: 11–20.5 mm) at the base of the prostate, 12.1 mm (range: 4–16 mm) at the middle and 8.9 mm at the apex (range: 5–15 mm). On average, rectal volumes receiving a dose of 70 Gy, 60 Gy and 50 Gy were significantly lower after balloon implantation: -4.81 cc (1.5 vs. 6.3; p < 0.0005), -8.08 cc (6.4 vs. 14.5; p = 0.002) and -9.06 cc (16.7 vs. 25.7; p = 0.003), respectively. There were significant differences in coverage after balloon implantation: Median V95% (p < 0.0005), median Dmin (p = 0.01) and median V98% (p < 0.001) were higher after balloon implantation. At 5 years, cumulative gastrointestinal toxicity was grade 1 in 6% (1/16 patients). No toxicity of grade 2 or higher was found. At 5 years, no urinary toxicity grade 3 or 4 toxicity was found. The QoL was not deteriorated.ConclusionsThe use of the ProSpace® balloon seems to be well accepted by patients, allowing a double dosimetric gain: a decrease in doses received by the rectum and an improvement in the coverage of the high-risk PTV. The long-term gastrointestinal toxicity remains low and QoL is preserved in all treated patients.

Salvage radiotherapy for locally recurrent cervical and endometrial carcinoma: clinical outcomes and toxicities

BackgroundThe management of locally recurrent gynecological carcinoma remains a challenge due to the limited availability of data. This study aims to share our institutional experience in using definitive radiotherapy (RT) for the treatment of locally recurrent cervical and endometrial carcinoma.MethodsThe study retrospectively reviewed 20 patients in our hospital completing salvage 3D image-based HDR brachytherapy, with or without EBRT, for locally recurrent cervical and endometrial carcinoma after surgery. The Kaplan–Meier method was applied to estimate the disease-free survival (DFS) and overall survival (OS). The toxicities were assessed by CTCAEv5.ResultsDuring a median observation period of 21 months, the study reported a tumor objective response rate of 95%. The 3-year DFS and OS rates were 89.4% and 90.9%, respectively. The EBRT combined with brachytherapy achieved a median cumulative dose of 88 Gy to CTV D90. 14 patients received concurrent and/or systemic chemotherapy. Two patients suffered locoregional recurrence after salvage treatment, one of whom only received salvage brachytherapy for prior RT history. The analysis identified significant predictors for DFS, including tumor histology and FIGO stage. 5 patients observed acute grade 1–2 rectal (15%) or genitourinary (10%) toxicities. Late toxicities including grade 1–2 rectal bleeding (10%) and grade 2 pelvic fracture (5%) were seen in 3 patients.Conclusions3D image-guided brachytherapy combined with EBRT shows effective tumor control and acceptable toxicity profile for women with locally recurrent gynecologic cancer. The success in managing vaginal recurrence is notably influenced by histologic subtype and FIGO staging.

611 Hydrogel Vue Spacer in Prostate Cancer Radiotherapy for Patients with Inflammatory Bowel Disease (IBD): Pilot Study

Abstract Introduction Patients with Inflammatory Bowel Disease and those with previous rectal surgery may have challenges when undergoing prostate radiotherapy due to increased rectal toxicity after radiotherapy which may preclude them from having radiotherapy for their prostate cancer. We need solutions that can minimize rectal toxicity while maintaining the efficacy of radiotherapy for patients. We report on our experience using SpaceOAR Hydrogel Spacer as a solution to minimize the radiation dose to the rectum and reduce toxicities. Aim To assess the benefits of SpaceOAR Hydrogel spacers following radiotherapy in patients who are at risk than average of rectal toxicity. Method We collected data from patients with IBD or previous rectal/bowel surgery who received radical radiotherapy with SpaceOAR Vue™ Hydrogel from period between Sep/2021 and Sep/2022. Data was collected including age, stage, baseline PSA, Gleason score, number of endoscopic assessment required and need for any surgical/medical intervention within one-year after completion of their radiotherapy. Results 16 patients were included in the study with one year follow up. The range of age is (62-82 years), the dose of radiotherapy varies between 6000-7400Gy and the initial PSA range was (6.1-89). 8 patients required endoscopic assessment within 1 year of treatment (As a part of their normal follow-up). was normal in all patients except in 3 patients who has mild colitis. Biochemical control at one year was excellent. Conclusions Results demonstrated that the use of Hydrogel spacer in patients with IBD or previous bowel surgery undergoing radical prostate cancer radiotherapy is safe and is a reasonable strategy.

Helical Tomotherapy Versus 3-Dimensional Conformal Radiation Therapy in High-Risk Prostate Cancer: A Phase 3 Randomized Controlled Trial

We present long-term outcomes from a phase 3 randomized controlled trial that compared helical tomotherapy with 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of high-risk prostate cancer. Newly diagnosed patients with high-risk prostate cancer were randomly allocated to receive radical radiation therapy (RT) using 3D-CRT or helical tomotherapy. In both arms, patients received an initial dose of 46 Gy in 23 fractions to the prostate and pelvic lymph nodes, followed by an additional boost to the prostate of 32 Gy in 16 fractions. RT was combined with 3 years of adjuvant androgen deprivation. The primary endpoint was late (>90 days since RT initiation) rectal toxicity. Overall,123 patients were randomly assigned to either the 3D-CRT (n = 60) or tomotherapy (n = 63) arms. The median follow-up was 161 months. Overall, the proportion of patients with grade ≥ 2 late rectal toxicity was 8.3% (95% CI, 3.1-19.1; n = 5) in the 3D-CRT arm and 11.1% (95% CI, 5.0-22.2; n = 7) in the tomotherapy arm with no significant between-arm difference (P = .83). There was no significant difference (P = .17) in the proportion of patients with late grade ≥ 2 genitourinary toxicity:10.0% (95% CI, 4.1-21.2) in the 3D-CRT arm and 20.6% (95% CI, 11.9-33.0) in the tomotherapy arm. There was no significant difference in the hazard of biochemical progression or death between the 2 groups (hazard ratio for the tomotherapy arm: 0.72; 95% CI, 0.46-1.15; P = .17). In this phase 3 trial, the overall incidence of grade ≥ 2 rectal toxicity was low and was not significantly different between the 2 arms. There was no significant evidence of improved biochemical progression-free survival in patients treated with tomotherapy. These findings should be interpreted considering the possibility of type II errors due to limited sample size and low event rates.

Utilization of machine learning methods for prediction of acute and late rectal toxicity due to curative prostate radiotherapy.

Rectal toxicity is one of the primary dose-limiting side effects of prostate cancer radiotherapy, and consequential impairment on quality of life in these patients with long survival is an important problem. In this study, we aimed to evaluate the possibility of predicting rectal toxicity with artificial intelligence model which was including certain dosimetric parameters. One hundred and thirty-seven patients with a diagnosis of prostate cancer who received curative radiotherapy for prostate +/- pelvic lymphatics were included in the study. The association of the clinical data and dosimetric data between early and late rectal toxicity reported during follow-up was evaluated. The sample size was increased to 274 patients by synthetic data generation method. To determine suitable models, 15 models were studied with machine learning algorithms using Python 2.3, Pycaret library. Random forest classifier was used with to detect active variables. The area under the curve and accuracy were found to be 0.89-0.97 and 95%-99%, respectively, with machine learning algorithms. The sensitivity values for acute and toxicity were found to be 0.95 and 0.99, respectively. Early or late rectal toxicity can be predicted with a high probability via dosimetric and physical data and machine learning algorithms of patients who underwent prostate +/- pelvic radiotherapy. The fact that rectal toxicity can be predicted before treatment, which may result in limiting the dose and duration of treatment, makes us think that artificial intelligence can enter our daily practice in a short time in this sense.

Salvage low-dose-rate brachytherapy for locally recurrent prostate cancer after definitive irradiation

PurposeThe optimal management of locally recurrent prostate cancer after definitive irradiation is still unclear but local salvage treatments are gaining interest. A retrospective, single-institution analysis of clinical outcomes and treatment-related toxicity after salvage I-125 low-dose-rate (LDR) brachytherapy (BT) for locally-recurrent prostate cancer was conducted in a Comprehensive Cancer Center. Patients and methodsA total of 94 patients treated with salvage LDR-BT between 2006 and 2021 were included. The target volume was either the whole-gland +/- a boost on the GTV, the hemigland, or only the GTV. The prescribed dose ranged from 90 to 145 Gy. Toxicity was graded by Common Terminology Criteria for Adverse Events (CTCAE) v5.0. ResultsMedian follow-up was 34 months. Initial radiotherapy was external beam radiotherapy in 73 patients (78 %) with a median dose of 76 Gy and I-125 BT in 21 patients (22 %) with a prescribed dose of 145 Gy. Median PSA at salvage was 3.75 ng/ml with a median interval between first and salvage irradiation of 9.4 years. Salvage brachytherapy was associated with androgen deprivation therapy for 32 % of the patients. Only 4 % of the patients were castrate-resistant. Failure free survival was 82 % at 2 years and 66 % at 3 years. The only factors associated with failure-free survival on multivariate analysis were hormonosensitivity at relapse and European Association of Urology (EAU) prognostic group. Late grade 3 urinary and rectal toxicities occurred in 12 % and 1 % of the patients respectively.No significant difference in toxicity or efficacy was observed between the three implant volume groups. ConclusionThe efficacy and toxicity results are consistent with those in the LDR group of the MASTER meta-analysis. Salvage BT confirms to be an effective and safe option for locally recurrent prostate cancer. A focal approach could be interesting to reduce late severe toxicities, especially urinary.

Impact of Rectal Spacer on Toxicity Reduction in Men Treated With Proton Versus Photon Therapy

PurposeRectal toxicity after prostate cancer (PCa) radiation therapy (RT) may be greater with protons compared with photon intensity-modulated RT, perhaps due to lateral penumbra and end-of-range uncertainty. Rectal spacers (RSs) have been shown to mitigate RT-associated acute/late rectal toxicity in men treated with photons. The relative benefit of RS in men treated with protons versus photons is unknown. We hypothesize that RS will confer greater bowel toxicity benefits in PCa treated with protons versus photons. Materials and MethodsWe conducted a single institution, retrospective review of men receiving photon intensity-modulated RT or pencil-beam scanning proton RT for localized PCa. Four cohorts were compared: photon with or without RS, and proton with or without RS. Acute (<3 months), late (≥3 months), and most recent toxicity were compared among the 4 cohorts. The cumulative incidence of physician-reported grade 1 to 2 gastrointestinal (GI) toxicity (common terminology criteria for adverse events V5.0) was compared using χ2 or Fisher exact test. Patient-reported toxicity was evaluated using the International Prostate Expanded Prostate Composite Index-Clinical Practice and compared using linear mixed modeling. ResultsIn total, 164 patients were eligible for analysis: 38 photons without RS, 50 photons with RS, 26 protons without RS, and 50 protons with RS. The median follow-up was 17.6 months. In proton patients, acute (6.12% vs 30.77%, P = .009) and most recent (4.26% vs 26.09%, P = .01) G1-2 GI toxicity was lower with versus without RS. In photon patients, there were no significant differences in toxicity with versus without RS. No significant differences in patient-reported outcomes were observed with versus without RS in photon or proton groups. ConclusionThe rectal spacer was associated with lower G1-2 acute and most recent GI toxicity in men treated with protons; this difference was not observed in men treated with photons. While this study is limited by sample size, a relatively greater benefit of RS with proton versus photon therapy was observed.

Effect of synthetic CT on dose-derived toxicity predictors for MR-only prostate radiotherapy.

Toxicity-driven adaptive radiotherapy (RT) is enhanced by the superior soft tissue contrast of magnetic resonance (MR) imaging compared with conventional computed tomography (CT). However, in an MR-only RT pathway synthetic CTs (sCT) are required for dose calculation. This study evaluates 3 sCT approaches for accurate rectal toxicity prediction in prostate RT. Thirty-six patients had MR (T2-weighted acquisition optimized for anatomical delineation, and T1-Dixon) with same day standard-of-care planning CT for prostate RT. Multiple sCT were created per patient using bulk density (BD), tissue stratification (TS, from T1-Dixon) and deep-learning (DL) artificial intelligence (AI) (from T2-weighted) approaches for dose distribution calculation and creation of rectal dose volume histograms (DVH) and dose surface maps (DSM) to assess grade-2 (G2) rectal bleeding risk. Maximum absolute errors using sCT for DVH-based G2 rectal bleeding risk (risk range 1.6% to 6.1%) were 0.6% (BD), 0.3% (TS) and 0.1% (DL). DSM-derived risk prediction errors followed a similar pattern. DL sCT has voxel-wise density generated from T2-weighted MR and improved accuracy for both risk-prediction methods. DL improves dosimetric and predicted risk calculation accuracy. Both TS and DL methods are clinically suitable for sCT generation in toxicity-guided RT, however, DL offers increased accuracy and offers efficiencies by removing the need for T1-Dixon MR. This study demonstrates novel insights regarding the effect of sCT on predictive toxicity metrics, demonstrating clear accuracy improvement with increased sCT resolution. Accuracy of toxicity calculation in MR-only RT should be assessed for all treatment sites where dose to critical structures will guide adaptive-RT strategies. Patient data were taken from an ethically approved (UK Health Research Authority) clinical trial run at Guy's and St Thomas' NHS Foundation Trust. Study Name: MR-simulation in Radiotherapy for Prostate Cancer. ClinicalTrials.gov Identifier: NCT03238170.

Effect of Polyacrylamide-Based Rectal Gel Spacers on Dose Distribution and Rectal Toxicity during High-Dose-Rate Brachytherapy for Prostate Cancer

Effect of Polyacrylamide-Based Rectal Gel Spacers on Dose Distribution and Rectal Toxicity during High-Dose-Rate Brachytherapy for Prostate Cancer

145: Radiomics with accumulated delivered dose to enhance rectal toxicity prediction in prostate cancer

145: Radiomics with accumulated delivered dose to enhance rectal toxicity prediction in prostate cancer

Predictors of radiation-induced late rectal toxicity in prostate cancer treatment: a volumetric and dosimetric analysis.

Prostate cancer (PCa) is a prevalent malignancy in European men, often treated with radiotherapy (RT) for localized disease. While modern RT achieves high success rates, concerns about late gastrointestinal (GI) toxicities persist. This retrospective study aims to identify predictors for late GI toxicities following definitive conventionally fractionated external beam RT (EBRT) for PCa, specifically exploring the dose to the rectal wall. A cohort of 96 intermediate- to high-risk PCa patients underwent EBRT between 2008 and 2016. Rectum and rectum wall contours were delineated, and 3D dose matrices were extracted. Volumetric and dosimetric indices were computed, and statistical analyses were performed to identify predictors using the Mann-Whitney U-rank test, logistic regression, and recursive feature elimination. In our cohort, 15 out of 96 patients experienced grade II late proctitis. Our analysis reveals distinct optimal predictors for rectum and rectum wall (RW) structures varying with α/β values (3.0 and 2.3 Gy) across prescribed doses of 68 to 76 Gy. Despite variability, RW predictors demonstrate greater consistency, notably V68Gy[%] to V74Gy[%] for α/β 3.0 Gy, and V68Gy[%] to V70Gy[%] for α/β 2.3 Gy. The model with α/β 2.3 Gy, featuring RW volume receiving 70 Gy (V70Gy[%]), stands out with a BIC value of 62.92, indicating its superior predictive effectiveness. Finally, focusing solely on the rectum structure, the V74Gy[%] emerges the best predictor for α/β 3.0 Gy, with a BIC value of 66.73. This investigation highlights the critical role of V70Gy[%] in the rectum wall as a robust predictor for grade II late gastrointestinal (GI) toxicity following external beam radiation therapy (EBRT) for prostate cancer (PCa). Furthermore, our findings suggest that focusing on the rectum wall specifically, rather than the entire rectum, may offer improved accuracy in assessing proctitis development. A V70Gy (in EQD2 with α/β 2.3 Gy) of ≤5% and if possible ≤1% for the rectal wall should be achieved to minimize the risk of late grade II proctitis.

10-yr Results of Moderately Hypofractionated Postoperative Radiotherapy for Prostate Cancer Focused on Treatment Related Toxicity

IntroductionTo retrospectively report long term outcomes following postoperative hypofractionated radiotherapy (RT) for prostate cancer, emphasizing treatment related toxicity. Material and MethodsPatients for whom adjuvant or salvage RT was indicated after prostatectomy were treated with a course of moderate hypofractionation consisting in the delivery of 62.5 Gy in 25 fractions (2.5 Gy per fraction) on the prostate bed in 5 consecutive weeks (EQD21.5 = 70 Gy) by means of 3D-CRT in most of them. Androgen deprivation therapy (ADT) was allowed at physician's discretion. Patients were evaluated for urinary and rectal complications according to the Common Terminology Criteria for Adverse Events v4 (CTCAE v.4). Overall survival (OS), biochemical recurrence free survival (bRFS), and metastasis-free survival (MFS) were estimated using the Kaplan–Meier method. ResultsOne hundred and ten patients with a median age of 67 years (range 51-78) were enrolled. The majority of them (82%) had adverse pathologic features only, while 31 (28%) had early biochemical relapse. Median PSA level before RT was 0.12 ng/mL (range 0-9 ng/mL). Median time from surgery was 4 months (range 1-136 months). Twenty-eight patients (25.4%) also received ADT. At a median follow up of 103 months (range 19-138 months), late Grade 3 and Grade 4 rectal toxicity were 0.9% (1 case of hematochezia) and 0.9% (1 case of fistula), respectively, while late Grade 3 GU side effects (urethral stenosis) occurred in 9 cases (8%). No late Grade 4 events were observed, respectively. Ten-year OS, b-RFS and MFS were 77.3% (95%CI: 82.1%-72.5%), 53.3% (95%CI: 59.9%-47.6%), and 76.7% (95%CI: 81.2%-72.2%), respectively. ConclusionOur study provides long term data that a shortened course of postoperative RT is as safe and effective as a long course of conventionally fractionated RT and would improve patients’ convenience and significantly reduce RT department workloads.

Preventing Rectal Toxicity in Prostate Cancer: Diet and Supplement Alternative to Enemas or Rectal Spacer

Background: Rectal toxicity is an important side effect of prostate cancer irradiation affecting 25% of patients. The role of dosimetric variables has a set of dose-volume constraints and curves to estimate the risk of rectal damage. The rectum position at the time of CT planning is different from the position during radiotherapy. Three methods are available to achieve optimal rectum position: enema; prostate cancer spacer; fiber-/fat-free diet. Methods: A 70.2 Gray radiation divided into 26 hypo-fractions was administered to 115 patients with prostate cancer by VMAT referred to a single center in Italy. To empty the rectum, all patients were administered a fiber-/fat-free diet and those with Eating Disorders (ED) were also added with activated charcoal (2 tablets/day) and a macrogol-based medical device (2 sachets/day). During treatment, the volumetric amount of rectum in the target was measured by comparing control-CT with simulation-CT, and acute toxicity was also checked. Results: The rectum position during control-CT in diet-only patients (29) predicted toxicity recorded during treatment, while in the ED group rectum position was adherent to position during simulations. Rectal volume target &gt; 0.25 cc receiving a dose &gt; V70 caused acute G3 toxicity that attenuated or worsened with rectal displacement. Acute rectal toxicity occurred in 6/29 (20.68%) patients (1 G3, 5 G1) in the diet-only group, while only in 1/86 (1.16%) patients (G1) in the ED group. No chronic toxicity was recorded in either group. Conclusion: Prostate cancer patients treated with VMAT, diet, charcoal, and macrogol emptied the rectum optimally and reduced incidence and severity of acute rectal toxicity, also with benefit on late toxicity.

A Review of the Efficacy of the Low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols (FODMAP) Diet in Managing Gastrointestinal Symptoms Related to Cancer Treatment.

The low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet, designed to alleviate symptoms in individuals with irritable bowel syndrome (IBS), focuses on limiting the consumption of poorly absorbed fermentable carbohydrates known as FODMAP. These FODMAP are believed to be the primary triggers for food-related gastrointestinal symptoms in functional gastrointestinal disorders. However, there is currently insufficient direct evidence investigating the role of low FODMAP diets in cancer patients undergoing treatment. This review aims to summarize the current evidence on the low FODMAP diet and its potential implications for cancer patients in terms of treatment outcomes, alleviating gastrointestinal symptoms, and overall health. A systematic literature search was conducted using databases, including PubMed, Scopus, Google Scholar, Web of Science, and Cochrane. Five studies met the criteria for inclusion in the review, and these studies covered rectal toxicity during radiotherapy, gastrointestinal symptoms in colorectal cancer patients, acute gastrointestinal toxicity during pelvic external beam radiotherapy, symptoms in patients with radiation-induced enteropathy, and chronic gastrointestinal sequelae resulting from pelvic organ cancer treatment. The available evidence suggests that a low FODMAP diet may offer advantages in reducing rectal gas and volume during radiotherapy, alleviating diarrhea symptoms, reducing symptom deterioration, and improving quality of life. However, these studies highlight the need for large-scale randomized trials, long-term follow-up, and guidelines to establish the efficacy, safety, and implementation strategies of the low FODMAP diet in different cancer contexts and patient populations. While preliminary findings reported some possible benefits of a low FODMAP diet for certain cancer patients, rigorous studies with large sample sizes are needed to provide more robust evidence. Further research is warranted to optimize the utilization of this diet as an adjunctive intervention for managing gastrointestinal symptoms in this population.

Comprehensive 3DCRT Hypofractionated Radiotherapy Schedule for Localized Prostate Adenocarcinoma in the Era of IMRT: Dosimetric and Endoscopic Analysis.

Background: Moderate hypofractionated radiotherapy (MHRT) has emerged as the preferred treatment modality for localized prostate cancer based on randomized controlled studies regarding efficacy and toxicity using contemporary radiotherapy techniques. In the setting of MHRT, available data on dosimetric parameters and late rectal toxicity are limited. Aim: To present the effects of MHRT on late rectal toxicity while conducting an extensive dosimetric analysis in conjunction with rectoscopy results. Methods: This is a prospective study including patients with intermediate-risk prostate adenocarcinoma. All patients were treated with MHRT 44 Gy in 16 fractions to the seminal vesicles and to the prostate, followed by a sequential boost to the prostate alone of 16.5 Gy in 6 fractions delivered with three-dimensional conformal radiation therapy (3DCRT). Acute and late toxicity were assessed. Endoscopy was performed at baseline, every 3 months post-therapy for the first year, and every 6 months for the year after. The Vienna Rectoscopy Score (VRS) was used to assess rectal mucosal injury related to radiotherapy. Dosimetric analysis for the rectum, rectal wall, and its subsegments (upper, mid, and low 1/3) was performed. Results: Between September 2015 and December 2019, 20 patients enrolled. Grade 1 late gastrointestinal toxicity occurred in 10% of the patients, whereas 5% had a grade ≥2. Twelve months post radiotherapy: 4 (20%) patients had VRS 1; 2 (10%) patients had VRS 2; 1(5%) patient had VRS 3. 24 months post radiotherapy, VRS 1 was observed in 4 patients (20%) and VRS 2 in 3 (15%) patients. The dosimetric analysis demonstrated noticeable variations between the rectum, rectal wall, and rectal wall subsegments. The dosimetric analysis of the rectum, rectal wall, and its mid and low segments with respect to rectoscopy findings showed that the higher dose endpoints V52.17Gy and V56.52Gy are associated with rectal mucosal injury. Conclusions: A thorough delineation of the rectal wall and its subsegments, together with the dosimetric analysis of these structures, may reduce late rectal toxicity. Dosimetric parameters such as V52.17Gy and V56.52Gy were identified to have a significant impact on rectal mucosal injury; additional dose endpoint validation and its relation to late GI toxicity is needed.

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