Endoscopic scoring of late rectal mucosal damage after conformal radiotherapy for prostatic carcinoma

Role of dynamic contrast-enhanced MRI in predicting severe acute radiation-induced rectal injury in patients with rectal cancer

OBJECTIVES

To explore the potential of dynamic contrast-enhanced MRI (DCE-MRI) quantitative parameters in predicting severe acute radiation-induced rectal injury (RRI) in rectal cancer.

METHODS

This retrospective study enrolled 49 patients with rectal cancer who underwent neoadjuvant chemoradiotherapy and rectal MRI including a DCE-MRI sequence from November 2014 to March 2021. Two radiologists independently measured DCE-MRI quantitative parameters, including the forward volume transfer constant (Ktrans), rate constant (kep), fractional extravascular extracellular space volume (ve), and the thickness of the rectal wall farthest away from the tumor. These parameters were compared between mild and severe acute RRI groups based on histopathological assessment. Receiver operating characteristic curve analysis was performed to analyze statistically significant parameters.

RESULTS

Forty-nine patients (mean age, 54 years ± 12 [standard deviation]; 37 men) were enrolled, including 25 patients with severe acute RRI. Ktrans was lower in severe acute RRI group than mild acute RRI group (0.032 min-1 vs 0.054 min-1; p = 0.008), but difference of other parameters (kep, ve and rectal wall thickness) was not significant between these two groups (all p > 0.05). The area under the receiver operating characteristic curve of Ktrans was 0.72 (95% confidence interval: 0.57, 0.84). With a Ktrans cutoff value of 0.047 min-1, the sensitivity and specificity for severe acute RRI prediction were 80% and 54%, respectively.

CONCLUSION

Ktrans demonstrated moderate diagnostic performance in predicting severe acute RRI.

CLINICAL RELEVANCE STATEMENT

Dynamic contrast-enhanced MRI can provide non-invasive and objective evidence for perioperative management and treatment strategies in rectal cancer patients with acute radiation-induced rectal injury.

KEY POINTS

• To our knowledge, this study is the first to evaluate the predictive value of contrast-enhanced MRI (DCE-MRI) quantitative parameters for severe acute radiation-induced rectal injury (RRI) in patients with rectal cancer. • Forward volume transfer constant (Ktrans), derived from DCE-MRI, exhibited moderate diagnostic performance (AUC = 0.72) in predicting severe acute RRI of rectal cancer, with a sensitivity of 80% and specificity of 54%. • DCE-MRI is a promising imaging marker for distinguishing the severity of acute RRI in patients with rectal cancer.

Stereotactic body radiotherapy (SIB-VMAT technique) to dominant intraprostatic lesion (DIL) for localized prostate cancer: a dose-escalation trial (DESTROY-4)

PURPOSE

DESTROY-4 (DOSE-ESCALATION STUDY OF STEREOTACTIC BODY RADIATION THERAPY) was a Phase I trial aimed to evaluate the safety and the feasibility of escalating doses of stereotactic body radiation therapy (SBRT) on MRI-defined Dominant Intraprostatic Lesion (DIL) in low- and intermediate-risk pCa patients using a simultaneous integrated boost-volumetric arc therapy (SIB-VMAT) technique.

METHODS

Eligible patients included those with low- and intermediate-risk prostate carcinoma (NCCN risk classes) and an International Prostatic Symptoms Score (IPSS) ≤ 15. No restriction about DIL and prostate volumes was set. Pretreatment preparation required an enema and the placement of intraprostatic gold fiducials. SBRT was delivered in five consecutive daily fractions. For the first three patients, the DIL radiation dose was set at 8 Gy per fraction up to a total dose of 40 Gy (PTV1) and was gradually increased in succeeding cohorts to total doses of 42.5 Gy, 45.0 Gy, 47.5 Gy, and finally, 50.0 Gy, while keeping the prescription of 35 Gy/7 Gy per fraction for the entire prostate gland. Dose-limiting toxicity (DLT) was defined as grade 3 or worse gastrointestinal (GI) or genitourinary (GU) toxicity occurring within 90 days of follow-up (Common Terminology Criteria of Adverse Events scale 4.0). Patients completed quality-of-life questionnaires at defined intervals.

RESULTS

Twenty-four patients with a median age of 75 (range, 58-89) years were enrolled. The median follow-up was 26.3 months (8.9-84 months). 66.7% of patients were classified as intermediate-risk groups, while the others were low-risk groups, according to the NCCN guidelines. Enrolled patients were treated as follows: 8 patients (40 Gy), 5 patients (42.5 Gy), 4 patients (45 Gy), 4 patients (47.5 Gy), and 3 patients (50 Gy). No severe acute toxicities were observed. G1 and G2 acute GU toxicities occurred in 4 (16%) and 3 patients (12.5%), respectively. Two patients (8.3%) and 3 patients (12.5%) experienced G1 and G2 GI toxicities, respectively. Since no DLTs were observed, 50 Gy in five fractions was considered the MTD. The median nadir PSA was 0.20 ng/mL. A slight improvement in QoL values was registered after the treatment.

CONCLUSION

This trial confirms the feasibility and safety of a total SIB-VMAT dose of 35 Gy on the whole gland and 50 Gy on DIL in 5 fractions daily administered in a well-selected low- and intermediate-risk prostate carcinoma population. A phase II study is ongoing to confirm the tolerability of the schedule and assess the efficacy.

Long-term findings of rectal endoscopy and rectal bleeding after moderately hypofractionated, intensity-modulated radiotherapy for prostate cancer

To present rectal endoscopic findings and toxicity after definitive moderately hypofractionated, intensity-modulated radiotherapy (IMRT) for prostate cancer. We retrospectively reviewed patients who underwent IMRT for prostate cancer and underwent post-radiotherapy endoscopies between 2008 and 2018. Endoscopic findings were reviewed and graded using Vienna Rectoscopy Score (VRS). We have analyzed the association between endoscopic findings and rectal bleeding, and investigated risk factors for rectal bleeding. Total 162 patients met the inclusion criteria of this study. There was a trend of VRS worsening during the initial 3 years after radiotherapy followed by recovery. Rectal bleeding was highest at 1 year after radiotherapy and improved thereafter. The 5-year cumulative incidence of grade ≥ 2 rectal bleeding was 14.8%. In the multivariable Cox regression analysis, cardiovascular disease (hazard ratio [HR] 2.732, P = 0.037), rectal wall V65 (HR 1.158, P = 0.027), and VRS ≥ 3 in first post-radiotherapy endoscopy (HR 2.573, P = 0.031) were significant risk factors for rectal bleeding. After IMRT for prostate cancer, VRS and rectal bleeding worsened over 1-3 years after radiotherapy and recovered. Cardiovascular disease, rectal wall V65, and VRS ≥ 3 in first post-radiotherapy endoscopy were significant risk factors for rectal bleeding.

The Safety and Efficacy of Salvage Stereotactic Radiation Therapy in Patients with Intraprostatic Tumor Recurrence After Previous External Radiation Therapy: Phase 1 Results from the GETUG-AFU 31 Study

BACKGROUND

There is no consensus on the best local salvage treatment for prostate cancer recurrence after primary external beam radiotherapy. Prospective data on stereotactic body radiation therapy (SBRT) are very scarce.

OBJECTIVE

To determine the optimal dose regimen for salvage SBRT.

DESIGN, SETTING, AND PARTICIPANTS

The present report concerns the phase 1 part of the GETUG-AFU 31 multicenter open-label study. The main inclusion criteria were histologically proven biochemical recurrence, clinical stage T1-T2 upon relapse, multiparametric magnetic resonance imaging data, prostate-specific antigen (PSA) level ≤10 ng/ml prior to salvage SBRT, PSA doubling time >10 mo, and an International Prostate Symptom Score of ≤12.

INTERVENTION

Five or six fractions of 6 Gy were delivered using focal SBRT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Dose-limiting toxicity (DLT) was defined as grade ≥3 gastrointestinal or genitourinary tract toxicity, or any grade 4 toxicity (according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.03) occurring in the first 18 wk following treatment initiation. A time-to-event continual reassessment method was used to select the dose regimen.

RESULTS AND LIMITATIONS

Twenty-one patients were treated (median [interquartile range] age: 76.8 yr [72.2-80.8]), including 12 at 6 × 6 dose level. No DLT was observed. The acute grade 2 genitourinary tract toxicity rate was 19%. With a median follow-up of 12.3 mo, the estimated cumulative incidence of late grade 2 genitourinary toxicity was 41.2% (95% confidence interval: 18.1-63.1%). No grade >2 genitourinary toxicity and no grade ≥2 gastrointestinal toxicity were reported. All treated patients were alive and relapse free at the last follow-up.

CONCLUSIONS

A 6 × 6 Gy dose regimen was selected for our phase 2 study of salvage SBRT. With a short follow-up period, the level of toxicity appears to be acceptable.

PATIENT SUMMARY

There is no consensus on the best local treatment for patients with local relapse after radiotherapy for prostate cancer. Prospective data are very scarce. Our early phase trial allowed us to recommend six fractions of 6 Gy using high-precision radiotherapy for further studies.

The Lymphatic Endothelium in the Context of Radioimmuno-Oncology

The study of lymphatic tumor vasculature has been gaining interest in the context of cancer immunotherapy. These vessels constitute conduits for immune cells' transit toward the lymph nodes, and they endow tumors with routes to metastasize to the lymph nodes and, from them, toward distant sites. In addition, this vasculature participates in the modulation of the immune response directly through the interaction with tumor-infiltrating leukocytes and indirectly through the secretion of cytokines and chemokines that attract leukocytes and tumor cells. Radiotherapy constitutes the therapeutic option for more than 50% of solid tumors. Besides impacting transformed cells, RT affects stromal cells such as endothelial and immune cells. Mature lymphatic endothelial cells are resistant to RT, but we do not know to what extent RT may affect tumor-aberrant lymphatics. RT compromises lymphatic integrity and functionality, and it is a risk factor to the onset of lymphedema, a condition characterized by deficient lymphatic drainage and compromised tissue homeostasis. This review aims to provide evidence of RT's effects on tumor vessels, particularly on lymphatic endothelial cell physiology and immune properties. We will also explore the therapeutic options available so far to modulate signaling through lymphatic endothelial cell receptors and their repercussions on tumor immune cells in the context of cancer. There is a need for careful consideration of the RT dosage to come to terms with the participation of the lymphatic vasculature in anti-tumor response. Here, we provide new approaches to enhance the contribution of the lymphatic endothelium to radioimmuno-oncology.

A nomogram to predict risk factors of frequent defecation early after ileostomy reversal for rectal cancer patients

Background

Defecation disorders after ileostomy reversal are among the most common complications for rectal cancer patients, and significantly diminish their quality of life. The aim of this study was to identify the risk factors associated with frequent defecation early after ileostomy reversal for rectal cancer patients.

Methods

We retrospectively collected the data of rectal cancer patients who underwent ileostomy reversal from January 2018 to December 2019 at the Sixth Affiliated Hospital of Sun Yat-sen University. We divided patients into two groups: a no frequent defecation group (≤7 times/day) and a frequent defecation group (>7 times/day).

Results

Of the 264 included patients, 59 patients (22.35%) had frequent defecation within 1 month after ileostomy closure and were defined as the frequent defecation group. There were no significant differences between the two groups in terms of gender, age, hypertension, and diabetes. Univariate and multivariate analyses showed that proctitis (P=0.04) and anastomotic stenosis (P=0.02) were independent risk factors for frequent defecation. Four factors, including proctitis, anastomotic stenosis, hypertension, and age were included to construct the nomogram. The consistency index of the nomogram was 0.949 and the area under the curve value was 0.623.

Conclusions

For rectal cancer patients, proctitis and anastomotic stenosis were correlated with frequent defecation within 1 month after ileostomy closure. Surgeons should pay attention to the rectal examination before ileostomy reversal surgery.

Hyperbaric oxygen therapy as a complementary treatment for radiation proctitis: Useless or useful? - A literature review

Radiotherapy (RT) is the backbone of multimodality treatment of more than half of cancer cases. Despite new modern RT techniques, late complications may occur such as radiation proctitis (RP). The natural history of RP is unpredictable. Minor symptoms may resolve spontaneously or require conservative treatment. On the other hand, for similar and uncomplicated clinical contexts, symptoms may persist and can even be refractory to the progressive increase in treatment measures. Over the last decades, an enormous therapeutic armamentarium has been considered in RP, including hyperbaric oxygen therapy (HBOT). Currently, the evidence regarding the impact of HBOT on RP and its benefits is conflicting. Additional prospective and randomised studies are necessary to validate HBOT's effectiveness in the 'real world' clinical practice. This article reviewed the relevant literature on pathophysiology, clinical presentation, different classifications and discuss RP management including a proposal for a therapeutic algorithm with a focus on HBOT.

Rectum Protection by Rectal Gel Injection in Cervical Cancer Brachytherapy: A Dosimetric Study via Deformable Surface Dose Accumulation and Machine-Learning-Based Discriminative Modeling

PURPOSE

This retrospective study aimed to evaluate the dosimetric effects of a rectal insertion of Kushen Ningjiao on rectal protection using deformable dose accumulation and machine learning-based discriminative modelling.

MATERIALS AND METHODS

Sixty-two patients with cervical cancer enrolled in a clinical trial, who received a Kushen Ningjiao injection of 20 g into their rectum for rectal protection via high-dose rate brachytherapy (HDR-BT, 6 Gy/f), were studied. The cumulative equivalent 2-Gy fractional rectal surface dose was deformably summed using an in-house-developed topography-preserved point-matching deformable image registration method. The cumulative three-dimensional (3D) dose was flattened and mapped to a two-dimensional (2D) plane to obtain the rectal surface dose map (RSDM). For analysis, the rectal dose (RD) was further subdivided as follows: whole, anterior, and posterior 3D-RD and 2D-RSDM. The dose-volume parameters (DVPs) were extracted from the 3D-RD, while the dose geometric parameters (DGPs) and textures were extracted from the 2D-RSDM. These features were fed into 192 classification models (built with 8 classifiers and 24 feature selection methods) for discriminating the dose distributions between pre-Kushen Ningjiao and pro-Kushen Ningjiao.

RESULTS

The rectal insertion of Kushen Ningjiao dialated the rectum in the ambilateral direction, with the rectal column increased from pre-KN 15 cm3 to post-KN 18 cm3 (P < 0.001). The characteristics of DGPs accounted for the largest portions of the top-ranked features. The top-ranked dosimetric features extracted from the posterior rectum were more reliable indicators of the dosimetric effects/changes introduced by the rectal insertion of Kushen Ningjiao. A significant dosimetric impact was found on the dose-volume parameters D1.0cc-D2.5cc extracted on the posterior rectal wall.

CONCLUSIONS

The rectal insertion of Kushen Ningjiao incurs significant dosimetric changes on the posterior rectal wall. Whether this effect is eventually translated into clinical gains requires further long-term follow-up and more clinical data for confirmation.

Endoscopically delivered Purastat for the treatment of severe haemorrhagic radiation proctopathy: a service evaluation of a new endoscopic treatment for a challenging condition

BACKGROUND

A total of 30 000 people are treated with pelvic radiotherapy annually in the UK. Rectal bleeding is common following pelvic radiotherapy and one of the main causes is radiation proctopathy (RP). Six per cent develop severe bleeding from RP, leading to anaemia requiring iron +/- blood transfusion. There are very few safe, effective, evidence-based treatments. Purastat is a haemostatic agent licensed for gastrointestinal bleeding. It is a self-assembling peptide that forms a molecular mesh in contact with blood, thereby sealing blood vessels. There are numerous studies showing its efficacy and safety in various surgical/endoscopic settings. This service evaluation reports the first experience of the use of Purastat in RP.

METHODS

Consecutive patients attending pelvic radiation disease clinic with severe refractory RP were offered treatment with Purastat. This was defined as rectal bleeding into the pan±anaemia with no response to rectal sucralfate. Purastat was applied endoscopically at four weekly intervals up to three times, with more as required. Bleeding severity, endoscopic grade and haemoglobin were recorded.

RESULTS

Twenty-one patients were treated (18 men, median age 76 years) with a median of three treatments. Ten were on antithrombotics, 1 had thrombocytopenia and 13 had anaemia at baseline. Median episodes of bleeding reduced from 4.5 (0-27) to 2 (0-16) in the 7 days prior to the first and third treatment, respectively. Endoscopic grade was improved. Mean haemoglobin increased from 116.0 to 122.7. There were no complications.

CONCLUSION

Even in this cohort of severe refractory RP, there was an improvement in bleeding and endoscopic grade with Purastat. A randomised controlled trial is planned.

A Randomized Controlled Trial of Novel Treatment for Hemorrhagic Radiation Proctitis

Background:

Various methods have been used for treatment of hemorrhagic radiation proctitis (HRP) with variable results. Currently, the preferred treatment is formalin application or endoscopic therapy with argon plasma coagulation. Recently, a novel therapy with colonic water irrigation and oral antibiotics showed promising results and more effective compared to 4% formalin application for HRP. The study objective is to compare the effect of water irrigation and oral antibiotics versus 4% formalin application in improving per rectal bleeding due to HRP and related symptoms such as diarrhoea, tenesmus, stool frequency, stool urgency and endoscopic findings.

Methods:

We conducted a study on 34 patients with HRP and randomly assigned the patients to two treatment arm groups (n=17). The formalin group underwent 4% formalin dab and another session 4 weeks later. The irrigation group self-administered daily rectal irrigation at home for 8 weeks and consumed oral metronidazole and ciprofloxacin during the first one week. We measured the patients’ symptoms and endoscopic findings before and after total of 8 weeks of treatment in both groups.

Results:

Our study showed that HRP patients had reduced per rectal bleeding (p = 0.003) in formalin group, whereas irrigation group showed reduced diarrhoea (p=0.018) and tenesmus (p=0.024) symptoms. The comparison between the two treatment arms showed that irrigation technique was better than formalin technique for tenesmus (p=0.043) symptom only.

Conclusion:

This novel treatment showed benefit in treating HRP. It could be a new treatment option which is safe and conveniently self-administered at home or used as a combination with other therapies to improve the treatment outcome for HRP.

X irradiation induced colonic mucosal injury and the detection of apoptosis through PARP-1/p53 regulatory pathway

This study aimed to explore whether PARP-1 regulatory pathway mediated X irradiation induced cell cycle arrest and apoptosis or not. In this regard, colonic mucosal injury caused by whole-body X-irradiation induced apoptosis through PARP-1, caspase 3 and p53 regulatory pathway were evaluated in experimental rat models. Eighteen Wistar albino rats were divided into three groups. Two radiation groups received 8.3 Gy dose of whole-body X-irradiation as a single dose and the control group received physiological saline intraperitoneally. Radiation groups were sacrificed after 6 h and 4 days of irradiation. PARP-1 and caspase 3 expression in the nuclei of colonic crypt cells significantly increased 6 h after irradiation, and declined 4 days after irradiation. In conflict with other studies that reported p53 as not being expressed widely in colonic mucosa, in our study the expressions of p53 were elevated both in the cytoplasm and in the nucleus of the crypt cells, especially 6 h after irradiation. In the radiation groups, colonic mucosal injury score was significantly elevated compared with that of the control group. Our data demonstrated that PARP-1, caspase-3 and p53 expression increased in colonic mucosa 6 h after irradiation.

Association between acute histopathological changes of rectal walls and late radiation proctitis following radiotherapy for prostate cancer

PURPOSE

The impact of acute histopathological changes (HC) of the rectum on development of late clinical proctitis (LCP) after external radiotherapy (RT) for prostate cancer is poorly explored and was the primary end point of this prospective study.

METHODS

In 70 patients, 15 HC of early rectal biopsies after RT were identified, whereby RT was conventional 2D RT in 41 cases and conformational 3D RT in 29. Associations of HC in anterior and posterior rectal walls (ARW, PRW) with LCP, acute endoscopic (AEP) and acute clinical proctitis (ACP) were statistically evaluated considering as explicative variables the patient general characteristics and the HC.

RESULTS

The mean patients' follow-up was 123.5 months (24-209). The median prostatic dose was 72 Gy (2 Gy/fraction). For the 41 and 29 patients the ARW and PRW doses were 64 and 49 Gy vs. 63 and 50 Gy, respectively. The incidence of LCP ≥ grade 2 at 10 years was 12.9%. The univariate (p = 0.02) and Kaplan-Meyer methods (p = 0.007) showed that the gland (or crypts) loss in the ARW was significantly associated with LCP. AEP and ACP occurred in 14.3 and 55.7% of cases. At multivariate level AEP significantly correlated with hemorrhoids (p = 0.014) and neutrophilia in ARW (p = 0.042).

CONCLUSIONS

Early after RT, substantial gland loss in ARW is predictive of LCP. To reduce this complication with conventional fractionation, we suggest keeping the mean dose to ARW ≤48-52 Gy.

Evaluating the predictive value of quantec rectum tolerance dose suggestions on acute rectal toxicity in prostate carcinoma patients treated with IMRT

Aim

To investigate the predictive value of convenience of rectum dosimetry with Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) dose limits, maximum rectum dose (Dmax), total rectal volume (TVrectum), rectal volume included in PTV (VrectumPTV) on Grade 2-3 acute rectal toxicity for utilization in clinical practice.

Background

Numerous previous data have reported frequent acute proctitis after external-beam RT of prostate cancer. Predicting toxicity limited with dose information is inadequate in clinical practice due to comorbidities and medications used.

Materials and Method

Sixty-four non-metastatic prostate cancer patients treated with IMRT were enrolled. Patients were treated to a total dose of 70-76 Gy. Rectal dose volume histograms (DVH) of all patients were evaluated retrospectively, and a QUANTEC Score between 0 and 5 was calculated for each patient. The correlation between the rectal DVH data, QUANTEC score, TVrectum, VrectumPTV, rectum Dmax and Grade 2-3 rectal toxicity was investigated.

Results

In the whole group grade 1, 2 and 3 acute rectal toxicities were 25%, 18.8% and 3.1%, respectively. In the DVH data, rectum doses of all patients were under RTOG dose limits. Statistically significant correlation was found between grade 2-3 rectal toxicity and TVrectum (p = 0,043); however. It was not correlated with QUANTEC score, VrectumPTV and Dmax.

Conclusion

Our results were not able to show any significant correlation between increasing convenience with QUANTEC limits and lower rectal toxicity. Conclusively, new dosimetric definitions are warranted to predict acute rectal toxicity more accurately in prostate cancer patients during IMRT treatment.

Rectal wall dose-volume effect of pre- or post KUSHEN Ningjiaos relationship with 3D brachytherapy in cervical cancer patients

BACKGROUND

The present prospective study evaluated the safety and efficacy of the rectum following KUSHEN Ningjiaos in cervical cancer. We compared rectal wall changes during brachytherapy with or without KUSHEN Ningjiaos in cervical cancer patients and analyzed the difference in spatial dose distribution, including whole rectum-wall (R-w), anterior rectum-wall (R-a) and posterior rectum-wall (R-p).

METHODS AND MATERIALS

One hundred cervical cancer patients with and without KUSHEN Ningjiaos were treated with brachytherapy (600 cGy). The whole R-w was divided into two areas of R-a and R-p, and R-w dose surface map were constructed. The volume of each R-w was compared in patients pre- and post-KUSHEN Ningjiaos.

RESULTS

When the pre- vs. post-KUSHEN groups were compared the volume of R-w increased. In the post-KUSHEN group, a significantly higher proportion of the D2cc of V_R-w and V_R-a compared with the pre-KUSHEN group showed that the D2cc_mean increased from 532.45 cGy to 564.7 cGy and 533.51 cGy to 565.26 cGy, respectively; however, results demonstrated a decrease in the D2cc_mean of R-p from 260.5 cGy to 240.0868 cGy (P < 0.05). The insertion of KUSHEN Ningjiaos resulted in a reduction of the relative volume of R-p exposed to high doses, and regressive analysis showed that the D_R-p-max correlated most strongly with V_R-w and D2cc_R-p (P < 0.01 and P < 0.05, respectively).

CONCLUSION

The insertion of KUSHEN Ningjiaos can protect the rectum. KUSHEN Ningjiaos appears to be safe and well tolerated; therefore, we believe that there will be fewer adverse events after brachytherapy for patients.

TRIAL REGISTRATION

A multi-center, prospective clinical trial for KUSHEN Ningjiaos was inserted into rectum to reduce the rate of radiation proctitis in three-dimensional brachytherapy of cervical cancer. ChiCTR1900021631 . 2 Mar 2019-Retrospectively registered.

GETUG-AFU 31: a phase I/II multicentre study evaluating the safety and efficacy of salvage stereotactic radiation in patients with intraprostatic tumour recurrence after external radiation therapy-study protocol

INTRODUCTION

Prostate cancer is the third most important cancer in terms of mortality in men. No standard local treatment exists for patients with an intraprostatic recurrence after radiotherapy. Stereotatic body radiotherapy (SBRT) could be a curative treatment for local recurrence. The phase I/II primary objective is the selection of the recommended dose for salvage-SBRT and to estimate the efficacy.

METHODS AND ANALYSIS

We plan to perform a multicentre prospective phase I/II study including at least 47 patients. Eligible patients are patients with biochemical recurrence occurring at least 2 years after external radiotherapy for prostatic adenocarcinoma by the Phoenix definition (prostate-specific antigen (PSA) nadir +2 ng/mL) and histologically proven intraprostatic recurrence only (stage T1-T2 on relapse, PSA level ≤10 ng/mL, PSA doubling time >10 months, absence of pelvic or metastatic recurrence proven by choline or PSMA positron emission tomography scan, and pelvic and prostatic assessment by multiparametric MRI). The phase I primary objective is the selection of the recommended dose for salvage-SBRT (5×6, 6×6 or 5×5 Gy) based on dose-limiting toxicity (DLT). The dose of salvage-SBRT will be selected using a time-to-event continual reassessment method based on DLT defined as grade ≥3 gastrointestinal or urinary toxicity or any other grade 4 adverse event. The phase II primary outcome is to estimate the efficacy of the salvage-SBRT in terms of biochemical relapse-free survival rate (Phoenix definition: increase in serum total PSA ≥2 ng/mL above the nadir). Phase II secondary outcomes are acute and late toxicities, quality of life, clinical progression-free survival defined as the time interval between the date of registration and the date of clinical progression or death irrespective of the cause.

ETHICS AND DISSEMINATION

The study has received ethical approval from the Ethics committee 'Ile-de-France III'. Academic dissemination will occur through publication and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03438552.

The role of endoscopic evaluation for radiation proctitis in patients receiving intermediate-dose postoperative radiotherapy for rectal cancer

Objectives

High-dose pelvic radiotherapy (RT) is known to be associated with chronic radiation proctitis (RP). However, the effects of intermediate radiation doses are unknown. We assessed the incidence of late clinical RP among patients with rectal cancer receiving intermediate-dose postoperative RT, as well as the role of early endoscopic abnormalities in predicting RP development.

Methods

We retrospectively reviewed 153 patients with rectal cancer who received postoperative RT at a median dose of 54 Gy between 2005 and 2009 and who underwent endoscopic examination within 12 months thereafter. Endoscopic RP was assessed using the Vienna rectoscopy score (VRS). Late clinical RP toxicity was evaluated, as was its correlation with endoscopic RP.

Results

All patients underwent an endoscopic examination at a median of 9 months after postoperative pelvic RT. Endoscopic RP was detected in 45 patients (29.4%); the predominant patterns were telangiectasia and congested mucosa. During the median 88-month follow-up period, 29 patients (19.0%) experienced late clinical RP; only 3 (2.0%) had Grade 3 or above. The VRS predicted the development of late clinical RP as well as its cumulative incidence (P < 0.001). Endoscopic evidence of telangiectasia was significantly associated with the development of late clinical RP (P < 0.001).

Conclusions

Early endoscopic findings using VRS are useful for predicting the possibility of late clinical RP, although the incidences of severe cases were low. Patients with endoscopic abnormalities should be followed closely owing to their susceptibility to clinical RP.

Phase I Study of Carbon Ion Radiotherapy and Image-Guided Brachytherapy for Locally Advanced Cervical Cancer

A phase I study was performed to determine the recommended dose of carbon ion radiotherapy and 3D image-guided brachytherapy for histologically confirmed stage II (≥4 cm), III, or IVA cervical cancer. Dose-limiting toxicities (treatment-related toxicities occurring within three months from the start of carbon ion radiotherapy) included Grade 3 non-hematological toxicity, Grade 4 hematological toxicity, or interruption of treatment for more than two weeks due to treatment-related toxicities. Carbon ion radiotherapy consisted of whole-pelvic irradiation with 36.0 Gy (relative biological effectiveness) in 12 fractions and local boost with 19.2 Gy in four fractions for the primary site, and for positive lymph nodes. Three sessions of three-dimensional (3D) image-guided brachytherapy were administered after completion of carbon ion radiotherapy. Weekly cisplatin at a dose of 40 mg/m² was given concurrently. At a dose level of one, a total rectosigmoid D2cc dose between 67.2 Gy and 71.3 Gy at a biological equivalent dose of 2 Gy per fraction from carbon ion radiotherapy and 3D image-guided brachytherapy was prescribed. Six patients were enrolled into this dose level. No patients developed the pre-defined dose-limiting toxicities. For late toxicities, however, one patient developed Grade 3 rectal hemorrhage requiring transfusion at 10 months after treatment. The median survival time was 50.0 months for the five surviving patients. No further dose escalation was performed, and we determined the dose of level one as the recommended rectosigmoid dose. Although our results are preliminary, the study regimen encourages further investigation (registration: UMIN000013340).

Predictive Factors of Late-onset Rectal Mucosal Changes After Radiotherapy of Prostate Cancer

BACKGROUND/AIM

The Vienna Rectoscopy Score (VRS; from 0, absence of rectal mucosal changes, to 5) assessed 1 year after radiotherapy is a surrogate end-point of late rectal toxicity. The aim of this study was to investigate the association between treatment-related factors and 1-year VRS.

PATIENTS AND METHODS

We performed a retrospective analysis of prospectively collected data. Patients with prostate adenocarcinoma treated with definitive or postoperative radiotherapy (RT) underwent endoscopy 1 year after RT. Relationships between VRS of 2 or more and treatment parameters were investigated by univariate and multivariate logistic analyses.

RESULTS

One hundred and ninety-five patients (mean age=69 years; range=43-81 years) were considered eligible for the study. At univariate analysis, patients treated with hypofractionation plus radiosurgery boost (p<0.001) and an equivalent dose in 2 Gy per fraction (EQD2) (α/β=3) ≥75 Gy (p<0.001) was associated with a significantly higher incidence of VRS ≥2 after 1 year of follow-up. At multivariate analysis, radiosurgery boost was an independent risk factor for developing rectal mucosal lesions (VRS ≥2), yielding an odds ratio (OR) of 4.14 (95% confidence interval (CI)=1.2-13.8), while pelvic surgery was inversely associated with VRS ≥2 (OR=0.39; 95% CI=0.17-0.94).

CONCLUSION

Hypofractionation followed by radiosurgery boost significantly increased the risk of developing late-onset rectal mucosal changes. Therefore, special care and preventative treatment strategies are needed when using radiosurgery boost after hypofractionated RT.

Expression of vascular endothelial growth factor and its correlation with clinical symptoms and endoscopic findings in patients with chronic radiation proctitis

AIM

The aim of this study was to assess the expression of vascular endothelial growth factor (VEGF) as a key proangiogenic factor and determine whether there is any correlation between its expression and clinical symptoms or endoscopic changes in patients with chronic radiation proctitis (ChRP).

METHOD

Fifty patients who had all undergone radiotherapy for prostate, cervical or uterine cancer were included in the study (37 women, 13 men). There was a control group of 20 patients (9 women, 11 men). The Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) scoring system was used for grading the severity of the proctitis. Endoscopic scoring of late rectal mucosal damage was performed using Gilinsky's classification. Serum levels of VEGF were analysed by the enzyme-linked immunosorbent assay method.

RESULTS

Most patients presented with Grade 1 symptoms. Endoscopic assessment showed that most patients had Grade 1 late rectal mucosal damage. The predominant endoscopic finding was the presence of telangiectasia. Assessment of VEGF correlation between the control group and the degrees of endoscopic changes showed statistically significant differences for all three degrees (P < 0.0001, P = 0.0251 and P = 0.0005, respectively). Due to the small numbers of patients with Grades 2 and 3 symptoms using the RTOG/EORTC scoring system, they were grouped with Grades 1 and 4 respectively forming two groups for statistical purposes. VEGF expression differed significantly between controls and group I and between controls and group II (P = 0.0001, P = 0.0009, respectively).

CONCLUSION

A significant increase in VEGF expression was found to correlate with clinical symptoms and endoscopic rectal mucosa changes in patients with ChRP, suggesting that it may play an important role in pathological angiogenesis.

The Optimal Application of Transrectal Ultrasound in Staging of Rectal Cancer Following Neoadjuvant Therapy: A Pragmatic Study for Accuracy Investigation

Background: Transrectal ultrasound (TRUS) is a cost-effective test for preoperative assessment of rectal cancer. However, whether the accuracy of TRUS staging is correlated with tumor location remains obscured. This study is designed to explore their relationship and confirm an optimal application of TRUS in rectal cancer restaging.

Methods: From 2005 to 2011, rectal cancer patients with TRUS data were retrospectively reviewed. Patients were divided into five groups according to tumor-involved rectal segment (SEG) above the anal verge: SEG I 1-3cm, II 3-6cm, III 6-9cm, IV 9-12cm, and V 12-16cm. The accuracy and long-term outcomes of tumor staging were compared between ultrasonographic and pathological stages.

Results: 219 patients were included, with 55 (25.1%) in SEG I, 123 (56.2%) in SEG II, 32 (14.6%) in SEG III, 4 (1.8%) in SEG IV and 5 (2.3%) in SEG V. The overall accuracy of TRUS staging was remarkably superior to clinical staging by CT (64.8% vs. 34.7%, P<0.001), with 70.3% and 82.2% for ultrasonographic T and N stages respectively. The accuracy of TRUS reached its peak value when tumors were located in SEG II. The 5-year overall survival had no significant difference between TRUS and pathology staging for all stages. A cox regression analysis indicated that high levels of CEA and tumor location were risk factors of inaccurate staging.

Conclusions: TRUS is still a valuable examination for restaging of rectal cancer after neoadjuvant therapy. The application of TRUS would be optimal for rectal cancer located 3-6cm above the anal verge.

Interventions to reduce acute and late adverse gastrointestinal effects of pelvic radiotherapy for primary pelvic cancers

BACKGROUND

An increasing number of people survive cancer but a significant proportion have gastrointestinal side effects as a result of radiotherapy (RT), which impairs their quality of life (QoL).

OBJECTIVES

To determine which prophylactic interventions reduce the incidence, severity or both of adverse gastrointestinal effects among adults receiving radiotherapy to treat primary pelvic cancers.

SEARCH METHODS

We conducted searches of CENTRAL, MEDLINE, and Embase in September 2016 and updated them on 2 November 2017. We also searched clinical trial registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions to prevent adverse gastrointestinal effects of pelvic radiotherapy among adults receiving radiotherapy to treat primary pelvic cancers, including radiotherapy techniques, other aspects of radiotherapy delivery, pharmacological interventions and non-pharmacological interventions. Studies needed a sample size of 20 or more participants and needed to evaluate gastrointestinal toxicity outcomes. We excluded studies that evaluated dosimetric parameters only. We also excluded trials of interventions to treat acute gastrointestinal symptoms, trials of altered fractionation and dose escalation schedules, and trials of pre- versus postoperative radiotherapy regimens, to restrict the vast scope of the review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. We used the random-effects statistical model for all meta-analyses, and the GRADE system to rate the certainty of the evidence.

MAIN RESULTS

We included 92 RCTs involving more than 10,000 men and women undergoing pelvic radiotherapy. Trials involved 44 different interventions, including radiotherapy techniques (11 trials, 4 interventions/comparisons), other aspects of radiotherapy delivery (14 trials, 10 interventions), pharmacological interventions (38 trials, 16 interventions), and non-pharmacological interventions (29 trials, 13 interventions). Most studies (79/92) had design limitations. Thirteen studies had a low risk of bias, 50 studies had an unclear risk of bias and 29 studies had a high risk of bias. Main findings include the following:Radiotherapy techniques: Intensity-modulated radiotherapy (IMRT) versus 3D conformal RT (3DCRT) may reduce acute (risk ratio (RR) 0.48, 95% confidence interval (CI) 0.26 to 0.88; participants = 444; studies = 4; I2 = 77%; low-certainty evidence) and late gastrointestinal (GI) toxicity grade 2+ (RR 0.37, 95% CI 0.21 to 0.65; participants = 332; studies = 2; I2 = 0%; low-certainty evidence). Conformal RT (3DCRT or IMRT) versus conventional RT reduces acute GI toxicity grade 2+ (RR 0.57, 95% CI 0.40 to 0.82; participants = 307; studies = 2; I2 = 0%; high-certainty evidence) and probably leads to less late GI toxicity grade 2+ (RR 0.49, 95% CI 0.22 to 1.09; participants = 517; studies = 3; I2 = 44%; moderate-certainty evidence). When brachytherapy (BT) is used instead of external beam radiotherapy (EBRT) in early endometrial cancer, evidence indicates that it reduces acute GI toxicity (grade 2+) (RR 0.02, 95% CI 0.00 to 0.18; participants = 423; studies = 1; high-certainty evidence).Other aspects of radiotherapy delivery: There is probably little or no difference in acute GI toxicity grade 2+ with reduced radiation dose volume (RR 1.21, 95% CI 0.81 to 1.81; participants = 211; studies = 1; moderate-certainty evidence) and maybe no difference in late GI toxicity grade 2+ (RR 1.02, 95% CI 0.15 to 6.97; participants = 107; studies = 1; low-certainty evidence). Evening delivery of RT may reduce acute GI toxicity (diarrhoea) grade 2+ during RT compared with morning delivery of RT (RR 0.51, 95% CI 0.34 to 0.76; participants = 294; studies = 2; I2 = 0%; low-certainty evidence). There may be no difference in acute (RR 2.22, 95% CI 0.62 to 7.93, participants = 110; studies = 1) and late GI toxicity grade 2+ (RR 0.44, 95% CI 0.12 to 1.65; participants = 81; studies = 1) between a bladder volume preparation of 1080 mls and that of 540 mls (low-certainty evidence). Low-certainty evidence on balloon and hydrogel spacers suggests that these interventions for prostate cancer RT may make little or no difference to GI outcomes.Pharmacological interventions: Evidence for any beneficial effects of aminosalicylates, sucralfate, amifostine, corticosteroid enemas, bile acid sequestrants, famotidine and selenium is of a low or very low certainty. However, evidence on certain aminosalicylates (mesalazine, olsalazine), misoprostol suppositories, oral magnesium oxide and octreotide injections suggests that these agents may worsen GI symptoms, such as diarrhoea or rectal bleeding.Non-pharmacological interventions: Low-certainty evidence suggests that protein supplements (RR 0.23, 95% CI 0.07 to 0.74; participants = 74; studies = 1), dietary counselling (RR 0.04, 95% CI 0.00 to 0.60; participants = 74; studies = 1) and probiotics (RR 0.43, 95% CI 0.22 to 0.82; participants = 923; studies = 5; I2 = 91%) may reduce acute RT-related diarrhoea (grade 2+). Dietary counselling may also reduce diarrhoeal symptoms in the long term (at five years, RR 0.05, 95% CI 0.00 to 0.78; participants = 61; studies = 1). Low-certainty evidence from one study (108 participants) suggests that a high-fibre diet may have a beneficial effect on GI symptoms (mean difference (MD) 6.10, 95% CI 1.71 to 10.49) and quality of life (MD 20.50, 95% CI 9.97 to 31.03) at one year. High-certainty evidence indicates that glutamine supplements do not prevent RT-induced diarrhoea. Evidence on various other non-pharmacological interventions, such as green tea tablets, is lacking.Quality of life was rarely and inconsistently reported across included studies, and the available data were seldom adequate for meta-analysis.

AUTHORS' CONCLUSIONS

Conformal radiotherapy techniques are an improvement on older radiotherapy techniques. IMRT may be better than 3DCRT in terms of GI toxicity, but the evidence to support this is uncertain. There is no high-quality evidence to support the use of any other prophylactic intervention evaluated. However, evidence on some potential interventions shows that they probably have no role to play in reducing RT-related GI toxicity. More RCTs are needed for interventions with limited evidence suggesting potential benefits.

Validation of genetic predictors of late radiation-induced morbidity in prostate cancer patients

INTRODUCTION

Normal tissue morbidity sets the dose limit for radiotherapy (RT) in cancer treatment and has importance for quality of life for cancer survivors. A previous study of prostate cancer patients treated with RT generated clinical data for radiation-induced morbidity measured by anorectal physiological methods and validated questionnaires. Other studies have identified genetic predictors associated with late radiation-induced morbidity outcome. We have expanded biobank material aiming to validate single nucleotide polymorphisms (SNPs) and a gene expression classifier with endpoints on patient-reported outcomes and biomechanical properties of the anorectum from our cohort matching originally published endpoints.

MATERIALS AND METHODS

The present cohort of prostate cancer patients was treated with RT curative intent in 1999-2007. Nine SNPs associated with late radiation-induced morbidity were tested in 96 patients (rs2788612, rs1800629, rs264663, rs2682585, rs2268363, rs1801516, rs13035033, rs7120482 and rs17779457). A validated gene expression profile predictive of resistance to radiation-induced skin fibrosis was tested in 42 patients. An RT-induced anorectal dysfunction score (RT-ARD) served as a fibrosis-surrogate and a measure of overall radiation-induced morbidity.

RESULTS

The lowest p-value found in the genotype analyses was for SNP rs2682585 minor allele (A) in the FSHR gene and the RT-ARD score with odds ratios (OR) = 1.76; 95% CI (0.98-3.17) p = .06, which was out of concordance with original data showing a protective effect of the minor allele. The gene expression profile in patients classified as fibrosis-resistant was associated with high RT-ARD scores OR 4.18; 95% CI (1.1-16.6), p = .04 conflicting with the hypothesis that fibrosis-resistant patients would experience lower RT-ARD scores.

CONCLUSIONS

We aimed to validate nine SNPs and a gene expression classifier in a cohort of prostate cancer patients with unique scoring of radiation-induced morbidity. One significant association was found, pointing to the opposite direction of originally published data. We conclude that the material was not able to validate previously published genetic predictors of radiation-induced morbidity.

Correlation between Disease Activity and Endorectal Ultrasound Findings of Chronic Radiation Proctitis

The aim of this study was to summarize the imaging features of chronic radiation proctitis (CRP) on endorectal ultrasound (ERUS) and investigate the value of ERUS in the evaluation of disease activity. 40 CRP patients and 30 control patients were investigated by ERUS. Rectal wall thickness and layers, ulcers and rectovaginal fistulas were evaluated by B-mode ultrasound. Power Doppler imaging was used to evaluate the vascularity of the rectal wall using a semiquantitative score. Disease activity was calculated according to the National Cancer Institute Common Terminology Criteria for Adverse Events 4.0 (CTCAE 4.0). Imaging findings for patients with mild and severe CRP were compared. For 30 patients in the control group, the average maximum thickness of the rectal wall was 3.07 ± 0.73 mm, with all exhibiting typical wall stratification and level 0 vascularity. For the 40 CRP patients, there was marked thickening of the rectal wall (average thickness = 9.42 ± 1.94 mm), which was significantly thicker than in the control group (p < 0.05). The rectal walls of the mild group were significantly thinner than those of the severe group (8.71 ± 1.67 mm vs. 10.00 ± 2.00 mm, p < 0.05). Among the 22 severe cases, 19 cases (19/22, 86.4%) exhibited hyper-vascularity (level IV) or blurred wall stratification (including hypo-echoic submucosa, ulcer and fistula); 12 of the 18 mild cases (166.7%) exhibited a vascularity of level III and typical wall stratification. A significant association (p < 0.05) was observed between stratification and vascularity of the rectal wall and CRP activity. When ERUS findings of blurred rectal wall stratification or increasing vascularity (level IV) were used to evaluate CRP activity, the sensitivity was 86.4% (95% confidence interval: 64.0-96.4) and the specificity was 66.7% (95% confidence interval: 41.2-85.6). Thickening of the rectal wall, blurred wall stratification and increased vascularity are characteristic ERUS findings of CRP. ERUS is helpful in the comprehensive evaluation of disease activity and may provide objective evidence during treatment planning and follow-up.

Nomogram to predict rectal toxicity following prostate cancer radiotherapy

BACKGROUND

To identify predictors of acute and late rectal toxicity following prostate cancer radiotherapy (RT), while integrating the potential impact of RT technique, dose escalation, and moderate hypofractionation, thus enabling us to generate a nomogram for individual prediction.

METHODS

In total, 972 patients underwent RT for localized prostate cancer, to a total dose of 70 Gy or 80 Gy, using two different fractionations (2 Gy or 2.5 Gy/day), by means of several RT techniques (3D conformal RT [3DCRT], intensity-modulated RT [IMRT], or image-guided RT [IGRT]). Multivariate analyses were performed to identify predictors of acute and late rectal toxicity. A nomogram was generated based on the logistic regression model used to predict the 3-year rectal toxicity risk, with its accuracy assessed by dividing the cohort into training and validation subgroups.

RESULTS

Mean follow-up for the entire cohort was 62 months, ranging from 6 to 235. The rate of acute Grade ≥2 rectal toxicity was 22.2%, decreasing when combining IMRT and IGRT, compared to 3DCRT (RR = 0.4, 95%CI: 0.3-0.6, p<0.01). The 5-year Grade ≥2 risks for rectal bleeding, urgency/tenesmus, diarrhea, and fecal incontinence were 9.9%, 4.5%, 2.8%, and 0.4%, respectively. The 3-year Grade ≥2 risk for overall rectal toxicity increased with total dose (p<0.01, RR = 1.1, 95%CI: 1.0-1.1) and dose per fraction (2Gy vs. 2.5Gy) (p = 0.03, RR = 3.3, 95%CI: 1.1-10.0), and decreased when combining IMRT and IGRT (RR = 0.50, 95% CI: 0.3-0.8, p<0.01). Based on these three parameters, a nomogram was generated.

CONCLUSIONS

Dose escalation and moderate hypofractionation increase late rectal toxicity. IMRT combined with IGRT markedly decreases acute and late rectal toxicity. Performing combined IMRT and IGRT can thus be envisaged for dose escalation and moderate hypofractionation. Our nomogram predicts the 3-year rectal toxicity risk by integrating total dose, fraction dose, and RT technique.

Spatial features of dose-surface maps from deformably-registered plans correlate with late gastrointestinal complications

This study investigates the associations between spatial distribution of dose to the rectal surface and observed gastrointestinal toxicities after deformably registering each phase of a combined external beam radiotherapy (EBRT)/high-dose-rate brachytherapy (HDRBT) prostate cancer treatment. The study contains data for 118 patients where the HDRBT CT was deformably-registered to the EBRT CT. The EBRT and registered HDRBT TG43 dose distributions in a reference 2 Gy/fraction were 3D-summed. Rectum dose-surface maps (DSMs) were obtained by virtually unfolding the rectum surface slice-by-slice. Associations with late peak gastrointestinal toxicities were investigated using voxel-wise DSM analysis as well as parameterised spatial patterns. The latter were obtained by thresholding DSMs from 1-80 Gy (increment  =  1) and extracting inferior-superior extent, left-right extent, area, perimeter, compactness, circularity and ellipse fit parameters. Logistic regressions and Mann-Whitney U-tests were used to correlate features with toxicities. Rectal bleeding, stool frequency, diarrhoea and urgency/tenesmus were associated with greater lateral and/or longitudinal spread of the high doses near the anterior rectal surface. Rectal bleeding and stool frequency were also influenced by greater low-intermediate doses to the most inferior 20% of the rectum and greater low-intermediate-high doses to 40-80% of the rectum length respectively. Greater low-intermediate doses to the superior 20% and inferior 20% of the rectum length were associated with anorectal pain and urgency/tenesmus respectively. Diarrhoea, completeness of evacuation and proctitis were also related to greater low doses to the posterior side of the rectum. Spatial features for the intermediate-high dose regions such as area, perimeter, compactness, circularity, ellipse eccentricity and confinement to ellipse fits were strongly associated with toxicities other than anorectal pain. Consequently, toxicity is related to the shape of isodoses as well as dose coverage. The findings indicate spatial constraints on doses to certain sections of the rectum may be important for reducing toxicities and optimising dose.

Intensity-Modulated Radiation Therapy with Stereotactic Body Radiation Therapy Boost for Unfavorable Prostate Cancer: A Report on 3-Year Toxicity

Background

Recent data suggest that intensity-modulated radiation therapy (IMRT) plus brachytherapy boost for unfavorable prostate cancer provides improved biochemical relapse-free survival over IMRT alone. Stereotactic body radiation therapy (SBRT) may be a less invasive alternative to brachytherapy boost. Here, we report the 3-year gastrointestinal (GI) and genitourinary (GU) toxicities of IMRT plus SBRT boost.

Materials and methods

Between March 2008 and September 2012, patients with prostate cancer were treated with robotic SBRT (19.5 Gy in three fractions) followed by fiducial-guided IMRT (45–50.4 Gy) on an institutional protocol. Toxicity was prospectively graded using the common terminology criteria for adverse events version 4.0 (CTCAEv.4) at the start of and at 1- to 6-month intervals after therapy. Rectal telangiectasias were graded using the Vienna Rectoscopy Score (VRS).

Results

At a median follow-up of 4.2 years (2.4–7.5), 108 patients (4 low-, 45 intermediate-, and 59 high-risk) with a median age of 74 years (55–92) were treated with SBRT plus IMRT, with 8% on anticoagulation and an additional 48% on antiplatelet therapy at the start of therapy. The cumulative incidence of late ≥grade 2 GI toxicity was 12%. Of these, 7% were due to late rectal bleeding, with six patients requiring up to two coagulation procedures. One patient with rectal telangiectasias was treated with hyperbaric oxygen (grade 3 toxicity). No rectal fistulas or stenoses were observed. Ten patients had multiple non-confluent telangiectasias (VRS grade 2), and three patients had multiple confluent telangiectasias (VRS grade 3). The cumulative incidence of late grade 3 GU toxicity was 6%. Most late toxicities were due to hematuria requiring bladder fulguration. There were no late ≥grade 4 GU toxicities.

Conclusion

Rates of clinically significant GI and GU toxicities are modest following IMRT plus SBRT boost. Future studies should compare cancer control, quality of life, and toxicity with other treatment modalities for patients with high-risk prostate cancer.

Novel and Effective Almagate Enema for Hemorrhagic Chronic Radiation Proctitis and Risk Factors for Fistula Development

Radiation proctitis is a common complication after radiotherapy for pelvic malignant tumors. This study was conducted to assess the efficacy of novel almagate enemas in hemorrhagic chronic radiation proctitis (CRP) and evaluate risk factors related to rectal deep ulcer or fistula secondary to CRP. All patients underwent a colonoscopy to confirm the diagnosis of CRP and symptoms were graded. Typical endoscopic and pathological images, risk factors, and quality of life were also recorded. A total of 59 patients were enrolled. Gynecological cancers composed 93.1% of the primary malignancies. Complete or obvious reduction of bleeding was observed in 90% (53/59) patients after almagate enema. The mean score of bleeding improved from 2.17 to 0.83 (P<0.001) after the enemas. The mean response time was 12 days. No adverse effects were found. Moreover, long-term successful rate in controlling bleeding was 69% and the quality of life was dramatically improved (P=0.001). The efficacy was equivalent to rectal sucralfate, but the almagate with its antacid properties acted more rapidly than sucralfate. Furthermore, we firstly found that moderate to severe anemia was the risk factor of CRP patients who developed rectal deep ulcer or fistulas (P= 0.015). We also found abnormal hyaline-like thick wall vessels, which revealed endarteritis obliterans and the fibrosis underlying this disease. These findings indicate that almagate enema is a novel effective, rapid and well-tolerated method for hemorrhagic CRP. Moderate to severe anemia is a risk factor for deep ulceration or fistula.

Long-Term Endoscopic Follow-Up of Patients with Chronic Radiation Proctopathy after Brachytherapy for Prostate Cancer

Background. Chronic radiation proctopathy (CRP) is late toxicity and associated with morbidity. Aim. To investigate the predictors of prognosis in patients with CRP after brachytherapy (BT). Methods. One hundred four patients with prostate cancer were treated with BT or BT followed by external-beam radiotherapy (BT + EBRT). We retrospectively investigated the 5-year incidence of rectal bleeding and endoscopic findings of CRP using the Vienna Rectoscopy Score (VRS). Twenty patients with VRS ≥ 1 were divided into the improved VRS group without treatment, unchanged VRS group, and treated group. The parameters associated with alteration of VRS were analyzed. Results. The incidence of rectal bleeding was 24%. The risk of rectal bleeding was higher in patients treated with BT + EBRT compared to those treated with BT (p < 0.0001). The incidence of superficial microulceration was higher in the improved VRS group than in the unchanged VRS group (p < 0.05). The incidence of multiple confluent telangiectasia or superficial ulcers > 1 cm² was higher in the treated group than in both the improved and unchanged VRS groups (p < 0.05). Conclusions. Patients treated with BT + EBRT have a high risk of CRP. Endoscopic findings were useful for prognostic prediction of CRP.

Colostomy is a simple and effective procedure for severe chronic radiation proctitis

AIM: To assess the efficacy and safety of diverting colostomy in treating severe hemorrhagic chronic radiation proctitis (CRP).

METHODS: Patients with severe hemorrhagic CRP who were admitted from 2008 to 2014 were enrolled into this study. All CRP patients were diagnosed by a combination of pelvic radiation history, clinical rectal bleeding, and endoscopic findings. Inclusion criteria were CRP patients with refractory bleeding with moderate to severe anemia with a hemoglobin level < 90 g/L. The study group included patients who were treated by diverting colostomy, while the control group included patients who received conservative treatment. The remission of bleeding was defined as complete cessation or only occasional bleeding that needed no further treatment. The primary outcome was bleeding remission at 6 mo after treatment. Quality of life before treatment and at follow-up was evaluated according to EORTC QLQ C30. Severe CRP complications were recorded during follow-up.

RESULTS: Forty-seven consecutive patients were enrolled, including 22 in the colostomy group and 27 in the conservative treatment group. When compared to conservative treatment, colostomy obtained a higher rate of bleeding remission (94% vs 12%), especially in control of transfusion-dependent bleeding (100% vs 0%), and offered a better control of refractory perianal pain (100% vs 0%), and a lower score of bleeding (P < 0.001) at 6 mo after treatment. At 1 year after treatment, colostomy achieved better remission of both moderate bleeding (100% vs 21.5%, P = 0.002) and severe bleeding (100% vs 0%, P < 0.001), obtained a lower score of bleeding (0.8 vs 2.0, P < 0.001), and achieved obvious elevated hemoglobin levels (P = 0.003), when compared to the conservative treatment group. The quality of life dramatically improved after colostomy, which included global health, function, and symptoms, but it was not improved in the control group. Pathological evaluation after colostomy found diffused chronic inflammation cells, and massive fibrosis collagen depositions under the rectal wall, which revealed potential fibrosis formation.

CONCLUSION: Diverting colostomy is a simple, effective and safe procedure for severe hemorrhagic CRP. Colostomy can improve quality of life and reduce serious complications secondary to radiotherapy.

Data Pooling and Analysis to Build a Preliminary Item Bank

Assessing bowel function (BF) in prostate cancer can help determine therapeutic trade-offs. We determined the components of BF commonly assessed in prostate cancer studies as an initial step in creating an item bank for clinical and research application. We analyzed six archived data sets representing 4,246 men with prostate cancer. Thirty-one items from validated instruments were available for analysis. Items were classified into domains (diarrhea, rectal urgency, pain, bleeding, bother/distress, and other) then subjected to conventional psychometric and item response theory (IRT) analyses. Items fit the IRT model if the ratio between observed and expected item variance was between 0.60 and 1.40. Four of 31 items had inadequate fit in at least one analysis. Poorly fitting items included bleeding (2), rectal urgency (1), and bother/distress (1). A fifth item assessing hemorrhoids was poorly correlated with other items. Our analyses supported four related components of BF: diarrhea, rectal urgency, pain, and bother/distress.

Identification of a rectal subregion highly predictive of rectal bleeding in prostate cancer IMRT

BACKGROUND AND PURPOSE

To identify rectal subregions at risks (SRR) highly predictive of 3-year rectal bleeding (RB) in prostate cancer IMRT.

MATERIALS AND METHODS

Overall, 173 prostate cancer patients treated with IMRT/IGRT were prospectively analyzed, divided into "training" (n=118) and "validation" cohorts (n=53). Dose-volume histograms (DVHs) were calculated in three types of rectal subregions: "geometric", intuitively defined (hemi-rectum,…); "personalized", obtained by non-rigid registration followed by voxel-wise statistical analysis (SRRp); "generic", mapped from SRRps, located within 8×8 rectal subsections (SRRg). DVHs from patients with and without RB were compared and used for toxicity prediction.

RESULTS

Training cohort SRRps were primarily within the inferior anterior hemi-rectum and upper anal canal, with 3.8Gy mean dose increase for Grade⩾1 RB patients. The SRRg, representing 15% of the absolute rectal volume, was located in 10 inferior-anterior rectal subsections. V18-V70 for SRRps and V58-V65 for SRRg were significantly higher for RB patients than non-RB. Maximum areas under the curve (AUCs) for SRRp and SRRg RB prediction were 71% and 64%, respectively. The validation cohort confirmed the predictive value of SRRg for Grade⩾1 RB. The total cohort confirmed the predictive value of SRRg for Grade⩾2 RB. Geometrical subregions were not RB predictors.

CONCLUSION

The inferior-anterior hemi anorectum was highly predictive of RB.

Chronic radiation proctitis: tricks to prevent and treat

OBJECTIVE

The purpose of this study was to give an overview of the measures used to prevent chronic radiation proctitis (CRP) and to provide an algorithm for the treatment of CRP.

METHODS

Medical literature databases including PubMed and Medline were screened and critically analyzed for relevance in the scope of our purpose.

RESULTS

CRP is a relatively frequent late side effect (5-20%) and mainly dependent on the dose and volume of irradiated rectum. Radiation treatment (RT) techniques to prevent CRP are constantly improving thanks to image-guided RT and intensity-modulated RT. Also, newer techniques like protons and new devices such as rectum spacers and balloons have been developed to spare rectal structures. Biopsies do not contribute to diagnosing CRP and should be avoided because of the risk of severe rectal wall damage, such as necrosis and fistulas. There is no consensus on the optimal treatment of CRP. A variety of possibilities is available and includes topical and oral agents, hyperbaric oxygen therapy, and endoscopic interventions.

CONCLUSIONS

CRP has a natural history of improving over time, even without treatment. This is important to take into account when considering these treatments: first be conservative (topical and oral agents) and be aware that invasive treatments can be very toxic.

Radiation proctopathy

Radiation therapy is a widely utilized treatment modality for pelvic malignancies, including prostate cancer, rectal cancer, and cervical cancer. Given its fixed position in the pelvis, the rectum is at a high risk for injury secondary to ionizing radiation. Despite advances made in radiation science, up to 75% of the patients will suffer from acute radiation proctitis and up to 20% may experience chronic symptoms. Symptoms can be variable and include diarrhea, bleeding, incontinence, and fistulization. A multitude of treatment options exist. This article summarizes the latest knowledge relating to radiation proctopathy focusing on the vast array of treatment options.

Radiotherapy-induced mesorectum alterations: histological evaluation of 90 consecutive cases

OBJECTIVE

In order to identify the radiotherapy-induced histological modifications in the mesorectum, we reviewed the surgical specimens of 90 rectal resections comprehensive of the total mesorectal excision (23 cases radiologically classified as cT2N0M0 and 67 as cT3N0M0). All patients were preoperative treated with radiotherapy: 20 with 50 Gy, 20 with 20 Gy and 50 Gy irradiation associated to FOLFOX scheme chemotherapy.

MATERIAL AND METHODS

Routine hematoxylin and eosin stained serial slides at 5 mm of intervals were obtained from surgical specimens and included the tumor site and the adjacent irradiated mucosa, the submucosa and the muscular layers of the rectal wall and the mesorectal adipose tissue, completely removed until to the mesorectal fascia. Ten subjects (eight cT2N0M0 and two cT3N0M0), who did not received preoperative oncological treatments were adopted as controls.

RESULTS

Histologically, examination revealed fibrosis of the adipose tissue in 86 cases (95%), vascular damage including vasculities and fibrotic thickening wall of arteries and veins in 46 cases (51%), sclero-hyalinosis of lymph nodes with pericapsular fibrosis in 22 cases (23%) and perineural deposition of fibrosis in 12 (13%). These findings were ubiquitously observed in the whole mesorectum. Fibrosis of the adipose tissue and vasculitis were mainly associated to the combination of 50 Gy radiations plus chemotherapy (p < 0.05).

CONCLUSION

The detection of histopathological alterations in the mesorectum can give reason of the well-known postoperative complications and long-term sequels.

Late rectal toxicity after low-dose-rate brachytherapy: incidence, predictors, and management of side effects

As clinical outcomes for patients with clinically localized prostate cancer continue to improve, patients and physicians are increasing making treatment decisions based on concerns regarding long-term morbidity. A primary concern is late radiation proctitis, a clinical entity embodied by various signs and symptoms, ranging from diarrhea to rectal fistulas. Here, we present a comprehensive literature review examining the clinical manifestations and pathophysiology of late radiation proctitis after low-dose-rate brachytherapy (BT), as well as its incidence and predictors. The long-term risks of rectal bleeding after BT are on the order of 5-7%, whereas the risks of severe ulceration or fistula are on the order of 0.6%. The most robust predictor appears to be the volume of rectum receiving the prescription dose. In certain situations (e.g., salvage setting, for patients with increased radiosensitivity, and following aggressive biopsy after BT), the risk of these severe toxicities may be increased by up to 10-fold. A variety of excellent management options exist for rectal bleeding, with endoscopic methods being the most commonly used.

Proctitis following stereotactic body radiation therapy for prostate cancer

Background

Proctitis after radiation therapy for prostate cancer remains an ongoing clinical challenge and critical quality of life issue. SBRT could minimize rectal toxicity by reducing the volume of rectum receiving high radiation doses and offers the potential radiobiologic benefits of hypofractionation. This study sought to evaluate the incidence and severity of proctitis following SBRT for prostate cancer.

Methods

Between February 2008 and July 2011, 269 men with clinically localized prostate cancer were treated definitively with SBRT monotherapy at Georgetown University Hospital. All patients were treated to 35-36.25Gy in 5 fractions delivered with the CyberKnife Radiosurgical System (Accuray). Rectal bleeding was recorded and scored using the CTCAE v.4. Telangiectasias were graded using the Vienna Rectoscopy Score (VRS). Proctitis was assessed via the Bowel domain of the Expanded Prostate Index Composite (EPIC)-26 at baseline and at 1, 3, 6, 9, 12, 18 and 24 months post-SBRT.

Results

The median age was 69 years with a median prostate volume of 39 cc. The median follow-up was 3.9 years with a minimum follow-up of two years. The 2-year actuarial incidence of late rectal bleeding ≥ grade 2 was 1.5%. Endoscopy revealed VRS Grade 2 rectal telangiectasias in 11% of patients. All proctitis symptoms increased at one month post-SBRT but returned to near-baseline with longer follow-up. The most bothersome symptoms were bowel urgency and frequency. At one month post-SBRT, 11.2% and 8.5% of patients reported a moderate to big problem with bowel urgency and frequency, respectively. The EPIC bowel summary scores declined transiently at 1 month and experienced a second, more protracted decline between 6 months and 18 months before returning to near-baseline at two years post-SBRT. Prior to treatment, 4.1% of men felt their bowel function was a moderate to big problem which increased to 11.5% one month post-SBRT but returned to near-baseline at two years post-SBRT.

Conclusions

In this single institution cohort, the rate and severity of proctitis observed following SBRT is low. QOL decreased on follow-up; however, our results compare favorably to those reported for patients treated with alternative radiation modalities. Future prospective randomized studies are needed to confirm these observations.

Optimization of radiation therapy techniques for prostate cancer with prostate-rectum spacers: a systematic review

Dose-escalated radiation therapy for localized prostate cancer improves disease control but is also associated with worse rectal toxicity. A spacer placed between the prostate and rectum can be used to displace the anterior rectal wall outside of the high-dose radiation regions and potentially minimize radiation-induced rectal toxicity. This systematic review focuses on the published data regarding the different types of commercially available prostate-rectum spacers. Dosimetric results and preliminary clinical data using prostate-rectum spacers in patients with localized prostate cancer treated by curative radiation therapy are compared and discussed.

Pathophysiology of late anorectal dysfunction following external beam radiotherapy for prostate cancer

BACKGROUND

Patients treated with external beam radiotherapy (EBRT) may suffer from long-term anorectal adverse effects. The purpose of the present study was to assess long-term functional and structural anorectal changes in patients previously treated with EBRT for prostate cancer and to suggest the mechanism behind the development of the adverse effects.

MATERIAL AND METHODS

Our previously proposed RT-induced anorectal dysfunction (RT-ARD) score, developed with the intention to survey anorectal dysfunction was used to identify patients with and without anorectal symptoms. Among 309 patients surveyed with the questionnaire, we chose 23 patients with the highest RT-ARD score and 19 patients with the lowest RT-ARD score. They were investigated by multimodal rectal sensory stimulation, standard anal physiological tests. Changes of the rectal mucosa were assessed by flexible sigmoidoscopy and graded by the Vienna Rectoscopy Score (VRS).

RESULTS

The mean follow-up time was 3.8 (range, 2.8; 8.6) years in patients with high RT-ARD and 3.8 (range, 2.6; 5.9) in patients with low RT-ARD. Endoscopic evaluation revealed higher VRS scores in patients with high RT-ARD compared to patients with low RT-ARD (p = 0.002). Patients with high RT-ARD had increased rectal sensory response to distension manifested both as volume (p = 0.006) and cross-sectional area (p = 0.04), and they had reduced maximum anal resting pressure assessed by anal manometri (p = 0.02).

CONCLUSIONS

Long-term anorectal symptoms correlate to changes in anorectal biomechanical properties and rectal mucosal injury. Our data suggests that RT-induced long-term anorectal dysfunction is multifactorial caused by injury of the rectal mucosa and the internal anal sphincter combined with increased rectal sensitivity and reduced rectal functional capacity.

A randomized controlled clinical trial of formalin for treatment of chronic hemorrhagic radiation proctopathy in cervical carcinoma patients

PURPOSE

Chronic hemorrhagic radiation proctopathy is not uncommon after radiotherapy for cervical carcinoma. The outcomes of several treatments have been variable. Many studies demonstrate that topical treatment with 4 % formalin is effective and safe. However, a nonrandomized control study showed a high response rate and good tolerance in chronic radiation proctopathy patients treated with 10 % formalin. The optimal concentration of formalin therefore remains unclear.

METHODS

To compare the effectiveness and safety of 4 and 10 % formalin for the treatment of chronic hemorrhagic radiation proctopathy, a prospective trial was conducted at the Department of Gynecology of the Affiliated Hospital of Binzhou Medical College from January 2009 to December 2012. One hundred and twenty patients with chronic hemorrhagic radiation proctopathy following radiotherapy for cervical carcinoma were recruited and randomized to receive 4 or 10 % formalin. A standard protocol was followed for formalin application. Symptom and rectoscopy scores were evaluated before and at 12 weeks after treatment.

RESULTS

In the 4 % formalin group, 49 (86.0 %) and 53 (91.4 %) patients showed an improvement in symptom score and rectoscopy score, respectively (P = 0.36). Symptom and rectoscopy scores decreased significantly after treatment in both the 4 % formalin group and the 10 % formalin group (P < 0.001). Symptom score was correlated with rectoscopy score (P < 0.001). More patients in the 10 % group suffered treatment-related complications than did those in the 4 % group (P = 0.03).

CONCLUSIONS

For the treatment of chronic hemorrhagic radiation proctopathy, 4 % should be the preferred formalin concentration.

The association of rectal equivalent dose in 2 Gy fractions (EQD2) to late rectal toxicity in locally advanced cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University

Purpose

To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University.

Materials and Methods

Retrospective study was designed for the patients with locally advanced cervical cancer, treated by radical radiotherapy from 2004 to 2009 and were evaluated by rectosigmoidoscopy. The cumulative doses of WPRT and ICBT to the maximally rectal point were calculated to the EQD2 and evaluated the association of toxicities.

Results

Thirty-nine patients were evaluated for late rectal toxicity. The mean cumulative dose in term of EQD2 to rectum was 64.2 Gy. Grade 1 toxicities were the most common findings. According to endoscopic exam, the most common toxicities were congested mucosa (36 patients) and telangiectasia (32 patients). In evaluation between rectal dose in EQD2 and toxicities, no association of cumulative rectal dose to rectal toxicity, except the association of cumulative rectal dose in EQD2 >65 Gy to late effects of normal tissue (LENT-SOMA) scale ≥ grade 2 (p = 0.022; odds ratio, 5.312; 95% confidence interval, 1.269-22.244).

Conclusion

The cumulative rectal dose in EQD2 >65 Gy have association with ≥ grade 2 LENT-SOMA scale.

Absorbable hydrogel spacer use in men undergoing prostate cancer radiotherapy: 12 month toxicity and proctoscopy results of a prospective multicenter phase II trial

BACKGROUND

Radiation therapy is one of the recommended treatment options for localized prostate cancer. In randomized trials, dose escalation was correlated with better biochemical control but also with higher rectal toxicity. A prospective multicenter phase II study was carried out to evaluate the safety, clinical and dosimetric effects of the hydrogel prostate-rectum spacer. Here we present the 12 months toxicity results of this trial.

METHODS

Fifty two patients with localized prostate cancer received a transperineal PEG hydrogel injection between the prostate and rectum, and then received IMRT to a dose of 78 Gy. Gastrointestinal and genitourinary toxicity were recorded during treatment and at 3, 6 and 12 months following irradiation by using the RTOG/EORTC criteria. Additionally, proctoscopy was performed 12 months after treatment and the results were scored using the Vienna Rectoscopy Scale (VRS).

RESULTS

Of the patients treated 39.6% and 12.5% experienced acute Grade 1 and Grade 2 GI toxicity, respectively. There was no Grade 3 or Grade 4 acute GI toxicity experienced in the study. Only 4.3% showed late Grade 1 GI toxicity, and there was no late Grade 2 or greater GI toxicity experienced in the study. A total of 41.7%, 35.4% and 2.1% of the men experienced acute Grade 1, Grade 2 and Grade 3 GU toxicity, respectively. There was no Grade 4 acute GU toxicity experienced in the study. Late Grade 1 and Grade 2 GU toxicity was experienced in 17.0% and 2.1% of the patients, respectively. There was no late Grade 3 or greater GU toxicity experienced in the study. Seventy one percent of the patients had a VRS score of 0, and one patient (2%) had Grade 3 teleangiectasia. There was no evidence of ulceration, stricture or necrosis at 12 months.

CONCLUSION

The use of PEG spacer gel is a safe and effective method to spare the rectum from higher dose and toxicity.

Systematic review: anal and rectal changes after radiotherapy for prostate cancer

PURPOSE

Pelvic radiotherapy may lead to changes of anorectal function resulting in incontinence-related complaints. The aim of this study was to systematically review objective findings of late anorectal physiology and mucosal appearance after irradiation for prostate cancer.

METHODS

MEDLINE, EMBASE, and the Cochrane library were searched. Original articles in which anal function, rectal function, or rectal mucosa were examined ≥3 months after EBRT for prostate cancer were included.

RESULTS

Twenty-one studies were included with low to moderate quality. Anal resting pressures significantly decreased in 6 of the 9 studies including 277 patients. Changes of squeeze pressure and rectoanal inhibitory reflex were less uniform. Rectal distensibility was significantly impaired after EBRT in 7 of 9 studies (277 patients). In 4 of 9 studies on anal and in 5 of 9 on rectal function, disturbances were associated with urgency, frequent bowel movements or fecal incontinence. Mucosal changes as assessed by the Vienna Rectoscopy Score revealed telangiectasias in 73 %, congestion in 33 %, and ulceration in 4 % of patients in 8 studies including 346 patients, but no strictures or necrosis. Three studies reported mucosal improvement during follow-up. Telangiectasias, particularly multiple, were associated with rectal bleeding. Not all bowel complaints (30 %) were related to radiotherapy.

CONCLUSIONS

Low to moderate quality evidence indicates that EBRT reduces anal resting pressure, decreases rectal distensibility, and frequently induces telangiectasias of rectal mucosa. Objective changes may be associated with fecal incontinence, urgency, frequent bowel movements, and rectal bleeding, but these symptoms are not always related to radiation damage.

Repeated autologous bone marrow-derived mesenchymal stem cell injections improve radiation-induced proctitis in pigs

The management of proctitis in patients who have undergone very-high-dose conformal radiotherapy is extremely challenging. The fibrosis-necrosis, fistulae, and hemorrhage induced by pelvic overirradiation have an impact on morbidity. Augmenting tissue repair by the use of mesenchymal stem cells (MSCs) may be an important advance in treating radiation-induced toxicity. Using a preclinical pig model, we investigated the effect of autologous bone marrow-derived MSCs on high-dose radiation-induced proctitis. Irradiated pigs received repeated intravenous administrations of autologous bone marrow-derived MSCs. Immunostaining and real-time polymerase chain reaction analysis were used to assess the MSCs' effect on inflammation, extracellular matrix remodeling, and angiogenesis, in radiation-induced anorectal and colon damages. In humans, as in pigs, rectal overexposure induces mucosal damage (crypt depletion, macrophage infiltration, and fibrosis). In a pig model, repeated administrations of MSCs controlled systemic inflammation, reduced in situ both expression of inflammatory cytokines and macrophage recruitment, and augmented interleukin-10 expression in rectal mucosa. MSC injections limited radiation-induced fibrosis by reducing collagen deposition and expression of col1a2/col3a1 and transforming growth factor-β/connective tissue growth factor, and by modifying the matrix metalloproteinase/TIMP balance. In a pig model of proctitis, repeated injections of MSCs effectively reduced inflammation and fibrosis. This treatment represents a promising therapy for radiation-induced severe rectal damage.

Rectal endoscopy findings following stereotactic body radiation therapy for clinically localized prostate cancer

Background

Treating prostate cancer with SBRT could potentially minimize radiation proctitis by reducing high-dose rectal irradiation. In addition, it offers the potential radiobiologic benefits of hypofractionation. This study reports the endoscopic changes and the associated clinical rectal toxicity in these patients.

Methods

We reviewed the records of patients treated from 2008–2011 for localized prostate cancer who had rectal endoscopy following SBRT. SBRT was delivered either as primary treatment in 5 fractions of 7–7.25 Gy, or as an initial boost in 3 fractions of 6.5 Gy followed by conventionally fractionated radiotherapy to 45–50.4 Gy. Endoscopic changes were graded using the Vienna Rectoscopy Score (VRS). Rectal toxicity was graded via CTCAEv.4. Rectal quality of life (QOL) was assessed via the bowel domain of the EPIC-26 questionnaire.

Results

Fifty-one patients with a median 23 months follow-up were analyzed. Thirty-five patients completed SBRT monotherapy and 16 patients received SBRT as a boost to conventionally fractionated IMRT. The median interval from SBRT to rectal endoscopy was 13 months. Endoscopy revealed VRS Grade 1–2 telangiectasias for 10 patients and VRS Grade 1–2 mucosal edema for 12 patients. No rectal ulcerations, strictures or necrosis were observed. Grade 1–2 late rectal bleeding occurred in 10 patients. There were no CTCAEv.4 Grade ≥3 toxicities. Mean EPIC bowel scores decreased from a baseline value of 96.9 to 82.3 at 1-month, but subsequently increased to 91.0 at 24 months.

Conclusions

In this cohort that is skewed towards patients with rectal complaints, the rate and severity of endoscopic changes following SBRT is low. Rectal toxicity and QOL were comparable to patients treated with other radiation modalities. Prospective trials examining the endoscopic outcomes following SBRT for prostate cancer are needed for confirmation of the findings of this study.

Trial registration

The Georgetown Institutional Review Board has approved this retrospective study (IRB 2009–510).