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Simple Summary: Early prediction of response to cancer therapies is critical for treatment personalisation. In patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiation therapy (nCRT), delta radiomics applied to mesorectal features could potentially lead to the development of predictive models of treatment response. Pre- and post-treatment MRIs of patients treated at a single institution were analysed. Radiomic features of the mesorectum and GTV were extracted and predictive models of pathological complete response (pCR) and two-year disease-free survival (2yDFS) were developed. In 203 patients with LARC, a total of 565 variables were evaluated; the best performing 2yDFS prediction model was based on one GTV and two mesorectal features with an AUC of 0.79 in the training set and 0.70 in the validation set. The mesorectum may contain important radiomics information for predicting response to nCRT treatment in LARC patients. Background: The aim of this study is to evaluate the delta radiomics approach based on mesorectal radiomic features to develop a model for predicting pathological complete response (pCR) and 2-year disease-free survival (2yDFS) in locally advanced rectal cancer (LARC) patients undergoing neoadjuvant chemoradiotherapy (nCRT). Methods: Pre- and post-nCRT MRIs of LARC patients treated at a single institution from May 2008 to November 2016 were retrospectively collected. Radiomic features were extracted from the GTV and mesorectum. The Wilcoxon–Mann–Whitney test and area under the receiver operating characteristic curve (AUC) were used to evaluate the performance of the features in predicting pCR and 2yDFS. Results: Out of 203 LARC patients, a total of 565 variables were evaluated. The best performing pCR prediction model was based on two GTV features with an AUC of 0.80 in the training set and 0.69 in the validation set. The best performing 2yDFS prediction model was based on one GTV and two mesorectal features with an AUC of 0.79 in the training set and 0.70 in the validation set. Conclusions: The results of this study suggest a possible role for delta radiomics based on mesorectal features in the prediction of 2yDFS in patients with LARC. [ABSTRACT FROM AUTHOR]

Intraductal biliary lesions can involve the main hepatic confluence. Assessment of the extension of pedunculated biliary lesions during per-oral cholangioscopy (POCS) can optimize and personalize the surgical strategy. Four consecutive cases of pedunculated biliary lesions were analysed. Cholangioscopy was performed with a disposable single-operator cholangioscope. POSC was successfully performed in four patients (three female, mean age 50 years), showing involvement of the main biliary confluence in three of four pedunculated biliary lesions; direct biopsy sampling was diagnostic in two of three cases (in one patient, biopsy were not performed due to the smooth appearance of the intrabiliary lesion). No adverse events occurred after POCS. Surgery required excision of the main hepatic confluence in two of three cases (one patient was not resectable). POCS can diagnose intrabiliary extension of protruding biliary lesions, providing important information to plan the surgical intervention. [ABSTRACT FROM AUTHOR]

Background: The standard approach for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision (TME). After nCRT 20% of patients achieve a clinical complete response (pCR) and could be treated with a non-operative management (NOM).Methods: The panel of the Italian Association of Medical Oncology (AIOM) Guidelines on rectal cancer applied the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach addressing the following question: Should NOM vs. TME be used for patients with rectal cancer with clinical complete response after nCRT? Five outcomes were identified: disease-free survival (DFS), mortality, local recurrence, colostomy rate, and functional outcomes.Results: Nine studies were included in the analysis. A higher risk of disease recurrence was observed in the NOM group compared to the TME group (RR = 1.69, 95% CI 1.08, 2.64) on the other hand, we observed a slightly positive but not significant effect on mortality of NOM (RR = 0.82, 95% CI 0.46, 1.45). Patients in the NOM group were more likely to experience local recurrence (RR = 5.37, 95% CI 2.56, 11.27) and patients in the TME group were more likely to have a permanent colostomy (RR = 0.15, 95% CI 0.08, 0.29). Only one study evaluated functional outcomes. The overall certainty of evidence was rated as very low.Conclusions: NOM was found to correlate with a higher risk of local recurrence which did not translate in worse OS and a lower colostomy rate. Due to the paucity of evidences, no recommendations are possible. NOM remains an experimental treatment; thus, patients managed with NOM should be enrolled in clinical trials with a dedicated follow-up schedule. [ABSTRACT FROM AUTHOR]

Introduction The delineation of Clinical Target Volume (CTV) is a critical step in radiotherapy. Several guidelines suggest different subvolumes and anatomical boundaries in rectal cancer (RC), potentially leading to a misunderstanding in the CTV definition. International consensus guidelines (CG) are needed to improve uniformity in RC CTV delineation. Material and methods The 7 radiation oncologist experts defined a roadmap to produce RC CG. Step 1: revision of the published guidelines. Step 2: selection of RC cases with different clinical stages. Step 3: delineation of cases using Falcon following previously published guidelines. Step 4: meeting in person to discuss the initial delineation outcome, followed by a CTV proposal based on revised and if needed, adapted anatomical boundaries. Step 5: peer review of the agreed consensus. Step 6: peer review meeting to validate the final outcome. Step 7: completion of RC delineation atlases. Results A new ontology of structure sets was defined and the related table of anatomical boundaries was generated. The major modifications were about the lateral lymph nodes and the ischio-rectal fossa delineation. Seven RC cases were made available online as consultation atlases. Conclusion The definition of international CG for RC delineation endorsed by international experts might support a future homogeneous comparison between clinical trial outcomes. [ABSTRACT FROM AUTHOR]

Purpose: Tumor control probability (TCP)-based early regression index (ERITCP) is a radiobiological parameter that showed promising results in predicting pathologic complete response (pCR) on T2-weighted 1.5 T magnetic resonance (MR) images of patients with locally advanced rectal cancer. This study aims to validate the ERITCP in the context of low-tesla MR-guided radiation therapy, using images acquired with different magnetic field strength (0.35 T) and image contrast (T2/T1). Furthermore, the optimal timing for pCR prediction was estimated, calculating the ERI index at different biologically effective dose (BED) levels.Methods and Materials: Fifty-two patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy were enrolled in this multi-institutional retrospective study. For each patient, a 0.35 T T2/T1-weighted MR image was acquired during simulation and on each treatment day. Gross tumor volume was contoured according to International Commission on Radiation Units Report 83 guidelines. According to the original definition, ERITCP was calculated considering the residual tumor volume at BED = 25 Gy. ERI was also calculated in correspondence with several BED levels: 13, 21, 32, 40, 46, 54, 59, and 67. The predictive performance of the different ERI indices were evaluated in terms of receiver operating characteristic curve. The robustness of ERITCP with respect to the interobserver variability was also evaluated considering 2 operators and calculating the intraclass correlation index.Results: Fourteen patients showed pCR. ERITCP correctly 47 of 52 cases (accuracy = 90%), showing good results in terms of sensitivity (86%), specificity (92%), negative predictive value (95%), and positive predictive value (80%). The analysis at different BED levels shows that the best predictive performance is obtained when this parameter is calculated at BED = 25 Gy (area under the curve = 0.93). ERITCP results are robust with respect to interobserver variability (intraclass correlation index = 0.99).Conclusions: This study confirmed the validity and the robustness of ERITCP as a pCR predictor in the context of low-tesla MR-guided radiation therapy and indicate 25 Gy as the best BED level to perform predictions. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the impact of tumor response; tumor and nodal downstaging; and cTNM, yTNM (clinical stage after chemoradiation, based on preoperative imaging), and pTNM classifications on long-term outcome in patients with rectal cancer treated with preoperative 5-fluorouracil (5-FU)-based concurrent chemoradiation.Methods and Materials: Between January 1990 and March 1998, 165 consecutive patients with locally advanced extraperitoneal cancer of the rectum were treated with preoperative chemoradiation. Four patients had a cT2 lesion (2.5%), 120 had a cT3 lesion (74.5%), and 41 had a cT4 lesion (23%). The nodal involvement at combined imaging was cN0 in 21%, cN1 in 41%, cN2 in 34%, and cN3 in 4%. Preoperative chemoradiation was delivered according to 1 of 3 schedules: (1) FUMIR-T3 (from 1990 to 1995) for patients with cT3N0-2 or cT2N1-2 rectal carcinoma (82 patients): 37.8 Gy (1.8 Gy/fraction) plus 5-FU, 1 g/m2/d on Days 1–4, continuous infusion, and mitomycin-C, 10 mg/m2/d on Day 1; (2) FUMIR-T4 (from 1990 to 1999) for patients with cT4N0-3 or cT3-4N3 rectal carcinoma (40 patients): 45 Gy (1.8 Gy/fraction) plus 5-FU, 1 g/m2/d on Days 1–4 and 29–32, continuous infusion, and mitomycin-C, 10 mg/m2/d on Days 1 and 29; and (3) PLAFUR-4 (from 1995 to 1998) for patients with cT3N0-2 or cT2N1-2 rectal carcinoma (42 patients): 50.4 Gy (1.8 Gy/fraction) plus 5-FU, 1 g/m2/d on Days 1–4 and 29–32, continuous infusion, and cisplatin, 60 mg/m2/d on Days 1 and 29. Four to five weeks after chemoradiation, patients were reevaluated for clinical response by imaging studies (CT scan, transrectal ultrasonography, barium enema, liver ultrasonography, chest X-rays) and restaged (yTNM). Surgery was performed 6–8 weeks after chemoradiation. Adjuvant chemotherapy (5-FU + l-folinic acid) was delivered to 26 patients in the FUMIR-T4 protocol group. Local control (LC), freedom from distant metastases (FDM), disease-free survival, and overall survival (OS) were evaluated according to the clinical response and cTNM, yTNM, and pTNM classification. The median follow-up was 67 months.Results: The 5-year survival rate was 100% for cT2, 77% for cT3, and 62% for cT4 (p = 0.0497); after chemoradiation, it ranged between 81% and 91% for pT0-pT2 and dropped to 66% for pT3 and 47% for pT4 (p = 0.014). The 5-year local control rate was, at the first staging, 84% for cT3 and 72% for cT4; after chemoradiation, the pT stage correlated significantly with LC (p = 0.0012): 100% for pT0, 83% for pT1, 88% for pT2, 79% for pT3, and 46% for pT4. N stage was statistically significant in predicting FDM and OS at any staging step. A significant impact of tumor response, tumor downstaging, and nodal downstaging on LC, FDM, disease-free survival, and OS was also recorded. If the residual tumor, before surgery, had a tumor index <30 (i.e., width less than one-quarter of rectal circumference and length in its caudocranial axis ≤30 mm), the 5-year LC, FDM, disease-free survival, and OS rates were significantly higher at both the univariate and the multivariate analyses. The surgical procedure was tailored according to tumor downstaging, and thus the choice of sphincter-preserving surgery was based on the distance between the lower pole of the tumor and the anorectal ring “after” chemoradiation. In 36 patients with the lower pole of the lesion in the range of 0–30 mm from the anorectal ring, 16 patients (44%) underwent a sphincter-saving procedure. All clinical outcomes were similar compared with 20 patients with tumor located at the same rectum level who received an abdominoperineal resection.Conclusion: After preoperative chemoradiation, clinical response and tumor/nodal pathologic downstaging showed a close correlation with improved outcomes. The better 5-year survival and local control in pT0-2 patients regardless of their initial stage seems to confirm a heterogeneity in rectal cancer patients. The responder population showed a behavior similar to rectal cancer diagnosed at Stage cT1-2 and treated with conservative surgery alone. Additional studies aimed at improving local tumor response seem justified. Trials of sphincter-saving surgery after a major response are warranted. [Copyright &y& Elsevier]