Evaluation of Neoadjuvant Chemoradiotherapy Response in Rectal Cancer Using MR Images and Deep Learning Neural Networks.

INTRODUCTION: The aim of the study was to develop deep-learning neural networks to guide treatment decisions and for the accurate evaluation of tumor response to neoadjuvant chemoradiotherapy (nCRT) in rectal cancer using magnetic resonance (MR) images. METHODS: Fifty-nine tumors with stage 2 or 3 rectal cancer that received nCRT were retrospectively evaluated. Pathological tumor regression grading was carried out using the Dworak (Dw-TRG) guidelines and served as the ground truth for response predictions. Imaging-based tumor regression grading was performed according to the MERCURY group guidelines from pre-treatment and post-treatment para-axial T2-weighted MR images (MR-TRG). Tumor signal intensity signatures were extracted by segmenting the tumors volumetrically on the images. Normalized histograms of the signatures were used as input to a deep neural network (DNN) housing long short-term memory (LSTM) units. The output of the network was the tumor regression grading prediction, DNN-TRG. RESULTS: In predicting complete or good response, DNN-TRG demonstrated modest agreement with Dw-TRG (Cohen's kappa= 0.79) and achieved 84.6% sensitivity, 93.9% specificity, and 89.8% accuracy. MR-TRG revealed 46.2% sensitivity, 100% specificity, and 76.3% accuracy. In predicting a complete response, DNN-TRG showed slight agreement with Dw-TRG (Cohen's kappa= 0.75) with 71.4% sensitivity, 97.8% specificity, and 91.5% accuracy. MR-TRG provided 42.9% sensitivity, 100% specificity, and 86.4% accuracy. DNN-TRG benefited from higher sensitivity but lower specificity, leading to higher accuracy than MR-TRG in predicting tumor response. CONCLUSION: The use of deep LSTM neural networks is a promising approach for evaluating the tumor response to nCRT in rectal cancer.

Evaluating complete response prediction rates in locally advanced rectal cancer with different radiomics segmentation approaches.

Purpose: Studies examining prediction of complete response (CR) in locally advanced rectum cancer (LARC) from pre/post chemoradiotherapy (CRT) magnetic resonance imaging (MRI) are performed mostly with segmentations of the tumor, whereas only in two studies segmentation included tumor and mesorectum. Additionally, pelvic extramesorectal region, which is included in the clinical target volume (CTV) of radiotherapy, may contain information. Therefore, we aimed to compare predictive rates of radiomics analysis with features extracted from segmentations of tumor, tumor+mesorectum, and CTV. Methods and materials: Ninety-three LARC patients who underwent CRT in our institution between 2012 and 2019 were retrospectively scanned. Patients were divided into CR and non-CR groups. Tumor, tumor+mesorectum and CTV were segmented on T2 preCRT MRI images. Extracted features were compared for best area under the curve (AUC) of CR prediction with 15 machine-learning models. Results: CR was observed in 25 patients (26.8%), of whom 13 had pathological, and 12 had clinical complete response. For tumor, tumor+mesorectum and CTV segmentations, the best AUC were 0.84, 0.81, 0.77 in the training set and 0.85, 0.83 and 0.72 in the test set, respectively; sensitivity and specificity for the test set were 76%, 90%, 76% and 71%, 67% and 62%, respectively. Conclusion: Although the highest AUC result is obtained from the tumor segmentation, the highest accuracy and sensitivity are detected with tumor+mesorectum segmentation and these findings align with previous studies, suggesting that the mesorectum contains valuable insights for CR. The lowest result is obtained with CTV segmentation. More studies with mesorectum and pelvic nodal regions included in segmentation are needed.

Cisplatin-docetaxel induction chemotherapy for patients with nasopharyngeal carcinoma in a non-endemic cohort.

This is the report on our clinic's 15 years of experience (2004-2018) on nasopharyngeal carcinoma (NPC), treated with induction chemotherapy (IC) and subsequent concomitant chemoradiotherapy (CCRT), comprising population characteristics and treatment outcomes of 203 patients with non-metastatic NPC. IC comprised docetaxel (75 mg/m2) and cisplatin (75 mg/m2) combination (TP). Concurrent cisplatin (P) was applied either weekly (40 mg/m2, 32 cases) or every-3-week (100 mg/m2, 171 cases). The median follow-up duration was 85 months (range, 5-204 months). Overall and distant failure rates were observed in 27.1% (n = 55) and 13.8% (n = 28) patients, respectively. The 5-year locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) rates were 84.1%, 86.4%, 75%, and 78.7% respectively. The overall stage was an independent prognostic factor for the LRRFS, DMFS, DFS, and OS. The WHO histological type was a prognostic factor for the LRRFS, DFS, and OS. Age was a prognostic factor for the DMFS, DFS, and OS. Concurrent P schedule was independent prognostic only the LRRFS.

Isolated adnexal torsion in a 20-week spontaneous twin pregnancy.

BACKGROUND: Adnexal torsion can be a life-threatning condition in pregnancy, while the risk of late diagnosis is increased, in second and third trimester in particular. Laparoscopy is an effective approach in diagnosis and treatment of adnexal torsion. However, entry to abdomen may be challenging in more advanced pregnancies. CASE REPORT: Herein, we report a case of adnexal torsion during 20th week of twin pregnancy, which was detorsioned laparoscopically. The woman delivered healthy infants at her 36th week of pregnancy. DISCUSSION: Adnexal torsion as a cause of acute abdomen may be kept in mind in pregnants, even if there is no predisposing factor. Laparoscopy may be performed safely in 2nd trimester for acute abdomen.