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Purpose: The aims of this study are to evaluate the stability of radiomic features from Apparent Diffusion Coefficient (ADC) maps of cervical cancer with respect to: (1) reproducibility in inter-observer delineation, and (2) image pre-processing (normalization/quantization) prior to feature extraction.Materials and methods: Two observers manually delineated the tumor on ADC maps derived from pretreatment diffusion-weighted Magnetic Resonance imaging of 81 patients with FIGO stage IB-IVA cervical cancer. First-order, shape, and texture features were extracted from the original and filtered images considering 5 different normalizations (four taken from the available literature, and one based on urine ADC) and two different quantization techniques (fixed-bin widths from 0.05 to 25, and fixed-bin count). Stability of radiomic features was assessed using intraclass correlation coefficient (ICC): poor (ICC Results: The approach using urine-normalized values together with a smaller bin width (0.05) was the most reproducible (428/552, 78% features with ICC >= 0.75); the fixed-bin count approach was the least (215/552, 39% with ICC >= 0.75). Without normalization, using a fixed bin width of 25, 348/552 (63%) of features had an ICC >= 0.75. Overall, 26% (range 25-30%) of the features were volume-dependent (rho >= 0.6). None of the volume-independent shape features were found to be reproducible.Conclusion: Applying normalization prior to features extraction increases the reproducibility of ADC-based radiomics features. When normalization is applied, a fixed-bin width approach with smaller widths is suggested. (C) 2019 The Author(s). Published by Elsevier B.V.

This study investigates the impact of dosimetric parameters on acute and late toxicity for patients with anal squamous cell carcinoma (SCC) treated with image-guided intensity modulated radiation therapy (IG-IMRT) and concurrent chemotherapy.Patients were enrolled in an observational cohort study between 2008 and 2013 (median follow-up 3.4 years). They were treated with standardized target and organ-at-risk (OAR) contouring, planning, and IG-IMRT. Radiotherapy dose, based on clinicopathologic features, ranged from 45 Gy to 63 Gy to gross targets and 27 Gy to 36 Gy to elective targets. Chemotherapy was concurrent 5-fluorouracil and mitomycin C (weeks 15). Toxicity was prospectively graded using NCI CTCAE v.3 and RTOG scales. Logistic regression was used to assess the association between dose/volume parameters (e.g small bowel V5) and corresponding grade 2 + and 3+ (G2+/3 + ) toxicities (e.g. diarrhea).In total, 87 and 79 patients were included in the acute and late toxicity analyses, respectively. The most common acute G2 + toxicities were skin (dermatitis in 87 % [inguino-genital skin], 91 % [perianal skin]) and hematologic in 58 %. G2 + late anal toxicity (sphincter dysfunction), gastrointestinal toxicity, and skin toxicity were respectively experienced by 49 %, 38 %, and 44 % of patients. Statistically significant associations were observed between: G2 + acute diarrhea and small bowel V35; G2 + acute genitourinary toxicity and bladder DStatistically significant dose-volume parameters were identified and may be used to offer individualized risk prediction and to inform treatment planning. Additional validation of the results is required.

Purpose: The aims of this study are to evaluate the stability of radiomic features from T2-weighted MRI of cervical cancer in three ways: (1) repeatability via test-retest; (2) reproducibility between diagnostic MRI and simulation MRI; (3) reproducibility in inter-observer setting.Materials and methods: This retrospective cohort study included FIGO stage IB-IVA cervical cancer patients treated with chemoradiation between 2005 and 2014. There were three cohorts of women corresponding to each aim of the study: (1) 8 women who underwent test-retest MRI; (2) 20 women who underwent MRI on different scanners (diagnostic and simulation MRI); (3) 34 women whose diagnostic MRIs were contoured by three observers. Radiomic features based on first-order statistics, shape features and texture features were extracted from the original, Laplacian of Gaussian (LoG)-filtered and wavelet-filtered images, for a total of 1761 features. Stability of radiomic features was assessed using intraclass correlation coefficient (ICC).Results: The inter-observer cohort had the most reproducible features (95.2% with ICC >= 0.75) whereas the diagnostic-simulation cohort had the fewest (14.1% with ICC >= 0.75). Overall, 229 features had ICC >= 0.75 in all three tests. Shape features emerged as the most stable features in all cohorts.Conclusion: The diagnostic-simulation test resulted in the fewest reproducible features. Further research in MRI-based radiomics is required to validate the use of reproducible features in prognostic models. (C) 2019 Elsevier B.V. All rights reserved.

This study aims to compare the efficacy, efficiency and comfort level of two immobilization systems commonly used in lung stereotactic body radiation therapy (SBRT): the Bodyfix and the abdominal compression plate (ACP).Twenty-four patients undergoing SBRT for medically inoperable stage I lung cancer or pulmonary metastases were entered on this prospective randomized study. All underwent 4DCT simulation with free breathing, the Bodyfix, and the ACP to assess respiratory tumor motion. After CT simulation, patients were randomly assigned to immobilization with either the Bodyfix or the ACP for the actual SBRT treatment. Cone beam CTs (CBCTs) were acquired before and after each treatment to assess intrafraction tumor motion. Setup time and patient comfort were recorded.There were 16 upper lobe, two middle lobe and seven lower-lobe lesions. Both the Bodyfix and the ACP significantly reduced the superior-inferior (SI) and overall respiratory tumor motion compared to free breathing (4.6 and 4.0 vs 5.3mm; 5.3 and 4.7 vs 6.1mm, respectively, p0.05). The ACP further reduced the SI and overall respiratory tumor motion compared to the Bodyfix (p0.05). The mean overall intrafraction tumor motion was 2.3mm with the Bodyfix and 2.0mm with the ACP (p0.05). The ACP was faster to set up and rated more comfortable by patients than the Bodyfix (p0.05).While there is no significant difference between the Bodyfix and ACP in reducing intrafraction tumor motion, the ACP is more comfortable, faster to set up, and superior to the Bodyfix in reducing SI and overall respiratory tumor motion.