Posttreatment Surveillance Imaging After Radiation for Head and Neck Cancer.

Importance: The role of surveillance imaging after treatment for head and neck cancer is controversial and evidence to support decision-making is limited. Objective: To determine the use of surveillance imaging in asymptomatic patients with head and neck cancer in remission after completion of chemoradiation. Design, Setting, and Participants: This was a retrospective, comparative effectiveness research review of adult patients who had achieved a complete metabolic response to initial treatment for head and neck cancer as defined by having an unequivocally negative positron emission tomography (PET) scan using the PET response criteria in solid tumors (PERCIST) scale within the first 6 months of completing therapy. The medical records of 501 consecutive patients who completed definitive radiation therapy (with or without chemotherapy) for newly diagnosed squamous cell carcinoma of the head and neck between January 2014 and June 2022 were reviewed. Exposure: Surveillance imaging was defined as the acquisition of a PET with computed tomography (CT), magnetic resonance imaging (MRI), or CT of the head and neck region in the absence of any clinically suspicious symptoms and/or examination findings. For remaining patients, subsequent surveillance after the achievement of a complete metabolic response to initial therapy was performed on an observational basis in the setting of routine follow-up using history-taking and physical examination, including endoscopy. This expectant approach led to imaging only in the presence of clinically suspicious symptoms and/or physical examination findings. Main Outcome and Measures: Local-regional control, overall survival, and progression-free survival based on assignment to either the surveillance imaging or expectant management cohort. Results: This study included 340 patients (mean [SD] age, 59 [10] years; 201 males [59%]; 88 Latino patients [26%]; 145 White patients [43%]) who achieved a complete metabolic response during this period. There was no difference in 3-year local-regional control, overall survival, progression-free survival, or freedom from distant metastasis between patients treated with surveillance imaging vs those treated expectantly. Conclusions and Relevance: In this comparative effectiveness research, imaging-based surveillance failed to improve outcomes compared with expectant management for patients who were seemingly in remission after completion of primary radiation therapy for head and neck cancer.

Timing of chemotherapy and radiation delivery for patients receiving chemoradiation for head and neck cancer: When does "concurrent" mean concurrent?

PURPOSE: To analyze practice patterns focusing on variations in the timing of chemotherapy relative to radiation in patients treated with concurrent chemoradiation for head and neck cancer. METHODS AND MATERIALS: The medical records of 302 consecutive adult patients treated with concurrent chemoradiation for head and neck cancer between April 2014 and February 2022 were reviewed. After excluding 38 patients who received non-platinum-based regimens, induction chemotherapy, and/or had non-squamous cell histology, a total of 264 patients formed the primary population. To study the variability in which concurrent chemoradiation was delivered, descriptive statistics were used to determine the percentage of patients who deviated from starting chemotherapy and radiation on the same day. The chi-square statistic was used to compare differences in proportion among various subsets. A Cox proportional hazards model was then used to perform a multi-variate analysis to identify factors which independently influenced the likelihood for non-adeherence. RESULTS: Among the 264 patients, a total of 187 patients (70.8%) had chemotherapy and radiation started on the same day with 171 of these (91.4%) receiving chemotherapy prior to radiation delivery. On multivariate analysis, both non-Caucasian ethnicity (OR: 1.13, 95% C.I. 1.01-1.20) and being non-English speaking (OR: 1.39; 95% C.I. 1.18--1.51) was significantly associated with greater likelihood of the receipt of radiation and chemotherapy on different days. CONCLUSION: Significant variation exists in the timing of chemotherapy relative to radiation for concurrent chemoradiation in the clinical setting. The potential repercussions on outcome warrante further invesigtation and are discussed.

A comparative study between deep learning and radiomics models in grading liver tumors using hepatobiliary phase contrast-enhanced MR images.

PURPOSE: To compare a deep learning model with a radiomics model in differentiating high-grade (LR-3, LR-4, LR-5) liver imaging reporting and data system (LI-RADS) liver tumors from low-grade (LR-1, LR-2) LI-RADS tumors based on the contrast-enhanced magnetic resonance images. METHODS: Magnetic resonance imaging scans of 361 suspected hepatocellular carcinoma patients were retrospectively reviewed. Lesion volume segmentation was manually performed by two radiologists, resulting in 426 lesions from the training set and 83 lesions from the test set. The radiomics model was constructed using a support vector machine (SVM) with pre-defined features, which was first selected using Chi-square test, followed by refining using binary least absolute shrinkage and selection operator (LASSO) regression. The deep learning model was established based on the DenseNet. Performance of the models was quantified by area under the receiver-operating characteristic curve (AUC), accuracy, sensitivity, specificity and F1-score. RESULTS: A set of 8 most informative features was selected from 1049 features to train the SVM classifier. The AUCs of the radiomics model were 0.857 (95% confidence interval [CI] 0.816-0.888) for the training set and 0.879 (95% CI 0.779-0.935) for the test set. The deep learning method achieved AUCs of 0.838 (95% CI 0.799-0.871) for the training set and 0.717 (95% CI 0.601-0.814) for the test set. The performance difference between these two models was assessed by t-test, which showed the results in both training and test sets were statistically significant. CONCLUSION: The deep learning based model can be trained end-to-end with little extra domain knowledge, while the radiomics model requires complex feature selection. However, this process makes the radiomics model achieve better performance in this study with smaller computational cost and more potential on model interpretability.

Esophageal optical coherence tomography image synthesis using an adversarially learned variational autoencoder.

Endoscopic optical coherence tomography (OCT) imaging offers a non-invasive way to detect esophageal lesions on the microscopic scale, which is of clinical potential in the early diagnosis and treatment of esophageal cancers. Recent studies focused on applying deep learning-based methods in esophageal OCT image analysis and achieved promising results, which require a large data size. However, traditional data augmentation techniques generate samples that are highly correlated and sometimes far from reality, which may not lead to a satisfied trained model. In this paper, we proposed an adversarial learned variational autoencoder (AL-VAE) to generate high-quality esophageal OCT samples. The AL-VAE combines the generative adversarial network (GAN) and variational autoencoder (VAE) in a simple yet effective way, which preserves the advantages of VAEs, such as stable training and nice latent manifold, and requires no extra discriminators. Experimental results verified the proposed method achieved better image quality in generating esophageal OCT images when compared with the state-of-the-art image synthesis network, and its potential in improving deep learning model performance was also evaluated by esophagus segmentation.

MRI-based radiomics model for distinguishing endometrial carcinoma from benign mimics: A multicenter study.

PURPOSE: To develop and validate an MRI-based radiomics model for preoperatively distinguishing endometrial carcinoma (EC) with benign mimics in a multicenter setting. METHODS: Preoperative MRI scans of EC patients were retrospectively reviewed and divided into training set (158 patients from device 1 in center A), test set #1 (78 patients from device 2 in center A) and test set #2 (109 patients from device 3 in center B). Two radiologists performed manual delineation of tumor segmentation on the map of apparent diffusion coefficient (ADC), diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI). The features were extracted and firstly selected using Chi-square test, followed by refining using binary least absolute shrinkage and selection operator (LASSO) regression. The support vector machine (SVM) was employed to build the radiomics model, which is tuned in the training set using 10-fold cross-validation, and then assessed on the test set. Performance of the model was determined by area under the receiver-operating characteristic curve (AUC), accuracy, sensitivity, specificity and F1-score. RESULTS: Five most informative features are selected from the extracted 3142 features. The SVM with linear kernel was employed to build the radiomics model. The AUCs of the model were 0.989 (95% confidence interval [CI]: 0.968-0.997) for the training set, 0.999 (95% CI: 0.991-1.000) for test set #1, 0.961 (95% CI: 0.902-0.983) for test set #2. Accuracies of the model were 0.937 for the training set (precision: 0.919, recall: 0.963, F1-score: 0.940), 0.974 for test set #1 (precision: 0.949, recall: 1.000, F1-score: 0.974) and 0.908 for test set #2 (precision: 0.899, recall: 0.954, F1-score: 0.925). These results confirmed the efficacy of this model in predicting EC in different centers. CONCLUSION: The MRI-based radiomics model showed promising potential for distinguishing EC with benign mimics and might be useful for surgical management of EC.

Outcomes and complications of radiation therapy in patients with familial adenomatous polyposis.

BACKGROUND: The outcomes, complications, and rates of secondary malignancies from radiation therapy (RT) are not known for patients with familial adenomatous polyposis (FAP). METHODS: We queried the Hereditary Gastrointestinal Cancer Registry (HGCR) for patients with FAP who received RT. Outcomes assessed included acute and late treatment toxicity and secondary malignancies. RESULTS: We identified 15 patients undergoing 18 treatment courses. Median follow-up was 3.1 years after RT. Treated sites included rectal cancer, desmoid, prostate cancer, breast cancer, melanoma, medulloblastoma, gastric cancer, and glioma. Secondary tumors occurred in two patients: a medulloblastoma was diagnosed in a patient treated for glioma, and a desmoid tumor was diagnosed in a patient treated for rectal cancer. All nine patients treated with intra-abdominal or pelvic RT had prior prophylactic proctocolectomies, yet only one patient experienced grade 3 gastrointestinal toxicity. Common Terminology Criteria for Adverse Events version 4 (CTCAE v4) toxicities were grade 1 in seven treatment courses (39%), grade 2 in five courses (28%), and grade 3 in two courses (11%). CONCLUSIONS: In this cohort, RT was well tolerated with adverse effects comparable with non-FAP patients. Secondary in-field tumors occurred in 2 of 15 patients and their increased risk in this cohort was likely due to prior predilection from FAP itself, although an increased role of RT cannot be ruled out.

The "decay" of brachytherapy use in tumors of the oral cavity: A population-based patterns of care and outcomes analysis from 1973 to 2012.

PURPOSE: We aimed to evaluate if use of brachytherapy (BT) is associated with improved survival in patients with oral cavity cancer who do not receive surgery and to analyze patterns of care. METHODS AND MATERIALS: We queried the Surveillance, Epidemiology, and End Results database for patients who received radiation therapy for squamous cell carcinoma of the oral cavity between 1973 and 2012. Patients were grouped by treatment modality: external beam radiotherapy alone vs. external beam radiotherapy + BT. Surgical patients were excluded. Trends in BT utilization over the study period and patterns of care were analyzed. Propensity scores were generated, and a nearest-neighbor matching algorithm was used to balance the 2 groups. Cox regression modeling was used to estimate the effect of BT on overall survival. Sensitivity analysis was conducted to estimate the effect of unmeasured confounders on the analysis. RESULTS: Of 5,161 patients with squamous cell carcinoma of the oral cavity who received radiotherapy, 12% of patients received BT. The rate of BT use has decreased by 0.58% per year (p < 0.001). Factors that predicted for omission of radiation therapy included age ≥ 65 years (adjusted odds ratio [aOR], 0.56; p < 0.001), regional nodal disease (aOR, 0.57; p < 0.001), and black race (aOR, 0.45; p < 0.001). Use of BT was associated with a decreased risk of death (hazard ratio, 0.75; p < 0.001). CONCLUSIONS: The use of BT is associated with improved survival in oral cavity tumors treated with definitive radiotherapy. Rates of BT utilization have declined by 0.58% per year and are currently very low.

Establishment of canine models of lunatomalacia through liquid nitrogen freezing.

The aim of this study was to investigate the feasibility of establishing dog models of lunatomalacia through liquid nitrogen freezing. Twelve adult crossbred dogs were divided into three groups. Unilateral lunates were peeled off the parenchyma and frozen to result in avascular necrosis. They were observed dynamically through X-ray, computed tomography (CT) and magnetic resonance imaging (MRI). Furthermore, gross and histomorphological observations of samples were performed. Disseminated punctate hyperintense images and abnormal manifestations were detected, respectively. At 12 weeks after surgery, uneven bone density of the lunate and a flattened lunate of irregular shape were detected. A large area of irregular hypointense foci and hyperintensity was observed. Gross sample observation revealed a large area of dead bone. A decrease in the density of the trabecular bones and several vacant bone lacunas were visible. Liquid nitrogen freezing is a successful and reliable method for preparing animal models of lunatomalacia.