Comparison of MR-soft tissue based versus biliary stent based alignment for image guidance in pancreatic SBRT.

PURPOSE: The role of biliary stents in image-guided localization for pancreatic cancer has been inconclusive. To date, stent accuracy has been largely evaluated against implanted fiducials on cone beam computed tomography. We aim to use magnetic resonance (MR) soft tissue as a direct reference to examine the geometric and dosimetric impacts of stent-based localization on the newly available MR linear accelerator. METHODS: Thirty pancreatic cancer patients (132 fractions) treated on our MR linear accelerator were identified to have a biliary stent. In our standard adaptive workflow, patients were set up to the target using soft tissue for image registration and structures were re-contoured on daily MR images. The original plan was then projected on treatment anatomy and dose predicted, followed by plan re-optimization and treatment delivery. These online predicted plans were soft tissue-based and served as reference plans. Retrospective image registration to the stent was performed offline to simulate stent-based localization and the magnitude of shifts was taken as the geometric accuracy of stent localization. New predicted plans were generated based on stent-alignment for dosimetric comparison. RESULTS: Shifts were within 3 mm for 90% of the cases (mean = 1.5 mm); however, larger shifts up to 7.2 mm were observed. Average PTV coverage dropped by 1.1% with a maximum drop of 26.8%. The mean increase in V35Gy was 0.15, 0.05, 0.02, and 0.02 cc for duodenum, stomach, small bowel and large bowel, respectively. Stent alignment was significantly worse for all metrics except for small bowel (p = 0.07). CONCLUSIONS: Overall discrepancy between stent- and soft tissue-alignment was modest; however, large discrepancies were observed for select cases. While PTV coverage loss may be compensated for by using a larger margin, the increase in dose to gastrointestinal organs at risk may limit the role of biliary stents in image-guided localization.

Experience of Telemedicine Visits in Radiation Oncology During the COVID-19 Pandemic: A US National Survey and Lessons Learned for Incorporating Telemedicine Post-COVID-19.

Purpose: We sought to survey the attitudes and perceptions of US radiation oncologists toward the adoption of telemedicine during the COVID-19 pandemic and offer suggestions for its integration in the postpandemic era. Methods and Materials: A 25-question, anonymous online survey was distributed nationwide to radiation oncologists. Results: One hundred and twenty-one respondents completed the survey, with 92% from academia. Overall, 79% worked at institutions that had implemented a work-from-home policy, with which 74% were satisfied. Despite nearly all visit types being conducted in-person before COVID-19, 25%, 41%, and 5% of the respondents used telemedicine for more than half of their new consultations, follow-up, and on-treatment visits, respectively, during the COVID-19 pandemic. Most (83%) reported being comfortable integrating telemedicine. Although telemedicine was appreciated as being more convenient for patients (97%) and reducing transmission of infectious agents (83%), the most commonly perceived disadvantages were difficulty in performing physical examinations (90%), patients' inability to use technology adequately (74%), and technical malfunctions (72%). Compared with in-person visits, telemedicine was felt to be inferior in establishing a personal connection during consultation (90%) and assessing for toxicity while on-treatment (88%) and during follow-up (70%). For follow-up visits, genitourinary and thoracic were perceived as most appropriate for telemedicine while gynecologic and head and neck were considered the least appropriate. Overall, 70% were in favor of more telemedicine, even after pandemic is over. Conclusions: Telemedicine will likely remain part of the radiation oncology workflow in most clinics after the pandemic. It should be used in conjunction with in-person visits, and may be best used for conducting follow-up visits in certain disease sites such as genitourinary and thoracic malignancies.

Ablative radiotherapy for liver tumors using stereotactic MRI-guidance: A prospective phase I trial.

BACKGROUND AND PURPOSE: To prospectively determine the feasibility, safety, and efficacy of stereotactic body radiation therapy (SBRT) to primary and secondary liver tumors with MR-guided radiation therapy (MRgRT). MATERIALS AND METHODS: Treatment plans with a conventional CT-guided linear accelerator and a MRI-guided tri-60Co teletherapy unit (MR-Co) were generated and compared for patients undergoing liver-directed SBRT from 2015 to 2017. If dosimetric parameters were met on MR-Co, patients were treated with MRgRT. The highest priority constraint was >1000 cc or >800 cc of normal liver receiving <15 Gy for single- or multiple-lesion treatments, respectively. Treatment was delivered every other day. RESULTS: Of 23 patients screened, 20 patients (8 primary, 12 secondary) and 25 liver tumors underwent MR-guided SBRT to a median dose of 54 Gy (range 11.5-60) in a median of 3 fractions (range 1-5). With a median follow up of 18.9 months, the 1- and 2-year estimate of local control were 94.7% and 79.6%, respectively. A difference in local control between single and multiple lesions or BED ≥ 100 Gy10 and BED < 100 Gy10, respectively, was observed. The 2-year estimate of overall survival (OS) was 50.7% with a median OS of 29 months. There were no acute grade ≥ 3 toxicities and one late grade 3/4 toxicity from a single patient whose plan exceeded an unrecognized dose constraint at the time. CONCLUSION: MR-guided SBRT is a viable and safe option in the delivery of ultrahypofractionated ablative radiation treatment to primary and secondary liver tumors resulting in high rates of local control and very favorable toxicity profiles.

Stereotactic Body Radiotherapy for High-Risk Localized Carcinoma of the Prostate (SHARP) Consortium: Analysis of 344 Prospectively Treated Patients.

PURPOSE: To explore the efficacy and toxicity of stereotactic body radiation therapy (SBRT) in high-risk prostate cancer (HRPCa) in a consortium of 7 institutional phase 2 trials and prospective registries. METHODS AND MATERIALS: Individual patient data were pooled for 344 patients with a minimum follow-up of 24 months. Biochemical recurrence-free survival (BCRFS) and distant metastasis-free survival (DMFS) were estimated using a Kaplan-Meier framework. Fine and Gray competing risk and Cox proportional hazards regression models were developed to assess the association between time to BCR and time to distant metastasis and prespecified variables of interest. Logistic regression models were developed to evaluate associations between acute and late grade ≥2 genitourinary and gastrointestinal and the following a priori-specified variables: age, dose per fraction, ADT use, and nodal radiation therapy. RESULTS: Median follow-up was 49.5 months. Seventy-two percent of patients received ADT, with a median duration of 9 months, and 19% received elective nodal radiation therapy. Estimated 4-year BCRFS and DMFS rates were 81.7% (95% CI, 77.2%-86.5%) and 89.1% (95% CI, 85.3%-93.1%). The crude incidences of late grade ≥3 genitourinary and gastrointestinal toxicity were 2.3% and 0.9%. CONCLUSIONS: These data support a favorable toxicity and efficacy profile for SBRT for HRPCa. Further prospective studies are needed to evaluate the optimal dose and target volume in the context of SBRT for HRPCa.

Deep learning-based radiomic features for improving neoadjuvant chemoradiation response prediction in locally advanced rectal cancer.

Radiomic features achieve promising results in cancer diagnosis, treatment response prediction, and survival prediction. Our goal is to compare the handcrafted (explicitly designed) and deep learning (DL)-based radiomic features extracted from pre-treatment diffusion-weighted magnetic resonance images (DWIs) for predicting neoadjuvant chemoradiation treatment (nCRT) response in patients with locally advanced rectal cancer (LARC). 43 Patients receiving nCRT were included. All patients underwent DWIs before nCRT and total mesorectal excision surgery 6-12 weeks after completion of nCRT. Gross tumor volume (GTV) contours were drawn by an experienced radiation oncologist on DWIs. The patient-cohort was split into the responder group (n = 22) and the non-responder group (n = 21) based on the post-nCRT response assessed by postoperative pathology, MRI or colonoscopy. Handcrafted and DL-based features were extracted from the apparent diffusion coefficient (ADC) map of the DWI using conventional computer-aided diagnosis methods and a pre-trained convolution neural network, respectively. Least absolute shrinkage and selection operator (LASSO)-logistic regression models were constructed using extracted features for predicting treatment response. The model performance was evaluated with repeated 20 times stratified 4-fold cross-validation using receiver operating characteristic (ROC) curves and compared using the corrected paired t-test. The model built with handcrafted features achieved the mean area under the ROC curve (AUC) of 0.64, while the one built with DL-based features yielded the mean AUC of 0.73. The corrected paired t-test on AUC showed P-value < 0.05. DL-based features extracted from pre-treatment DWIs achieved significantly better classification performance compared with handcrafted features for predicting nCRT response in patients with LARC.

Chemotherapy and Survival in Patients with Primary High-Grade Extremity and Trunk Soft Tissue Sarcoma.

The use of upfront chemotherapy for primary localized soft tissue sarcoma (STS) of the extremity and trunk is debated. It remains unclear if chemotherapy adds clinical benefit, which patients are likely to benefit, and whether the timing of therapy affects outcomes. We used the National Cancer Database (NCDB) to examine the association between overall survival (OS) and chemotherapy in 5436 patients with the five most common subtypes of STS with primary disease localized to the extremity or trunk, mirroring the patient population of a modern phase 3 clinical trial of neoadjuvant chemotherapy. We then examined associations between timing of multi-agent chemotherapy (neoadjuvant or adjuvant) and OS. We used a Cox proportional hazards model and propensity score matching (PSM) to account for covariates including demographic, patient, clinical, treatment, and facility factors. In the overall cohort, we observed no association between multi-agent chemotherapy or its timing and improved OS. Multi-agent chemotherapy was associated with improved OS in several subgroups, including patients with larger tumors (>5 cm), those treated at high-volume centers, or those who received radiation. We also identified an OS benefit to multi-agent chemotherapy among the elderly (>70 years) and African American patients. Multi-agent chemotherapy was associated with improved survival for patients with tumors >5 cm, who receive radiation, or who receive care at high-volume centers. Neither younger age nor chemotherapy timing was associated with better outcomes. These 'real-world' findings align with recent randomized trial data supporting the use of multi-agent chemotherapy in high-risk patients with localized STS.

A Phase II Trial of 5-Day Neoadjuvant Radiotherapy for Patients with High-Risk Primary Soft Tissue Sarcoma.

PURPOSE: In a single-institution phase II study, we evaluated the safety of a 5-day dose-equivalent neoadjuvant radiotherapy (RT) regimen for high-risk primary soft tissue sarcoma. PATIENTS AND METHODS: Patients received neoadjuvant RT alone (30 Gy in five fractions) to the primary tumor with standard margins. The primary endpoint was grade ≥2 late-radiation toxicity. Major wound complications, local recurrences, and distant metastases were also examined. In exploratory analysis, we evaluated germline biomarkers for wound toxicity and the effects of the study on treatment utilization. RESULTS: Over 2 years, 52 patients were enrolled with median follow-up of 29 months. Seven of 44 evaluable patients (16%) developed grade ≥2 late toxicity. Major wound complications occurred in 16 of 50 patients (32%); a signature defined by 19 germline SNPs in miRNA-binding sites of immune and DNA damage response genes, in addition to lower extremity tumor location, demonstrated strong predictive performance for major wound complications. Compared with the preceding 2-year period, the number of patients treated with neoadjuvant RT alone at our institution increased 3-fold, with a concomitant increase in the catchment area. CONCLUSIONS: A shorter 5-day neoadjuvant RT regimen results in favorable rates of wound complications and grade ≥2 toxicity after 2-year follow-up. Five-day RT significantly increased utilization of neoadjuvant RT at our high-volume sarcoma center. With further validation, a putative germline biomarker for wound complications may guide safer RT utilization.

Impact of Health-Related Quality of Life and Prediagnosis Risk of Major Depressive Disorder on Treatment Choice for Stage I Lung Cancer.

PURPOSE: We hypothesized that prediagnosis depressive symptoms and patient-reported health-related quality of life (HRQOL) would be associated with treatment choice for stage I non-small-cell lung cancer (NSCLC). METHODS: Using the SEER and Medicare Health Outcomes Survey (SEER-MHOS)-linked data set, we identified patients age 65 years and older with stage I NSCLC diagnosed between 2004 and 2013 who completed the HOS 24 or fewer months before diagnosis. HRQOL was measured by the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores of the Medical Outcomes Study Short Form-36 and the Veterans RAND 12-Item Health Survey instruments. Major depressive disorder (MDD) risk was derived from responses to HOS questions that screen for depressive symptoms. Associations with treatment choice were assessed with multivariable multinomial logistic regression while controlling for prespecified patient characteristics. RESULTS: We analyzed 515 evaluable patients, of whom 140 (27%) met criteria for risk of MDD. On univariable analysis, a higher proportion of patients who received radiotherapy (RT) versus surgery were at risk for MDD (34% v 22%, respectively; P = .011). On multivariable analysis, higher PCS and MCS scores were associated with a decreased likelihood of receiving RT compared with surgery (adjusted odds ratio per 10-point PCS increase, 0.60 [95% CI, 0.45 to 0.79; P < .001]; adjusted odds ratio per 10-point MCS increase, 0.61 [95% CI 0.46 to 0.80; P < .001]). CONCLUSION: Among older patients with stage I NSCLC, there was a significant association between those who self-reported lower HRQOL and receipt of RT. There was also a nonsignificant association in MDD risk and increased likelihood of RT receipt. Additional studies are warranted to examine the impact of pretreatment HRQOL and MDD risk on clinical decision making.

Adjuvant hypofractionated partial-brain radiation therapy for pediatric Ewing sarcoma brain metastases: case report.

This case report demonstrates that hypofractionated partial-brain radiation therapy with limited margins is a reasonable approach following gross tumor resection of Ewing sarcoma metastases to the brain. The patient presented with 2 intracranial metastases treated with gross-total resection followed by radiation therapy to 30 Gy in 5 fractions. The patient experienced symptomatic treatment-related inflammatory changes with resolution after receiving dexamethasone. He remains alive at 21 months of follow-up with no evidence of disease.