The Next Chapter in Immunotherapy and Radiation Combination Therapy: Cancer-Specific Perspectives

Immunotherapeutic agents have revolutionized cancer treatment over the past decade. However, most patients fail to respond to immunotherapy alone. A growing body of preclinical studies highlights the potential for synergy between radiation therapy and immunotherapy, but the outcomes of clinical studies have been mixed. This review summarizes the current state of immunotherapy and radiation combination therapy across cancers, highlighting existing challenges and promising areas for future investigation.

Health Care Cost Reductions with Machine Learning-Directed Evaluations during Radiation Therapy - An Economic Analysis of a Randomized Controlled Study

BACKGROUND

Machine learning (ML) may cost-effectively direct health care by identifying patients most likely to benefit from preventative interventions to avoid negative and expensive outcomes. System for High-Intensity Evaluation During Radiation Therapy (SHIELD-RT; NCT04277650) was a single-institution, randomized controlled study in which electronic health record-based ML accurately identified patients at high risk for acute care (emergency visit or hospitalization) during radiotherapy (RT) and targeted them for supplemental clinical evaluations. This ML-directed intervention resulted in decreased acute care utilization. Given the limited prospective data showing the ability of ML to direct interventions cost-efficiently, an economic analysis was performed.

METHODS

A post hoc economic analysis was conducted of SHIELD-RT that included RT courses from January 7, 2019, to June 30, 2019. ML-identified high-risk courses (≥10% risk of acute care during RT) were randomized to receive standard of care weekly clinical evaluations with ad hoc supplemental evaluations per clinician discretion versus mandatory twice-weekly evaluations. The primary outcome was difference in mean total medical costs during and 15 days after RT. Acute care costs were obtained via institutional cost accounting. Physician and intervention costs were estimated via Medicare and Medicaid data. Negative binomial regression was used to estimate cost outcomes after adjustment for patient and disease factors.

RESULTS

A total of 311 high-risk RT courses among 305 patients were randomized to the standard (n=157) or the intervention (n=154) group. Unadjusted mean intervention group supplemental visit costs were $155 per course (95% confidence interval, $142 to $168). The intervention group had fewer acute care visits per course (standard, 0.47; intervention, 0.31; P=0.04). Total mean adjusted costs were $3110 per course for the standard group and $1494 for the intervention group (difference in means, $1616 [95% confidence interval, $1450 to $1783]; P=0.03).

CONCLUSIONS

In this economic analysis of a randomized controlled, health care ML study, mandatory supplemental evaluations for ML-identified high-risk patients were associated with both reduced total medical costs and improved clinical outcomes. Further study is needed to determine whether economic results are generalizable. (Funded in part by The Duke Endowment, The Conquer Cancer Foundation, the Duke Department of Radiation Oncology, and the National Cancer Institute of the National Institutes of Health [R01CA277782]; ClinicalTrials.gov number, NCT04277650.).

Stereotactic body radiotherapy with or without selective dismutase mimetic in pancreatic adenocarcinoma: an adaptive, randomised, double-blind, placebo-controlled, phase 1b/2 trial

BACKGROUND

Stereotactic body radiotherapy (SBRT) has the potential to ablate localised pancreatic ductal adenocarcinoma. Selective dismutase mimetics sensitise tumours while reducing normal tissue toxicity. This trial was designed to establish the efficacy and toxicity afforded by the selective dismutase mimetic avasopasem manganese when combined with ablative SBRT for localised pancreatic ductal adenocarcinoma.

METHODS

In this adaptive, randomised, double-blind, placebo-controlled, phase 1b/2 trial, patients aged 18 years or older with borderline resectable or locally advanced pancreatic cancer who had received at least 3 months of chemotherapy and had an Eastern Cooperative Oncology Group performance status of 0-2 were enrolled at six academic sites in the USA. Eligible patients were randomly assigned (1:1), with block randomisation (block sizes of 6-12) with a maximum of 24 patients per group, to receive daily avasopasem (90 mg) or placebo intravenously directly before (ie, within 180 min) SBRT (50, 55, or 60 Gy in five fractions, adaptively assigned in real time by Bayesian estimates of 90-day safety and efficacy). Patients and physicians were masked to treatment group allocation, but not to SBRT dose. The primary objective was to find the optimal dose of SBRT with avasopasem or placebo as determined by the late onset EffTox method. All analyses were done on an intention-to-treat basis. This study is registered with ClinicalTrials.gov, NCT03340974, and is complete.

FINDINGS

Between Jan 25, 2018, and April 29, 2020, 47 patients were screened, of whom 42 were enrolled (median age was 71 years [IQR 63-75], 23 [55%] were male, 19 [45%] were female, 37 [88%] were White, three [7%] were Black, and one [2%] each were unknown or other races) and randomly assigned to avasopasem (n=24) or placebo (n=18); the placebo group was terminated early after failing to meet prespecified efficacy parameters. At data cutoff (June 28, 2021), the avasopasem group satisfied boundaries for both efficacy and toxicity. Late onset EffTox efficacy response was observed in 16 (89%) of 18 patients at 50 Gy and six (100%) of six patients at 55 Gy in the avasopasem group, and was observed in three (50%) of six patients at 50 Gy and nine (75%) of 12 patients at 55 Gy in the placebo group, and the Bayesian model recommended 50 Gy or 55 Gy in five fractions with avasopasem for further study. Serious adverse events of any cause were reported in three (17%) of 18 patients in the placebo group and six (25%) of 24 in the avasopasem group. In the placebo group, grade 3 adverse events within 90 days of SBRT were abdominal pain, acute cholangitis, pyrexia, increased blood lactic acid, and increased lipase (one [6%] each); no grade 4 events occurred. In the avasopasem group, grade 3-4 adverse events within 90 days of SBRT were acute kidney injury, increased blood alkaline phosphatase, haematoma, colitis, gastric obstruction, lung infection, abdominal abscess, post-surgical atrial fibrillation, and pneumonia leading to respiratory failure (one [4%] each).There were no treatment-related deaths but one late death in the avasopasem group due to sepsis in the setting of duodenal obstruction after off-study treatment was reported as potentially related to SBRT.

INTERPRETATION

SBRT that uses 50 or 55 Gy in five fractions can be considered for patients with localised pancreatic ductal adenocarcinoma. The addition of avasopasem might further enhance disease outcomes. A larger phase 2 trial (GRECO-2, NCT04698915) is underway to validate these results.

FUNDING

Galera Therapeutics.

Pembrolizumab, Radiotherapy, and Chemotherapy in Neoadjuvant Treatment of Malignant Esophago-Gastric Diseases (PROCEED): Assessment of Pathologic Response in a Prospective, Phase II Single-Arm Trial

PURPOSE/OBJECTIVE(S)

A standard treatment paradigm for locally advanced, resectable, non-metastatic esophageal or gastric adenocarcinomas (EGA) is neoadjuvant chemoradiation (CRT) followed by surgical resection. Historical pathologic complete response (pCR) rate after CRT with carboplatin/paclitaxel per the CROSS trial was 23%. The efficacy of immune checkpoint inhibition in the adjuvant setting has since been demonstrated in this patient population. The primary objective of this trial was to investigate whether neoadjuvant CRT combined with pembrolizumab improves pCR compared to the historical control of CRT alone.

MATERIALS/METHODS

Single-institution, prospective phase II trial (NCT03064490) evaluating the efficacy and safety of neoadjuvant pembrolizumab combined with CRT followed by adjuvant pembrolizumab in patients with locally advanced operable EGA. CRT (45 Gy in 25 fractions with concurrent, weekly carboplatin [AUC 2] and paclitaxel [50mg/m2 of BSA]) with three cycles of pembrolizumab were administered as neoadjuvant therapy. Patients also received three cycles of adjuvant pembrolizumab after surgical resection. Baseline characteristics were collected. Pathologic response was scored from 0-3 based on tumor regression grading (TRG), with 0 indicating a complete response, 1 indicating marked response (<10% residual disease), 2 indicating partial response, and 3 indicating poor or no response. The percentage of patients with pCR and major pathologic response (MPR, score of 0-1) are described.

RESULTS

Accrual of this trial is now complete, with 35 patients with cT2-3N0-2M0 EGA enrolled from 10/10/2017-10/07/2022. 89% of enrolled patients are male, and 94% are white. 97% of patients have an esophageal primary. One patient withdrew from the study prior to completing neoadjuvant therapy due to a severe drug reaction. Two other patients did not undergo surgery, one due to preference and the other due to development of metastatic disease. Of 32 remaining eligible patients, 28 have completed neoadjuvant therapy and surgical resection to date. 100% of patients underwent IMRT/VMAT. 27/28 (97%) patients underwent R0 resection. 10/28 (35.7%: 95% CI: 17%, 53%) patients achieved a pCR, and 14/28 (50%: 95% CI: 31%, 68%) patients achieved an MPR.

CONCLUSION

Patients undergoing neoadjuvant CRT combined with pembrolizumab for EGA experienced a higher rate of pCR/MPR compared to historical controls treated with CRT alone. This phase II trial demonstrates the efficacy of this treatment paradigm, which warrants assessment in future prospective studies.

Comparing Survival After Resection, Ablation, and Radiation in Small Intrahepatic Cholangiocarcinoma

BACKGROUND

Hepatectomy is the cornerstone of curative-intent treatment for intrahepatic cholangiocarcinoma (ICC). However, in patients unable to be resected, data comparing efficacy of alternatives including thermal ablation and radiation therapy (RT) remain limited. Herein, we compared survival between resection and other liver-directed therapies for small ICC within a national cancer registry.

PATIENTS AND METHODS

Patients with clinical stage I-III ICC < 3 cm diagnosed 2010-2018 who underwent resection, ablation, or RT were identified in the National Cancer Database. Overall survival (OS) was compared using Kaplan-Meier and multivariable Cox proportional hazards methods.

RESULTS

Of 545 patients, 297 (54.5%) underwent resection, 114 (20.9%) ablation, and 134 (24.6%) RT. Median OS was similar between resection and ablation [50.5 months, 95% confidence interval (CI) 37.5-73.9; 39.5 months, 95% CI 28.7-58.4, p = 0.14], both exceeding that of RT (20.9 months, 95% CI 14.1-28.3). RT patients had high rates of stage III disease (10.4% RT vs. 1.8% ablation vs. 11.8% resection, p < 0.001), but the lowest rates of chemotherapy utilization (9.0% RT vs. 15.8% ablation vs. 38.7% resection, p < 0.001). In multivariable analysis, resection and ablation were associated with reduced mortality compared with RT [hazard ratio (HR) 0.44, 95% CI 0.33-0.58 and HR 0.53, 95% CI 0.38-0.75, p < 0.001, respectively].

CONCLUSION

Resection and ablation were associated with improved survival in patients with ICC < 3 cm compared with RT. Acknowledging confounders, anatomic constraints of ablation, limitations of available data, and need for prospective study, these results favor ablation in small ICC where resection is not feasible.

Quantifying Cardiac Chamber Motion for Noninvasive Stereotactic Cardiac Radiosurgery Using Deformable Image Registration

PURPOSE/OBJECTIVE(S)

Noninvasive Stereotactic Cardiac Radiosurgery (NSCR) is a novel treatment for drug resistant ventricular tachycardia. One of the major issues with this new treatment style is uncertainty in the target location due to cardiac and respiratory motion. This motion uncertainty results in planning target volumes that are 3 to 4 times the original target volume. Quantification of this motion requires accurate segmentation of the heart chambers throughout cardiac and respiratory phases. Manual segmentation of the heart is incredibly time consuming and not feasible to be done for each patient. This work aimed to develop a semi-automated workflow that takes manual contours of the heart chambers in one phase of a breath-hold ECG cardiac 4DCT and warp these contours onto all other phases.

MATERIALS/METHODS

Four chambers of the heart and the aorta were manually contoured on one phase of a patient's breath-hold ECG cardiac 4DCT. A single shot deep learning deformable image registration code called GroupRegNet was used to propagate the contours onto the additional phases. This code uses a global smoothness parameter that does not work well in cardiac cases. To account for the type of motion that is expected in the cardiac 4DCTs, a piecewise smoothing parameter that only enforces smoothness within each of the original contours was added to the code. To determine the accuracy of the registration, a second phase with significant motion from the contoured phase was also manually contoured. The Dice coefficient and surface-to-surface distance between the manual and propagated contours were calculated.

RESULTS

The tables below show the improvement of the contour propagation accuracy, measured as the Dice coefficients and the mean surface-to-surface distance using the original global smoothing and piecewise-smoothing only within the original contours.

CONCLUSION

These results show an improvement in registration accuracy due to using a piecewise smoothing factor instead of global smoothness. Along with improvements in registration accuracy, this work shows promise for this semi-automated methodology to be further improved with the hope of fully automating the process and eventually implemented into the workflow for NSCR treatment to quantify cardiac chamber motion more accurately and eventually reduce the margins during radiation treatment.

NCCN Guidelines® Insights: Biliary Tract Cancers, Version 2.2023

In 2023, the NCCN Guidelines for Hepatobiliary Cancers were divided into 2 separate guidelines: Hepatocellular Carcinoma and Biliary Tract Cancers. The NCCN Guidelines for Biliary Tract Cancers provide recommendations for the evaluation and comprehensive care of patients with gallbladder cancer, intrahepatic cholangiocarcinoma, and extrahepatic cholangiocarcinoma. The multidisciplinary panel of experts meets at least on an annual basis to review requests from internal and external entities as well as to evaluate new data on current and emerging therapies. These Guidelines Insights focus on some of the recent updates to the NCCN Guidelines for Biliary Tract Cancers as well as the newly published section on principles of molecular testing.

Advances in the treatment of intrahepatic cholangiocarcinoma: An overview of the current and future therapeutic landscape for clinicians

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver tumor and remains a fatal malignancy in the majority of patients. Approximately 20%-30% of patients are eligible for resection, which is considered the only potentially curative treatment; and, after resection, a median survival of 53 months has been reported when sequenced with adjuvant capecitabine. For the 70%-80% of patients who present with locally unresectable or distant metastatic disease, systemic therapy may delay progression, but survival remains limited to approximately 1 year. For the past decade, doublet chemotherapy with gemcitabine and cisplatin has been considered the most effective first-line regimen, but results from the recent use of triplet regimens and even immunotherapy may shift the paradigm. More effective treatment strategies, including those that combine systemic therapy with locoregional therapies like radioembolization or hepatic artery infusion, have also been developed. Molecular therapies, including those that target fibroblast growth factor receptor and isocitrate dehydrogenase, have recently received US Food and Drug Administration approval for a defined role as second-line treatment for up to 40% of patients harboring these actionable genomic alterations, and whether they should be considered in the first-line setting is under investigation. Furthermore, as the oncology field seeks to expand indications for immunotherapy, recent data demonstrated that combining durvalumab with standard cytotoxic therapy improved survival in patients with ICC. This review focuses on the current and future strategies for ICC treatment, including a summary of the primary literature for each treatment modality and an algorithm that can be used to drive a personalized and multidisciplinary approach for patients with this challenging malignancy.

Healthcare provider evaluation of machine learning-directed care: reactions to deployment on a randomised controlled study

OBJECTIVES

Clinical artificial intelligence and machine learning (ML) face barriers related to implementation and trust. There have been few prospective opportunities to evaluate these concerns. System for High Intensity EvaLuation During Radiotherapy (NCT03775265) was a randomised controlled study demonstrating that ML accurately directed clinical evaluations to reduce acute care during cancer radiotherapy. We characterised subsequent perceptions and barriers to implementation.

METHODS

An anonymous 7-question Likert-type scale survey with optional free text was administered to multidisciplinary staff focused on workflow, agreement with ML and patient experience.

RESULTS

59/71 (83%) responded. 81% disagreed/strongly disagreed their workflow was disrupted. 67% agreed/strongly agreed patients undergoing intervention were high risk. 75% agreed/strongly agreed they would implement the ML approach routinely if the study was positive. Free-text feedback focused on patient education and ML predictions.

CONCLUSIONS

Randomised data and firsthand experience support positive reception of clinical ML. Providers highlighted future priorities, including patient counselling and workflow optimisation.

Feasibility of establishing and drug screening patient-derived rectal organoid models from pretreatment rectal cancer biopsies

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Background: Response to neoadjuvant chemotherapy and radiation therapy in the treatment of locally advanced rectal cancer is heterogenous and prognostic of clinical outcomes, necessitating the need for predictive biomarkers to guide personalized treatment recommendations. Sensitivity to a given chemotherapy in patient-derived organoids predicts patient response to that chemotherapy, establishing it as a promising model for efforts to ascertain predictive biomarkers and personalize treatment decisions. This study assessed the feasibility of obtaining patient-derived rectal organoids from standard of care pre-treatment proctoscopy biopsies. Methods: In this clinical trial (NCT04371198), biopsies were obtained from patients with stage II rectal adenocarcinoma prior to receipt of neoadjuvant therapy. Tissue samples were mechanically and enzymatically dissociated to obtain a single cell suspension. Cells were then mixed with matrigel at a ratio of 2,000 cells:5 µL Matrigel in a 50ul dome and plated on a 24 well tissue culture plate with colorectal cancer organoid media at 37oC/5% CO2. Established patient-derived organoids were then used to perform drug screens with clinically-applicable chemotherapeutics including oxaliplatin, irinotecan and 5-FU, followed by high throughput drug screen using our recently published MicroOrganoSpheres platform using the NCI Approved Oncology Drugs Set VI* library. Results: Of the 20 patients enrolled, 17 (85%) patient-derived organoids were created from pre-treatment specimens. 15 (88%) of these samples were successfully established as defined by the ability to passage organoids for at least two passages. All established samples were used to perform standard of care drug screens and high throughout drug screens, which demonstrated differences in drug sensitivities among the samples. Moreover, within two weeks of receiving the sample, four established quickly enough to complete drug screening with oxaliplatin, SN38, and 5-Fluorouracil. Conclusions: These results demonstrate the feasibility of establishing patient-derived rectal organoids from biopsy specimens obtained by proctoscopy, and reinforce the utility of patient-derived organoids as a tractable ex vivo platform to personalize rectal cancer treatment. Planned future directions include in vitro determination of radiation therapy sensitivity as well as systematic assessment of the correlation between individual patients and their organoid model. Clinical trial information: NCT04371198 .

Implementation of machine learning in the clinic: challenges and lessons in prospective deployment from the System for High Intensity EvaLuation During Radiation Therapy (SHIELD-RT) randomized controlled study

Background

Artificial intelligence (AI) and machine learning (ML) have resulted in significant enthusiasm for their promise in healthcare. Despite this, prospective randomized controlled trials and successful clinical implementation remain limited. One clinical application of ML is mitigation of the increased risk for acute care during outpatient cancer therapy. We previously reported the results of the System for High Intensity EvaLuation During Radiation Therapy (SHIELD-RT) study (NCT04277650), which was a prospective, randomized quality improvement study demonstrating that ML based on electronic health record (EHR) data can direct supplemental clinical evaluations and reduce the rate of acute care during cancer radiotherapy with and without chemotherapy. The objective of this study is to report the workflow and operational challenges encountered during ML implementation on the SHIELD-RT study.

Results

Data extraction and manual review steps in the workflow represented significant time commitments for implementation of clinical ML on a prospective, randomized study. Barriers include limited data availability through the standard clinical workflow and commercial products, the need to aggregate data from multiple sources, and logistical challenges from altering the standard clinical workflow to deliver adaptive care.

Conclusions

The SHIELD-RT study was an early randomized controlled study which enabled assessment of barriers to clinical ML implementation, specifically those which leverage the EHR. These challenges build on a growing body of literature and may provide lessons for future healthcare ML adoption.

Trial registration: NCT04277650. Registered 20 February 2020. Retrospectively registered quality improvement study.

Comparing Outcomes of Oligometastases Treated with Hypofractionated Image-Guided Radiotherapy (HIGRT) with a Simultaneous Integrated Boost (SIB) Technique versus Metastasis Alone: A Multi-Institutional Analysis

Simple Summary

Hypofractionated image-guided radiotherapy (HIGRT) is a common method in which high doses of radiation are delivered to treat oligometastatic disease. We have previously reported on the clinical outcomes of treating oligometastases with radiation using an elective simultaneous integrated boost technique (SIB), delivering higher doses to known metastases and reduced doses to adjacent bone or nodal basins. Here we compare outcomes of oligometastases receiving radiation targeting metastases alone (MA) versus those treated via an SIB. Both SIB and MA irradiation of oligometastases achieved high rates of tumor metastases control and similar pain control. Further investigation of this technique with prospective trials is warranted.

Abstract

Purpose: We previously reported on the clinical outcomes of treating oligometastases with radiation using an elective simultaneous integrated boost technique (SIB), delivering higher doses to known metastases and reduced doses to adjacent bone or nodal basins. Here we compare outcomes of oligometastases receiving radiation targeting metastases alone (MA) versus those treated via an SIB. Methods: Oligometastatic patients with ≤5 active metastases treated with either SIB or MA radiation at two institutions from 2013 to 2019 were analyzed retrospectively for treatment-related toxicity, pain control, and recurrence patterns. Tumor metastasis control (TMC) was defined as an absence of progression in the high dose planning target volume (PTV). Marginal recurrence (MR) was defined as recurrence outside the elective PTV but within the adjacent bone or nodal basin. Distant recurrence (DR) was defined as any recurrence that is not within the PTV or surrounding bone or nodal basin. The outcome rates were estimated using the Kaplan–Meier method and compared between the two techniques using the log-rank test. Results: 101 patients were treated via an SIB to 90 sites (58% nodal and 42% osseous) and via MA radiation to 46 sites (22% nodal and 78% osseous). The median follow-up among surviving patients was 24.6 months (range 1.4–71.0). Of the patients treated to MA, the doses ranged from 18 Gy in one fraction (22%) to 50 Gy in 10 fractions (50%). Most patients treated with an SIB received 50 Gy to the treated metastases and 30 Gy to the elective PTV in 10 fractions (88%). No acute grade ≥3 toxicities occurred in either cohort. Late grade ≥3 toxicity occurred in 3 SIB patients (vocal cord paralysis and two vertebral body compression), all related to the high dose PTV and not the elective volume. There was similar crude pain relief between cohorts. The MR-free survival rate at 2 years was 87% (95% CI: 70%, 95%) in the MA group and 98% (95% CI: 87%, 99%) in the SIB group (p = 0.07). The crude TMC was 89% (41/46) in the MA group and 94% (85/90) in the SIB group. There were no significant differences in DR-free survival (65% (95% CI: 55–74%; p = 0.24)), disease-free survival (60% (95% CI: 40–75%; p = 0.40)), or overall survival (88% (95% CI: 73–95%; p = 0.26)), between the MA and SIB cohorts. Conclusion: Both SIB and MA irradiation of oligometastases achieved high rates of TMC and similar pain control, with a trend towards improved MR-free survival for oligometastases treated with an SIB. Further investigation of this technique with prospective trials is warranted.

Transfer learning for fluence map prediction in adrenal stereotactic body radiation therapy

Objective:To design a deep transfer learning framework for modeling fluence map predictions for stereotactic body radiation therapy (SBRT) of adrenal cancer and similar sites that usually have a small number of cases.Approach:We developed a transfer learning framework for adrenal SBRT planning that leverages knowledge in a pancreas SBRT planning model. Treatment plans from the two sites had different dose prescriptions and beam settings but both prioritized gastrointestinal sparing. A base framework was first trained with 100 pancreas cases. This framework consists of two convolutional neural networks (CNN), which predict individual beam doses (BD-CNN) and fluence maps (FM-CNN) sequentially for 9-beam intensity-modulated radiation therapy (IMRT) plans. Forty-five adrenal plans were split into training/validation/test sets with the ratio of 20/10/15. The base BD-CNN was re-trained with transfer learning using 5/10/15/20 adrenal training cases to produce multiple candidate adrenal BD-CNN models. The base FM-CNN was directly used for adrenal cases. The deep learning (DL) plans were evaluated by several clinically relevant dosimetric endpoints, producing a percentage score relative to the clinical plans.Main results:Transfer learning significantly reduced the number of training cases and training time needed to train such a DL framework. The adrenal transfer learning model trained with 5/10/15/20 cases achieved validation plan scores of 85.4/91.2/90.7/89.4, suggesting that model performance saturated with 10 training cases. Meanwhile, a model using all 20 adrenal training cases without transfer learning only scored 80.5. For the final test set, the 5/10/15/20-case models achieved scores of 73.5/75.3/78.9/83.3.Significance:It is feasible to use deep transfer learning to train an IMRT fluence prediction framework. This technique could adapt to different dose prescriptions and beam configurations. This framework potentially enables DL modeling for clinical sites that have a limited dataset, either due to few cases or due to rapid technology evolution.

Survey of Healthcare Providers Utilization and Perception of Telehealth On-Treatment Visits During COVID-19 Pandemic

Purpose/Objective(s)

Materials/Methods

Results

Conclusion

Evolving role of an oncology telehealth nurse at an NCI-designated cancer institute

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Background: Oncology telehealth (TH) services may improve access, mitigate care delays, and augment care in select settings. However, logistical and workflow barriers hinder the sustainable adoption of TH services by providers. We created a novel oncology TH nurse (OTN) position to address these barriers. Methods: An OTN was introduced into oncology provider groups (physician + advanced practice provider) in a staggered, opt-in fashion across the Duke Cancer Institute between 9/2020 and 12/2020. The OTN performed individualized interventions to decrease provider burden, improve TH workflows, and increase TH utilization. Specific interventions performed by the OTN were recorded. We monitored the primary outcome, TH utilization, as a proportion of all visits at baseline (month 0) and 3 months post-OTN intervention. Patient TH satisfaction surveys were reviewed at baseline and 3 months post-OTN intervention. Provider surveys were sent 3 months post-OTN intervention. Results: The OTN was implemented across 10 provider groups and 25 providers [gastrointestinal (GI) medical oncology (n = 10), thoracic medical oncology (n = 3), melanoma medical oncology (n = 3), adult bone marrow transplant (n = 2), lung cancer screening (n = 2), melanoma surgical oncology (n = 1), hematological malignancies (n = 1), head and neck medical oncology (n = 1), central nervous system radiation oncology (n = 1), and GI radiation oncology (n = 1)]. 25 providers utilized 1 or more OTN interventions: support for patients on the TH platform (n = 13), construction of TH clinic schedule templates (n = 6), creation of workflows to order and obtain outside imaging/labs (n = 5), provider TH education (n = 4), creation of Epic SmartPhrases (n = 4), and identifying patients appropriate for TH (n = 3). Baseline TH utilization was 15.6% of all visits, and 3-month post-OTN utilization was 23.8%. TH patient satisfaction data was available for 10 providers at baseline and 13 providers at 3 months post-OTN. Patients’ global approval rating of TH was 85.0% at baseline and 98.5% at month 3. 16/25 providers returned the post-intervention survey. Providers requested continued assistance from the OTN for supporting patients on the TH platform (43.5%), staff TH education (43.5%), provider TH education (25%), creation of SmartPhrases (25%), and creation of TH clinic templates (13%). Providers requested new additional OTN support to 1) order and retrieve imaging/laboratory tests for TH visits and 2) explore patients' willingness to undergo TH visits. Conclusions: OTN interventions were individualized to providers and evolved over time. While TH utilization was increased at 3 months post-OTN, it is possible that utilization was confounded by the dynamic COVID-19 pandemic and provider/patient preferences over time. Nevertheless, these results demonstrate feasibility of OTN implementation and provide support for this novel role in promoting TH services in oncology.

Impact of machine learning-directed on-treatment evaluations on cost of acute care visits: Economic analysis of SHIELD-RT

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Background: SHIELD-RT was a randomized controlled quality improvement study (NCT03775265) that implemented electronic health record-based machine learning (ML) to direct supplemental visits for high risk (HR) patients undergoing radiotherapy (RT). Acute care visits (ER visits or hospitalizations) were reduced from 22% to 12%. We evaluated the costs associated with acute visits in this study. Methods: Patients who initiated RT between 1/7/19 and 6/30/19 at a single institution were evaluated by a ML algorithm to identify HR courses (>10% risk of acute visit during RT). HR patients were randomized to standard weekly (S) or intervention of twice weekly (TW) evaluation during RT. Cost data associated with acute visits were obtained and compared between patients who underwent S or TW evaluations. Missing cost data were imputed using disease related groups (DRGs). Mean costs (standard deviation) were compared between arms with non-parametric Wilcoxon Rank Sum tests. Results: 311 HR courses were identified and randomized to either S (n=157) or TW (n=154) evaluations during RT. 85 patients (S: 51; TW: 34) had 121 distinct acute care visits (S: 74; TW: 47). Patients in the TW evaluation arm had fewer hospitalizations (29 vs 41) and ER visits (18 vs 33) than those in the S arm. There were fewer acute visits per patient in the TW arm (0.34) compared to S arm (0.49). Actual cost data was available for 102 visits at our institution, and imputed for 19 outside hospital visits. Mean cost associated with acute visits was lower in the TW arm ($1939, SD $5912) compared with the S arm ($4002, SD $11568; p=0.03). Differences in mean cost between arms are presented in the table. Conclusions: ML-directed evaluations for HR patients undergoing RT resulted in decreased costs of ER visits and hospitalizations. Costs were decreased across revenue centers, with the largest difference related to inpatient room costs. Future analyses will incorporate intervention costs, which are currently bundled with RT reimbursement.[Table: see text]

Hepatobiliary Cancers, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Hepatobiliary Cancers focus on the screening, diagnosis, staging, treatment, and management of hepatocellular carcinoma (HCC), gallbladder cancer, and cancer of the bile ducts (intrahepatic and extrahepatic cholangiocarcinoma). Due to the multiple modalities that can be used to treat the disease and the complications that can arise from comorbid liver dysfunction, a multidisciplinary evaluation is essential for determining an optimal treatment strategy. A multidisciplinary team should include hepatologists, diagnostic radiologists, interventional radiologists, surgeons, medical oncologists, and pathologists with hepatobiliary cancer expertise. In addition to surgery, transplant, and intra-arterial therapies, there have been great advances in the systemic treatment of HCC. Until recently, sorafenib was the only systemic therapy option for patients with advanced HCC. In 2020, the combination of atezolizumab and bevacizumab became the first regimen to show superior survival to sorafenib, gaining it FDA approval as a new frontline standard regimen for unresectable or metastatic HCC. This article discusses the NCCN Guidelines recommendations for HCC.

Ipilimumab and Radiation in Patients with High-risk Resected or Regionally Advanced Melanoma

PURPOSE

In this prospective trial, we sought to assess the feasibility of concurrent administration of ipilimumab and radiation as adjuvant, neoadjuvant, or definitive therapy in patients with regionally advanced melanoma.

PATIENTS AND METHODS

Twenty-four patients in two cohorts were enrolled and received ipilimumab at 3 mg/kg every 3 weeks for four doses in conjunction with radiation; median dose was 4,000 cGy (interquartile range, 3,550-4,800 cGy). Patients in cohort 1 were treated adjuvantly; patients in cohort 2 were treated either neoadjuvantly or as definitive therapy.

RESULTS

Adverse event profiles were consistent with those previously reported with checkpoint inhibition and radiation. For the neoadjuvant/definitive cohort, the objective response rate was 64% (80% confidence interval, 40%-83%), with 4 of 10 evaluable patients achieving a radiographic complete response. An additional 3 patients in this cohort had a partial response and went on to surgical resection. With 2 years of follow-up, the 6-, 12-, and 24-month relapse-free survival for the adjuvant cohort was 85%, 69%, and 62%, respectively. At 2 years, all patients in the neoadjuvant/definitive cohort and 10/13 patients in the adjuvant cohort were still alive. Correlative studies suggested that response in some patients were associated with specific CD4+ T-cell subsets.

CONCLUSIONS

Overall, concurrent administration of ipilimumab and radiation was feasible, and resulted in a high response rate, converting some patients with unresectable disease into surgical candidates. Additional studies to investigate the combination of radiation and checkpoint inhibitor therapy are warranted.

Deep Learning-Based Fluence Map Prediction for Pancreas Stereotactic Body Radiation Therapy With Simultaneous Integrated Boost

Purpose

Treatment planning for pancreas stereotactic body radiation therapy (SBRT) is a challenging task, especially with simultaneous integrated boost treatment approaches. We propose a deep learning (DL) framework to accurately predict fluence maps from patient anatomy and directly generate intensity modulated radiation therapy plans.

Methods and Materials

The framework employs 2 convolutional neural networks (CNNs) to sequentially generate beam dose prediction and fluence map prediction, creating a deliverable 9-beam intensity modulated radiation therapy plan. Within the beam dose prediction CNN, axial slices of combined structure contour masks are used to predict 3-dimensional (3D) beam doses for each beam. Each 3D beam dose is projected along its beam’s-eye-view to form a 2D beam dose map, which is subsequently used by the fluence map prediction CNN to predict its fluence map. Finally, the 9 predicted fluence maps are imported into the treatment planning system to finalize the plan by leaf sequencing and dose calculation. One hundred patients receiving pancreas SBRT were retrospectively collected for this study. Benchmark plans with unified simultaneous integrated boost prescription (25/33 Gy) were manually optimized for each case. The data set was split into 80/20 cases for training and testing. We evaluated the proposed DL framework by assessing both the fluence maps and the final predicted plans. Further, clinical acceptability of the plans was evaluated by a physician specializing in gastrointestinal cancer.

Results

The DL-based planning was, on average, completed in under 2 minutes. In testing, the predicted plans achieved similar dose distribution compared with the benchmark plans (-1.5% deviation for planning target volume 33 V_33Gy), with slightly higher planning target volume maximum (+1.03 Gy) and organ at risk maximum (+0.95 Gy) doses. After renormalization, the physician rated 19 cases clinically acceptable and 1 case requiring minor improvement.

Conclusions

The DL framework can effectively plan pancreas SBRT cases within 2 minutes. The predicted plans are clinically deliverable, with plan quality approaching that of manual planning.

Survival Advantage With Adjuvant Chemotherapy for Locoregionally Advanced Rectal Cancer: A Veterans Health Administration Analysis

BACKGROUND

Adjuvant chemotherapy (AC) after chemoradiation (CRT) and surgery for locoregionally advanced rectal cancer (LARC) is a standard of care in the United States. This study examined the role, optimal regimen, and duration of AC using data from the largest integrated health system in the United States.

PATIENTS AND METHODS

Using the Veterans Affairs Central Cancer Registry, patients with stage II-III rectal cancer diagnosed in 2001 through 2011 who received neoadjuvant CRT and surgery with or without AC were identified. Kaplan-Meier analysis, log-rank tests, and propensity score (PS) adjustment analysis were used to assess survival.

RESULTS

A total of 866 patients were identified; 417 received AC and 449 did not (observation [OBS] group). Median follow-up was 109 months. Median disease-specific survival (DSS) was not reached. Six-year DSS was 73.7%; 79.5% for the AC group versus 68.0% for the OBS group. PS-matched analysis for DSS favored AC (P=.0002). Median overall survival (OS) was 90.8 months. Six-year OS was 56.7%; 64.3% for AC versus 49.6% for OBS. In PS-matched analysis, median OS was 117.4 months for AC and 74.3 months for OBS (P<.0001). A DSS advantage was seen when comparing ≥4 months with <4 months of AC (P=.023). No difference in DSS or OS was seen with single-agent versus multiagent AC.

CONCLUSIONS

In this population of patients with LARC treated with neoadjuvant CRT and surgery, OS and DSS were improved among those treated with AC versus OBS. DSS benefits were seen with ≥4 months of AC. No additional benefit was observed with multiagent therapy. In the absence of phase III data, these findings support the use of AC for LARC.

Natural language processing for abstraction of cancer treatment toxicities: accuracy versus human experts

Objectives

Expert abstraction of acute toxicities is critical in oncology research but is labor-intensive and variable. We assessed the accuracy of a natural language processing (NLP) pipeline to extract symptoms from clinical notes compared to physicians.

Materials and Methods

Two independent reviewers identified present and negated National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) v5.0 symptoms from 100 randomly selected notes for on-treatment visits during radiation therapy with adjudication by a third reviewer. A NLP pipeline based on Apache clinical Text Analysis Knowledge Extraction System was developed and used to extract CTCAE terms. Accuracy was assessed by precision, recall, and F1.

Results

The NLP pipeline demonstrated high accuracy for common physician-abstracted symptoms, such as radiation dermatitis (F1 0.88), fatigue (0.85), and nausea (0.88). NLP had poor sensitivity for negated symptoms.

Conclusion

NLP accurately detects a subset of documented present CTCAE symptoms, though is limited for negated symptoms. It may facilitate strategies to more consistently identify toxicities during cancer therapy.

System for High-Intensity Evaluation During Radiation Therapy (SHIELD-RT): A Prospective Randomized Study of Machine Learning–Directed Clinical Evaluations During Radiation and Chemoradiation

PURPOSE

Patients undergoing outpatient radiotherapy (RT) or chemoradiation (CRT) frequently require acute care (emergency department evaluation or hospitalization). Machine learning (ML) may guide interventions to reduce this risk. There are limited prospective studies investigating the clinical impact of ML in health care. The objective of this study was to determine whether ML can identify high-risk patients and direct mandatory twice-weekly clinical evaluation to reduce acute care visits during treatment.

PATIENTS AND METHODS

During this single-institution randomized quality improvement study (ClinicalTrials.gov identifier: NCT04277650 ), 963 outpatient adult courses of RT and CRT started from January 7 to June 30, 2019, were evaluated by an ML algorithm. Among these, 311 courses identified by ML as high risk (> 10% risk of acute care during treatment) were randomized to standard once-weekly clinical evaluation (n = 157) or mandatory twice-weekly evaluation (n = 154). Both arms allowed additional evaluations on the basis of clinician discretion. The primary end point was the rate of acute care visits during RT. Model performance was evaluated using receiver operating characteristic area under the curve (AUC) and decile calibration plots.

RESULTS

Twice-weekly evaluation reduced rates of acute care during treatment from 22.3% to 12.3% (difference, −10.0%; 95% CI, −18.3 to −1.6; relative risk, 0.556; 95% CI, 0.332 to 0.924; P = .02). Low-risk patients had a 2.7% acute care rate. Model discrimination was good in high- and low-risk patients undergoing standard once-weekly evaluation (AUC, 0.851).

CONCLUSION

In this prospective randomized study, ML accurately triaged patients undergoing RT and CRT, directing clinical management with reduced acute care rates versus standard of care. This prospective study demonstrates the potential benefit of ML in health care and offers opportunities to enhance care quality and reduce health care costs.

An Interpretable Planning Bot for Pancreas Stereotactic Body Radiation Therapy

PURPOSE

Pancreas stereotactic body radiation therapy (SBRT) treatment planning requires planners to make sequential, time-consuming interactions with the treatment planning system to reach the optimal dose distribution. We sought to develop a reinforcement learning (RL)-based planning bot to systematically address complex tradeoffs and achieve high plan quality consistently and efficiently.

METHODS AND MATERIALS

The focus of pancreas SBRT planning is finding a balance between organ-at-risk sparing and planning target volume (PTV) coverage. Planners evaluate dose distributions and make planning adjustments to optimize PTV coverage while adhering to organ-at-risk dose constraints. We formulated such interactions between the planner and treatment planning system into a finite-horizon RL model. First, planning status features were evaluated based on human planners' experience and defined as planning states. Second, planning actions were defined to represent steps that planners would commonly implement to address different planning needs. Finally, we derived a reward system based on an objective function guided by physician-assigned constraints. The planning bot trained itself with 48 plans augmented from 16 previously treated patients, and generated plans for 24 cases in a separate validation set.

RESULTS

All 24 bot-generated plans achieved similar PTV coverages compared with clinical plans while satisfying all clinical planning constraints. Moreover, the knowledge learned by the bot could be visualized and interpreted as consistent with human planning knowledge, and the knowledge maps learned in separate training sessions were consistent, indicating reproducibility of the learning process.

CONCLUSIONS

We developed a planning bot that generates high-quality treatment plans for pancreas SBRT. We demonstrated that the training phase of the bot is tractable and reproducible, and the knowledge acquired is interpretable. As a result, the RL planning bot can potentially be incorporated into the clinical workflow and reduce planning inefficiencies.

Fluence Map Prediction Using Deep Learning Models - Direct Plan Generation for Pancreas Stereotactic Body Radiation Therapy

Purpose: Treatment planning for pancreas stereotactic body radiation therapy (SBRT) is a difficult and time-consuming task. In this study, we aim to develop a novel deep learning framework to generate clinical-quality plans by direct prediction of fluence maps from patient anatomy using convolutional neural networks (CNNs).

Materials and Methods: Our proposed framework utilizes two CNNs to predict intensity-modulated radiation therapy fluence maps and generate deliverable plans: (1) Field-dose CNN predicts field-dose distributions in the region of interest using planning images and structure contours; (2) a fluence map CNN predicts the final fluence map per beam using the predicted field dose projected onto the beam's eye view. The predicted fluence maps were subsequently imported into the treatment planning system for leaf sequencing and final dose calculation (model-predicted plans). One hundred patients previously treated with pancreas SBRT were included in this retrospective study, and they were split into 85 training cases and 15 test cases. For each network, 10% of training data were randomly selected for model validation. Nine-beam benchmark plans with standardized target prescription and organ-at-risk constraints were planned by experienced clinical physicists and used as the gold standard to train the model. Model-predicted plans were compared with benchmark plans in terms of dosimetric endpoints, fluence map deliverability, and total monitor units.

Results: The average time for fluence-map prediction per patient was 7.1 s. Comparing model-predicted plans with benchmark plans, target mean dose, maximum dose (0.1 cc), and D_95% absolute differences in percentages of prescription were 0.1, 3.9, and 2.1%, respectively; organ-at-risk mean dose and maximum dose (0.1 cc) absolute differences were 0.2 and 4.4%, respectively. The predicted plans had fluence map gamma indices (97.69 ± 0.96% vs. 98.14 ± 0.74%) and total monitor units (2,122 ± 281 vs. 2,265 ± 373) that were comparable to the benchmark plans.

Conclusions: We develop a novel deep learning framework for pancreas SBRT planning, which predicts a fluence map for each beam and can, therefore, bypass the lengthy inverse optimization process. The proposed framework could potentially change the paradigm of treatment planning by harnessing the power of deep learning to generate clinically deliverable plans in seconds.

Guidelines Insights: Hepatobiliary Cancers, Version 2.2019

The NCCN Guidelines for Hepatobiliary Cancers provide treatment recommendations for cancers of the liver, gallbladder, and bile ducts. The NCCN Hepatobiliary Cancers Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize the panel's discussion and updated recommendations regarding systemic therapy for first-line and subsequent-line treatment of patients with hepatocellular carcinoma.

Multi-Institutional Analysis of Synchronous Prostate and Rectosigmoid Cancers

Purpose: To perform a multi-institutional analysis of patients with synchronous prostate and rectosigmoid cancers.

Materials and Methods: A retrospective review of Duke University and Durham Veterans Affairs Medical Center records was performed for men with both prostate and rectosigmoid adenocarcinomas from 1988 to 2017. Synchronous presentation was defined as symptoms, diagnosis, or treatment of both cancers within 12 months of each other. The primary study endpoint was overall survival. Univariate and multivariable Cox regression was performed.

Results: Among 31,883 men with prostate cancer, 330 (1%) also had rectosigmoid cancer and 54 (16%) of these were synchronous. Prostate cancer was more commonly the initial diagnosis (59%). Fifteen (28%) underwent prostatectomy or radiotherapy before an established diagnosis of rectosigmoid cancer. Stage I, II–III, or IV rectosigmoid cancer was present in 26, 57, and 17% of men, respectively. At a median follow-up of 43 months, there were 18 deaths due rectosigmoid cancer and two deaths due to prostate cancer. Crude late grade ≥3 toxicities include nine (17%) gastrointestinal and six (11%) genitourinary. Two anastomotic leaks following low anterior resection occurred in men who received a neoadjuvant radiotherapy prostate dose of 70.6–76.4 Gy. Rectosigmoid cancer stages II–III (HR 4.3, p = 0.02) and IV (HR 16, p < 0.01) as well as stage IV prostate cancer (HR 31, p < 0.01) were associated with overall survival on multivariable analysis.

Conclusions: Synchronous rectosigmoid cancer is a greater contributor to mortality than prostate cancer. Men aged ≥45 with localized prostate cancer should undergo colorectal cancer screening prior to treatment to evaluate for synchronous rectosigmoid cancer.

Evaluating treatment protocols for rectal squamous cell carcinomas: the Duke experience and literature

Background

Colorectal cancer is the third most common cancer in the United States and associated with significant morbidity and mortality. Within colorectal cancer histologies, squamous cell carcinomas (SCC) are rare compared to adenocarcinomas, with only about 200 cases reported to date. Because rectal SCC is rarely encountered, there is a lack of literature and clinical consensus surrounding its optimal treatment approach. Staging and management of SCC can be partly analogous to both rectal adenocarcinoma and anal canal SCC, which leads to a dilemma in how to best approach these patients. As large randomized prospective trials are unrealistic in the setting of this rare malignancy, this study evaluates an institutional experience and reviews the existing literature to help guide future management approaches.

Methods

This retrospective study compared various treatment regimens for rectal SCC patients treated at Duke University Medical Center from January 1, 1980 through December 31, 2016. Patients ≥18 years old with histologically confirmed, nonmetastatic rectal SCC were included. Due to small sample size, all statistical analyses were descriptive. For our systematic review, a comprehensive search of PubMed from 1933 to March 2018 was performed, with selected articles referenced to ensure all relevant publications were included. A qualitative analysis was performed to examine patient diagnoses, treatments, and disease- and treatment-related outcomes.

Results

Eight patients were included. Three patients underwent initial, curative attempt surgery and two of these patients required colostomy. With follow-up ranging from 7.1 to 31.5 months, one patient was alive with no evidence of disease while two developed local/regional recurrences. Five patients received definitive chemoradiation. Of these, three patients developed local/regional and/or metastatic recurrence. Two patients achieved complete response on imaging and currently remain disease-free (follow-up of 31.5 and 33.6 months).

Conclusions

Although the review of our institutional experience is limited by small numbers, our analysis suggests that definitive chemoradiation therapy is the preferred treatment approach to rectal SCC based on improved disease-related outcomes, sphincter preservation and morbidity profiles. This conclusion is supported by a systematic literature review.

Mind the gap: Gendered publication trends in oncology

BACKGROUND

Investigating scientific publication trends in the field of oncology may highlight opportunities for improved representation, mentorship, collaboration, and advancement for women.

METHODS

We conducted a bibliometric analysis of Annals of Surgical Oncology; Cancer; International Journal of Radiation Oncology, Biology, Physics (IJROBP); JAMA Oncology; and Journal of Clinical Oncology in 1990, 2000, 2010, and 2017. Full name and degree credentials per author role (ie, first or senior author), article type, publication year, and citation metrics were collected. First names were used to identify author gender.

RESULTS

Across 9189 articles, female representation rose between 1990 and 2017 (first authors: 17.7% in 1990, 36.6% in 2017; senior authors: 11.7% in 1990, 28.5% in 2017). For the 50 most cited articles per year, women comprised a smaller percent of first (26.5%) and senior (19.9%) authors. The average citation count was higher for male first (44.8 per article) and senior (47.1) authors compared to female first (39.7) and senior (44.1) authors. With male senior authors, the first author was more likely male (71.4% male; 25.0% female); with female senior authors, first authors were 50.2% male and 47.6% female. IJROBP had the lowest total female representation among first (25.1%) and senior (16.7%) authors. Women had more MDs with Masters degrees, whereas men held more MDs only and more MDs with PhDs.

CONCLUSION

Despite positive trends, substantial gendered differences in oncology publications persist. Fostering more women in oncology research will benefit female representation at many levels of academia and improve productivity, collaboration, and recruitment, especially in technical fields such as radiation and surgical oncology.

The Treatment of Hepatocellular Carcinoma With Portal Vein Tumor Thrombosis

Hepatocellular carcinoma (HCC) is the sixth most common cancer and third leading cause of cancer-related death worldwide. HCC is also is a tumor with a distinct ability to invade and grow within the hepatic vasculature. Approximately 20% of patients with HCC have macrovascular invasion (MVI) at the time of diagnosis. MVI is associated with dismal prognosis, with median survival ranging from 2 to 5 months. Current staging systems designate MVI as advanced disease. Recent advances in multimodal approaches, including systemic therapies, radiation therapy, liver-directed therapies, and surgical approaches, in the treatment of HCC with MVI have rendered this disease process more treatable with improved outcomes and are discussed here.

Predicting Emergency Visits and Hospital Admissions During Radiation and Chemoradiation: An Internally Validated Pretreatment Machine Learning Algorithm

PURPOSE

Patients undergoing radiotherapy (RT) or chemoradiotherapy (CRT) may require emergency department evaluation or hospitalization. Early identification may direct preventative supportive care, improving outcomes and reducing health care costs. We developed and evaluated a machine learning (ML) approach to predict these events.

METHODS

A total of 8,134 outpatient courses of RT and CRT from a single institution from 2013 to 2016 were identified. Extensive pretreatment data were programmatically extracted and processed from the electronic health record (EHR). Training and internal validation cohorts were randomly generated (3:1 ratio). Gradient tree boosting (GTB), random forest, support vector machine, and least absolute shrinkage and selection operator logistic regression approaches were trained and internally validated based on area under receiver operating characteristic (AUROC) curve. The most predictive ML approach was also evaluated using only disease- and treatment-related factors to assess predictive gain of extensive EHR data.

RESULTS

All methods had high predictive accuracy, particularly GTB (validation AUROC, 0.798). Extensive EHR data beyond disease and treatment information improved accuracy (delta AUROC, 0.056). A Youden-based cutoff corresponded to validation sensitivity of 81.0% (175 of 216 courses with events) and specificity of 67.3% (1,218 of 1811 courses without events). Interpretability is an important advantage of GTB. Variable importance identified top predictive factors, including treatment (planned RT and systemic therapy), pretreatment encounters (emergency department visits and admissions in the year before treatment), vital signs (weight loss and pain score in the year before treatment), and laboratory values (albumin level at weeks before treatment).

CONCLUSION

ML predicts emergency visits and hospitalization during cancer therapy. Incorporating predictions into clinical care algorithms may help direct personalized supportive care, improve quality of care, and reduce costs. A prospective trial investigating ML-assisted direction of increased clinical assessments during RT is planned.

Radiation Therapy for Pancreatic Cancer: Executive Summary of an ASTRO Clinical Practice Guideline

PURPOSE

This guideline systematically reviews the evidence for treatment of pancreatic cancer with radiation in the adjuvant, neoadjuvant, definitive, and palliative settings and provides recommendations on indications and technical considerations.

METHODS AND MATERIALS

The American Society for Radiation Oncology convened a task force to address 7 key questions focused on radiation therapy, including dose fractionation and treatment volumes, simulation and treatment planning, and prevention of radiation-associated toxicities. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

The guideline conditionally recommends conventionally fractionated or stereotactic body radiation for neoadjuvant and definitive therapy in certain patients and conventionally fractionated regimens for adjuvant therapy. The task force suggests a range of appropriate dose-fractionation schemes and provides recommendations on target volumes and sequencing of radiation and chemotherapy. Motion management, daily image guidance, use of contrast, and treatment with modulated techniques are all recommended. The task force supported prophylactic antiemetic medication, and patients may also benefit from medications to reduce acid secretion.

CONCLUSIONS

The role of radiation in the management of pancreatic cancer is evolving, with many ongoing areas of active investigation. Radiation therapy is likely to become even more important as new systemic therapies are developed and there is increased focus on controlling local disease. It is important that the nuances of available data are discussed with patients and families and that care be coordinated in a multidisciplinary fashion.

Hypofractionated Image-Guided Radiation Therapy With Simultaneous-Integrated Boost Technique for Limited Metastases: A Multi-Institutional Analysis

Purpose: To perform a multi-institutional analysis following treatment of limited osseous and/or nodal metastases in patients using a novel hypofractionated image-guided radiotherapy with simultaneous-integrated boost (HIGRT-SIB) technique.

Methods: Consecutive patients treated with HIGRT-SIB for ≤5 active metastases at Duke University Medical Center or Durham Veterans' Affairs Medical Center between 2013 and 2018 were analyzed to determine toxicities and recurrence patterns following treatment. Most patients received 50 Gy to the PTV_boost and 30 Gy to the PTV_elect simultaneously in 10 fractions. High-dose treatment volume recurrence (HDTVR) and low-dose treatment volume recurrence (LDTVR) were defined as recurrences within PTV_boost and PTV_elect, respectively. Marginal recurrence (MR) was defined as recurrence outside PTV_elect, but within the adjacent bone or nodal chain. Distant recurrence (DR) was defined as recurrences not meeting HDTVR, LDTVR, or MR criteria. Freedom from pain recurrence (FFPR) was calculated in patients with painful osseous metastases prior to HIGRT-SIB. Outcome rates were estimated at 12 months using the Kaplan-Meier method.

Results: Forty-two patients met inclusion criteria with 59 sites treated with HIGRT-SIB (53% nodal and 47% osseous). Median time from diagnosis to first metastasis was 31 months and the median age at HIGRT-SIB was 69 years. The most common primary tumors were prostate (36%), gastrointestinal (24%), and lung (24%). Median follow-up was 11 months. One acute grade ≥3 toxicity (febrile neutropenia) occurred after docetaxel administration immediately following HIGRT-SIB. Four patients developed late grade ≥3 toxicities: two ipsilateral vocal cord paralyzes and two vertebral compression fractures. The overall pain response rate was 94% and the estimated FFPR at 12 months was 72%. The estimated 12 month rate of HDTVR, LDTVR, MR, and DR was 3.6, 6.2, 7.6, and 55.8%, respectively. DR preceded MR, HDTVR, or LDTVR in each instance. The estimated 12 month probability of in-field and marginal control was 90.0%.

Conclusion: Targeting areas at high-risk for occult disease with a lower radiation dose, while simultaneously boosting gross disease with HIGRT in patients with limited osseous and/or nodal metastases, has a high rate of treated metastasis control, a low rate of MR, acceptable toxicity, and high rate of pain palliation. Further investigation with prospective trials is warranted.

Role of pelvic chemoradiation therapy in patients with initially metastatic anal canal cancer: A National Cancer Database review

BACKGROUND

Although the management of localized anal canal squamous cell carcinomas is well established, the role of pelvic chemoradiation (CRT) in the treatment of patients presenting with synchronous metastatic (stage IV) disease is poorly defined. This study used a national cancer database to compare the overall survival (OS) rates of patients with synchronous metastatic disease receiving CRT to the pelvis and patients treated with chemotherapy (CT) alone.

METHODS

This study included adult patients with anal canal squamous cell carcinomas presenting with synchronous metastases diagnosed from 2004 to 2012. Multiple imputation and 2:1 propensity score matching were used to create a matched data set for testing. The proportional hazards model was used to estimate the hazard ratio (HR) for the effect of the treatment group on OS. With only patients in the matched data set, the OS of the treatment groups was estimated with the Kaplan-Meier method by treatment group.

RESULTS

This study started with an unmatched data set of 978 patients, and 582 patients were selected for the matched data set: 388 in the CRT group and 194 in the CT-alone group. The HR for the group effect was 0.75 (95% confidence interval [CI], 0.61-0.92; P = .006). The median OS was 21.1 months in the CRT group (95% CI, 17.4-24.0 months) and 14.6 months in the CT group (95% CI, 12.2-18.4 months). The corresponding 5-year OS rates were 23% (95% CI, 18%-28%) and 14% (95% CI, 7%-21%), respectively.

CONCLUSIONS

In this large series analyzing OS in patients with stage IV anal cancer, CRT was associated with improved OS in comparison with CT alone. Because of the lack of prospective data in this setting, this evidence will help to guide treatment approaches in this group of patients.

Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma: Current State and Future Opportunities

Hepatocellular carcinoma is a rising cause of morbidity and mortality in the USA and around the world. Surgical resection and liver transplantation are the preferred management strategies; however, less than 30% of patients are eligible for surgery. Stereotactic body radiation therapy is a promising local treatment option for non-surgical candidates. Local control rates between 95 and 100% have been reported at 1-2 years post-treatment, and classical radiation-induced liver disease described with conventional radiation is an unlikely complication from stereotactic radiotherapy. Enrollment in randomized trials will be essential in establishing the role of stereotactic radiation in treatment paradigms for hepatocellular carcinoma.

Multi-institutional analysis of synchronous prostate and rectosigmoid cancers

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Background: Synchronous prostate cancer (PC) and rectosigmoid (RS) cancer (RSC) is a challenging clinical situation. Methods: A retrospective review of Duke University and Durham VA charts was performed for men with adenocarcinomas of the prostate and RS colon from 1988-2017. Synchronous presentation was defined as symptoms, diagnosis (dx), or treatment (tx) of PC/RSC within 12 months. The primary endpoint was overall survival (OS), calculated from latest dx date. Univariate and multivariate (MVA) Cox regression was performed using STATA 15.1. Results: Among 31,883 men with PC identified, 330 (1%) also had RSC. 54 (16%) were considered synchronous (median age 67, IQR 62-72). PC was more commonly the first dx (59%), and 15 (28%) underwent prostatectomy (n=13) or radiotherapy (RT, n=2) before a dx of synchronous RSC. 26%, 57%, and 17% had stage I, II-III, and IV RSC, respectively. Prostatectomy, LAR, APR, and combined surgery for both PC/RSC was performed in 17 (31%), 24 (44%), 10 (19%), and 2 (4%) men, respectively. 35 (65%) received RT with median RS dose of 50.4 Gy (IQR 50.4-54 Gy) and prostate boost to 66 Gy (IQR 61-72 Gy). 34 (63%) received 5-FU based chemotherapy, 23 (43%) received ADT, and 9 (17%) received no PC-specific tx. After a median follow up of 43 (IQR 21-93) months, there were 34 deaths: 18 (53%) due to RSC, 2 (6%) due to PC, 3 (9%) due to grade 5 toxicity, 7 (21%) due to another malignancy, and 4 (12%) due to unknown cause without recurrence. Grade 5 toxicities resulted from sequential hepatectomy/LAR, combined prostatectomy/APR, and myocardial infarction while on ADT. Crude late grade ≥3 toxicities include 9 (17%) GI and 6 (11%) GU. Two anastomotic leaks <2.3 years after LAR occurred in men who received neoadjuvant prostate RT boost of 70.6-76.4 Gy. Stages II-III (HR 4.3, p=0.02) and IV (HR 16, p<0.01) for RSC but only stage IV (HR 31, p<0.01) for PC were significantly associated with OS on MVA. Among 30 men with stage II-III RSC and non-metastatic PC, 5-FU based chemotherapy (HR 0.34, p=0.04) but no PC-specific tx was significantly associated with OS on MVA. Conclusions: Synchronous RSC is a greater contributor to mortality than PC. Men aged ≥50 with localized PC should undergo colorectal cancer screening prior to tx to evaluate for synchronous RSC.