FMEA of MR-Only Treatment Planning in the Pelvis

Purpose: To evaluate the implementation of a magnetic resonance (MR)-only workflow (ie, implementing MR simulation as the primary planning modality) using failure mode and effects analysis (FMEA) in comparison with a conventional multimodality (MR simulation in conjunction with computed tomography simulation) workflow for pelvis external beam planning. Methods and Materials: To perform the FMEA, a multidisciplinary 9-member team was assembled and developed process maps, identified potential failure modes (FMs), and assigned numerical values to the severity (S), frequency of occurrence (O), and detectability (D) of those FMs. Risk priority numbers (RPNs) were calculated via the product of S, O, and D as a metric for evaluating relative patient risk. An alternative 3-digit composite number (SOD) was computed to emphasize high-severity FMs. Fault tree analysis identified the causality chain leading to the highest-severity FM. Results: Seven processes were identified, 3 of which were shared between workflows. Image fusion and target delineation subprocesses using the conventional workflow added 9 and 10 FMs, respectively, with 6 RPNs \u3e100. By contrast, synthetic computed tomography generation introduced 3 major subprocesses and propagated 46 unique FMs, 15 with RPNs \u3e100. For the conventional workflow, the largest RPN scores were introduced by image fusion (RPN range, 120-192). For the MR-only workflow, the highest RPN scores were from inaccuracies in target delineation resulting from misinterpretation of MR images (RPN = 240) and insufficient management of patient- and system-level distortions (RPN = 210 and 168, respectively). Underestimation (RPN = 140) or overestimation (RPN = 192) of bone volume produced higher RPN scores. The highest SODs for both workflows were related to changes in target location because of internal anatomy changes (conventional = 961, MR-only = 822). Conclusions: FMEA identified areas for mitigating risk in MR-only pelvis RTP, and SODs identified high-severity process modes. Efforts to develop a quality management program to mitigate high FMs are underway

A Deep Dive into Understanding Tumor Foci Classification using Multiparametric MRI Based on Convolutional Neural Network

Deep learning models have had a great success in disease classifications using large data pools of skin cancer images or lung X-rays. However, data scarcity has been the roadblock of applying deep learning models directly on prostate multiparametric MRI (mpMRI). Although model interpretation has been heavily studied for natural images for the past few years, there has been a lack of interpretation of deep learning models trained on medical images. This work designs a customized workflow for the small and imbalanced data set of prostate mpMRI where features were extracted from a deep learning model and then analyzed by a traditional machine learning classifier. In addition, this work contributes to revealing how deep learning models interpret mpMRI for prostate cancer patients stratification

A Prospective Phase II Study of Induction Carboplatin and Vinorelbine followed by Concomitant Topotecan and Accelerated Radiotherapy (ART) in Locally Advanced Non-small Cell Lung Cancer (NSCLC)

BackgroundSurvival of locally advanced/unresectable non-small cell lung cancer (NSCLC) has improved with the use of concurrent radiation and chemotherapy over the past decades, but local and distant failure remain high. In addition, a key limiting factor in combining chemotherapy with accelerated radiotherapy (ART) is severe esophagitis. We investigated the toxicity, response rate, and overall survival (OS) with induction carboplatin and vinorelbine followed by concomitant topotecan and ART in patients with locally advanced/unresectable NSCLC.MethodsIn this phase II trial, stage IIIA or IIIB NSCLC patients with a Karnofsky performance score >60 were eligible. Patients received induction carboplatin (area under the curve = 5.5) on days 1 and 22, and vinorelbine (25 mg/m2) on days 1, 8, 22, and 29. During the concurrent chemoradiation, patients received intravenous topotecan (0.5 mg/m2) on days 43 to 47, days 57 to 61, and days 71 to 75 before the morning radiotherapy (RT) fraction. RT was administered in an accelerated fashion at 2 Gy per fraction, twice daily for five consecutive days, every other week, to a cumulative dose of 60 Gy during a 5-week period.ResultsThirty-seven patients were accrued; of these, 35 were evaluable. Overall response rate was 71% (14% complete response, 57% partial response). Six of 35 (17%) patients had stable disease. Four (11%) patients progressed during treatment. At a median follow-up of 45 months for surviving patients, the median survival based on Kaplan–Meier estimates is 17.9 months. OS at 1, 2, and 3 years is 62%, 41%, and 33%, respectively. Actuarial 5-year OS is 21%. The median time to first relapse is 12.2 months (9.1–24.7 months). There were no cases of grade 3 or 4 esophagitis.ConclusionsThis combined-modality regimen yielded encouraging OS rates, with no severe esophagitis. Using four-dimensional RT treatment planning, we plan to further evaluate altered fractionation RT and chemotherapy for this group of patients

Evaluation of Practice Patterns and Outcomes after Implementing SMART for Pancreatic Cancer

Purpose/Objective(s): Stereotactic MRI-guided adaptive radiation therapy (SMART) enables safe dose escalation for locally advanced, borderline resectable, and medically inoperable pancreatic cancer and has shown favorable toxicity and survival outcomes. In late 2018, our institution commissioned SMART for these patients, making it available to all patient referrals. We wanted to review changes in our patient population and differences in clinical outcomes for patients before and after the implementation of SMART. Materials/Methods: In this IRB approved analysis, we retrospectively reviewed 167 consecutive patients from 2015-2021 with locally advanced, borderline resectable, or medically unresectable pancreatic cancer who were treated with radiation therapy. Chemoradiation (chemoRT) was defined as any 28-30 fraction radiation regimen that included concurrent chemotherapy. SMART was defined as 50 Gy over 5 consecutive daily fractions without concurrent chemotherapy. Baseline patient characteristics were compared between groups. Overall survival (OS) was evaluated by Kaplan-Meier (KM) and log-rank test. Univariate (UVA) and multivariate analysis (MVA) were also performed on multiple treatment variables. Results: Of the patients included, 58 received chemoRT (2015-2018) and 109 received SMART (2018-2021). Median follow up from time of diagnosis for the chemoRT and SMART cohorts were 53.7 months and 29.2 months respectively. Cohorts did not have significant differences in age, gender, race, T or N staging, rates of surgery or surgical margin status. Patients receiving SMART had overall worse performance (p = 0.011) including a lower percentage of PS 0 patients (22.9% vs 44.8%) and a higher percentage of PS 2+ patients (34% vs 15.5%). Similarly, the SMART patients did numerically more often have locally advanced (50% vs 43%) and medically inoperable (26% vs 21%) disease (p = 0.294). The SMART cohort did have longer neoadjuvant chemotherapy with mean of 3.5 months vs 2.3 months in the chemoRT cohort (p = 0.002). There was no OS difference between each group when measured from diagnosis (p=0.79) or from first day of radiation (p=0.2). Median survival in the chemoRT and SMART groups was 18.7 vs 17.4 months from diagnosis. When including only PS 0-1 patients, the median survival in the chemoRT and SMART groups was 18.8 vs 22.3 months (p=0.37). There was also no difference in locoregional control, distant control, or progression free survival using KM. On MVA positive prognostic factors for OS from diagnosis included ECOG \u3c2 (HR 0.54, p=0.015), increasing months of neoadjuvant chemo (HR 0.88, p=0.004) and pancreatectomy (HR 0.14, p \u3c0.001). Conclusion: Despite the fact that the patient cohort receiving radiation therapy per the SMART approach had poorer performance status compared with chemoRT, OS was not significantly different. The multidisciplinary team was highly supportive of SMART with increased patients being treated

Development and evaluation of a clinical model for lung cancer patients using stereotactic body radiotherapy (SBRT) within a knowledge-based algorithm for treatment planning

The purpose of this study was to describe the development of a clinical model for lung cancer patients treated with stereotactic body radiotherapy (SBRT) within a knowledge-based algorithm for treatment planning, and to evaluate the model performance and applicability to different planning techniques, tumor locations, and beam arrangements. 105 SBRT plans for lung cancer patients previously treated at our institution were included in the development of the knowledge-based model (KBM). The KBM was trained with a combination of IMRT, VMAT, and 3D CRT techniques. Model performance was validated with 25 cases, for both IMRT and VMAT. The full KBM encompassed lesions located centrally vs. peripherally (43:62), upper vs. lower (62:43), and anterior vs. posterior (60:45). Four separate sub-KBMs were created based on tumor location. Results were compared with the full KBM to evaluate its robustness. Beam templates were used in conjunction with the optimizer to evaluate the model\u27s ability to handle suboptimal beam placements. Dose differences to organs-at-risk (OAR) were evaluated between the plans gener-ated by each KBM. Knowledge-based plans (KBPs) were comparable to clinical plans with respect to target conformity and OAR doses. The KBPs resulted in a lower maximum spinal cord dose by 1.0 ± 1.6 Gy compared to clinical plans, p = 0.007. Sub-KBMs split according to tumor location did not produce significantly better DVH estimates compared to the full KBM. For central lesions, compared to the full KBM, the peripheral sub-KBM resulted in lower dose to 0.035 cc and 5 cc of the esophagus, both by 0.4Gy ± 0.8Gy, p = 0.025. For all lesions, compared to the full KBM, the posterior sub-KBM resulted in higher dose to 0.035 cc, 0.35 cc, and 1.2 cc of the spinal cord by 0.2 ± 0.4Gy, p = 0.01. Plans using template beam arrangements met target and OAR criteria, with an increase noted in maximum heart dose (1.2 ± 2.2Gy, p = 0.01) and GI (0.2 ± 0.4, p = 0.01) for the nine-field plans relative to KBPs planned with custom beam angles. A knowledge-based model for lung SBRT consisting of multiple treatment modalities and lesion loca-tions produced comparable plan quality to clinical plans. With proper training and validation, a robust KBM can be created that encompasses both IMRT and VMAT techniques, as well as different lesion locations

Stereotactic MRI-guided Adaptive Radiation Therapy for Non-metastatic Pancreatic Cancer; Outcomes and Toxicity Analysis for Patients Treated in an Underserved Urban Center

Background: Stereotactic MRI-guided Adaptive Radiation Therapy (SMART) is an emerging technology for treatment of pancreatic cancer patients. Initial results show favorable survival and toxicity. However, data is still sparse overall, and especially in underserved patient populations. The purpose of this study is to review SMART outcomes at our underserved urban academic cancer. Objectives: Stereotactic MRI-guided Adaptive Radiation Therapy (SMART) is an emerging technology for treatment of pancreatic cancer patients. Initial results show favorable survival and toxicity. However, data is still sparse overall, and especially in underserved patient populations. The purpose of this study is to review SMART outcomes at our underserved urban academic cancer. Methods: In this IRB approved retrospective chart review we reviewed 98 patients with non-metastatic pancreatic cancer, who completed SMART between November 2018-January 2021. All 98 patients were treated with 50 Gy in 5 daily fractions with adaptive technique as deemed appropriate by treating radiation oncologist. The primary endpoints were overall survival (OS), progression free survival (PFS), and both acute and late grade 3+ GI toxicity. OS, PFS, locoregional control and distant control were estimated by Kaplan-Meier method and compared using log-rank test. The effect of clinical features on OS was assessed using univariate and multivariate Cox proportional hazard models. OS and PFS were calculated from completion of radiation. Grade 3+ GI toxicity probably or definitively related to radiation was recorded. All incidences of GI bleeding, regardless of attribution, were also recorded. Results: Median follow up was 20.9 months from time of diagnosis and 14 months from radiation. 21 (21%) patients were borderline resectable, 42 (43%) locally advanced, 22 (22%) medically inoperable and 13 (13%) resectable. Neoadjuvant chemotherapy was given to 86 (88%) patients with a median of 3.5 months of chemotherapy (range 1-12), leaving 11 (12%) patients who did not have systemic chemotherapy. Median overall survival from radiation for the whole group was 15.7 months, and 1-year OS was 58%. There was a statistically significant worsening of overall survival from diagnosis between ECOG 2+ and ECOG 0/1 patients (HR 1.94, 1.05-3.57). 27 (27%) patients went on to have surgical resection with 23 (82%) having R0 resection, and 3 (11%) have an R1 resection. Improved OS was seen in patients with surgical resection (HR 0.06, 0.02-0.23). Acute grade 3+ GI toxicity from radiation was seen in 4 (4%) patients and late toxicity from radiation was seen in 6 (6%) patients. GI bleeding was seen in 16(16%) patients, 10 (62%) of which were on anticoagulation at the time of GI bleed and 5 (19%) of which had surgery. Portal vein complications occurred with 7 (7%) having portal vein thrombosis and 6 (6%) portal vein stenosis. Conclusions: SMART showed durable responses in pancreatic cancer patients with an acceptable toxicity profile. Attention needs to be paid to the moderate incident of GI bleeding, however further work is necessary to determine if bleeding was due to radiation, surgery, or disease progression. Surgical resection as well as performance status of ECOG 0-1 were associated with improved overall survival. Further follow up will be necessary to determine further durability of treatment response and long-term survival in these patients

Palliative thoracic radiotherapy in lung cancer: An American Society for Radiation Oncology evidence-based clinical practice guideline

AbstractPurposeTo provide guidance to physicians and patients with regard to the use of external beam radiotherapy, endobronchial brachytherapy, and concurrent chemotherapy in the setting of palliative thoracic treatment for lung cancer, based on available evidence complemented by expert opinion.Methods and MaterialsA Task Force authorized by the American Society for Radiation Oncology (ASTRO) Board of Directors synthesized and assessed evidence from 3 systematic reviews on the following topics: (1) dose fractionation in thoracic external beam radiotherapy (EBRT); (2) clinical utility of initial and salvage endobronchial brachytherapy (EBB); and (3) use of concurrent chemotherapy (CC) with palliative thoracic radiotherapy. Practice guideline recommendations were produced and are contained herein.ResultsStudies suggest that higher dose/fractionation palliative EBRT regimens (eg, 30 Gy/10 fraction equivalent or greater) are associated with modest improvements in survival and total symptom score, particularly in patients with good performance status. As these improvements are associated with an increase in esophageal toxicity, various shorter EBRT dose/fractionation schedules (eg, 20 Gy in 5 fractions, 17 Gy in 2 weekly fractions, 10 Gy in 1 fraction), which provide good symptomatic relief with fewer side effects, can be used for patients requesting a shorter treatment course and/or in those with a poor performance status. No defined role for EBB in the routine initial palliative treatment of chest disease has been demonstrated; however, EBB can be a reasonable option for the palliation of endobronchial lesions causing obstructive symptomatology including lung collapse, or for hemoptysis after EBRT failure. The integration of concurrent chemotherapy with palliative intent/fractionated radiotherapy is not currently supported by the medical literature.ConclusionThis Guideline is intended to serve as a guide for the use of EBRT, EBB, and CC in thoracic palliation of lung cancer outside the clinical trial setting. Further prospective clinical investigations with relevant palliative endpoints into the respective roles of EBB and CC/targeted therapy in the thoracic palliation of lung cancer are warranted, given the current state of the medical literature in these areas