Pancreas sbrt

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BACKGROUND AND PURPOSE: Chemotherapy followed by margin-negative resection (R0) is the treatment of choice for patients with localized pancreatic ductal adenocarcinoma (PDAC). Neoadjuvant multiagent chemotherapy (MAC) or MAC then radiotherapy (RT) may optimize surgical candidacy. The purpose of this study was to compare pathologic outcomes of MAC followed by conventionally fractionated radiotherapy (CRT) versus stereotactic body radiotherapy (SBRT) for patients with resected PDAC. METHODS: Patients diagnosed with nonmetastatic PDAC between 2012 and 2017 and who received preoperative MAC or MAC+RT were identified in the National Cancer Database...

BACKGROUND: Localized pancreatic adenocarcinoma carries a poor prognosis even after aggressive therapy. Up to 40% of patients may develop locoregional disease as the first site of failure. As such, there may be a role for intensification of local therapy such as radiation therapy. Radiation dose escalation for pancreatic cancer is limited by proximity of the tumor to the duodenum. However, the duodenum is removed during Whipple procedure, allowing the opportunity to dose escalate with intraoperative radiation therapy (IORT)...

Pancreas cancer has a poor prognosis despite aggressive treatment and is the fourth leading cause of cancer death in the United States. At diagnosis, most patients have either metastatic or locally advanced disease. In this article, we review the evolution of treatments in locally advanced pancreas cancer (LAPC) and discuss the various radiation therapy fractionation schemes. Furthermore, we examine the data supporting dose escalation and the delivery of ablative biologically effective doses in the setting of LAPC...

Objective: The objectives of this study were to evaluate whether dose to the vasculature is associated with local control after surgery in patients with borderline resectable (BLR) and resectable pancreatic cancer (PCA) receiving neoadjuvant radiation therapy (RT) and to identify a dose threshold for clinical use. Methods: Patients with BLR and resectable PCA treated with neoadjuvant RT were retrospectively reviewed. During this period, the institutional paradigm shifted from standard fractionation to hypofractionation/stereotactic body radiation therapy (SBRT)...

Background: Induction chemotherapy (iC) followed by concurrent chemoradiation has been shown to improve overall survival (OS) for locally advanced pancreatic cancer (LAPC). However, the survival benefit of stereotactic body radiation therapy (SBRT) versus conventionally fractionated radiation therapy (CFRT) following iC remains unclear. Methods: The National Cancer Database (NCDB) was queried for primary stage III, cT4N0-1M0 LAPC (2004-2015). Kaplan-Meier analysis, Cox proportional hazards method, and propensity score matching were used...

BACKGROUND: Magnetic resonance-guided radiotherapy (MRgRT) utilization is rapidly expanding, driven by advanced capabilities including better soft tissue imaging, continuous intrafraction target visualization, automatic triggered beam delivery, and the availability of on-table adaptive replanning. Our objective was to describe patterns of 0.35 Tesla (T)-MRgRT utilization in Europe and Asia among early adopters of this novel technology. METHODS: Anonymized administrative data from all 0...

BACKGROUND: In clinical practice, the organs at risk (OARs) should be carefully determined when performing pancreatic stereotactic body radiotherapy (SBRT). We conducted a simulation study to examine the effect of the stomach size on the radiation dose to the OARs when performing pancreatic SBRT. METHODS: Twenty-five cases were included in this study. Pancreatic head and body tumors were 2-cm-sized pseudotumors, which were included as gross target volume (GTV) contours...

The increased adoption of stereotactic body radiation therapy (SBRT) has allowed for delivery of higher doses, potentially associated with better outcomes, but at the risk of higher toxicity. The intimate association of radiosensitive organs at risk (e.g., stomach, duodenum, bowel) has historically limited the delivery of ablative doses to the pancreas. The advent of MR-guided radiotherapy with improved soft tissue contrast allows for gated delivery without an internal target volume (ITV) and online adaptive replanning to maximize the therapeutic ratio...

PURPOSE: The purpose of this critical review is to provide an overview of the role and outcomes associated with the use of local therapy for patients with oligometastatic gastrointestinal cancers. METHODS AND MATERIALS: A review of clinical data was performed to describe outcomes associated with the use of systemic therapy and/or locoregional therapies for patients with oligometastatic gastrointestinal cancers including esophagus, gastric, liver, biliary, pancreas, colorectal, and anal canal...

Purpose: To determine the dosimetric impact of using unedited autocontours in daily plan adaptation of patients with locally advanced pancreatic cancer (LAPC) treated with stereotactic body radiotherapy using tumor tracking. Materials and Methods: The study included 98 daily CT scans of 35 LAPC patients. All scans were manually contoured (MAN), and included the PTV and main organs-at-risk (OAR): stomach, duodenum and bowel. Precision and MIM deformable image registration (DIR) methods followed by contour propagation were used to generate autocontour sets on the daily CT scans...

Purpose: The purpose of this work is to explore delta-radiomics texture features for predicting response using setup images of pancreatic cancer patients treated with magnetic resonance image guided (MRI-guided) stereotactic ablative radiotherapy (SBRT). Methods: The total biological effective dose (BED) was calculated for 30 patients treated with MRI-guided SBRT that delivered physical doses of 30-60 Gy in three to five fractions. Texture features were then binned into groups based upon BED per fraction by dividing BED by the number of fractions...

We present the update of the recommendations of the French society of oncological radiotherapy on radiotherapy of pancreatic tumors. Currently, the use of radiation therapy for patients with pancreatic cancer is subject to discussion. In the adjuvant setting, the standard treatment is six months of chemotherapy with 5-fluorouracile, irinotecan and oxaliplatin. Chemoradiation may improve the survival of patients with incompletely resected tumours (R1). This remains to be confirmed by a prospective trial. Neoadjuvant chemoradiation is a promising treatment especially for patients with borderline resectable tumours...

BACKGROUND: Artificial intelligence (AI) based radiotherapy treatment planning tools have gained interest in automating the treatment planning process. It is essential to understand their overall robustness in various clinical scenarios. This is an existing gap between many AI based tools and their actual clinical deployment. This study works to fill the gap for AI based treatment planning by investigating a clinical robustness assessment (CRA) tool for the AI based planning methods using a phantom simulation approach...

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...

PURPOSE/OBJECTIVE(S): Artificial intelligence (AI) driven tools have been maturing in automating the radiation treatment planning process. To prepare for clinical deployment of these tools, it is essential to understand their robustness in clinical scenarios. This study works to fill the existing gap between research initiated and clinically ready AI tools by investigating a clinical assessment approach based on phantom design and planning complexity simulation. The hypothesis is that AI tool assessment program provides more clinically relevant and comprehensive evaluations beyond typical model validation studies...

PURPOSE/OBJECTIVE(S): We hypothesized that escalated biological effective dose (BED) via stereotactic body radiation therapy (SBRT) would improve outcomes for patients with borderline resectable (BRPC) and locally advanced pancreatic cancer (LAPC). MATERIALS/METHODS: A retrospective review was performed on consecutive patients who received pancreas SBRT from June 2009 to June 2020, were non-metastatic at the time of SBRT, received neoadjuvant chemotherapy, and had available gross tumor volume (GTV) dosimetry...

PURPOSE/OBJECTIVE(S): The optimal treatment for unresectable pancreatic cancer remains unclear, as patients with locally advanced pancreatic cancer (LAPC) have poor outcomes despite aggressive therapies. Due to these poor outcomes, there has been interest in advanced techniques for definitive radiation, and robust literature has emerged for the definitive irradiation of LAPC, including photon-based techniques such as SBRT and IMRT/VMAT, proton, and carbon-ion irradiation. Despite promising early results, there are few advanced-stage clinical trials comparing these modalities...

PURPOSE/OBJECTIVE(S): To report on our early experience of treating patients with pancreas ductal adenocarcinoma (PDAC) with ablative SBRT (50 Gy in 5 fractions) on the Elekta Unity MR-Linac. MATERIALS/METHODS: Ten PDAC patients were treated with abdominal compression (AC) and daily online plan adaptation using Adapt-to-Shape (ATS) workflow. AC is the method of choice to reduce breathing motion since automatic breath-hold/gating or other motion management options are not yet available on Unity MR-Linac...

PURPOSE/OBJECTIVE(S): Magnetic Resonance Image-guided Adaptive Radiation Therapy (MRgART) is ideal for intra-abdominal tumors as it accounts for daily anatomical changes in target volumes and nearby organs at risk (OAR) caused by soft-tissue deformation, respiration, organ filling/emptying and patient weight changes. The dosimetric gains associated with MRgART may be undermined by longer treatment times, resulting in unaccounted for intra-fractional OAR changes and patient motion. In this study, we aim to evaluate each step in our MRgART workflow for optimal resource utilization and potential treatment time savings...