Pancreatic sbrt

PURPOSE/OBJECTIVE(S): Accurate measurement of daily target motion on online plan adaptation is essential for re-optimizing the internal target volume (ITV) margins. In this study, by analyzing 2D cine MR images acquired in a 1.5T MR-Linac, we assessed daily target motion and its inter-fractional variations, which is then used to customize ITV margins for MR-based online adaptive plan of liver and pancreatic stereotactic body radiotherapy (SBRT). MATERIALS/METHODS: Twenty-threepatients, enrolled in this study, underwent MR-guided online adaptive SBRT on 1...

PURPOSE/OBJECTIVE(S): Stereotactic magnetic resonance guided on-table adaptive radiotherapy (SMART) is an increasingly utilized radiotherapy (RT) treatment for locally advanced pancreatic cancer (LAPC), providing improved local control and overall survival with reduced toxicity. Computed tomography (CT) guided RT options include stereotactic body radiotherapy (SBRT) and hypofractionated RT with volumetric modulated arc therapy (VMAT). Currently there are no financial comparisons for MR vs CT-guided RT for LAPC...

PURPOSE/OBJECTIVE(S): The purpose of this study was to determine if mutations in biological pathways are associated with clinical outcomes in patients with localized pancreatic cancer who undergo neoadjuvant chemoradiation followed by surgical resection. MATERIALS/METHODS: Patients treated with neoadjuvant chemoradiation followed by oncologic resection from 2015-2019 who also underwent next generation sequencing (NGS) of the primary tumor were included in this retrospective analysis...

PURPOSE/OBJECTIVE(S): Unresectable pancreatic cancer (UPC) is associated with dismal survival outcomes, with a reported median survival of 8-12 months. The role of radiotherapy (RT) and the choice of optimal fractionation remains unclear. Our objective was analyzing the outcomes associated with local radiotherapy as well as determine the best radiotherapeutic approach to treat these patients. MATERIALS/METHODS: From a database of 209 radiation plans of patients treated for pancreatic cancer in a single institution between August 2007 to August 2021, patients with UPC were selected for this REB approved retrospective study...

PURPOSE/OBJECTIVE(S): Local treatment options for patients with locally recurrent pancreatic adenocarcinoma (L-PAC) are limited, with expected median survival time (MST) of 8-11 months (mo) following recurrence. MRI-guided radiation therapy (MRgRT) provides the ability to dose escalate while sparing normal tissue. The literature for MR-guided Stereotactic Body Radiotherapy (MRgSBRT) for L-PAC is sparse. Here we report on the early outcomes of MRgSBRT in patients with L-PAC. MATERIALS/METHODS: Patients with prior resection of pancreatic adenocarcinoma with post-operative chemotherapy as indicated followed by local recurrence of disease at prior surgical site and treated with MRgSBRT at a single tertiary referral center from 5-2021 to 8-2022 for L-PAC were identified from our prospective database...

PURPOSE/OBJECTIVE(S): The role of radiation for pancreatic cancer remains controversial, with recent studies showing conflicting results, highlighting the need to develop biomarkers of radiation response. Despite its potential utility in predicting radiosensitivity, the landscape of somatic mutations in borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC), as related to DNA damage response (DDR), has not been well characterized. This study aimed to characterize the frequency of such mutations in a cohort of patients with BRPC/LAPC treated with neoadjuvant chemotherapy and stereotactic body radiotherapy (SBRT)...

PURPOSE/OBJECTIVE(S): The role of pre-operative radiation therapy (RT) for localized pancreatic ductal adenocarcinoma (PDAC) with peri-pancreatic vascular involvement remains controversial, with two recent randomized controlled trials, namely PREOPANC-1 and Alliance A021501, showing conflicting results. Opponents of pre-operative radiation point towards the unclear oncologic benefit and potential added toxicity. While hemorrhage from a pseudoaneurysm (PsA) rupture is a known rare but potentially fatal complication after pancreaticoduodenectomy (PD), with published incidence rates of around 2 to 5%, it has been increasingly common in the pancreatic cancer surgical community for pre-operative RT to be cited as a risk factor for PsA development, despite the absence of data supporting this notion...

PURPOSE/OBJECTIVE(S): A previous analysis on an institutional cohort of LAPC patients, treated with intensive induction chemotherapy followed by SBRT, proved that local failures (LFs) predominantly occurred within the RT field. This suggests a specific efficacy of a complete covering of the macroscopic (GTV) aggressive disease with high doses (i.e., simultaneous boost [SIB] doses). Still, this is often not feasible due to the proximity of extremely radiosensitive organs at risk (OARs), which forces the use of "Simultaneous Integrated Protection" (SIP), limiting the dose to safe values in a portion of the GTV...

PURPOSE/OBJECTIVE(S): MR-guided SBRT with a 1.5 T MR-Linac is a relatively new therapy for pancreatic tumors with varying expertise levels. Moreover, treatment planning in the upper abdomen can be challenging as target coverage is often compromised by dosimetric constraints of abutting bowel structures. This may lead to large differences between centers in protocols, practices. To increase harmonization a worldwide consortium was founded among 1.5 T MR-Linac users. In this work we report on the outcome of the first phase within this collaboration, which is the assessment of the baseline variation between the treatment planning protocols and subsequent dose distributions...

PURPOSE/OBJECTIVE(S): CT-guided SBRT for locally advanced pancreatic cancer (LAPC) is usually non-ablative (BED < 100 Gy10 ) to minimize grade 3+ toxicity risks given the concern of interfraction anatomic changes (IACs) in GI anatomy and imaging quality associated with kV-CBCT. Emerging data demonstrate that MR guidance facilitates 5-fraction (fx) dose escalation due to superior soft tissue contrast, continuous intrafraction imaging, automatic beam gating, and on-table adaptive replanning capability...

PURPOSE/OBJECTIVE(S): Stereotactic body radiation therapy (SBRT) to patients with inoperable pancreas cancer has shown promising outcomes. Dose escalation is challenging given the associated risks to nearby organs at risk and requires treatment plan adaptation and motion management. This study reports the treatment related adverse events and treatment outcomes of MRI-guided SBRT utilizing gated-real time online adaptive radiotherapy to patients with pancreatic tumors. MATERIALS/METHODS: This is a single institution retrospective IRB approved study and included patients with pancreatic tumors who were treated with MRI-guided SBRT utilizing gated-real time online adaptive radiotherapy, consecutively between 2019 and 2022...

PURPOSE/OBJECTIVE(S): The optimal neoadjuvant therapy regimen for patients with borderline resectable pancreas cancer (BRPC) remains to be defined, with a recent ALLIANCE study reporting that chemotherapy alone prior to resection is an acceptable standard of care. However, pathologic differences in response between patients receiving chemotherapy alone and chemotherapy with radiation with stereotactic technique is not clear. In this study, we sought to compare differences in pathologic outcomes between patients undergoing surgery in 2018 compared with 2021 at our comprehensive cancer center, after the new data of chemotherapy alone had been reported and after our center integrated stereotactic MRI guided online adaptive radiotherapy (SMART)...

PURPOSE/OBJECTIVE(S): It is now widely accepted that radiotherapy, especially hypofractionated radiation therapy (HFRT) or stereotactic radiotherapy (SBRT), can modulate tumor phenotypes, enhance antigen presentation and provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). The PRaG therapy is an innovative iRT, when combined with HFRT/SBRT, PD-1/L1 inhibitor and GM-CSF to activate the immune response and modulate the tumor microenvironment to exert the desired in abscopal effect...

PURPOSE/OBJECTIVE(S): Stereotactic body radiation therapy (SBRT) offers an important treatment option for metastatic liver tumors. The introduction of magnetic resonance (MR) guided SBRT has paved the way for optimal tumor visualization and daily plan adaptation. The purpose of this study is to review tolerability of MR-guided SBRT of liver metastases and to present early toxicity and quality of life outcomes. MATERIALS/METHODS: All patients with liver metastases who were treated on a 1...

PURPOSE/OBJECTIVE(S): SBRT for pancreatic ductal adenocarcinoma (PDAC) is routinely delivered with non-ablative dose to only gross disease resulting in locoregional failure (LRF) rates of >50%, most commonly near the celiac artery (CA) and/or superior mesenteric artery (SMA). It is unclear whether an alternative approach of prescribing ablative dose to gross disease plus elective coverage prevents and/or delays LRF. The study objective was to describe the incidence and anatomic distribution of LRF using this treatment approach...

PURPOSE/OBJECTIVE(S): In patients with borderline resectable or locally advanced pancreatic adenocarcinoma (BRPC/LAPC), advances in neoadjuvant therapy have led to an increased proportion of patients undergoing margin negative resection. Nevertheless, locoregional recurrence rates remain high. We have previously reported that the location of locoregional recurrences in this setting map to the "Triangle Volume (TV)," the anatomical space between the celiac artery, superior mesenteric artery, common hepatic artery, and portal vein, which is enriched in extrapancreatic perineural tracts at risk for microscopic residual disease after resection...

Background: The dose distribution in different optimization algorithm plans of stereotactic radiotherapy (SBRT) for locally advanced pancreatic cancer (LAPC) were compared and analyzed using monte carlo dose calculate algorithm (MC). Methods: A retrospective study analyzed 26 LAPC patients treated with SBRT. The SBRT plans were designed by raytracing (RT) and fine size pencil beam (FSPB) algorithms in the CyberKnife (CK) precision system, all of which met the requirements of clinical target dose and organ at risk (OAR)...

Pancreatic Cancer is associated with poor treatment outcomes compared to other cancers. High local control rates have been achieved by using hypofractionated stereotactic body radiotherapy (SBRT) to treat pancreatic cancer. Challenges in delivering SBRT include close proximity of several organs at risk (OARs) and target volume inter and intra fraction positional variations. Magnetic resonance image (MRI) guided radiotherapy has shown potential for online adaptive radiotherapy for pancreatic cancer, with superior soft tissue contrast compared to CT...

BACKGROUND: YKL-40, also known as chitinase-3-like protein 1 (CHI3L1), is a secreted glycoprotein produced by various cell types including stromal, immune, and cancer cells. It contributes to cancer progression through tumor-promoting inflammation and has been shown to inhibit the cytotoxicity of T and NK lymphocytes. In vivo studies have demonstrated synergistic anti-cancer effects of blocking YKL-40 in combination with immune checkpoint inhibitors (ICIs). Biomarkers for the prediction of the response to ICIs are highly needed...

BACKGROUND: For patients with pancreatic ductal adenocarcinoma (PDAC), surgical resection remains the only potentially curative treatment. Surgery is generally followed by postoperative chemotherapy associated with improved survival, yet neoadjuvant therapy is a rapidly emerging concept requiring to be explored and validated in terms of treatment options and oncological outcomes. In this context, stereotactic body radiation (SBRT) appears feasible and can be safely integrated into a neoadjuvant chemotherapy regimen of modified FOLFIRINOX (mFFX) with promising benefits in terms of R0 resection, local control and survival...