Radiation in Pancreatic Cancer: ASTRO Updates Its Guidance

Updated guidance from the American Society for Radiation Oncology (ASTRO) gives radiation therapy a more clearly defined and, in some cases, broader role in pancreatic cancer, reflecting both new clinical trial data and advances that allow clinicians to deliver radiation more precisely while protecting nearby organs. Since ASTRO published its previous guideline in 2019, the evidence base for radiation therapy in pancreatic cancer has changed substantially, with several important randomized trials supporting more definitive roles for radiation therapy in various clinical scenarios, Daniel Chang, MD, chair of the guideline task force and professor and chair of radiation oncology at the University of Michigan, Ann Arbor, told Medscape Medical News. Overall, “as systemic therapy improves, patients are living longer, and local disease control methods are becoming increasingly important,” said William A. Hall, MD, professor and chair of radiation oncology at the Medical College of Wisconsin, Milwaukee. Hall noted that the updates do not represent a dramatic shift in contemporary practice but rather summarize and formalize evidence that has already been incorporated into current practice patterns. The new clinical guideline, published online this month in Practical Radiation Oncology, is based on a systematic review of 166 studies, with the literature search updated through June 16, 2026, to capture potentially practice-changing studies published during guideline development. A multidisciplinary task force addressed a range of key questions, including indications for radiation therapy in nonmetastatic, metastatic, reirradiation, and palliative settings as well as optimal dosing and target volumes across different stages. Task force members, which included radiation, medical, and surgical oncologists, as well as a radiation oncology resident, medical physicist, and patient representative, indicated their level of agreement on each recommendation from “strongly agree” to “strongly disagree.” One of the most consequential changes from the 2019 guideline, Chang said, is the strong recommendation for preoperative radiation or chemoradiation therapy for borderline resectable pancreatic cancer to help improve local control and increase the possibility of a margin-negative resection. The recommendation is supported by randomized data, including the PREOPANC trial, which showed improved 5-year overall survival with neoadjuvant gemcitabine-based chemoradiotherapy vs upfront surgery in patients with resectable or borderline resectable disease. The guideline also recognizes that the optimal role and sequence of radiation or chemoradiation with modern multiagent chemotherapy remains an area of ongoing investigation. Another significant change is the strong recommendation for chemoradiation or radiation after multiagent chemotherapy for locally advanced pancreatic cancer, including dose escalation when appropriate image guidance and motion management are available. The recommendation reflects evidence that radiation can improve local control, along with emerging evidence supporting dose escalation with modern radiation techniques, though randomized trials of conventional-dose chemoradiation did not show an overall survival benefit. Adaptive radiation therapy is also now recommended when delivering dose-escalated stereotactic body radiation therapy (SBRT) to account for day-to-day changes in the relationship between the tumor and adjacent organs. "This is clinically important because historically the radiation dose that could be safely delivered to pancreatic tumors was limited by the close proximity of the stomach and intestines,” Chang said. With modern image guidance, motion management, and adaptive radiation therapy, “patients can receive substantially higher doses while still respecting normal tissue constraints,” he added. The guidelines conditionally recommend preoperative chemoradiation for patients with resectable pancreatic cancer, although the task force notes that the role of preoperative radiation in clearly resectable disease requires further study. For patients who undergo surgery without preoperative radiation, postoperative chemoradiation following multiagent chemotherapy is conditionally recommended for those with pathologically node-negative disease. Another major change involves treatment volumes. The 2019 guideline generally focused SBRT on the visible tumor. The updated guideline now recommends elective targeting of anatomic regions at risk for microscopic disease, which include the peritumoral margin, extrapancreatic neural pathways, and regional nodal basins. “This is clinically meaningful because durable local control may depend not only on controlling the visible tumor but also on addressing microscopic disease immediately beyond it,” Chang said. The updated guideline provides recommendations for several clinical scenarios that were not as well established previously, including medically inoperable resectable disease, locoregional recurrence, reirradiation, oligometastatic and oligoprogressive disease, and palliation. For instance, for patients with resectable disease who are medically inoperable or decline surgery, the guideline recommends chemoradiation or radiation therapy following multiagent chemotherapy as definitive treatment. While this received a strong recommendation, it was based on expert opinion, not direct trial data. In oligometastatic and oligoprogressive disease, definitive-intent radiation or chemoradiation is conditionally recommended for selected patients to treat metastatic lesions and the primary tumor, if it hasn’t already received definitive local therapy. For isolated locoregional recurrence after surgery in patients who have not previously received radiation, definitive radiation or chemoradiation is recommended; reirradiation is conditionally recommended for selected patients who previously received radiation. The updated guideline also now highlights disparities in access to radiation therapy, noting that factors including age, race and ethnicity, insurance status, geography, and socioeconomic status can affect whether patients receive radiation. The task force called for improved referral pathways, greater use of multidisciplinary virtual tumor boards, and increased enrollment of older and underrepresented patients in clinical trials. “Collectively, these recommendations reflect an expanding role for radiation therapy across the pancreatic cancer disease spectrum,” Chang told Medscape Medical News. Despite the expanded recommendations, the task force emphasized that evidence remains limited for several newer applications, including dose-escalated radiation therapy, elective treatment volumes, reirradiation, and radiation therapy for oligometastatic or oligoprogressive disease. “As better technology becomes available and is established as standard of care, clinical trials can be designed using modern techniques, which can unlock higher doses of radiation and/or improved treatment-related toxicity, both of which can improve cancer outcomes,” Chang said. The guideline was developed jointly with the American Society of Clinical Oncology, European Society for Radiotherapy and Oncology, and Society of Surgical Oncology. This work had no commercial funding. Disclosures for the guideline panel are available with the published article. Hall had no relevant disclosures.