Applying The IORT Technique to a Pancreatic Cancer Case
Experts from Vanderbilt University Medical Center discuss the use of intraoperative radiation therapy in a 64-year-old patient with pancreatic cancer.
Kamran Idrees, MD, MSCI, MMHC, FACS, and Natalie A. Lockney, MD, spoke with CancerNetwork® about how they incorporated intraoperative radiation therapy (IORT) into a treatment regimen for a patient with pancreatic cancer at their institution.
Lockney, an assistant professor in radiation oncology and the program director for the radiation oncology medical residency at Vanderbilt University Medical Center, first highlighted prior data supporting the use of IORT in this patient population. Afterward, she and Idrees, the chief of the Division of Surgical Oncology & Endocrine Surgery, an associate professor of surgery, an Ingram Associate Professor of Cancer Research, and director of Pancreatic and Gastro-Intestinal Surgical Oncology at Vanderbilt University Medical Center, reviewed the treatment methods and outcomes of a case involving a 64-year-old patient.
Transcript:
Lockney:
To talk a little bit about the data for intraoperative radiation therapy, we know that [since the] 1980s, there have been over 30 published retrospective articles [showing] what’s been found. We know more contemporary data available from Mayo Clinic1 and Massachusetts General Hospital,2 where the local control after IORT has been reported to be in the range of 73% to 94%, with overall survival ranging from 23 to 35 months. We look forward to the completion of an ongoing, single-arm, prospective phase 2 trial that’s called the PACER trial [NCT03716531]. It’s being run out of Massachusetts General Hospital, led by Theodore Sunki Hong, MD. It’s looking at delivering intraoperative radiation in [patients with] pancreatic cancer who have either borderline resectable or unresectable disease with an intraoperative radiation therapy boost following standard preoperative radiation therapy.
It’s also important to note that we do have some guidelines available for the delivery of intraoperative radiation for pancreatic cancer. ESTRO, which is the European Society for Radiotherapy and Oncology, has an advisory committee for radiation oncology practice, and their task force published guidelines in 2020 recommending the use of IORT in certain settings for borderline resectable or unresectable pancreatic cancer.3
Idrees [will] show you through one of our recent patient cases.
Idrees:
Here’s a patient who was evaluated here at the Vanderbilt Ingram Cancer Center in our multidisciplinary pancreas clinic. She is a 64-year-old woman who had biopsy-proven pancreatic cancer in the body and neck of the pancreas. The cross-sectional imaging here shows the involvement of the celiac axis, the common hepatic artery, as well as the splenic artery along with the portal venous involvement. When we reviewed the patient’s case, we recommended that she should undergo neoadjuvant chemotherapy.
She received 12 cycles of modified leucovorin calcium, fluorouracil, irinotecan hydrochloride, and oxaliplatin [FOLFIRINOX] treatment followed by a restaging CT scan of her chest, abdomen, and pelvis, which revealed no evidence of distant metastases, but [there was] still involvement of the key blood vessels. At that time, she was evaluated by Lockney, and the multidisciplinary pancreas clinic recommendation was that she should undergo concurrent chemoradiation therapy. She underwent 50.4 Gy for the 8 fractions of radiation with capecitabine [Xeloda]. On subsequent follow-up imaging, she did not have any evidence of disease, and at that time, we recommended surgical resection with intraoperative radiation therapy.
We took her to the operating room and performed a diagnostic laparoscopy to ensure that she did not have any evidence of distant metastases, and once we did not see any disease, we proceeded with what we call a modified Appleby procedure. She underwent a subtotal distal pancreatectomy with removal of her spleen and en-bloc resection of her celiac axis and common hepatic artery. We also resected her portal vein where it was involved, which was primarily repaired. She then subsequently underwent intraoperative radiation therapy where my partner Lockney and our radiation physicist team performed radiation therapy to the tumor resection bed, celiac artery stump, and the aorta.
Lockney:
In the operating room, we determined an area at risk of about 5 cm, so we chose a 6-cm applicator with a 0° bevel. Here, you can see our prescription dose was 12.5 Gy. We had a 5 mm bolus with a tissue depth of 1 cm. Here at this curve, you can see that we’re delivering our prescription dose in this range, but by the time we get to a depth of approximately 3 cm, we have the dose fall off. [For] those underlying tissues—critical organs such as the spinal cord—we expect to get a negligible dose.
Idrees:
Her final pathology revealed that she had a residual invasive tumor, which was 1 cm in size in the [largest] fibrotic tissue bed. All her margins were negative, and her final pathological stage was ypT1cN0M0. All 31 of her lymph nodes that we procured at the time of surgery did not have any evidence of involvement. She has been disease-free for 14 months; she did not receive any adjuvant therapy. There’s no evidence of radiographic recurrence at this point.
References
- Ashman JB, Moss AA, Rule WG, et al. Preoperative chemoradiation and IOERT for unresectable or borderline resectable pancreas cancer. J Gastrointest Oncol. 2013;4(4):352-60. doi:10.3978/j.issn.2078-6891.2013.006.
- Keane FK, Wo JY, Ferrone CR, et al. Intraoperative radiotherapy in the era of intensive neoadjuvant chemotherapy and chemoradiotherapy for pancreatic adenocarcinoma. Am J Clin Oncol. 2018;41(6):607-612. doi:10.1097/COC.0000000000000336.
- Calvo FA, Asencio JM, Roeder F, et al. ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy in borderline-resected pancreatic cancer. Clin Transl Radiat Oncol. 2020;23:91-99. doi:10.1016/j.ctro.2020.05.005.
