Advances in Radiation Oncology (Nov 2021)

Stereotactic Versus Conventional Radiation Therapy for Patients With Pancreatic Cancer in the Modern Era

  • Joseph Abi Jaoude, MD,
  • Connor P. Thunshelle, BS,
  • Ramez Kouzy, MD,
  • Nicholas D. Nguyen, BA,
  • Daniel Lin, BA,
  • Laura Prakash, MD,
  • Isabela M. Bumanlag, BS,
  • Sonal S. Noticewala, MD,
  • Joshua S. Niedzielski, PhD,
  • Sam Beddar, PhD,
  • Ethan B. Ludmir, MD,
  • Emma B. Holliday, MD,
  • Prajnan Das, MD, MS, MPH,
  • Bruce D. Minsky, MD,
  • Joseph M. Herman, MD,
  • Matthew Katz, MD,
  • Albert C. Koong, MD, PhD,
  • Eugene J. Koay, MD, PhD,
  • Cullen M. Taniguchi, MD, PhD

Journal volume & issue
Vol. 6, no. 6
p. 100763

Abstract

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Purpose: Patients with pancreatic cancer often receive radiation therapy before undergoing surgical resection. We compared the clinical outcomes differences between stereotactic body radiation therapy (SBRT) and 3-dimensional (3D)/intensity-modulated radiation therapy (IMRT). Methods and Materials: We retrospectively collected data from the University of Texas MD Anderson Cancer Center. Patients with borderline resectable/potentially resectable or locally advanced pancreatic cancer receiving neoadjuvant SBRT (median, 36.0 Gy/5fx), 3D conformal radiation (median, 50.4 Gy/28 fx) or IMRT (median, 50.4 Gy/28 fx) were included. Overall survival (OS) and progression-free survival were analyzed using Cox regression. Results: In total, 104 patients were included in our study. Fifty-seven patients (54.8%) were treated with SBRT, and 47 patients (45.2%) were treated with 3D/IMRT. Patients in the SBRT group were slightly older (median age: 70.3 vs 62.7 in the 3D/IMRT group). Both groups had similar proportions of patients with locally advanced pancreatic cancer (SBRT: 30, 52.6%; 3D/IMRT: 24, 51.1%). All patients were treated with chemotherapy. Patients in the SBRT group underwent more surgical resection compared with the 3D/IMRT group (38.6% vs 23.4%, respectively). At a median follow-up of 22 months, a total of 60 patients (57.7%) died: 25 (25/57, 43.9%) in the SBRT group, and 35 (35/47, 74.5%) in the 3D/IMRT group. Median OS was slightly higher in the SBRT group (29.6 months vs 24.1 months in the 3D/IMRT group). On multivariable Cox regression, the choice of radiation therapy technique was not associated with differences in OS (adjusted hazard ratios [aHR] = 0.5; 95% confidence interval [CI], 0.2%-1.3%, P = .18). Moreover, patients that underwent surgical resection had better OS (aHR = 0.3, 95% CI, 0.1%-0.8%, P = .01). Furthermore, progression-free survival was also similar between patients treated with SBRT and those treated with 3D/IMRT (aHR = 0.9, 95% CI, 0.5%-1.8%, P = .81) Conclusions: SBRT was associated with similar clinical outcomes compared with conventional radiation techniques, despite being delivered over a shorter period of time which would spare patients prolonged treatment burden. Future prospective data are still needed to better assess the role of SBRT in patients with pancreatic cancer.