Dosimetric benefit of adaptive re-planning in pancreatic cancer stereotactic body radiotherapy

Journal Article · Thu Jan 01 00:00:00 EST 2015 · Medical Dosimetry

DOI:https://doi.org/10.1016/J.MEDDOS.2015.04.002· OSTI ID:22577843

Li, Yongbao ^[1]; Hoisak, Jeremy D.P.; Li, Nan; Jiang, Carrie ^[2]; Tian, Zhen ^[2]; Gautier, Quentin; Zarepisheh, Masoud ^[2]; Wu, Zhaoxia; Liu, Yaqiang ^[1]; Jia, Xun ^[2]; others, and

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1. Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing (China)
2. Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States)

Stereotactic body radiotherapy (SBRT) shows promise in unresectable pancreatic cancer, though this treatment modality has high rates of normal tissue toxicity. This study explores the dosimetric utility of daily adaptive re-planning with pancreas SBRT. We used a previously developed supercomputing online re-planning environment (SCORE) to re-plan 10 patients with pancreas SBRT. Tumor and normal tissue contours were deformed from treatment planning computed tomographies (CTs) and transferred to daily cone-beam CT (CBCT) scans before re-optimizing each daily treatment plan. We compared the intended radiation dose, the actual radiation dose, and the optimized radiation dose for the pancreas tumor planning target volume (PTV) and the duodenum. Treatment re-optimization improved coverage of the PTV and reduced dose to the duodenum. Within the PTV, the actual hot spot (volume receiving 110% of the prescription dose) decreased from 4.5% to 0.5% after daily adaptive re-planning. Within the duodenum, the volume receiving the prescription dose decreased from 0.9% to 0.3% after re-planning. It is noteworthy that variation in the amount of air within a patient's stomach substantially changed dose to the PTV. Adaptive re-planning with pancreas SBRT has the ability to improve dose to the tumor and decrease dose to the nearby duodenum, thereby reducing the risk of toxicity.

• OSTI ID: 22577843
• Journal Information: Medical Dosimetry, Vol. 40, Issue 4; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0958-3947
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMAL TISSUES
COMPUTERIZED TOMOGRAPHY
HOT SPOTS
NEOPLASMS
OPTIMIZATION
PANCREAS
PATIENTS
PLANNING
RADIATION DOSES
RADIOTHERAPY
SMALL INTESTINE
STOMACH
TOXICITY