Work

Potential Impact of Daily Setup Variation on Pencil-Beam Scanning for Head and Neck Cancer

Year: 2015

Type: article

Abstract: A 79-year-old woman underwent transoral robotic resection and selective dissection of the right side of the neck for a right tonsil squamous cell carcinoma, positive for human papillomavirus , final pathologic stage IVa, T2N2bM0. Given the finding of extracapsular extension, postoperative chemoradiation was recommended for the patient, and radiation was given via pencil-beam scanning proton therapy . During the course of radiation, regular evaluation computed tomography scans consistently revealed random variation in the position of large skinfolds in the posterior portion of the neck, which resulted in undercoverage of clinical targets. As a result, the decision was made to change the remainder of the patient's radiation therapy course to intensity-modulated photon radiation, which was less sensitive to the random variation of setup in the soft tissues of her neck. She remained disease free at the 20-month follow-up. This case illustrates the importance of routine evaluation of soft tissue anatomy with proton therapy and has implications on developing methods of immobilization and evaluation to minimize variation in setup.

Source: International Journal of Particle Therapy

DOI: 10.14338/ijpt-15-00007.1

Authors: Kanograt Tangsriwong, Maura Kirk, Stefan Both, Alexander Lin

Institution: University of Pennsylvania

Language: English

Topic: Advanced Radiotherapy Techniques

Subfield: Radiation

Field: Physics and Astronomy

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $1,700