Journal of Medical Physics
ORIGINAL ARTICLE
Year
: 2014  |  Volume : 39  |  Issue : 4  |  Page : 212--218

Dosimetric impact of number of treatment fields in uniform scanning proton therapy planning of lung cancer


Suresh Rana1, Hilarie Simpson2, Gary Larson3, Yuanshui Zheng1 
1 Department of Medical Physics, ProCure Proton Therapy Center, Oklahoma City, Oklahoma, USA
2 Department of Medical Dosimetry, ProCure Proton Therapy Center, Oklahoma City, Oklahoma, USA
3 Department of Radiation Oncology, ProCure Proton Therapy Center, Oklahoma City, Oklahoma, USA

Correspondence Address:
Suresh Rana
Department of Medical Physics, ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142
USA

The main purpose of this study was to perform a treatment planning study for lung cancer comparing 2-field (2F) versus 3-field (3F) techniques in uniform scanning proton therapy (USPT). Ten clinically approved lung cancer treatment plans delivered using USPT at our proton center were included in this retrospective study. All 10 lung cases included 4D computed tomography (CT) simulation. The delineation of target volumes was done based on the maximum intensity projection (MIP) images. Both the 3F and 2F treatment plans were generated for the total dose of 74 cobalt-gray-equivalent (CGE) with a daily dose of 2 CGE. 3F plan was generated by adding an extra beam in the 2F plan. Various dosimetric parameters between 2F and 3F plans were evaluated. 3F plans produced better target coverage and conformality as well as lower mean dose to the lung, with absolute difference between 3F and 2F plans within 2%. In contrast, the addition of third beam led to increase of low-dose regions (V20 and V5) in the lung in 3F plans compared to the ones in 2F plans with absolute difference within 2%. Maximum dose to the spinal cord was lower in 2F plans. Mean dose to the heart and esophagus were comparable in both 3F and 2F plans. In conclusion, the 3F technique in USPT produced better target coverage and conformality, but increased the low-dose regions in the lung when compared to 2F technique.


How to cite this article:
Rana S, Simpson H, Larson G, Zheng Y. Dosimetric impact of number of treatment fields in uniform scanning proton therapy planning of lung cancer.J Med Phys 2014;39:212-218


How to cite this URL:
Rana S, Simpson H, Larson G, Zheng Y. Dosimetric impact of number of treatment fields in uniform scanning proton therapy planning of lung cancer. J Med Phys [serial online] 2014 [cited 2021 Dec 1 ];39:212-218
Available from: https://www.jmp.org.in/article.asp?issn=0971-6203;year=2014;volume=39;issue=4;spage=212;epage=218;aulast=Rana;type=0