Open AccessImpact of multileaf collimator width on intraprostatic dose painting plans for dominant intraprostatic lesion of prostate cancer
Author(s) -
Abe Eisuke,
Mizowaki Takashi,
Norihisa Yoshiki,
Narita Yuuichirou,
Matsuo Yukinori,
Narabayashi Masaru,
Nagata Yasushi,
Hiraoka Masahiro
Publication year - 2010
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1120/jacmp.v11i4.3193
Subject(s) - multileaf collimator , prostate cancer , medicine , nuclear medicine , lesion , prostate , collimator , radiation therapy , cancer , physics , optics , radiology , radiation treatment planning , surgery
The aim of this study was to investigate the impact of multileaf collimator width (MLC‐W) on intraprostatic dose painting plans for prostate cancer. Prostate cancer maps based on the histopathological findings were superimposed onto simulation CT images. Clinical target volume (CTV) 1 was defined as the prostate and the base of the seminal vesicles, and CTV2 was defined as the dominant intraprostatic lesions. Planning target volume (PTV) 1 and PTV2 were delineated by adding 5 mm margins to CTV1 and CTV2, respectively. For each case, two dose painting plans were created to deliver 74 Gy to PTV1 and 84 Gy to PTV2 with dynamic multileaf collimator technique using two different MLCs: m3 (MLC‐W: 3 mm) and Millennium (5 mm). Plans were evaluated by comparing the conformation number (CN), a quantity that defines the degree of conformality. The CNs for plans using the m3 and Millennium were 0.68 and 0.67 for PTV1 and 0.59 and 0.58 for PTV2, respectively. The CNs tended to be higher for a thinner leaf width ( p < 0.05 ) . Dosimetric advantages associated with smaller leaves were observed. However, differences between 3 mm and 5 mm leaf width were relatively small, which suggested that 5 mm leaf width would be acceptable in dose painting plans for prostate cancer. PACS numbers: 87.56.N‐, 87.56.nk, 87.55.D‐