TY - JOUR
T1 - A methodology for selecting the beam arrangement to reduce the intensity-modulated radiation therapy (IMRT) dose to the SPECT-defined functioning lung
AU - McGuire, S. M.
AU - Marks, L. B.
AU - Yin, F. F.
AU - Das, S. K.
PY - 2010
Y1 - 2010
N2 - Macroaggregated albumin single-photon emission computed tomography (MAA-SPECT) provides a map of the spatial distribution of lung perfusion. Our previous work developed a methodology to use SPECT guidance to reduce the dose to the functional lung in IMRT planning. This study aims to investigate the role of beam arrangement on both low and high doses in the functional lung. In our previous work, nine-beam IMRT plans were generated with and without SPECT guidance and compared for five patients. For the current study, the dose-function histogram (DFH) contribution for each of the nine beams for each patient was calculated. Four beams were chosen based on orientation and DFH contributions to create a SPECT-guided plan that spared the functional lung and maintained target coverage. Four-beam SPECT-guided IMRT plans reduced the F 20 and F30 values by (16.5 6.8)% and (6.1 9.2)%, respectively, when compared to nine-beam conventional IMRT plans. Moreover, the SPECT-4F Plan reduces F5 and F13 for all patients by (11.0 8.2)% and (6.1 3.6)%, respectively, compared to the SPECT Plan. Using fewer beams in IMRT planning may reduce the amount of functional lung that receives 5 and 13 Gy, a factor that has recently been associated with radiation pneumonitis.
AB - Macroaggregated albumin single-photon emission computed tomography (MAA-SPECT) provides a map of the spatial distribution of lung perfusion. Our previous work developed a methodology to use SPECT guidance to reduce the dose to the functional lung in IMRT planning. This study aims to investigate the role of beam arrangement on both low and high doses in the functional lung. In our previous work, nine-beam IMRT plans were generated with and without SPECT guidance and compared for five patients. For the current study, the dose-function histogram (DFH) contribution for each of the nine beams for each patient was calculated. Four beams were chosen based on orientation and DFH contributions to create a SPECT-guided plan that spared the functional lung and maintained target coverage. Four-beam SPECT-guided IMRT plans reduced the F 20 and F30 values by (16.5 6.8)% and (6.1 9.2)%, respectively, when compared to nine-beam conventional IMRT plans. Moreover, the SPECT-4F Plan reduces F5 and F13 for all patients by (11.0 8.2)% and (6.1 3.6)%, respectively, compared to the SPECT Plan. Using fewer beams in IMRT planning may reduce the amount of functional lung that receives 5 and 13 Gy, a factor that has recently been associated with radiation pneumonitis.
UR - http://www.scopus.com/inward/record.url?scp=74549208424&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=74549208424&partnerID=8YFLogxK
U2 - 10.1088/0031-9155/55/2/005
DO - 10.1088/0031-9155/55/2/005
M3 - Article
C2 - 20019404
AN - SCOPUS:74549208424
SN - 0031-9155
VL - 55
SP - 403
EP - 416
JO - Physics in medicine and biology
JF - Physics in medicine and biology
IS - 2
ER -