@misc{oai:repo.qst.go.jp:00071378,
 author = {森, 慎一郎 and 森 慎一郎},
 month = {Nov},
 note = {Purpose: Amplitude-based gating aids treatment planning in scanned particle therapy, because it provides better control of uncertainty with the gate window. We evaluated the effects of this gating under realistic organ motion conditions using 4DCT data of lung and liver tumors.
\nMethods and Materials: 4DCT imaging was done for 24 lung and liver patients using the area-detector CT. We calculated the field-specific target volume (FTV) for the gating window, which was defined for a single respiratory cycle. Prescribed doses of 48 Gy(RBE)/1fr/4fields and 45 Gy(RBE)/2fr/2fields were delivered to the FTVs for lung and liver treatments, respectively. Dose distributions were calculated for the repeated 1st respiratory cycle (planning dose) and the whole respiratory data (treatment dose). We applied eight phase-controlled rescannings with the amplitude-based gating.
\nResults: For the lung cases, CTV-D95 of the treatment dose (= 96.0±1.0 %) was almost the same as that of the planning dose (= 96.6±0.9 %). CTV-Dmax/Dmin of the treatment dose (= 104.5±2.2 %/89.4±2.6 %) was slightly increased over that of the planning dose (= 102.1±1.0 %/89.8±2.5 %) due to hot spots. For the liver cases, CTV-D95 of the treatment dose (= 97.6±0.5 %) was decreased by approximately 1 % when compared with the planning dose (= 98.5±0.4 %). CTV-Dmax/Dmin of the treatment dose was degraded by 3.0 %/0.4 % compared to the planning dose. Average treatment times were extended by 46.5 s and 65.9 s from those of the planning dose for lung and liver cases, respectively.
\nConclusions: As with regular respiratory patterns, amplitude-based gated multiple phase-controlled rescanning preserves target coverage to a moving target under irregular respiratory patterns., 4D Treatment Planning Workshop 2013},
 title = {Amplitude-based gated phase-controlled rescanning in carbon-ion scanning beam treatment planning under irregular breathing conditions using lung and liver 4DCTs},
 year = {2013}
}