A treatment planning strategy for heavy-charged-particle radiotherapy of lung cancer by the use of computed tomography with projection data-based temporal maximum-intensity projection.
To design a range-compensating bolus for heavy-charged-particle radiotherapy of lung cancer, we propose an image-processing method that uses CT projection data for treatment planning. We studied six lung cancer patients in 4DCT mode. Three types of range-compensating bolus were designed with use of (1) each bolus for 4DCT images, (2) image-based maximum-intensity projection data (4DIM), and (3) CT images reconstructed by the use of maximum-attenuation projection data (4DPM) along the time axis around exhale (=respiratory-gated treatment). Carbon-ion dose distributions were calculated by the use of these designed range-compensating boluses and were compared. The dose distribution with 4DIM caused overdosing beyond the target. However, the dose distribution with 4DPM was similar to that with a composite of the range-compensating bolus (CCB) designed for the respiratory phases. Furthermore, the volume of the receiving dose for >95% (D95) for CTV and the volume of the lung receiving dose for >20 GyE (V20) with 4DPM were similar to that with the CCB. The range-compensating bolus with 4DPM provides dose distributions similar to that with the CCB in peripheral lung cancer and improves the calculating efficiency over CCB.
Asakura
Hiroshi
H
Accelerator Engineering Corporation, Chiba, Chiba, Japan. aec_asa@nirs.go.jp
Kumagai
Motoki
M
Kanematsu
Nobuyuki
N
Mori
Shinichiro
S
D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002244:Carbon / Q000627:therapeutic use; D005260:Female; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D063193:Heavy Ion Radiotherapy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008297:Male; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D013997:Time Factors
D002244:Carbon
Radiol Phys Technol. 2010 Jan;3(1):23-33
20821098
Int J Radiat Oncol Biol Phys. 2008 Jan 1;70(1):253-61
17967513
Med Phys. 2004 Jun;31(6):1348-56
15259638
Int J Radiat Oncol Biol Phys. 2005 Sep 1;63(1):253-60
16111596
Med Phys. 2006 Aug;33(8):2989-97
16964877
Int J Radiat Oncol Biol Phys. 2007 Mar 1;67(3):906-14
17293240
Med Phys. 2002 Dec;29(12):2823-9
12512716
Med Phys. 1983 May-Jun;10(3):344-6
6308408
Int J Radiat Oncol Biol Phys. 2000 Jul 1;47(4):1097-103
10863083
Phys Med Biol. 2007 Feb 21;52(4):1027-38
17264368