A novel support system for patient immobilization and transportation for daily computed tomographic localization of target prior to radiation therapy.
OBJECTIVE
To develop a method for quick and smooth transportation of patients from a computed tomography (CT) table to a linear accelerator (linac) table for confirming tumor center before radiation therapy.


METHODS
We developed a system using a subtable for patient immobilization that is transported via a customized stretcher. The patient lies on the subtable and is immobilized by a vacuum cushion and thermoplastic body cast. The subtable stretcher is used to carry the subtable from the CT table to the linac table. During transportation, the subtable is kept flat and shock to the subtable is carefully avoided. Between August 2001 and September 2002, a total of 9 patients with solitary upper lung tumors (superior to carina) were treated using this system.


RESULTS
Intrafractional tumor motion along the x (left-right), y (anterior-posterior), and z axis (superior-inferior) ranged from -2 mm to 2 mm, -2 mm to 2 mm, and -5 mm to 3 mm, respectively. The standard deviation of intrafractional tumor motion along the x, y, and z axis ranged from 0.5 mm to 1.5 mm, 0 mm to 1.7 mm, and 0.6 mm to 3.5 mm, respectively. Interfractional setup errors along the x, y, and z axis ranged from -5 mm to 4 mm, -6 mm to 8 mm, and -6 mm to 6 mm, respectively, and we could reduce interfractional setup errors in the majority of treatment sessions.


CONCLUSIONS
We developed a system that allows patients to be immobilized and transported to verify tumor location on a daily basis. This system is highly useful for reducing setup errors.
Nemoto
Kenji
K
Department of Radiation Oncology, Tohoku University School of Medicine, Sendai, Miyagi, Japan. knemoto@rad.med.tohoku.ac.jp
Seiji
Kazumasa
K
Sasaki
Kazuya
K
Kasamatsu
Nobutaka
N
Fujishima
Toshie
T
Ogawa
Yoshihiro
Y
Ariga
Hisanori
H
Takeda
Ken
K
Kimura
Tokihisa
T
Yamada
Shogo
S
D000368:Aged; D000369:Aged, 80 and over; D004867:Equipment Design; D004865:Equipment and Supplies, Hospital; D005260:Female; D006757:Hospital Units; D006801:Humans; D007103:Immobilization; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009068:Movement; D011859:Radiography; D014187:Transportation of Patients / Q000379:methods*