Basic evaluation of a novel four-dimensional target and human body phantom.

In this study, we investigated the basic performance of a multi-cell 4D phantom. All the CT numbers of the phantom were very close to those of human data. The geometric maximum amplitudes were 4.57 mm in the lateral direction, 4.59 mm in the ventrodorsal direction, and 3.68 mm in the cranio-caudal direction. Geometric errors were 0.84, 0.58, and 0.40 mm, respectively. Movements of the abdominal surface were stable for 60 seconds. Repeated measurements show no actual differences in target movements between multiple measurements and indicated high reproducibility (r > 0.97). End-to-end tests using Gafchromic film revealed a gamma pass rate of 98% or above (2 mm / 3%). Although our phantom performed limited reproducibility in the movement of the patient tumor at present, a satisfactory level of precision was confirmed in general. This is a very promising device for use in the verification of radiation therapy for moving targets.
PMID: 31146274 [PubMed - as supplied by publisher]

Source: Physics in Medicine and Biology - May 29, 2019 Category: Physics Authors: Matsumoto Y, Kabuki S, Sugawara A, Kitahara T, Akiba T, Fujita Y, Kawamata I, Yamada K, Amino K, Sasaki Y, Nishida M, Murakami K, Sugahara K, Saito N, Kunieda E Tags: Phys Med Biol Source Type: research