A study on beams passing through hip prosthesis for pelvic radiation treatment

Authors
Citation
Gx. Ding et Cw. Yu, A study on beams passing through hip prosthesis for pelvic radiation treatment, INT J RAD O, 51(4), 2001, pp. 1167-1175
Citations number
12
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Onconogenesis & Cancer Research
Journal title
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS
ISSN journal
03603016 → ACNP
Volume
51
Issue
4
Year of publication
2001
Pages
1167 - 1175
Database
ISI
SICI code
0360-3016(20011115)51:4<1167:ASOBPT>2.0.ZU;2-M
Abstract
Purpose: To study the dose distributions at the interface due to the presen ce of a metal implant; to show the dose distributions in combined fields in the presence of hip prostheses; and to demonstrate the capabilities and li mitations of a conventional system. Methods and Materials: Perturbations in the dose distribution caused by a h ip prosthesis can result in unacceptable dose inhomogeneities within the ta rget volume and in regions where tissues interface with implant. The Monte Carlo technique and a conventional treatment planning system are used to ca lculate the dose distributions. Results: Dose increases of 15% in tissue are seen at the interface between metal implant and tissue. Dose reductions of 5-25% or 10-45% are observed i n the shadow of the hip prosthesis made of 0.5-3-cm-thick titanium or steel alloy respectively. We compared predicted dose distribution between the Mo nte Carlo simulation and a commercial treatment planning system (CADPLAN). We found that CADPLAN underestimated the attenuation of hip prostheses. Thi s has led to overestimation of the target dose by 14% for a typical four-fi eld box technique. Conclusions: An acceptable dose distribution can be achieved with a proper lateral beam weighting and compensation using an eight-field technique. The beam compensation may be applied to achieve an adequate target dose. (C) 2 001 Elsevier Science Inc.