Radiation therapy dosimetry using magnetic resonance imaging of polymer gels

Medical Physics - Tập 23 Số 5 - Trang 699-705 - 1996
M Maryanski1,2, Geoffrey S. Ibbott3, Peter Eastman4, R. J. Schulz5,2, John C. Gore6
1Department of Diagnostic Radiology, Yale University School of Medicine, P.O. Box 208042, New Haven, Connecticut 06520-8042
2MGS Research, Inc., P.O. Box 581, Guilford, Connecticut 06437-0581
3Department of Radiation Medicine, University of Kentucky Medical School, Lexington, Kentucky 40536
4Department of Applied Physics, Yale University School of Medicine, New Haven, Connecticut 06520
5Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520
6Departments of Diagnostic Radiology and Applied Physics, Yale University School of Medicine, P.O. Box 208042, New Haven, Connecticut 06520-8042

Tóm tắt

Further progress in the development of polymer gel dosimetry using MRI is reported, together with examples of its application to verify treatment plans for stereotactic radiosurgery and high dose rate brachytherapy. The dose distribution image produced in the tissue‐equivalent gel by radiation‐induced polymerization, and encoded in the spatial distribution of the NMR transverse relaxation rates (R2) of the water protons in the gel, is permanent. Maps of R2 are constructed from magnetic resonance imaging data and serve as a template for dose maps, which can be used to verify complex dose distributions from external sources or brachytherapy applicators. The integrating, three‐dimensional, tissue‐equivalent characteristics of polymer gels make it possible to obtain dose distributions not readily measured by conventional methods. An improved gel formulation (BANG‐2) has a linear dose response that is independent of energy and dose rate for the situations studied to date. There is excellent agreement between the dose distributions predicted using treatment planning calculations and those measured using the gel method, and the clinical practical utility of MRI‐based polymer gel dosimetry is thereby demonstrated.

Từ khóa


Tài liệu tham khảo

Thông tin
Thông tin xuất bản

Medical Physics

Tập 23 Số 5

699-705

Thông tin tác giả