Effects of Geometrical Uncertainties on Whole Breast Radiotherapy: A Comparison of Four Different Techniques
Journal of Breast Cancer 2014³â 17±Ç 2È£ p.157 ~ p.160
(Nakamura Naoki) - St. Luke¡¯s International Hospital Department of Radiation Oncology
(Takahashi Osamu) - St. Luke¡¯s International Hospital Department of Medicine Division of General Internal Medicine
(Kamo Minobu) - St. Luke¡¯s International Hospital Department of Radiology
(Hatanaka Shogo) - St. Luke¡¯s International Hospital Department of Radiation Oncology
(Endo Haruna) - St. Luke¡¯s International Hospital Department of Radiation Oncology
(Mizuno Norifumi) - St. Luke¡¯s International Hospital Department of Radiation Oncology
(Shikama Naoto) - Saitama Medical University International Medical Center Department of Radiation Oncology
(Ogita Mami) - St. Luke¡¯s International Hospital Department of Radiation Oncology
(Sekiguchi Kenji) - St. Luke¡¯s International Hospital Department of Radiation Oncology
Abstract
Purpose: The purpose of this study was to quantify the target coverage, homogeneity, and robustness of the dose distributions against geometrical uncertainties associated with four whole breast radiotherapy techniques.
Methods: The study was based on the planning-computed tomography-datasets of 20 patients who underwent whole breast radiotherapy. A total of four treatment plans (wedge, field-in-field [FIF], hybrid intensity-modulated radiotherapy [IMRT], and full IMRT) were created for each patient. The hybrid IMRT plans comprised two opposed tangential open beams plus two IMRT beams. Setup errors were simulated by moving the beam isocenters by 5 mm in the anterior or posterior direction.
Results: With the original plan, the wedge technique yielded a high volume receiving ¡Ã107% of the prescription dose (V107; 7.5%¡¾4.2%), whereas the other three techniques yielded excellent target coverage and homogeneity. A 5 mm anterior displacement caused a large and significant increase in the V107 (+5.2%¡¾4.1%, p<0.01) with the FIF plan, but not with the hybrid IMRT (+0.4%¡¾1.2%, p=0.11) or full IMRT (+0.7%¡¾1.8%, p=0.10) plan. A 5-mm posterior displacement caused a large decrease in the V95 with the hybrid IMRT (-2.5%¡¾3.7%, p<0.01) and full IMRT (-4.3%¡¾5.1%, p<0.01) plans, but not with the FIF plan (+0.1%¡¾0.7%, p=0.74). The decrease in V95 was significantly smaller with the hybrid IMRT plan than with the full IMRT plan (p<0.01).
Conclusion: The FIF, hybrid IMRT, and full IMRT plans offered excellent target coverage and homogeneity. Hybrid IMRT provided better robustness against geometrical uncertainties than full IMRT, whereas FIF provided comparable robustness to that of hybrid IMRT.
Å°¿öµå
Breast neoplasms, Intensity-modulated radiotherapy
KMID :
1134120140170020157
¿ø¹® ¹× ¸µÅ©¾Æ¿ô Á¤º¸
µîÀçÀú³Î Á¤º¸
À¯È¿¼º°á°ú(Recomendation)