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Accelerated partial breast irradiation using proton beams: Initial dosimetric experience.

Alphonse G Taghian·Kevin R Kozak·Angela Katz·Judith Adams·Hsiao-Ming Lu·Simon N Powell·Thomas F DeLaney
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Abstract

PURPOSE: The unique dosimetric features of proton radiotherapy make it an attractive modality for normal tissue sparing. We present our initial experience with protons for three-dimensional, conformal, external-beam accelerated partial breast irradiation (3D-CPBI). METHODS AND MATERIALS: From March 2004 to June 2005, 25 patients with tumors < or =2 cm and negative axillary nodes were treated with proton 3D-CPBI. The prescribed dose was 32 Cobalt Gray Equivalents (CGE) in 4 CGE fractions given twice daily. One to three fields were used to provide adequate planning target volume (PTV) coverage and dose homogeneity. RESULTS: Excellent PTV coverage and dose homogeneity were obtained in all patients with one to three proton beams. The median PTV receiving 95% of the prescribed dose was 100%. Dose inhomogeneity exceeded 10% in only 1 patient (4%). The median volume of nontarget breast tissue receiving 50% of the prescribed dose was 23%. Median volumes of ipsilateral lung receiving 20 CGE, 10 CGE, and 5 CGE were 0%, 1%, and 2%, respectively. The contralateral lung and heart received essentially no radiation dose. Cost analysis suggests that proton 3D-CPBI is only modestly more expensive (25%) than traditional whole-breast irradiation (WBI). CONCLUSION: Proton 3D-CPBI is technically feasible, providing both excellent PTV coverage and normal tissue sparing. It markedly reduces the volume of nontarget breast tissue irradiated compared with photon-based 3D-CPBI, addressing a principle disadvantage of external-beam approaches to PBI. As proton therapy becomes more widely available, it may prove an attractive tool for 3D-CPBI.

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AgedBreast NeoplasmsCosts and Cost AnalysisFeasibility StudiesFemaleHeartHumansLungMiddle AgedProspective StudiesProton TherapyRadiotherapy DosageRadiotherapy Planning, Computer-AssistedRadiotherapy, ConformalProtonsClinical Trial, Phase IClinical Trial, Phase IIJournal ArticleMulticenter StudyResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov't

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Alphonse G Taghian, Kevin R Kozak, Angela Katz, Judith Adams, Hsiao-Ming Lu, Simon N Powell, Thomas F DeLaney. 2006-05-26. Accelerated partial breast irradiation using proton beams: Initial dosimetric experience.. https://doi.org/10.1016/j.ijrobp.2006.03.017

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