Accelerated intensity-modulated radiotherapy to breast in prone position: dosimetric results.
OBJECTIVE
To report the physics and dosimetry results of a trial of accelerated intensity-modulated radiotherapy to the whole breast with a concomitant boost to the tumor bed in patients treated in the prone position.


METHODS
Patients underwent computed tomography planning and treatment in the prone position on a dedicated treatment platform. The platform has an open aperture on the side to allow for the index breast to fall away from the chest wall. Noncontrast computed tomography images were acquired at 2.5- or 3.75-mm-thick intervals, from the level of the mandible to below the diaphragm. A dose of 40.5 Gy was delivered to the entire breast at 2.7-Gy fractions in 15 fractions. An additional dose of 0.5 Gy was delivered as a concomitant boost to the lumpectomy site, with a 1-cm margin, using inverse planning, for a total dose of 48 Gy in 15 fractions. No more than 10% of the heart and lung volume was allowed to receive >18 and >20 Gy, respectively.


RESULTS
Between September 2003 and August 2005, 91 patients were enrolled in the study. The median volume of heart that received > or =18 Gy was 0.5%, with a maximal value of 4.7%. The median volume of ipsilateral lung that received > or =20 Gy was 0.8%, with a maximum of 7.2%.


CONCLUSIONS
This technique for whole breast radiotherapy is feasible and enables an accelerated regimen in the prone position while sparing the lung and heart.
DeWyngaert
J Keith
JK
Department of Radiation Oncology, New York University School of Medicine, 160 E. 34th Street, New York, NY 10016, USA. keith.dewyngaert@med.nyu/edu
Jozsef
Gabor
G
Mitchell
James
J
Rosenstein
Barry
B
Formenti
Silvia C
SC
D001940:Breast; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D005260:Female; D006321:Heart; D006801:Humans; D008168:Lung; D016684:Prone Position; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D014057:Tomography, X-Ray Computed