Faculty Collaboration Database

Investigation of helical tomotherapy for partial-breast irradiation of prone-positioned patients. Int J Radiat Oncol Biol Phys 2009 May 01;74(1):275-82

Date

04/14/2009

Pubmed ID

19362247

DOI

10.1016/j.ijrobp.2008.11.028

Scopus ID

2-s2.0-64049118515 (requires institutional sign-in at Scopus site)   19 Citations

Abstract

PURPOSE: To investigate whether helical tomotherapy can provide conformal, uniform target-dose coverage for partial-breast irradiation (PBI) of patients positioned prone while achieving organ-at-risk sparing compliant with National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39/Radiation Therapy Oncology Group (RTOG) 0413 guidelines; and to report our initial experience with the delivery of prone-breast PBI treatments using tomotherapy.

METHODS AND MATERIALS: For our pilot study, we generated helical tomotherapy plans upon the images of 10 prone-positioned patients previously treated using conventional techniques. We also generated plans for 4 left-breast prone-positioned PBI patients who were treated using helical tomotherapy, and recalculated the planned sinograms upon the pretreatment megavoltage computed tomographic images. Of the planning target volume (PTV), 95% was prescribed to receive 38.5 Gy, administered twice daily for 5 days.

RESULTS: For our pilot study, on average the maximum point dose to the PTV was 41.3 Gy, and 99% or more of the PTV received 90% or more of the prescribed dose. RTOG 0413 dose-volume histogram objectives were fulfilled for all organs at risk except the contralateral breast, which received a maximum point dose as high as 3.2 Gy in 1 case. For the prospective prone-positioned tomotherapy PBI plans, all objectives were met except the contralateral-breast maximum dose, which was 3.7 Gy on average. Dose calculation using the planned sinogram upon the pretreatment megavoltage computed tomographic images indicated consistency with the planned dose distributions.

CONCLUSIONS: Helical tomotherapy can provide conformal and uniform target-dose coverage simultaneous with adequate sparing of critical structures; in this study only the contralateral breast dose exceeded RTOG 0413 guidelines. Dosimetric results for our 4 prospective patient cases were consistent with those for our 10-case pilot study.

Author List

Kainz K, White J, Herman J, Li XA

Author

Kristofer Kainz PhD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Breast
Breast Neoplasms
Female
Guideline Adherence
Humans
Immobilization
Pilot Projects
Prone Position
Prospective Studies
Radiation Injuries
Radiotherapy Dosage
Radiotherapy Planning, Computer-Assisted
Radiotherapy, Intensity-Modulated
Retrospective Studies
Tomography, Spiral Computed