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Simultaneous irradiation of the breast and regional lymph nodes in prone position using helical tomotherapy. Br J Radiol 2012 Oct;85(1018):e899-905

Date

03/30/2012

Pubmed ID

22457317

Pubmed Central ID

PMC3474030

DOI

10.1259/bjr/18685881

Scopus ID

2-s2.0-84866867343   8 Citations

Abstract

OBJECTIVE: We investigated dosimetric advantages of using helical tomotherapy to simultaneously irradiate the breast and regional lymph nodes for patients positioned prone, and compared tomotherapy plan qualities for the prone position with those previously published for the supine position.

METHODS: Tomotherapy plans for 11 patients (5 left breast, 6 right) simulated with the involved breast suspended downward were generated. Each target (ipsilateral breast and supraclavicular, axillary and internal mammary chain nodes) was to receive 45 Gy.

RESULTS: For targets, V(40.5)≥99.9% and V(42.8)≥99.5% for all patients, where V(40.5) and V(42.8) denote the relative target volume receiving at least 40.5 and 42.8 Gy, respectively. The targets' maximum dose was, on average, approximately 49.5 Gy. The mean doses to the contralateral lung and heart were lower for right-breast cases (2.8 Gy lung, 2.7 Gy heart) than for left-breast cases (3.8 Gy lung, 8.7 Gy heart). Mean organ doses to the ipsilateral lung (9.3 Gy) and contralateral breast (2.3 Gy) from the prone breast tomotherapy plans were similar to those reported for conventional radiotherapy techniques. For the left breast with regional nodes, tomotherapy plans for prone-positioned patients yielded lower mean doses to the contralateral breast and heart than previously reported data for tomotherapy plans for supine-positioned patients.

CONCLUSION: Helical tomotherapy with prone breast positioning can simultaneously cover the breast and regional nodes with acceptable uniformity and can provide reduced mean dose to proximal organs at risk compared with tomotherapy with supine position. The similarity of plan quality to existing data for conventional breast radiotherapy indicates that this planning approach is appropriate, and that the risk of secondary tumour formation should not be significantly greater.

Author List

Kainz K, White J, Chen GP, Hermand J, England M, Li XA

Authors

Guang-Pei Chen PhD Assistant Professor in the Radiation Oncology department at Medical College of Wisconsin
Kristofer Kainz PhD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin
X Allen Li PhD 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
Esophagus
Female
Heart
Humans
Lung
Lymph Nodes
Lymphatic Irradiation
Lymphatic Metastasis
Organs at Risk
Patient Positioning
Prone Position
Radiation Dosage
Radiotherapy Dosage
Radiotherapy Planning, Computer-Assisted
Supine Position