Evaluation of Breast Sentinel Lymph Node Coverage by Standard Radiation Therapy Fields

Journal Article · Tue Apr 01 04:00:00 EDT 2008 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2007.08.064· OSTI ID:21124154

Rabinovitch, Rachel ^[1]; Ballonoff, Ari; Newman, Francis M.S. ^[1]; Finlayson, Christina ^[2]

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1. Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, CO (United States)
2. Department of GI, Tumor, and Endocrine Surgery, University of Colorado Cancer Center, Aurora, CO (United States)

Background: Biopsy of the breast sentinel lymph node (SLN) is now a standard staging procedure for early-stage invasive breast cancer. The anatomic location of the breast SLN and its relationship to standard radiation fields has not been described. Methods and Materials: A retrospective review of radiotherapy treatment planning data sets was performed in patients with breast cancer who had undergone SLN biopsy, and those with a surgical clip at the SLN biopsy site were identified. The location of the clip was evaluated relative to vertebral body level on an anterior-posterior digitally reconstructed radiograph, treated whole-breast tangential radiation fields, and standard axillary fields in 106 data sets meeting these criteria. Results: The breast SLN varied in vertebral body level position, ranging from T2 to T7 but most commonly opposite T4. The SLN clip was located below the base of the clavicle in 90%, and hence would be excluded from standard axillary radiotherapy fields where the inferior border is placed at this level. The clip was within the irradiated whole-breast tangent fields in 78%, beneath the superior-posterior corner multileaf collimators in 12%, and outside the tangent field borders in 10%. Conclusions: Standard axillary fields do not encompass the lymph nodes at highest risk of containing tumor in breast cancer patients. Elimination of the superior-posterior corner MLCs from the tangent field design would result in inclusion of the breast SLN in 90% of patients treated with standard whole-breast irradiation.

• OSTI ID: 21124154
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 5 Vol. 70; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BIOPSY
CARCINOMAS
COLLIMATORS
EVALUATION
IMAGES
IRRADIATION
LYMPH NODES
MAMMARY GLANDS
PATIENTS
PLANNING
RADIOTHERAPY
SURGERY