Delineation of Supraclavicular Target Volumes in Breast Cancer Radiation Therapy.
OBJECTIVE
To map the location of gross supraclavicular metastases in patients with breast cancer, in order to determine areas at highest risk of harboring subclinical disease.


METHODS
Patients with axial imaging of gross supraclavicular disease were identified from an institutional breast cancer registry. Locations of the metastatic lymph nodes were transferred onto representative axial computed tomography images of the supraclavicular region and compared with the Radiation Therapy Oncology Group (RTOG) breast cancer atlas for radiation therapy planning.


RESULTS
Sixty-two patients with 161 supraclavicular nodal metastases were eligible for study inclusion. At the time of diagnosis, 117 nodal metastases were present in 44 patients. Forty-four nodal metastases in 18 patients were detected at disease recurrence, 4 of whom had received prior radiation to the supraclavicular fossa. Of the 161 nodal metastases, 95 (59%) were within the RTOG consensus volume, 4 nodal metastases (2%) in 3 patients were marginally within the volume, and 62 nodal metastases (39%) in 30 patients were outside the volume. Supraclavicular disease outside the RTOG consensus volume was located in 3 regions: at the level of the cricoid and thyroid cartilage (superior to the RTOG volume), in the posterolateral supraclavicular fossa (posterolateral to the RTOG volume), and in the lateral low supraclavicular fossa (lateral to the RTOG volume). Only women with multiple supraclavicular metastases had nodal disease that extended superiorly to the level of the thyroid cartilage.


CONCLUSIONS
For women with risk of harboring subclinical supraclavicular disease warranting the addition of supraclavicular radiation, coverage of the posterior triangle and the lateral low supraclavicular region should be considered. For women with known supraclavicular disease, extension of neck coverage superior to the cricoid cartilage may be warranted.
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Lindsay C
LC
Brown
Department of Radiology, Mayo Clinic, Rochester, Minnesota.
Felix E
FE
Diehn
Department of Surgery, Mayo Clinic, Rochester, Minnesota.
Judy C
JC
Boughey
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Stephanie K
SK
Childs
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Sean S
SS
Park
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Elizabeth S
ES
Yan
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
Ivy A
IA
Petersen
Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota. Electronic address: mutter.robert@mayo.edu.
Robert W
RW
Mutter
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D002968:Clavicle; D003413:Cricoid Cartilage / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D015182:Lymphatic Irradiation; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D013957:Thyroid Cartilage / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed