title: The three-dimensional localization of internal mammary lymph nodes by radionuclide lymphoscintigraphy.
abstract: In breast cancer patients, radiation therapy planning must account for individual anatomy to ensure optimal coverage of tumor and internal mammary nodes. To achieve this, three-dimensional radionuclide lymphoscintigraphy (RNLS) was performed in 167 patients by obtaining two images of the nodes using a 30-degree slant hole collimator rotated 180 degrees between images. Analysis of 768 nodes (mean 4.6/patient) visualized from the level of rib 1 through interspace 5 was performed. The number of nodes seen was not a function of patient age. Cross-communication to the contralateral node chain occurred in 13.8% of cases. Eighty-two percent of nodes were located near the first three ribs and interspaces; 23% were located beyond 3.0 cm from the mid-sternal line. At the level of the radiation beam match line (second rib or interspace), 4.5% of nodes were deeper than 3.0 cm. From rib 3 through interspace 5, 3.9% were deeper than 3.0 cm. Using an idealized tangential field, at least one node would have been missed in 16.2% of patients. Three-dimensional RNLS allows definition and localization of normal sized nodes and ensures that radiation therapy portals can be tailored for each individual under treatment.
authors.affiliation: Joint Program in Nuclear Medicine, Harvard Medical School, Boston, Massachusetts.
authors.forename: W D
authors.initials: WD
authors.lastname: Kaplan
authors.forename: J W
authors.initials: JW
authors.lastname: Andersen
authors.forename: R L
authors.initials: RL
authors.lastname: Siddon
authors.forename: B T
authors.initials: BT
authors.lastname: Connolly
authors.forename: C A
authors.initials: CA
authors.lastname: McCormick
authors.forename: S M
authors.initials: SM
authors.lastname: Laffin
authors.forename: E M
authors.initials: EM
authors.lastname: Rosenbaum
authors.forename: C A
authors.initials: CA
authors.lastname: Jennings
authors.forename: A
authors.initials: A
authors.lastname: Recht
authors.forename: J R
authors.initials: JR
authors.lastname: Harris
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001940:Breast / Q000000981:diagnostic imaging*; D001943:Breast Neoplasms / Q000532:radiotherapy; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008722:Methods; D008875:Middle Aged; D011877:Radionuclide Imaging