title: Lymphoscintigraphy and SPECT/CT in multicentric and multifocal breast cancer: does each tumour have a separate drainage pattern? Results of a Dutch multicentre study (MULTISENT).
abstract: OBJECTIVE
  To investigate whether lymphoscintigraphy and SPECT/CT after intralesional injection of radiopharmaceutical into each tumour separately in patients with multiple malignancies in one breast yields additional sentinel nodes compared to intralesional injection of the largest tumour only.
  
  
  METHODS
  Patients were included prospectively at four centres in The Netherlands. Lymphatic flow was studied using planar lymphoscintigraphy and SPECT/CT until 4 h after administration of (99m)Tc-nanocolloid in the largest tumour. Subsequently, the smaller tumour(s) was injected intratumorally followed by the same imaging sequence. Sentinel nodes were intraoperatively localized using a gamma ray detection probe and vital blue dye.
  
  
  RESULTS
  Included in the study were 50 patients. Additional lymphatic drainage was depicted after the second and/or third injection in 32 patients (64%). Comparison of planar images and SPECT/CT images after consecutive injections enabled visualization of the number and location of additional sentinel nodes (32 axillary, 11 internal mammary chain, 2 intramammary, and 1 interpectoral. A sentinel node contained metastases in 17 patients (34%). In five patients with a tumour-positive node in the axilla that was visualized after the first injection, an additional involved axillary node was found after the second injection. In two patients, isolated tumour cells were found in sentinel nodes that were only visualized after the second injection, whilst the sentinel nodes identified after the first injection were tumour-negative.
  
  
  CONCLUSIONS
  Lymphoscintigraphy and SPECT/CT after consecutive intratumoral injections of tracer enable lymphatic mapping of each tumour separately in patients with multiple malignancies within one breast. The high incidence of additional sentinel nodes draining from tumours other than the largest one suggests that separate tumour-related tracer injections may be a more accurate approach to mapping and sampling of sentinel nodes in patients with multicentric or multifocal breast cancer.
authors.affiliation: Department of Nuclear Medicine, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands. o.brouwer@nki.nl
authors.forename: O R
authors.initials: OR
authors.lastname: Brouwer
authors.forename: L
authors.initials: L
authors.lastname: Vermeeren
authors.forename: I M C
authors.initials: IM
authors.lastname: van der Ploeg
authors.forename: R A
authors.initials: RA
authors.lastname: Valdés Olmos
authors.forename: C E
authors.initials: CE
authors.lastname: Loo
authors.forename: L M
authors.initials: LM
authors.lastname: Pereira-Bouda
authors.forename: F
authors.initials: F
authors.lastname: Smit
authors.forename: P
authors.initials: P
authors.lastname: Neijenhuis
authors.forename: B C
authors.initials: BC
authors.lastname: Vrouenraets
authors.forename: F
authors.initials: F
authors.lastname: Sivro-Prndelj
authors.forename: S M
authors.initials: SM
authors.lastname: Jap-a-Joe
authors.forename: P J
authors.initials: PJ
authors.lastname: Borgstein
authors.forename: E J Th
authors.initials: EJ
authors.lastname: Rutgers
authors.forename: H S A
authors.initials: HS
authors.lastname: Oldenburg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D004322:Drainage; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000601:surgery; D008207:Lymphatic Metastasis; D061305:Lymphoscintigraphy / Q000379:methods; D008875:Middle Aged; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D021701:Sentinel Lymph Node Biopsy / Q000379:methods; D013668:Technetium Tc 99m Aggregated Albumin / Q000008:administration & dosage; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid