A new radiocolloid for sentinel node detection in breast cancer.
BACKGROUND
The optimal radioactive tracer and technique for sentinel lymph node localization in breast cancer is yet to be determined. The dilemma of small particle size with dispersion to second echelon nodes versus failure of migration of larger radiocolloids needs to be resolved. A new radiocolloid preparation with particle size under 0.1 micron was developed with excellent primary/post lymphatic entrapment ratio.


OBJECTIVE
To assess the feasibility of a new 99mTc radiocolloid cysteine-rhenium colloid in sentinel lymph node (SLN) localization for breast cancer.


METHODS
Forty-seven patients with newly diagnosed T1 or T2 breast cancer underwent injection of 99mTc-labeled cysteine-rhenium colloid followed by lymphoscintigraphy. Same day SLN biopsy with patent blue dye and intraoperative gamma probe to identify SLNs were performed.


RESULTS
SLN mapping and intraoperative localization were successful in 46/47 (98%) of patients. The blue dye radioactive tracer concordance was 94%. There was one false-negative in a patient with a nonpalpable tumor that underwent ultrasound-guided peritumoral radiocolloid injection.


CONCLUSIONS
99mTc-cysteine-rhenium colloid is highly effective in identifying SLNs. It has the advantage of smaller particle size than sulfur colloid with easier lymphatic migration. It has a more neutral pH with less pain on injection and does not require filtration, thereby minimizing radiation exposure to technologists.
Department of Surgery, London Health Sciences Center, University of Western Ontario, Canada.
N
N
Hodgson
P
P
Zabel
A G
AG
Mattar
C J
CJ
Engel
D
D
Girvan
R
R
Holliday
D000818:Animals; D001365:Axilla; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D004396:Coloring Agents / Q000008:administration & dosage; D003545:Cysteine / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D015609:Organotechnetium Compounds / Q000627:therapeutic use*; D011446:Prospective Studies; D011817:Rabbits; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*
D004396:Coloring Agents; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D003545:Cysteine