Can the sentinel lymph node technique affect decisions to offer internal mammary chain irradiation?
OBJECTIVE
Identification of the sentinel lymph node (SLN) for small mammary tumours (cT1N0) sometimes leads to detection of internal mammary chain (IMC) drainage. This information is often ignored by physicians. The present study sought to determine the frequency with which an internal mammary SLN was identified by peritumoral injection of radioactive tracer, and then to determine the patients in whom identification of an internal mammary SLN could have an impact on the radiation treatment plan.


METHODS
Between March 2002 and March 2008, 622 SLN biopsies performed in a cohort of 608 patients were analysed. Technetium-labelled nanocolloids were administered via three peritumoral injections, completed by a deep prepectoral injection, with the entire procedure performed under echographic guidance.


RESULTS
The SLN was identified in 607 of the 622 patients, including 174 (28.7%) in the IMC. A total of 161 successful internal mammary biopsies were performed. Of the 622 patients, 18 showed SLN involvement in the IMC. In 7 of these patients, only the internal mammary SLN was affected. Prophylactic irradiation of the IMC was indicated in 376 patients, but only in 18 (4.8%) of these patients was there effectively IMC involvement; internal mammary SLN biopsy failed in 7 patients (1.9%).


CONCLUSIONS
SLN detection by peritumoral injection, combined with the systematic removal of the internal mammary SLN, enabled the involvement of this region to be found in a nonnegligible number of patients. Such information should make it possible to personalize treatment for patients with stage cT1 mammary cancer and thereby avoid needless internal mammary radiation therapy in a large number of patients (93.4% in our study).
Bourre
Jean-Cyril
JC
Nuclear Medicine Department, Grenoble University Hospital, La Tronche, France. jcbourre@chu-grenoble.fr
Payan
Raoul
R
Collomb
Delphine
D
Gallazzini-Crepin
Céline
C
Calizzano
Alex
A
Desruet
Marie-Dominique
MD
Pasquier
Dominique
D
Bolla
Michel
M
Fagret
Daniel
D
Vuillez
Jean-Philippe
JP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D015331:Cohort Studies; D003102:Colloids / Q000737:chemistry; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D042361:Mammary Glands, Human / Q000473:pathology*; D008875:Middle Aged; D019275:Radiopharmaceuticals; D021701:Sentinel Lymph Node Biopsy / Q000379:methods; D013667:Technetium / Q000494:pharmacology
D003102:Colloids; D019275:Radiopharmaceuticals; D013667:Technetium