ABSTRACT
This case describes a patient who initially had peri-excisional injections of radiocolloid around a lumpectomy site that failed to visualize sentinel nodes during lymphoscintigraphy. After additional areolar-cutaneous junction injections, extremely indirect dermal lymphatic pathways were evident with resultant drainage to two sentinel nodes, both of which contained disease. Hybrid combination injections of radiotracer during sentinel lymph node biopsy is gaining in popularity. This case illustrates the validity of the hybrid injection techniques and the demonstrated accuracy despite seemingly disconnected and extremely tortuous pathways as demonstrated in the figure.
Subject(s)
Breast Neoplasms/surgery , Breast/anatomy & histology , Breast/diagnostic imaging , Carcinoma, Lobular/diagnostic imaging , Lymphatic System/anatomy & histology , Lymphoscintigraphy , Aged , Female , Humans , Mastectomy, Segmental , Radiopharmaceuticals , Sentinel Lymph Node Biopsy , Technetium Tc 99m Sulfur ColloidABSTRACT
PURPOSE: The authors report on a modified lymphoscintigraphy protocol for increasing activity in the sentinel node (SN) through a specific technique (LymphoBoost). It consists of an areolar-cutaneous "junction" injection, using a very shallow, high-volume, high-specific-activity injection of 100% filtered Tc-99m sulfur colloid, as an adjunct to their standard protocol. MATERIALS AND METHODS: Results from a previously optimized protocol (group 1, n = 28) were compared with those from their new protocol (group 2, n = 85), which consisted of two sets of consecutively applied (within 12 to 20 minutes) injections: group 2A composed of perilesional and intradermal injections (similar to the previous group 1) followed by group 2B LymphoBoost injections within 12 to 20 minutes in the same patients. Regions of interest were drawn around the SN and the injection sites (IS) at the end of the studies to calculate the end-of-study SN:IS ratio for both group 1 and group 2 studies. The SN:IS ratio is generally independent of dose and is a measurement of the "efficiency" of getting activity from the IS to the SN. RESULTS: The mean SN:IS ratio in group 2 was 3.34 times greater than that in group 1 studies (P < 0.0005). The median SN:IS ratio was 3.53 times greater in the group 2 studies. Many cases showed a dramatic increase in SN counts before the LymphoBoost injection was even completed, with more than 5% of injected activity reaching nodes at the end of the study in some patients. Multiple different lymphatic pathways were noted, but all led to the same node(s). No significant disagreement between group 2A and group 2B results was noted. CONCLUSIONS: Areolar-cutaneous junction injections, performed under these conditions, augment SN activity dramatically in most patients. Hotter nodes provide several benefits, especially when next-day surgery is contemplated, and should also reduce the extent of dissection needed to remove the sentinel node.
