CASES OF THE WEEK - “Identification of the sentinel lymph node by scintigraphy & gamma probe-guided sentinel lymph node biopsy in breast cancer patients: 99m technetium labeled nano colloid” by Dr Shekhar Shikare, Consultant & HOD, Nuclear Medicine & Dr Priya Devadas, Specialist General Surgery, NMC Royal Hospital Sharjah

IDENTIFICATION OF THE SENTINEL LYMPH NODE BY SCINTIGRAPHY & GAMMA PROBE-GUIDED SENTINEL LYMPH NODE BIOPSY IN BREAST CANCER PATIENTS: 99M TECHNETIUM LABELED NANO COLLOID

Fifty-three old female with history of left breast lump was investigated and Mammogram and MRI shows UIQ enhancing ill-defined speculated solid mass lesion located at 10 O’clock,16 mm away from the nipple, measuring 20 x 30 mm. axillary lymph nodes with no definite pathological malignant features noted.

Core needle biopsy was done which proved INVASIVE DUCTAL CARCINOMA

PET CT was negative for axillary and distant metastasis (The high specificity of PET/CT imaging indicates that patient who have a PET- positive axilla should have an axillary lymph node dissection (ALND) rather than sentinel lymph node biopsy (SNB). In contrast, FDG-PET showed poor sensitivity in the detection of axillary metastasis, confirming the need of sentinel lymph node biopsy (SNB) in cases where PET is negative in the axilla, J Nucl Med May 2010 vol. 51 no. supplement 2 1197.

Patient was planned for left mastectomy & sentinel lymph node biopsy & hence referred for sentinel lymph node scintigraphy for identification and localization of sentinel lymph nodes.

Identification of the SLN(s) is done during the surgery to remove the primary tumor of the breast. Prior to surgery, 99mTc Nano colloid is injected into subareolar location. The technique of injecting the radiolabeled agent and subsequent localization is known as lymphoscintigraphy and is typically performed on the day of surgery to identify the location of the SLN or group of nodes and lymphatic channels.

After two hours of injection- Static and SPECT-CT fused images identified and localized  SLN1 and SLN2 in mid axillary region at various depth (as shown with arrows) and subsequently underwent Gamma probe guided removal of the SLNS (During the tumor removal surgery, a hand-held gamma counter is used to locate the SLN, which will have a high radioactivity count, and under visual inspection. The SLN is then biopsied and the sample is assessed to determine whether it contains cancer cells.

SLNS biopsy showed negative for malignancy.

The sentinel node is the first lymph node that is affected when cancer spreads from a primary tumor to the lymph nodes. In breast cancer, the sentinel lymph node(s) (SLN) would generally be the lymph node that receives drainage from the breast. Once this node has been identified, it is biopsied (i.e., sampled [sentinel lymph node biopsy, or SLNB]). If these lymph nodes does not contain cancer cells, it is unlikely that the cancer has spread.1 If the SLN contains cancer cells, then an axillary lymph node dissection (ALND; dissection of many nodes throughout the axilla) or complete lymph node dissection (CLND) may be indicated.

We thank, Dr Menatallah Tawfik, Specialist Breast Radiologist, Dr Nadeem Akhtar, Consultant Plastic Surgery and Dr Ehsan Ahmed, Specialist Anatomic Pathology for their kind help and contribution.