CASES OF THE WEEK – “Usefulness of SPECT-CT sentinel lymph node scintigraphy in malignant melanoma patients, because of the unpredictability of lymphatic drainage, preoperative scintigraphy findings may lead to changes in surgical management (Four short cases)” by Dr ShekharShikare, Consultant & HOD, Nuclear Medicine

CASES OF THE WEEK – “Usefulness of SPECT-CT sentinel lymph node scintigraphy in malignant melanoma patients, because of the unpredictability of lymphatic drainage, preoperative scintigraphy findings may lead to changes in surgical management (Four short cases)” by Dr ShekharShikare, Consultant & HOD, Nuclear Medicine

99MTC LABELED NANO COLLOID CUTANEOUS MALIGNANT MELANOMA

- The procedure of sentinel lymph node biopsy in malignant melanoma evolved from the notion that the tumor spreads through the lymphatic system from the first to subsequent levels.

- As a consequence, the first lymph node encountered (the sentinel lymph node) will most likely be the first affected by metastasis.

- Negative sentinel lymph node biopsy makes it highly unlikely that other nodes in the same lymphatic basin are affected by metastasis.

- This procedure distinguishes patients without nodal metastasis, who can avoid nodal basin dissection with its associated risk of lymphedema from those with metastatic involvement, who benefit from additional therapy.

If sentinel node biopsy is to be useful in the evaluation and treatment of patients with melanoma, a reliable method for localizing these nodes is needed. Lymphoscintigraphy is highly sensitive (>95%) in the localization of sentinel nodes and their lymph node basins. The location of these basins cannot necessarily be predicted from the site of the primary lesion.

Discordance between drainage patterns identified at lymphoscintigraphy and those predicted based on classic anatomic drainage patterns has been reported in 32%–62% of truncal lesions and 63%–84% of head and neck melanomas. The number of sentinel nodes also varies by location. The upper extremity averages slightly more than one sentinel node, and the lower extremity averages 1.8 sentinel nodes the trunk and the head and neck average 1.7 and 2.7 sentinel nodes, respectively. Use of an intraoperative gamma probe can help localize and identify radiolabeled lymph nodes but may not help distinguish sentinel nodes from secondary nodes. The intraoperative blue dye technique, which involves intralesional injection of a blue dye with subsequent visualization of lymphatic channels and lymph nodes, can help confirm the identity of the sentinel node and has been reported to be successful in 80% of cases.

Thus, lymphoscintigraphy with use of an intraoperative Gamma probe and the blue dye technique are complementary rather than competing procedures.

FOUR SHORT CASES:

Case 1- 42 years male is case of melanoma left lower back medially (post operatively), Lymphoscintigraphy SPECT-CT images showed visualization of sentinel lymph nodes (SNLS) seen in both the sides of inguinal region (right side two big and one small & on left side two big and two small SLNS are seen (as shown in mages).

Case 2- 84 years male is case of melanoma right upper shoulder posteriorly (post operatively), Lymphoscintigraphy SPECT-CT images showed visualization of sentinel lymph node (SNL) in right lower cervical region (as shown in mages).

Case 3- 33 years male is case of melanoma right upper back posteriorly (post operatively), Lymphoscintigraphy SPECT-CT images showed visualization of two sentinel lymph nodes (SNLS) in right mid axillary region (as shown in mages).

Case 4- 32 years female is case of melanoma left upper arm laterally (post operatively), Lymphoscintigraphy SPECT-CT images showed visualization of sentinel lymph node (SNL) in left mid axillary region (as shown in mages).

lymphoscintigraphy is recommended as a cost-effective preoperative procedure in all patients planning to undergo elective lymph node dissection. Because of the unpredictability of lymphatic drainage, preoperative scintigraphy findings may lead to changes in surgical management.

Unique Cases 102b Unique Cases 102c Unique Cases 103a Unique Cases 103b