Lymphoscintigraphy for malignant melanoma. Surgical considerations

Area of Science:

• Oncology
• Nuclear Medicine
• Surgical Oncology

Background:

• Accurate identification of regional lymphatic drainage is crucial for staging and treatment of melanoma.
• Conventional methods may not precisely delineate lymphatic pathways, potentially leading to suboptimal surgical planning.

Purpose of the Study:

• To investigate regional lymphatic drainage patterns in melanoma patients using lymphoscintigraphy.
• To assess the utility of lymphoscintigraphy in predicting nodal metastases and guiding surgical interventions.

Main Methods:

• Lymphoscintigraphy with technetium-99m antimony sulfur colloid was performed in 22 melanoma patients.
• Analysis of lymphatic drainage patterns from primary lesions on the lower extremities, scalp, and trunk.
• Correlation of imaging findings with subsequent nodal metastasis development over a 3-year follow-up.

Main Results:

• Lower extremity melanomas primarily drained to inguinal nodes, bypassing popliteal nodes.
• Posterior scalp melanomas showed drainage to posterior cervical nodes, not parotid or anterior neck nodes.
• Lesions near the midline or Sappey's line exhibited predictable drainage patterns, and no metastases occurred in non-draining nodal basins.

Conclusions:

• Lymphoscintigraphy effectively maps melanoma lymphatic drainage, informing surgical approaches like neck dissections.
• The technique accurately identifies at-risk nodal basins, preventing unnecessary surgery in non-draining areas.
• No nodal metastases were found in areas without visualized colloidal uptake, validating the predictive value of lymphoscintigraphy.