Two-day lymphoscintigraphic imaging for melanoma.

Area of Science:

• Oncology
• Nuclear Medicine
• Surgical Pathology

Background:

• Sentinel lymph node (SLN) biopsy is crucial for melanoma staging.
• Current practice often involves same-day injection and imaging for SLN mapping.
• Delayed imaging may offer scheduling benefits and reduce background radioactivity.

Purpose of the Study:

• To evaluate the efficacy of 2-day lymphoscintigraphy compared to 1-day imaging for melanoma staging.
• To determine if next-day imaging affects the identification of lymph node basins and patterns.

Main Methods:

• Retrospective review of 172 melanoma patients undergoing 2-day lymphoscintigraphy.
• Comparison of lymph node basin and pattern identification on same-day versus next-day imaging.
• Analysis of node disappearance in relation to time post-injection.

Main Results:

• No significant difference in identified lymph node basins between same-day and next-day imaging (P=0.08), excluding non-surgical basins.
• Node patterns were generally consistent, with some nodes disappearing after 19-22 hours.
• The number of identified nodes remained stable or declined slightly in most cases on day 2.

Conclusions:

• Two-day lymphoscintigraphy is a viable alternative to 1-day imaging for melanoma SLN mapping.
• Effective detection is maintained if imaging occurs within 19 hours of radiocolloid injection.
• This approach can facilitate scheduling without compromising diagnostic accuracy.