How long the lymphoscintigraphy imaging should be continued for sentinel lymph node mapping?

Area of Science:

• Nuclear Medicine
• Oncology
• Surgical Oncology

Background:

• Sentinel lymph node (SLN) biopsy is crucial for staging early breast cancer.
• Accurate SLN detection impacts treatment decisions and patient prognosis.
• Optimizing lymphoscintigraphy protocols can improve efficiency and patient care.

Purpose of the Study:

• To evaluate the necessity of delayed lymphoscintigraphy imaging for SLN biopsy in early breast cancer.
• To determine the optimal imaging time for (99m)Tc-antimony sulfide colloid lymphoscintigraphy.
• To assess the impact of prior excisional biopsy on SLN detection rates.

Main Methods:

• Seventy-five early breast cancer patients underwent SLN biopsy.
• Intradermal injection of (99m)Tc-antimony sulfide colloid was administered periareolar or around the incision sites.
• Static lymphoscintigraphy images were acquired at 2 minutes, with delayed imaging up to 180 minutes if SLN was not visualized.

Main Results:

• The overall SLN detection rate was 96% (72/75).
• SLNs were identified on immediate (2-minute) images in 73.33% of patients.
• Delayed imaging up to 30 minutes was sufficient for SLN detection in the remaining patients; 4% of patients had no SLN detected by lymphoscintigraphy or surgery.

Conclusions:

• Lymphoscintigraphy for SLN biopsy using (99m)Tc-antimony sulfide colloid can be completed promptly.
• Delayed imaging beyond 30 minutes is generally not required, streamlining the nuclear medicine process.
• The study supports efficient SLN detection protocols without compromising accuracy in early breast cancer patients.