Surgical Oncologist · Hybrid tracer + OR workflow
The dual-modality workflow starts in nuclear medicine the morning of surgery and finishes with ex-vivo confirmation on both channels. Each step has a published reference; the joint NM-OR log carries the AERB and CDSCO trail. Here is the sequence the surgical-oncology team and the radiopharmacy share.
Day before / morning of surgery — Nuclear Medicine
Radiopharmacy compounds ICG-99mTc-nanocolloid as a single hybrid tracer. ICG is pre-bound to the same nanocolloid colloid the NM department already prepares for routine Tc-99m-nanocolloid SLN. One vial, two modalities. The activity range follows standard Tc-99m-nanocolloid SLN practice (10–74 MBq per injection depending on indication); the ICG content sits below the systemic-toxicity threshold by orders of magnitude.
Reference: PMC10250462 (ICG-99mTc-nanocolloid vs ICG-99mTc-nanoscan); LUMC hybrid-tracer development series.
Pre-induction — patient room or holding area
Inject per indication — peri-areolar / peri-tumoural for breast, intradermal at the primary for melanoma, paracervical for cervix / endometrium. Single injection delivers both modalities. The radiopharmacist hands over the syringe per the AERB radioisotope-handling chain; the surgical-oncology team records the time and site of injection in the joint NM-OR log.
Reference: AERB Safety Code for Nuclear Medicine Facility; ASCO / EANM SLN guideline.
Pre-incision — OR
Console boots in gamma mode; the foot-switch tests modality toggle (gamma ↔ fluorescence) before the sterile field is set up. Sterile single-use probe cover applied; the dual probe is handed across the drape. Energy window pre-set to the Tc-99m photopeak; fluorescence excitation laser at standby.
Reference: AORN OR sterile-field practice guideline; manufacturer pre-use checklist.
Initial node localisation — OR
Probe in gamma mode for the initial sweep — the longer-range channel locates the SLN region under the skin. Audio-pitch count rate rises as the probe approaches the hot focus. Mark the skin entry point at the count peak; make the incision; advance toward the node.
Reference: NSABP B-32 (Krag, Lancet Oncol 2010) surgical-technique appendix; MSLT-I (Morton, NEJM 2014) protocol.
Mid-dissection — OR
As the dissection deepens and the gamma signal becomes ambiguous (multiple adjacent hot foci, low signal-to-background near the injection site), foot-switch to fluorescence. The probe reads the ICG NIR signal at the probe tip — inside the wound, at the actual dissection depth. The fluorescence channel disambiguates which of the gamma hot spots is the true SLN.
Reference: Brouwer et al. Eur J Nucl Med Mol Imaging 2014 (dual opto-nuclear characterisation); Van der Vorst Ann Surg Oncol 2012.
Excision + verification — OR
Excise the dual-positive node. Recount the bed (gamma) and check residual fluorescence (NIR). Recount the specimen ex-vivo on both channels — dual-modality confirmation that the right tissue was excised. Repeat for every node within 10 % of the hottest node's count per ASCO guidance. Specimen disposal logged on the AERB chain.
Reference: ASCO SLN-Breast guideline; AERB specimen-disposal log requirement.
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