D. Ter Woerds*a (Ms), R. Verhoevena (Dr), S. Van Der Heidea (Mr), A. Verhagena (Prof), E. Aarntzena (Dr), E. Van Der Heijdena (Dr)

a Radboudumc, Nijmegen, NETHERLANDS

* desi.terwoerds@radboudumc.nl

Introduction: When early-stage lung cancer preferably treated by surgical resection or targeted radiotherapy. Despite their curative intent, recurrence rates are still high. The implementation of a sentinel lymph node (SLN) procedure could possibly increase staging accuracy by identifying nodes that are most likely to harbour metastasis. A successful SLN procedure is defined by drainage of a tracer to tumour-draining lymph node(s). We investigated the feasibility of an endobronchial SLN procedure by performing multiple injections of a tracer in human ex-vivo lung cancer specimens.

Methods: Ten specimens were acquired of patients who underwent surgery for a lung tumour. Specimens were peri- or intratumourally injected with 99mTc-ICG-nanocolloid (GE Healthcare, USA) using a dose escalation protocol. For injection, an intravascular catheter that combines radial ultrasound (US) visualization with a curved 25.5G needle was used (Philips B.V., the Netherlands). We aimed to determine feasibility of multi-depot injection in and around different tumour types and visibility of these depots on SPECT/CT-imaging.

Results: Of ten specimens, two were ground glass opacities (GGOs) and eight were solid tumours. The median tumour size was 30 mm (range 16-64 mm). Intratumoural US-guided injections were successful in 100% of GGOs and 64.3% of solid tumours. All performed peritumoural US-guided injections in solid tumours were successful. An average total volume of 0.7 ml (range, 0.3-1.2 ml), distributed over an average of 4 injections (range, 3-6 injections) with an average total radioactivity of and 89.5 MBq (range, 35.4-188.0 MBq) were performed. 77.7% of all injected depots could be identified individually on SPECT/CT-images.

Conclusion: Performing a SLN procedure using an endobronchial US-guided injection-catheter seems best feasible when the tracer is injected in a peritumoural fashion. Further research will verify the clinical applicability, lymphatic tracer-drainage for SLN detection and its added value.

Disclosure of funding source(s):

This work or part of this work was supported by departmental unrestricted research grants from Philips, Johnson & Johnson, Astra Zeneca Oncology Netherlands, Pentax Medical Europe.