"sentinel lymph node imaging with sequential SPECT/CT lymphoscintigraphy before and after neoadjuvant chemoradiotherapy in patients with cancer of the oesophagus or gastro-oesophageal junction - A pilot study"

Background: In current best practise, curatively intended treatment for oesophageal cancer usually consists of neoadjuvant chemo-radiotherapy (nCRT) or perioperative chemotherapy, and oesophagectomy. Sentinel Lymph Node Biopsy (SLNB) has the potential to identify patients without lymph node metastases and thus improve the staging accuracy and influence treatment. The impact of neoadjuvant treatment on the lymphatic drainage of oesophageal cancers and subsequently the SLNB procedure in this tumour type has previously not been well studied. Purpose: To evaluate changes in lymphatic drainage patterns of the tumour in patients with cancer of the oesophagus or gastro-oesophageal junction (GOJ) using Sentinel Lymph Node (SLN) hybrid SPECT/CT lymphoscintigraphy before and after nCRT. Methods: Patients with clinical stage T2-T3, any N-stage, M0 cancer of the oesophagus or GOJ underwent endoscopically guided peri-/intratumoral injection of radio-colloid followed by hybrid SPECT/CT lymphoscintigraphy prior to, and once again following, nCRT. SPECT/CT images were evaluated to number and location of SLNs and compared between the two examinations. Results: Ten patients were included in this pilot trial. SPECT/CT lymphoscintigraphy was performed in twenty procedures. The same Sentinel Lymph Node station before and after nCRT was observed in one single patient. In two patients, no SLN was detected before nCRT. In three patients no SLN was detected following nCRT. In four patients, the SLN stations were not the same station at baseline compared to follow-up examination. Conclusions: The reproducibility SLN detection in patients with cancer of the oesophagus/GOJ following nCRT was very poor. nCRT appears to alter lymphatic drainage patterns and thus may affect detection of SLNs and potentially also the accuracy of an SLNB in these patients. On the basis of these initial results, we abort further patient recruitment in our institution. Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR). Identifier ACTRN12618001433291. Date registered: 27/08/2018. Retrospectively registered.