Sentinel Lymph Node imaging with hybrid SPECT/CT in patients with cancer of the oesophagus or gastro-oesophageal junction.

Patients undergoing potentially curative oesophagectomy and lymphadenectomy. Patients will undergo hybrid SPECT/CT lymphoscintigraphy by means of endoscopically guided intra-tumoral injection of radiocolloid (4 X 0.5 mL in total of 60 MBq 99mTc-nanocoll (GE Healthcare Srl., Milan, Italy). The endocscopy and radiocolloid injection is done by a qualified surgeon with the assistance of a qualified nurse. Patients will undergo this procedure either the day before surgery unless the day of surgery is on a Monday. For logistical reasons, if the surgery is scheduled on a Monday the procedure will instead be done the week before surgery. In the second case, the procedure will be repeated once more on the morning of the day of surgery to allow for intra-operative radio-detection of SLNs. SPECT imaging is to be performed using a 128 x 128 matrix, 64 projections over 360° and 40 s per projection. Total scan time is 42 minutes. CT scans of the same anatomical region will be obtained with 110 kV, 75mAs and pitch 1.3. Iterative reconstruction of the SPECT data will be carried out with an ordered subset estimation maximation (OSEM) method, four iterations, eight subsets including resolution recovery. A gaussian postfiltration is to be applied with 0.75 cm FWHM. The images will be reviewed by qualified dual trained radiologists/nuclear medicine physicians. The location of the Sentinel Lymph Node will classified according to the Japanese Classification of Oesohageal Cancer (11th edition). Locations will be kept on record. Sentinel Lymph Node locations will be demonstrated to the operating surgeons immediately before surgery. Secondly, during surgery (oesophagectomy and lymphadenectomy) the Sentinel Lymph Node will be located intra-operativly by the operating surgeon with the use of a hand held gamma detector. The location of the Sentinel Lymph Node will be kept on record. The Sentinel Lymph Node will be extirpated and labeled accordingly for separate pathological examination. The surgeon will in the same session continue with a lymphadenectomy as part of established clinical routine in this patient group. These Sentinel Lymph Node biopsies will be examined by a qualified pathologist for signs of metastasis. The findings in the Sentinel Lymph Node will be compared to findings of metastatic disease in the rest of the lymph nodes extirpated as part of established clinical routine in this patient group.