La linfogammagrafía in vivo de los tumores del seno nasal identifica el ganglio retrofaríngeo y el nivel I como ganglios centinela predominantes

Abstract

Objective

To evaluate by in vivo lymphoscintigraphy and SPECT-CT imaging, the lymphatic drainage patterns of para-nasal sinus (PNS) tumours. To confirm or refute the belief of the retropharyngeal lymph node (RPLN) being the significant draining lymph node for such tumours.

Methods

Prospective cohort study conducted on previously untreated PNS tumours with no clinico-radiological evidence of lymph node metastasis. Lymphoscintigraphy undertaken by nasal endoscopic assisted peritumoral injection of ^99mTc sulphur colloid. Injections were classified as anterior or posterior as per a vertical line along the maxillary sinus ostium.

Results

Seventeen patients were included. Lymphoscintigraphy successfully identified 17 sentinel nodes in 15 patients and was unsuccessful (lymphoscintigraphy failure) in 2 patients. Predominant sites of sentinel lymphatic drainage were noted to be the RPLN (n = 8; 47%) and level I (n = 7; 42%). Occasional drainage was identified at the peri-parotid node (n = 1) and at level II (n = 1). Contralateral drainage was noted in 2 patients (level I-1 and RPLN-1).

Anterior injections drained predominantly to level I (6/8) and RPLN (2/8), while posterior injections drained predominantly to the RPLN (6/7). The relative risk of RPLN being identified as the sentinel node was significantly higher for posteriorly placed injections than for anteriorly placed injections (RR: 3.43; 95% CI: 1.0-11.8; P=.05).

Conclusion

The RPLN is noted as a frequent draining node for sino-nasal tumours and merits routine attention in all sino-nasal tumours. The radio-colloid SPECT-CT technique described here offers an excellent in vivo technique to further explore and validate the lymphatic drainage pathways of these tumours.