SentiNose – Evaluation of Sentinel Lymph Node Biopsy as a Treatment Option for Nasal Tumors

Sinonasal squamous cell carcinoma (SNSCC) is a rare, malignant tumor of the nasal cavity or paranasal sinuses and is classified as a head and neck tumor. Because the disease is often diagnosed at a late stage, there is an increased risk that tumor cells will spread via the lymphatic system. Although enlarged or abnormal lymph nodes are often not present at the time of initial diagnosis (no clinical lymph node involvement), so-called micrometastases—that is, tiny metastases that are not initially visible—may already be present. Currently, there are three treatment approaches for managing the cervical lymph nodes at the time of diagnosis: Either they are initially monitored only, completely removed as a preventive measure (a safe but relatively invasive method that may be associated with side effects), or the less invasive procedure of sentinel lymph node biopsy is used. The sentinel lymph node biopsy is an established procedure that is already being used successfully, for example, in the treatment of breast cancer or melanoma. In this procedure, only the lymph nodes that serve as the first “stop” in the tumor’s lymphatic drainage—and are therefore most likely to be affected by metastases—are specifically removed.

The aim of this study is to investigate whether the sentinel lymph node biopsy procedure is also safe and feasible for tumors in the nasal region. Prior to surgery, an imaging examination (positron emission tomography/magnetic resonance imaging, PET/MRI) is performed using a radiocolloid tracer to mark the lymph nodes. This means that shortly before surgery, a weakly radioactive substance is injected near the tumor. This substance spreads through the lymphatic vessels and reaches the lymph nodes, which are the first to receive lymph fluid from the tumor area. This makes it easier to identify these lymph nodes during the procedure and remove them specifically. The removed lymph nodes are then examined for previously undetectable micrometastases. All patients receive this treatment; the study is a single-arm trial. The study has several objectives aimed at comprehensively evaluating the use of sentinel lymph node biopsy in sinonasal squamous cell carcinomas. The central question is how safe the procedure is, particularly with regard to potential surgery-related complications (surgical morbidity). At the same time, the study examines how reliably the method can detect hidden lymph node metastases—that is, how high the so-called detection rate is. In addition, another part of the study examines the diagnostic value of a PET/MRI scan for lymph node staging. To this end, the imaging findings will be compared with the pathological results of the excised sentinel lymph nodes. In addition, certain radiological parameters will be analyzed for their prognostic value. Another objective is to record the length of the hospital stay following the procedure in order to better assess the burden on patients. Patients will be followed for up to 5 years as part of the study.

Eligible participants are patients aged 18 and older with a newly diagnosed squamous cell carcinoma of the nose or paranasal sinuses (SNSCC) with no evidence of lymph node involvement and a tumor that is resectable. Participation in the study requires good physical condition (ECOG ≤ 2, Karnofsky ≥ 60%). Excluded are, among others, patients with a history of tumors in the head and neck region, clinically visible metastases, serious comorbidities (e.g., heart failure, liver cirrhosis), or previous neck surgery.