Non-small cells lung carcinoma (NSCLC) represents one of the most common and lethal neoplasms. NSCLC is characterized by an early asymptomatic phase, which hinders the disease identification in its earliest stages. As a consequence, NSCLC is often diagnosed at a clinical stage when the potentially curative surgical approach is challenging. In general, NSCLC up to the TNM stage cT3N2M0 are considered operable; in particular, nodal localizations in the homolateral hilus (N1) and underneath the carina (N2) are considered surgically manageable. Identification of nodal disease on the pre-operative PET/CT does not guarantee that all disease-bearing lymph node will be retrieved in the course of the open operative procedure. Smaller nodes might be challenging to identify; moreover, the co-existence of macroscopic and microscopic disease might hinder the radicality of the surgical intervention. This process can be tracked using specific radioactive radiopharmaceuticals, such as radioisotope-labelled colloids, which can be injected in the immediate proximity of the primary and then travel toward the closest cluster of mediastinal lymph nodes. There, they are incorporated in the nodal structure and progress no farther. By employing a radioisotope probe during surgery, all of the first-line nodes (so-called sentinel lymph node, SLN), which receive the lymphatic flow from the tumor region directly, can be identified.

The hypothesis of the investigators is that, by performing a radioisotope SLN mapping intraoperatively, the surgeons will be able to detect the metastatization process more accurately than relying on pre-operative imaging alone.

The present study will be a prospective and monocentric trial. Clinical, histological, and imaging data collected from examinations performed according to the good clinical practice will be analyzed. The estimated duration of the study is 12 months. It will include the prospective inclusion of patients with a diagnosis of operable NSCLC, who will receive a surgical treatment with curative intent at the investigators' institution (ICH).

Inclusion Criteria:

• Age ≥ 18 years
• Newly diagnosis of stage I-IIIa NSCLC (higher stage could be considered, pending a multidisciplinary evaluation and approval).
• Baseline 18FFDG-PET-CT and ceCT
• Treatment according to good clinical practice

Exclusion criteria:

• Unavailability of baseline images
• Diagnosis other than NSCLC at definitive pathology
• Surgery carried without complete resection or with no curative intent