PET-CT SUV_max and Endobronchial Ultrasound Features for Prediction of Malignancy: A Prospective Study

Accurate and early staging of lung cancer has a critical impact on its prognosis. EBUS-TBNA is often the procedure of choice for mediastinal staging. Comprehension of the likelihood of malignancy of each lymph node (LN) can assist puncture decision-making during EBUS and offer insight of the procedure expected diagnostic yield.

Prospective analysis of mediastinal LN of patients undergoing EBUS-TBNA from April 2021 to May 2022. The relationship between PET-CT SUV_max levels, EBUS features, and malignancy on LN was investigated. For statistical analysis, patients were assigned to 3 groups: suspected malignancy (diagnosis and/or staging), confirmed malignancy (staging) or suspected benign disease.

A total of 363 LN from 132 patients (71% male, mean 62 years old) were analyzed. Among those with suspected benign disease, no LN puncture resulted in a diagnosis of malignancy. PET-CT SUV_max and short axis size were independent factors for malignancy in LN of patients who underwent EBUS for suspected (p < .001 and p = .047, respectively) or confirmed malignancy (p < .001 and p < .001, respectively). All malignant LN presented SUV_max≥1.85 (≥2.85 for staging EBUS cases) and/or short axis size ≥4.28mm. Vascularized LN were more often malignant in either those with suspected (p = .087) or confirmed (p = .095) malignancy, although not statistically significant. LN that were simultaneously vascularized and lacked central hilar structure were also more commonly malignant (p = .013).

LN that has higher SUV_max and are larger should be prioritized for puncture, followed by those vascularized and lacking central hilar structure. In staging EBUS cases, a systematic sampling (N3-N2-N1) is required and must precede any malignancy yield rationale.