Retention index of FDG-PET/CT SUVmax of the primary tumor in non-small cell lung cancer as a predictor of lymph node metastasis: a retrospective study

Abstract

Background Accurate staging of non-small cell lung cancer is key in treatment planning and prediction of prognosis. We investigated the correlation between the maximum standardized uptake value (SUVmax) retention index (RI) of the primary tumor and lymph node metastasis in non-small cell lung carcinoma. We also evaluated the tendencies according to the histological types. Methods We retrospectively evaluated 218 non-small cell lung cancer (NSCLC) tumors from 217 patients who underwent preoperative fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) followed by lung surgery and lymph node resection between July 2015 and August 2020. All primary tumors were calculated as the SUVmax at 50 min (SUVmaxearly [SUVmaxe]) and 120 min (SUVmaxdelayed [SUVmaxd]), and RI. The clinicopathological factors of interest were compared based on lymph node metastasis status and NSCLC histopathological subtype. Results The median SUVmaxe and SUVmaxd of the primary tumors were 3.3 and 4.2, respectively, and the median RI was 0.25. The RI was significantly higher in the pN(+) (n = 44) group (0.30) compared to the pN0 (n = 174) group (0.24) (p = 0.01). In patients with adenocarcinoma (n = 145), the RI was also significantly higher in the pN(+) (n = 29) group (0.29) compared to the pN0 (n = 116) group (0.16) (p < 0.01). A high RI of the primary tumor was an independent risk factor for lymph node metastasis, particularly in patients with adenocarcinoma (odds ratio: 12.30, p < 0.05). Conclusions The RI of primary NSCLC tumors can help predict lymph node metastases, particularly in patients with adenocarcinoma.

The Utility of 18F-FDG-PET–CT Metabolic Parameters in Evaluating the Primary Tumor Aggressiveness and Lymph Node Metastasis of Nasopharyngeal Carcinoma

“… 33 A study unveiled an association between the retention index (calculated as the difference between SUV max delayed point and SUV max early point, divided by SUV max early point) of the primary tumor and a heightened likelihood of LN metastasis in patients afflicted by non-small cell lung cancer (NSCLC). 34 Another study illustrated that the SUV max of the mediastinal LNM and primary tumor SUV max , SUV peak , SUV mean , MTV, and TLG were significantly associated with the presence of mediastinal LNM in NSCLC. In particular, the study found a strong correlation between the mediastinal LNM SUV max , the primary tumor SUV peak , and the occurrence of mediastinal LNM in patients with NSCLC.…”

Standardized uptake valuemax of the primary lesion combined with tumor markers for clinically predicting distant metastasis in de novo lung adenocarcinoma

“…Studies have shown that both imaging and TMs can be applied in diagnostic approaches for distant metastasis of lung adenocarcinoma, but the prediction accuracy of a single indicator is insufficient 14,18,19,24 . Recently, the joint application of 18 F‐FDG PET/CT and TMs in the diagnosis of recurrence and metastasis has attracted huge attentions in lung cancers 9,25 . 18F‐FDG PET/CT can provide anatomical and metabolic information about lesions 24 .…”

“…The evaluation of such parameters may be helpful in clinic for assessing whether lung adenocarcinomas have elevated odds of developing distant metastasis at presentation. Previously, researchers had paid more attention to differentiate between lymph node metastasis and benign lymph node lesions 9,25 . Nevertheless, it is equally important to identify the presence of distant metastasis for proper patient management 30 .…”

“…14,18,19,24 Recently, the joint application of 18 F-FDG PET/CT and TMs in the diagnosis of recurrence and metastasis has attracted huge attentions in lung cancers. 9,25 18F-FDG PET/CT can provide anatomical and metabolic information about lesions. 24 In the present study, compared with the non-metastatic patients, the pSUVmax of the primary lesion was significantly elevated in the metastatic patients.…”

“…Previously, researchers had paid more attention to differentiate between lymph node metastasis and benign lymph node lesions. 9,25 Nevertheless, it is equally important to identify the presence of distant metastasis for proper patient management. 30 This work highly indicates proper use of pSUVmax, LDH, CEA, CYFRA211, and CA125 could indicate distant metastasis.…”