Clinical use of 18F-FDG PET/CT in the differential diagnosis of patients with primary and secondary adenoid cystic carcinoma of the lung: a retrospective cohort study

Abstract

Background: Adenoid cystic carcinoma (ACC) of the lung (ACCL) is a rare malignancy and includes primary ACCL (PACCL) and secondary ACCL (SACCL) metastasized from the ACC of the head and neck.Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) has been shown to be useful in the differential diagnosis between primary and metastatic lung lesions. This study retrospectively investigated the role of 18 F-FDG PET/CT in combination with clinicopathological findings in the management of patients with primary or secondary ACCL.Methods: Clinicopathological characteristics and 18 F-FDG PET/CT metabolic parameters of 29 patients with PACCL and 11 patients with SACCL with pathological confirmation as gold standard were retrospectively collected. The association between PET/CT metabolic parameters and clinicopathological features was explored. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal maximum standard uptake value (SUV max ) cut-off value to distinguish PACCL from SACCL. The prognostic value of PET/CT metabolic parameters and clinicopathological features was evaluated by Cox regression analysis.Results: SACCL patients more often presented with multiple ACC lesions in the peripheral lung (81.8% vs. 17.2%, P<0.05) and tended to be asymptomatic compared to patients with PACCL (72.7% versus 27.6%, P<0.05). The SUV max was significantly higher in PACCL patients compared to SACCL patients (median 4.4 vs. 2.8, P<0.05). Furthermore, at a cut-off value of 3.2 for SUV max , the sensitivity and specificity of 18 F-FDG PET/CT in distinguishing PACCL from SACCL were 82.8% and 72.7%, respectively. Higher SUV max of ACCL was observed in patients with clinical symptoms, fewer ACC lesions, or larger tumor size (P<0.05).The median PFS of ACCL patients was 71.1 months, and the 12-and 24-month PFS rates were 96.1% and 91.6%, respectively. Univariate Cox regression analysis showed that SACCL from metastasis, lesions located ^ ORCID: 0000-0002-9479-132X. reporting checklist (available at https://tlcr.amegroups.com/ article/view/10.21037/tlcr-22-509/rc). Methods PatientsA total of 40 consecutive patients with pathologically confirmed ACCL who underwent 18 F-FDG PET/ CT examination in the Guangdong Provincial People's Hospital or the Shanghai Pulmonary Hospital from July 2008 to May 2021 were retrospectively included in this study. The following inclusion criteria were applied: (I) patients underwent tumor resection or puncture biopsy for pathological type confirmation within 2 weeks after the 18 F-FDG PET/CT scan; (II) patients could have a history at the peripheral lung or multiple ACC lesions present in the lung, were associated with poorer PFS (P<0.05).However, multivariate Cox regression analysis showed that none of the variables examined were independent predictors of prognosis.Conclusions: The use of 18 F-FDG PET/CT in combination with assessment of clinicopathological features was helpful in distinguishing PACCL from SACCL, which could provide guidan...

Pulmonary adenoid cystic carcinoma ‐ a spectrum of disease: two case reports

“…This translates to high sensitivity in those post treatment looking for residual or recurrent disease on surveillance imaging. 10 Due to its rarity and the lack of prospective data, no guidelines have been established on the management of PACCs and information is largely extrapolated from institutional experiences and published case reports.…”

“…CT is the most common modality but with increasing interest is PET‐CT, with primary PACCs and distant metastases demonstrating intense FDG activity. This translates to high sensitivity in those post treatment looking for residual or recurrent disease on surveillance imaging 10 …”

“…This translates to high sensitivity in those post treatment looking for residual or recurrent disease on surveillance imaging. 10 …”