Quantification of Intratumoral Metabolic Macroheterogeneity on 18F-FDG PET/CT and Its Prognostic Significance in Pathologic N0 Squamous Cell Lung Carcinoma.
OBJECTIVE
This study aimed to develop a novel quantification method for intratumoral metabolic macroheterogeneity (IMMH) on F-FDG PET/CT and evaluate its prognostic significance in pathologic N0 (pN0) squamous cell lung carcinoma (SQCLC) patients.


METHODS
A total of 83 patients who underwent pretreatment F-FDG PET/CT and were diagnosed with pN0 SQCLC after curative surgery were examined. Patients with tumor measuring greater than 2 cm were included. Metabolic parameters (SUVmax, metabolic tumor volume, and total lesion glycolysis) for the primary lesions were calculated on the F-FDG PET/CT, and IMMH was quantified as the macroheterogeneity factor (MHF), defined as surface/spherical surface area having volume of the primary tumor multiplied by the sphericity. Heterogeneity of the primary tumor was also visually assessed (visual heterogeneity score) and compared with MHF. Univariate and multivariate analyses for recurrence were performed using the Cox proportional hazards regression.


RESULTS
Recurrence was observed in 27 (32.5%) of 83 patients during follow-up period (37.6 ± 25.5 months). Significant correlations were observed between the visual heterogeneity score and the MHF (R = 0.534, P < 0.001). Macroheterogeneity factor was significantly higher in patients who experienced recurrence (median, 1.073 vs 1.016; P = 0.004). Univariate analysis showed that MHF was only significant prognostic factor for recurrence (P = 0.019), and multivariate analysis after adjusting for age, sex, tumor size, histologic grade, and pathologic T stage, high MHF exhibited an association with increased risk of recurrence.


CONCLUSIONS
New quantification method for IMMH on F-FDG PET/CT was developed, and the heterogeneity parameter MHF was well correlated with visual heterogeneity. Macroheterogeneity factor on pretreatment F-FDG PET/CT was the sole prognostic factor predicting recurrence in pN0 SQCLC patients.
From the Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
Do-Hoon
DH
Kim
Ji-Hoon
JH
Jung
Seung Hyun
SH
Son
Choon-Young
CY
Kim
Shin Young
SY
Jeong
Sang-Woo
SW
Lee
Jaetae
J
Lee
Byeong-Cheol
BC
Ahn
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18