Detection and Viability of Colorectal Liver Metastases After Neoadjuvant Chemotherapy: A Multiparametric PET/CT-MRI Study.
OBJECTIVE
The aim of this study was to compare combined gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA)-enhanced and diffusion-weighted (DW) MRI with IV contrast-enhanced F-FDG PET/CT to detect and assess the viability of colorectal liver metastases (CLMs) after neoadjuvant chemotherapy (NAC).


METHODS
After NAC, 45 patients with CLMs were prospectively enrolled and underwent combined Gd-EOB-DTPA-enhanced and DW-MRI and contrast-enhanced F-FDG PET/CT. Forty patients subsequently underwent surgery based on intraoperative ultrasound, which served as the reference standard for the presence of CLMs. The number of metastases detected by each technique was then compared. In 69 resected metastases, the SUVmean and SUVmax, mean and maximum target-to-background ratio (TBR), total lesion glycolysis, metabolic tumor volume, and mean and minimum apparent diffusion coefficient (ADC) were examined to identify correlations with the corresponding tumor viability (TV) determined from histological specimens.


RESULTS
Intraoperative ultrasound revealed 153 CLMs, 122 of which were resected. The detection rate of MRI and contrast-enhanced F-FDG PET/CT were similar (P = 0.61). The SUVmax and minimum ADC were negatively correlated (r = -0.34, P = 0.005) on preoperative imaging after NAC. However, TV was significantly correlated with the maximum TBR (r = 0.33, P = 0.006) and mean TBR (r = 0.37, P = 0.002), but not with the minimum ADC (r = -0.02, P = 0.9) or mean ADC (r = 0.01, P = 0.9).


CONCLUSIONS
Combined Gd-EOB-DTPA-enhanced and DW-MRI and contrast-enhanced F-FDG PET/CT allow confident detection of CLMs, but only F-FDG PET metrics are associated with TV after NAC.
From the Departments of *Diagnostic and Interventional Radiology, †Visceral Surgery, and ‡Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Lausanne; §Department of Radiology, Riviera and Chablais Hospitals, Vevey; and ∥Institute of Pathology, Lausanne University Hospital, Lausanne, Switzerland.
Vincent
V
Dunet
Nermin
N
Halkic
John O
JO
Prior
Anass
A
Anaye
Reto A
RA
Meuli
Christine
C
Sempoux
Alban
A
Denys
Sabine
S
Schmidt
D000368:Aged; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18; D019786:Gadolinium DTPA; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000556:secondary; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals
D003287:Contrast Media; D019275:Radiopharmaceuticals; C073590:gadolinium ethoxybenzyl DTPA; D019788:Fluorodeoxyglucose F18; D019786:Gadolinium DTPA