Performance of tumor growth kinetics as an imaging biomarker for response assessment in colorectal liver metastases: correlation with FDG PET.
OBJECTIVE
To correlate RECIST, volumetric criteria, and tumor growth kinetics at multidetector-computed tomography with tumor metabolic activity at FDG PET in colorectal liver metastases (CRCLM) treated with bevacizumab-based chemotherapy.


METHODS
Thirty-two CRCLM in 20 patients treated with bevacizumab-based chemotherapy were evaluated. Pre- and post-treatment CT scans were used to calculate reciprocal of doubling time (RDT), percentage change in the lesion's longest transaxial diameter (RECIST 1.1), and percentage change in the tumor volume. The accuracy of these parameters in predicting response based on standard uptake value analysis at FDG PET was assessed. Data were analyzed using Spearman's correlation, student's t, Mann-Whitney, Wilcoxon signed-rank, and Fisher's exact tests.


RESULTS
According to FDG PET, 24/32 (75%) lesions were categorized as responders and 8/32 (25%) lesions as nonresponders. Based on RDT, 26/32 (81.25%) lesions were classified as responders and 6/32 (18.75%) lesions as nonresponders. Response classification according to RDT and FDG PET was concordant in 30/32 (93.75%) lesions, whereas RECIST 1.1 and volumetric criteria were concordant with FDG PET for 20/32 (62.5%) and 21/32 (65.63%) lesions, respectively. A strong association was found between RDT and response based on FDG PET (odds ratio = 127.4; 95% CI 5.54-2997; P < 0.0001).


CONCLUSIONS
Tumor growth kinetics may be an effective imaging biomarker for response evaluation in CRCLM.
Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, 676 North Saint Clair Street Suite 800, Chicago, IL, 60611, USA.
Adeel R
AR
Seyal
Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, 676 North Saint Clair Street Suite 800, Chicago, IL, 60611, USA.
Keyur
K
Parekh
Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, 676 North Saint Clair Street Suite 800, Chicago, IL, 60611, USA.
Atilla
A
Arslanoglu
Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, 676 North Saint Clair Street Suite 800, Chicago, IL, 60611, USA.
Fernanda D
FD
Gonzalez-Guindalini
Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, 676 North Saint Clair Street Suite 800, Chicago, IL, 60611, USA.
Sandra M
SM
Tochetto
Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, 676 North Saint Clair Street Suite 800, Chicago, IL, 60611, USA.
Yuri S
YS
Velichko
Department of Radiology, Northwestern Memorial Hospital, Northwestern University-Feinberg School of Medicine, 676 North Saint Clair Street Suite 800, Chicago, IL, 60611, USA. v-yaghmai@northwestern.edu.
Vahid
V
Yaghmai
D000328:Adult; D000368:Aged; D020533:Angiogenesis Inhibitors; D000068258:Bevacizumab; D015415:Biomarkers; D015179:Colorectal Neoplasms / Q000473:pathology*; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D016896:Treatment Outcome
D020533:Angiogenesis Inhibitors; D015415:Biomarkers; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000068258:Bevacizumab
Colorectal cancer; Computed tomography; Liver metastases; RECIST; Tumor growth kinetics