Nucl Med Mol Imaging.  2017 Jun;51(2):147-153. 10.1007/s13139-016-0449-2.

Comparison of Quantitative Methods on FDG PET/CT for Treatment Response Evaluation of Metastatic Colorectal Cancer

• Bang JI
• Lim Y
• Paeng JC
• Han SW
• Park S
• Lee JM
• Kim HJ
• Cheon GJ
• Lee DS
• Chung JK
• Kim TY
• Kang KW

• KMID: 2446895
• DOI: http://doi.org/10.1007/s13139-016-0449-2

Abstract

PURPOSE
FDG PET is effective in treatment response evaluation of cancer. However, there is no standard method for quantitative evaluation of FDG PET, particularly regarding cytostatic drugs. We compared various FDG PET quantitative methods in terms of response determination.
METHODS
A total of 39 refractory metastatic colorectal cancer patients who received a multikinase inhibitor treatment were included. Baseline and posttreatment FDG PET/CT scans were performed before and two cycles after treatment. Standardized uptake value (SUV) and total lesion glycolysis (TLG) values using various margin thresholds (30-70 % of maximum SUV with increment 10 %, twice mean SUV of blood pool, SUV 3.0, and SUV 4.0) were measured, with measurement target of the hottest lesion or a maximum of five hottest lesions. Treatment response by the PERCIST criteria was also determined. Predictive values of the PET indexes were evaluated in terms of the treatment response determined by the RECIST 1.1 criteria.
RESULTS
The agreement rate was 38 % between response determined by the PERCIST and the RECIST criteria (κ = 0.381). When patients were classified into disease control group (PR, SD) and non-control group (PD) by the RECIST criteria, percent changes of TLG with various margin thresholds (particularly, 30-50%of maximum SUV) exhibited significant differences between the two groups, and high diagnostic power for the response by the RECIST criteria. TLG-based criteria, which used a margin threshold of 50 % of maximum SUV, exhibited a high agreement with the RECIST criteria compared with the PERCIST criteria (κ = 0.606).
CONCLUSION
In metastatic colorectal cancer, FDG PET/CT could be effective for treatment response evaluation by using TLG measured by margin thresholds of 30-50%of maximum SUV. Further studies are warranted regarding the optimal cutoff values for this method.

Keyword

Colorectal neoplasm; Fluorodeoxyglucose F18; Positron-emission tomography; Therapy

MeSH Terms

Colorectal Neoplasms*
Cytostatic Agents
Evaluation Studies as Topic
Fluorodeoxyglucose F18
Glycolysis
Humans
Methods*
Positron-Emission Tomography
Positron-Emission Tomography and Computed Tomography*
Response Evaluation Criteria in Solid Tumors
Cytostatic Agents
Fluorodeoxyglucose F18