RT Journal Article
SR Electronic
T1 Multifunctional Imaging Signature for V-KI-RAS2 Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) Mutations in Colorectal Cancer
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 386
OP 391
DO 10.2967/jnumed.113.120485
VO 55
IS 3
A1 Miles, Kenneth A.
A1 Ganeshan, Balaji
A1 Rodriguez-Justo, Manuel
A1 Goh, Vicky J.
A1 Ziauddin, Zia
A1 Engledow, Alec
A1 Meagher, Marie
A1 Endozo, Raymondo
A1 Taylor, Stuart A.
A1 Halligan, Stephen
A1 Ell, Peter J.
A1 Groves, Ashley M.
YR 2014
UL http://jnm.snmjournals.org/content/55/3/386.abstract
AB This study explores the potential for multifunctional imaging to provide a signature for V-KI-RAS2 Kirsten rat sarcoma viral oncogene homolog (KRAS) gene mutations in colorectal cancer. Methods: This prospective study approved by the institutional review board comprised 33 patients undergoing PET/CT before surgery for proven primary colorectal cancer. Tumor tissue was examined histologically for presence of the KRAS mutations and for expression of hypoxia-inducible factor-1 (HIF-1) and minichromosome maintenance protein 2 (mcm2). The following imaging parameters were derived for each tumor: 18F-FDG uptake (18F-FDG maximum standardized uptake value [SUVmax]), CT texture (expressed as mean of positive pixels [MPP]), and blood flow measured by dynamic contrast-enhanced CT. A recursive decision tree was developed in which the imaging investigations were applied sequentially to identify tumors with KRAS mutations. Monte Carlo analysis provided mean values and 95% confidence intervals for sensitivity, specificity, and accuracy. Results: The final decision tree comprised 4 decision nodes and 5 terminal nodes, 2 of which identified KRAS mutants. The true-positive rate, false-positive rate, and accuracy (95% confidence intervals) of the decision tree were 82.4% (63.9%–93.9%), 0% (0%–10.4%), and 90.1% (79.2%–96.0%), respectively. KRAS mutants with high 18F-FDG SUVmax and low MPP showed greater frequency of HIF-1 expression (P = 0.032). KRAS mutants with low 18F-FDG SUVmax, high MPP, and high blood flow expressed mcm2 (P = 0.036). Conclusion: Multifunctional imaging with PET/CT and recursive decision-tree analysis to combine measurements of tumor 18F-FDG uptake, CT texture, and perfusion has the potential to identify imaging signatures for colorectal cancers with KRAS mutations exhibiting hypoxic or proliferative phenotypes.