Imaging of cellular proliferation in liver metastasis by [18F]fluorothymidine positron emission tomography: effect of therapy.

Abstract

Although [(18)F]fluorothymidine positron emission tomography (FLT-PET) permits estimation of tumor thymidine kinase-1 expression, and thus, cell proliferation, high physiological uptake of tracer in liver tissue can limit its utility. We evaluated FLT-PET combined with a temporal-intensity information-based voxel-clustering approach termed kinetic spatial filtering (FLT-PET(KSF)) for detecting drug response in liver metastases. FLT-PET and computed tomography data were collected from patients with confirmed breast or colorectal liver metastases before, and two weeks after the first cycle of chemotherapy. Changes in tumor FLT-PET and FLT-PET(KSF) variables were determined. Visual distinction between tumor and normal liver was seen in FLT-PET(KSF) images. Of the 33 metastases from 20 patients studied, 26 were visible after kinetic filtering. The net irreversible retention of the tracer (Ki; from unfiltered data) in the tumor, correlated strongly with tracer uptake when the imaging variable was an unfiltered average or maximal standardized uptake value, 60 min post-injection (SUV(60,av): r = 0.9, SUV(60,max): r = 0.7; p < 0.0001 for both) and occurrence of high intensity voxels derived from FLT-PET(KSF) (r = 0.7, p < 0.0001). Overall, a significant reduction in the imaging variables was seen in responders compared to non-responders; however, the two week time point selected for imaging was too early to allow prediction of long term clinical benefit from chemotherapy. FLT-PET and FLT-PET(KSF) detected changes in proliferation in liver metastases.

• Authors: Kaiyumars Contractor, Amarnath Challapalli, Giampaolo Tomasi, Lula Rosso, Harpreet Wasan, Justin Stebbing, Laura Kenny, Stephen Mangar, Pippa Riddle, Carlo Palmieri, Adil Al-Nahhas, Rohini Sharma, Federico Turkheimer, R Charles Coombes, Eric Aboagye
• Journal: Physics in medicine and biology (Phys Med Biol) Vol. 57 Issue 11 Pg. 3419-33 (Jun 07 2012) ISSN: 1361-6560 [Electronic] England
• PMID: 22572708 (Publication Type: Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Dideoxynucleosides
• alovudine

Topics

• Aged
• Breast Neoplasms (pathology)
• Cell Proliferation (drug effects)
• Colorectal Neoplasms (pathology)
• Dideoxynucleosides
• Female
• Humans
• Liver Neoplasms (diagnostic imaging, drug therapy, pathology, secondary)
• Male
• Middle Aged
• Positron-Emission Tomography
• Treatment Outcome