RSNA 2014 

Abstract Archives of the RSNA, 2014


MKS380

Histogram Analysis of Iodine Maps from Dual Energy CT: Evaluation of an Objective Response Criterion for Monitoring Targeted Therapy of Melanoma Patients

Scientific Posters

Presented on December 3, 2014
Presented as part of MKS-WEA: Musculoskeletal Wednesday Poster Discussions

Participants

Monika Uhrig MD, DIPLPHYS, Presenter: Nothing to Disclose
David Simons MD, Abstract Co-Author: Nothing to Disclose
Marika Ganten MD, Abstract Co-Author: Nothing to Disclose
Jessica Hassel, Abstract Co-Author: Nothing to Disclose
Heinz-Peter Schlemmer MD, Abstract Co-Author: Nothing to Disclose

PURPOSE

Radiologic monitoring of molecular targeted therapy is essential. Routine CT-follow only focuses on the quantification of tumor size changes, a method which is known to be limited. Contrast-enhanced dual energy CT (DECT) enables additionally within one single examination quantitative assessment of contrast media uptake of tumors. Our purpose was to investigate patterns of contrast media enhancement under targeted therapy by performing histogram analyses (HA) of iodine maps based on DECT.

METHOD AND MATERIALS

11 stage IV-melanoma patients underwent DECT at baseline, follow up (FU) 1 and FU 2. Volume segmentation of 28 metastases was performed semi-automatically. Iodine uptake (IU) and HA including standard deviation (STD), maximum (max) and mean of 8 RECIST-responders (4 male, 4 female, mean age 63) to BRAF-inhibitor (BRAF-I) therapy was investigated. Furthermore one mixed responder to BRAF-inhibitor as well as two patients under ipilimumab (IPI)-therapy (1 responder, 1 non-responder) are presented.

RESULTS

In general, histograms of responder reveal a characteristic pattern including narrower shape and means moving towards origin. For BRAF-responder mean, max and STD of the iodine histograms decrease significantly (p<0.05 at FU 2). Progressive tumor parts show an increase of max and STD, while mean can also decrease. Histograms monitoring IPI treatment behave analogously.

CONCLUSION

HA of iodine maps based on DECT revealed a typical pattern of contrast media enhancement. It has potential to add an objective and functional criterion to traditional size measurements of standard CT examinations without additional radiation exposure to the patient. DECT can therefore contribute to accurate response assessment of targeted therapies in clinical routine.

CLINICAL RELEVANCE/APPLICATION

DECT enables quantification and histogram analysis of contrast media which allows for accurate response assessment of targeted therapy in order to avoid potential toxicity and escalating costs.

Cite This Abstract

Uhrig, M, Simons, D, Ganten, M, Hassel, J, Schlemmer, H, Histogram Analysis of Iodine Maps from Dual Energy CT: Evaluation of an Objective Response Criterion for Monitoring Targeted Therapy of Melanoma Patients.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017079.html