qPET - a quantitative extension of the Deauville scale to assess response in interim FDG-PET scans in lymphoma.
Eur J Nucl Med Mol Imaging
; 41(7): 1301-8, 2014 Jul.
Article
in En
| MEDLINE
| ID: mdl-24604592
ABSTRACT
BACKGROUND:
Interim FDG-PET is used for treatment tailoring in lymphoma. Deauville response criteria consist of five ordinal categories based on visual comparison of residual tumor uptake to physiological reference uptakes. However, PET-response is a continuum and visual assessments can be distorted by optical illusions.OBJECTIVES:
With a novel semi-automatic quantification tool we eliminate optical illusions and extend the Deauville score to a continuous scale. PATIENTS ANDMETHODS:
SUVpeak of residual tumors and average uptake of the liver is measured with standardized volumes of interest. The qPET value is the quotient of these measurements. Deauville scores and qPET-values were determined in 898 pediatric Hodgkin's lymphoma patients after two OEPA chemotherapy cycles.RESULTS:
Deauville categories translate to thresholds on the qPET scale Categories 3, 4, 5 correspond to qPET values of 0.95, 1.3 and 2.0, respectively. The distribution of qPET values is unimodal with a peak representing metabolically normal responses and a tail of clearly abnormal outliers. In our patients, the peak is at qPET = 0.95 coinciding with the border between Deauville 2 and 3. qPET cut values of 1.3 or 2 (determined by fitting mixture models) select abnormal metabolic responses with high sensitivity, respectively, specificity.CONCLUSIONS:
qPET methodology provides semi-automatic quantification for interim FDG-PET response in lymphoma extending ordinal Deauville scoring to a continuous scale. Deauville categories correspond to certain qPET cut values. Thresholds between normal and abnormal response can be derived from the qPET-distribution without need for follow-up data. In our patients, qPET < 1.3 excludes abnormal response with high sensitivity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Image Processing, Computer-Assisted
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Hodgkin Disease
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Fluorodeoxyglucose F18
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Positron-Emission Tomography
Type of study:
Prognostic_studies
Limits:
Adolescent
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Child
/
Humans
Language:
En
Journal:
Eur J Nucl Med Mol Imaging
Journal subject:
MEDICINA NUCLEAR
Year:
2014
Document type:
Article
Affiliation country: