PT - JOURNAL ARTICLE AU - Kathy Willowson AU - Dale Bailey AU - Clive Baldock AU - Geoff Schembri TI - Validation of CT-based quantitative SPECT for Tl-201 imaging in brain tumours DP - 2009 May 01 TA - Journal of Nuclear Medicine PG - 1506--1506 VI - 50 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/50/supplement_2/1506.short 4100 - http://jnm.snmjournals.org/content/50/supplement_2/1506.full SO - J Nucl Med2009 May 01; 50 AB - 1506 Objectives To achieve fully quantitative 201Tl SPECT data based on x-ray CT derived corrections for attenuation, scatter and partial volume effects, and to explore the possibility of using the method clinically in the investigation of brain tumour recurrence. Methods A previously validated technique for CT-based quantitative 99mTc SPECT was extended to include 201Tl. Evaluation was perfomed by comparing true and calculated activity concentrations in a cylindrical phantom and a RSI Striatal Brain phantom with three "lesions" of differing activities and target-to-background ratios in the simulated striatal compartments. The method was used to analyse a series of patient studies of recurrent brain tumours to explore the possibility of an SUV-like (Standardised Uptake Value) measure and how this might relate to prediction of recurrence and survival. Results The quantitative method calculated the total activity and concentration in the cylindrical phantom to within 3% and 1% of the true values, respectively. The activity concentrations (kBq/mL) calculated in the background and simulated "lesions" of the brain phantom were within 2%, 10%, 1% and 2% of the true values respectively. Initial analysis of patient glioma studies indicate that the quantitative method produces SUV measures that correlate with patient survival. Conclusions The quantitative technique has been validated in a realistic object and found to produce accurate results for the 201Tl. Initial investigation in clinical brain SPECT suggests a correlation exists between quantitative uptake (SUV) and survival.