Figure 2. Quantitative PET/CT measurement of DOTATOC uptake by Jurkat tumors and statistical analysis.

(A) Tumor volume (mm³) plotted against number of days after xenograft. (B) Measured DOTATOC uptake is quantified as percentage injection dose per volume (%ID/cm³) for Jurkat tumors (100%–0% SSTR2⁺) over the course of tumor growth. (C) Representative PET/CT images of mice xenografted with Jurkat T cells at 0%, 0.1%, 1%, 10%, and 100% SSTR2 expression. Images are maximum intensity projections (MIPs) of the entire mouse body (~20-mm-thick plane). PET intensity is pseudocolored in the range of 0–10 %ID/cm³. (D and G) DOTATOC uptake (%ID/cm³) for Jurkat tumors less or greater than 65 mm³, respectively. (E and H) Simulated Gaussian distribution as a function of the measured mean and standard deviation of DOTATOC uptake for each percentage SSTR2⁺ tumor when the volume is less or greater than 65 mm³, respectively. (F and I) Receiver operating characteristic (ROC) curves of percentage sensitivity and specificity are shown for tumors less than 65 mm³ (D) and greater than 65 mm³ (G). ** P < 0.01 vs. 0%, ***P < 0.001 vs. 0%, by Student’s t test.