PT - JOURNAL ARTICLE AU - Takehiro Nakahara AU - Jagat Narula AU - H. William Strauss TI - The relationship between the <sup>18</sup>F-NaF and calcium on the time course of vascular calcification. DP - 2017 May 01 TA - Journal of Nuclear Medicine PG - 444--444 VI - 58 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/58/supplement_1/444.short 4100 - http://jnm.snmjournals.org/content/58/supplement_1/444.full SO - J Nucl Med2017 May 01; 58 AB - 444Objectives: 18F-NaF was recently proposed for detection of vascular microcalcification1 and reflects calcium deposition in the early stages of plaque formation2. Previous studies confirmed that 18F-FDG uptake changes over time, either increasing or decreasing in intensity and extent, reflecting the waxing and waning course of atheroma3, 4. Similarly, more new inflammation could occur at sites of calcified atheroma 5-7. Serial 18F-NaF images and vascular calcification data will help understand the mechanisms. This study investigated vascular 18F-NaF uptake and calcium volume on serial scans performed on patients with prostate cancer.Methods: Prostate cancer patients who had at least 3 18F-NaF PET/CT scans over 1.5 years were enrolled in this retrospective study. On the PET images, ROIs were manually traced around the outer perimeter of the descending thoracic and abdominal aorta on axially oriented PET/CT images. ROIs excluded skeletal 18F-NaF activity by excluding these areas from the ROI8. The SUV max of each ROI were summed and divided by slice numbers (SUV/slice). The CT calcium burden of thoracic and abdominal aorta were determined by calculating the calcium volume (mm3) on every slice of the axially oriented CT images and dividing by the number of slices (mm3/slice)9. The calcium volumes were measured at baseline, 0.5 year, 1 year and 1.5 years. The changing rate of calcium volumes were calculated (mm3/slice/year). Measurement parameters were expressed as mean ± one standard deviation (SD). All parameters were assessed using the t-test, the Shapiro-Wilk test, Levene’s test, one-way analysis of variance (ANOVA) with Tukey’s HSD post-hoc analysis. The Pearson R was used to analyze the correlation. The multiple liner regression analysis with stepwise method was performed to examine the association between NaF uptake and calcium parameters. A p &lt; 0.05 was considered statistically significant.Results: 39 patients (age 67.6 ± 9.1 years old) met criteria for enrollment. Patients had an average of 5.0 ± 1.8 scans within 2.1 ± 0.7 years. Patients were divided into three groups: I: Young (under 65 years old, n=12), II: Middle (65-75 years old, n=18), III: Old (over 75 years, n=9), Middle and Old group had significantly higher thoracic and abdominal calcium volume than the Young group. There were no significant differences between the Middle and Old groups (young: 11.4 ± 33.7 mm3/slice, middle: 59.6 ± 86.7 mm3/slice, old: 62.7±57.8 mm3/slice). NaF uptakes changed slightly from scan to scan. SUV max was highest in the Middle group, slightly lower in the Old group and lowest in the Young group. (Young: 1.54 ± 0.30 SUVmax/slice, middle: 2.03 ± 0.46 SUVmax/slice, old: 1.80 ± 0.34 SUVmax/slice, p&lt;0.05). Consistently the rate of change of the calcium volume from the baseline scan date to one year later was significantly higher in the middle and old group compared to the young group, however; there was no significant different between the middle and the old group (Young: 1.7 ± 3.3 mm3/slice/year, middle: 11.0 ± 12.8 mm3/slice/year, old: 9.3 ± 10.6 mm3/slice/year, p&lt;0.05). When we analyze the calcium volume and NaF uptake, NaF uptake was correlated with the change rate of calcium volume (0-1 year: r=0.559, p&lt;0.01, n=202, 1-1.5 year: r=0.689, p&lt;0.01, n = 148). The multiple liner regression analysis with stepwise method showed NaF predicted the calcium change from 1 to 1.5 year from the baseline scan date.Conclusion: NaF vascular uptake predicts calcification 1 -1.5 years after the scan. Research Support: SNMMI Wagner-Torizuka Fellowship and Uehara Memorial Foundation to TN.