PT  - JOURNAL ARTICLE
AU  - Jinbo Yue
AU  - Lusheng Chen
AU  - Alvin R. Cabrera
AU  - Xindong Sun
AU  - Shuqiang Zhao
AU  - Fu Zheng
AU  - Anqin Han
AU  - Jinsong Zheng
AU  - Xuezhong Teng
AU  - Li Ma
AU  - Yidong Ma
AU  - Dali Han
AU  - Xianguang Zhao
AU  - Dianbin Mu
AU  - Jinming Yu
AU  - Yuhui Li
TI  - Measuring Tumor Cell Proliferation with <sup>18</sup>F-FLT PET During Radiotherapy of Esophageal Squamous Cell Carcinoma: A Pilot Clinical Study
AID  - 10.2967/jnumed.109.072124
DP  - 2010 Apr 01
TA  - Journal of Nuclear Medicine
PG  - 528--534
VI  - 51
IP  - 4
4099  - http://jnm.snmjournals.org/content/51/4/528.short
4100  - http://jnm.snmjournals.org/content/51/4/528.full
SO  - J Nucl Med2010 Apr 01; 51
AB  - The primary aim of this study was to use serial 18F-3′-deoxy-3′-fluorothymidine (FLT) PET/CT to measure tumor cell proliferation during radiotherapy of squamous cell carcinoma (SCC) of the esophagus. Methods: Twenty-one patients with inoperable locally advanced SCC of the esophagus underwent serial 18F-FLT PET/CT during radiotherapy. Each patient received a pretreatment scan, followed by 1–3 scans after delivery of 2, 6, 10, 20, 30, 40, 50, or 60 Gy to the tumor. Results: Among the 19 patients who completed radiotherapy without interruption, parameters reflecting 18F-FLT uptake in the tumor (i.e., maximum tumor standardized uptake value [SUVmax] and proliferation target volume) decreased steadily. All patients demonstrated an almost complete absence of proliferating esophageal tumor after 30 Gy and a complete absence after 40 Gy. In the 2 patients whose radiotherapy course was interrupted, 18F-FLT uptake in the tumor was greater after the interruption than before the interruption. Marked early reduction of 18F-FLT uptake in irradiated bone marrow was observed in all patients, even after only 2 Gy. All showed a complete absence of proliferating marrow in irradiated regions after 10 Gy. Both patients who underwent scans after completing the entire radiotherapy course showed no tumor uptake on 18F-FLT PET/CT but high uptake on 18F-FDG PET/CT. Pathologic examination of these regions revealed inflammatory infiltrates but no residual tumor. Conclusion: 18F-FLT uptake can be used to monitor the biologic response of esophageal SCC and normal tissue to radiotherapy. Increased uptake of 18F-FLT after treatment interruptions may reflect accelerated repopulation. 18F-FLT PET/CT may have an advantage over 18F-FDG PET/CT in differentiating inflammation from tumor.