An emerging noninvasive approach to assess tissue proliferation uses the PET tracer 3′-deoxy-3′-¹⁸F-fluorothymidine (¹⁸F-FLT). To evaluate the diagnostic value of this technique in myelofibrosis, ¹⁸F-FLT PET imaging results were compared with bone marrow histology and bone marrow scintigraphy (BMS), the gold standard techniques in this clinical situation. Methods: Fifteen patients with histology-proven myelofibrosis were included consecutively in the study. Tracers’ distributions were assessed using a visual grading assessment score of the uptake in the axial skeleton, proximal and distal limbs, liver, and spleen. This visual score was used to define patterns of tracer distribution and to compare the information provided either by PET or by BMS. A semiquantitative analysis with determination of SUV_max in the same localizations was performed for ¹⁸F-FLT PET. Results: The histology grade of fibrosis correlated with the SUV_max in the axial skeleton (spine and iliac crests) and proximal limbs. ¹⁸F-FLT uptake in these areas was much lower in patients with grade 3 fibrosis than in patients with grade 1 or 2 fibrosis. ¹⁸F-FLT PET showed the same distribution of uptake as BMS in 13 of 14 patients (1 patient did not undergo BMS). In 1 patient, ¹⁸F-FLT PET clearly showed an intense abnormal splenic uptake, whereas spleen uptake was inconclusive with BMS. Conclusion: ¹⁸F-FLT PET appears to be a reliable and convenient technique to assess hematopoietic activity in bone marrow. It yields results close to those observed with BMS. In our study population, ¹⁸F-FLT uptake in the axial skeleton and proximal limbs assessed by SUV_max correlated with the grade of fibrosis. Thus, ¹⁸F-FLT PET may be a useful tool to measure the severity of myelofibrosis, and to monitor noninvasively the patients’ status during follow-up. Finally, ¹⁸F-FLT PET may be foreseen as an alternative to BMS.

一种新兴的非侵入性方法，用于评估组织增殖，使用的是PET示踪剂3'-deoxy-3'- ¹⁸ F-氟胸苷（¹⁸ F-FLT）。为了评估该技术在骨髓纤维化中的诊断价值，将¹⁸ F-FLT PET成像结果与该临床情况下的金标准技术-骨髓组织学和骨髓闪烁显像术（BMS）进行了比较。方法：该研究连续纳入了15例经组织学证实的骨髓纤维化的患者。示踪剂的分布是通过使用视觉分级评估轴向骨骼，近端和远端肢体，肝脏和脾脏摄取的分数来评估的。该视觉分数用于定义示踪剂分布模式，并比较PET或BMS提供的信息。对¹⁸ F-FLT PET进行相同位置的SUV _max的半定量分析。结果：纤维化的组织学分级与轴向骨骼（脊柱和c峰）和近端肢体中的SUV _max相关。^18岁在这些区域，3级纤维化患者的F-FLT摄取要比1级或2级纤维化患者低得多。^18名F-FLT PET在14名患者中的13名患者中显示出与BMS相同的摄取分布（1名患者未接受BMS）。在1例患者中，¹⁸ F-FLT PET明显显示出强烈的脾脏异常摄取，而脾脏摄取对BMS尚无定论。结论： ¹⁸ F-FLT PET似乎是评估骨髓造血活性的可靠且方便的技术。它产生的结果接近于BMS观察到的结果。在我们的研究人群中，通过SUV _max评估的轴向骨骼和近肢四肢的¹⁸ F-FLT摄取与纤维化程度相关。因此，¹⁸F-FLT PET可能是一种有用的工具，可用于测量骨髓纤维化的严重程度，并在随访期间无创地监测患者的状况。最后，可以预见¹⁸ F-FLT PET可以替代BMS。