Eveslage Maria, Rassek Philipp, Riegel Arne, Maksoud Ziad, Bauer Jochen, Görlich Dennis, Noto Benjamin
Institute of Biostatistics and Clinical Research, University of Münster, 48149 Münster, Germany.
Department of Nuclear Medicine, University Hospital Münster, 48149 Münster, Germany.
Cancers (Basel). 2023 Jul 25;15(15):3757. doi: 10.3390/cancers15153757.
The apparent diffusion coefficient (ADC) is a candidate marker of treatment response in osteoblastic metastases that are not evaluable by morphologic imaging. However, it is unclear whether the ADC meets the basic requirement for reliable treatment response evaluation, namely a low variance of repeated measurements in relation to the differences found between viable and nonviable metastases. The present study addresses this question by analyzing repeated in vivo ADC measurements of 65 osteoblastic metastases in nine patients, as well as phantom measurements. PSMA-PET served as a surrogate for bone metastasis viability. Measures quantifying repeatability were calculated and differences in mean ADC values according to PSMA-PET status were examined. The relative repeatability coefficient %RC of ADC measurements was 5.8% and 12.9% for phantom and in vivo measurements, respectively. ADC values of bone metastases ranged from 595×10-6mm2/s to 2090×10-6mm2/s with an average of 63% higher values in nonviable metastases compared with viable metastases ( < 0.001). ADC shows a small repeatability coefficient in relation to the difference in ADC values between viable and nonviable metastases. Therefore, ADC measurements fulfill the technical prerequisite for reliable treatment response evaluation in osteoblastic metastases.
表观扩散系数（ADC）是成骨性转移瘤治疗反应的一个潜在标志物，而成骨性转移瘤无法通过形态学成像进行评估。然而，尚不清楚ADC是否满足可靠治疗反应评估的基本要求，即在存活和非存活转移瘤之间发现的差异方面，重复测量的方差较低。本研究通过分析9例患者中65个成骨性转移瘤的重复体内ADC测量值以及体模测量值来解决这个问题。PSMA-PET用作骨转移瘤存活情况的替代指标。计算了量化重复性的指标，并检查了根据PSMA-PET状态的平均ADC值差异。ADC测量的相对重复性系数%RC在体模测量和体内测量中分别为5.8%和12.9%。骨转移瘤的ADC值范围为595×10-6mm2/s至2090×10-6mm2/s，与存活转移瘤相比，非存活转移瘤的ADC值平均高63%（<0.001）。相对于存活和非存活转移瘤之间的ADC值差异，ADC显示出较小的重复性系数。因此，ADC测量满足了成骨性转移瘤可靠治疗反应评估的技术前提条件。
