Oncology Institute, Istanbul University, İstanbul, Turkey.
Diagn Interv Radiol. 2012 Nov-Dec;18(6):574-81. doi: 10.4261/1305-3825.DIR.5755-12.1. Epub 2012 Jul 13.
We aimed to prospectively determine if analyzing pre- and post-chemoradiotheraphy (CRT) changes in the signal intensity (SI) and apperent diffusion coefficient (ADC) values from diffusion-weighted magnetic resonance imaging (DW-MRI) can accurately predict complete responders for locally advanced rectal cancer.
Thirty patients (mean age, 54.3 years) with locally advanced rectal cancer who underwent neoadjuvant CRT and subsequent surgery were included in this study. All patients were evaluated pre- and post-CRT by standardized turbo spin echo and DW-MRI. Pre- and post-CRT tumor and normal rectal wall SI (which were gradually scored as very high, high, intermediate, low, and no signal) and ADC values were recorded.
Tumor SIs were decreased in all of the patients that had a therapy response. However, complete tumor SI loss was only seen in two (22.2%) of nine patients with a pathological complete response, while it regressed to low and/or intermediate SI levels in the remaining seven patients (77.8%). Post-CRT ADC values of rectal tumors were significantly higher from the preCRT ADC values (P < 0.0001; Z=-9.39). However, post-CRT ADC values from the complete and partial/no response patient groups were not significantly different (P = 0.071; Z=-1.99).
In re-staging of rectal tumors by DW-MRI, an increase in ADC values and decrease in SIs can predict therapy response but cannot unequivocally determine a complete response.
我们旨在前瞻性地确定分析直肠癌新辅助放化疗（CRT）前后扩散加权磁共振成像（DW-MRI）信号强度（SI）和表观扩散系数（ADC）值的变化是否能准确预测局部晚期直肠癌的完全缓解者。
本研究纳入了 30 例接受新辅助 CRT 及后续手术的局部晚期直肠癌患者。所有患者在 CRT 前后均通过标准化的涡轮自旋回波和 DW-MRI 进行评估。记录了 CRT 前后肿瘤和正常直肠壁的 SI（逐渐评分为很高、高、中、低和无信号）和 ADC 值。
所有有治疗反应的患者肿瘤 SI 均降低。然而，在 9 例病理完全缓解患者中，仅 2 例（22.2%）出现完全肿瘤 SI 丢失，而其余 7 例（77.8%）肿瘤 SI 则退至低或中水平。直肠肿瘤的 CRT 后 ADC 值明显高于 CRT 前 ADC 值（P<0.0001；Z=-9.39）。然而，完全缓解和部分/无缓解患者组的 CRT 后 ADC 值之间无显著差异（P=0.071；Z=-1.99）。
在 DW-MRI 对直肠肿瘤进行再分期时，ADC 值的增加和 SI 的降低可以预测治疗反应，但不能明确确定完全缓解。
