Seierstad T, Hole K H, Grøholt K K, Dueland S, Ree A H, Flatmark K, Redalen K R
1 Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
2 Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
Br J Radiol. 2015 Jul;88(1051):20150097. doi: 10.1259/bjr.20150097. Epub 2015 Apr 22.
To investigate if MRI-assessed tumour volumetry correlates with histological tumour response to neoadjuvant chemotherapy (NACT) and subsequent chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC).
Data from 69 prospectively enrolled patients with LARC receiving NACT followed by CRT and radical surgery were analysed. Whole-tumour volumes were contoured in T2 weighted MR images obtained pre-treatment (VPRE), after NACT (VNACT) and after the full course of NACT followed by CRT (VCRT). VPRE, VNACT and tumour volume changes relative to VPRE, ΔVNACT and ΔVCRT were calculated and correlated to histological tumour regression grade (TRG).
61% of good histological responders (TRG 1-2) to NACT followed by CRT were correctly predicted by combining VPRE < 10.5 cm(3), ΔVNACT > -78.2% and VNACT < 3.3 cm(3). The highest accuracy was found for VNACT, with 55.1% sensitivity given 100% specificity. The volume regression after completed NACT and CRT (VCRT) was not significantly different between good and poor responders (TRG 1-2 vs TRG 3-5).
MRI-assessed small tumour volumes after NACT correlated with good histological tumour response (TRG 1-2) to the completed course of NACT and CRT. Furthermore, by combining tumour volume measurements before, during and after NACT, more good responders were identified.
MRI volumetry may be a tool for early identification of good and poor responders to NACT followed by CRT and surgery in LARC in order to aid more individualized, multimodal treatment.
探讨在局部晚期直肠癌（LARC）中，磁共振成像（MRI）评估的肿瘤体积测量与新辅助化疗（NACT）及后续放化疗（CRT）的组织学肿瘤反应之间是否存在相关性。
分析了69例前瞻性纳入的LARC患者的数据，这些患者接受了NACT，随后进行CRT和根治性手术。在治疗前（VPRE）、NACT后（VNACT）以及NACT全程加CRT后（VCRT）获得的T2加权MR图像上勾勒出整个肿瘤体积。计算VPRE、VNACT以及相对于VPRE的肿瘤体积变化（ΔVNACT和ΔVCRT），并将其与组织学肿瘤退缩分级（TRG）相关联。
对于接受NACT后再进行CRT的良好组织学反应者（TRG 1 - 2），通过联合VPRE < 10.5 cm³、ΔVNACT > -78.2%和VNACT < 3.3 cm³可正确预测61%。VNACT的准确性最高，在特异性为100%时，敏感性为55.1%。良好和不良反应者（TRG 1 - 2与TRG 3 - 5）在完成NACT和CRT后的体积退缩（VCRT）无显著差异。
NACT后MRI评估的小肿瘤体积与对完整疗程的NACT和CRT的良好组织学肿瘤反应（TRG 1 - 2）相关。此外，通过结合NACT前、中、后的肿瘤体积测量，可识别出更多良好反应者。
MRI体积测量可能是一种工具，用于早期识别LARC中接受NACT后再进行CRT和手术的良好和不良反应者，以辅助更个体化的多模式治疗。
