Apparent diffusion coefficient for evaluating tumour response to neoadjuvant chemoradiation therapy for locally advanced rectal cancer

Abstract

Analyzing post-CRT ADC alone can reliably differentiate pCR from non-pCR in LARC.

Comparison of diffusion‐weighted MRI and MR volumetry in the evaluation of early treatment outcomes after preoperative chemoradiotherapy for locally advanced rectal cancer

“…This response is believed to be a consequence of CRT causing cellular damage that leads to necrosis (4). The application of DWI has also been investigated for its ability to predict the treatment response in rectal cancer (20). Several investigators studying rectal cancer have reported that the pretreatment mean ADC value of the responder group was statistically lower than that of the nonresponder group (15,21).…”

Prediction of response to preoperative chemoradiotherapy in patients with locally advanced rectal cancer

“…The ADC is related to tissue cellularity, tissue organization, extracellular space tortuosity, tumor proliferation, tumor grade, and tumor necrosis (9)(10)(11). With respect to ADC as a quantitative biomarker in rectal cancer, several investigations have reported promising results for the prediction and monitoring of therapeutic responses (10)(11)(12)(13)(14)(15)(16)(17)(18) (Table 1).…”

“…In a recent study, ADC for predicting response was confirmed using the area under the receiver-operating characteristic (ROC) curve analysis with a sensitivity of 75% and specificity of 48% (13). Despite the promising results, there is no consensus whether low ADC-pre value should be used as a predictor for response to CRT because in some studies the ADC-pre value could not reliably discriminate CR from non-CR (14,15). Therefore, relying on ADC-pre seems to be insufficient to select in advance poor responders who might need to undergo early surgery.…”

From multislice CT to whole-body biomarker imaging in lymphoma patients

“…Therapy-induced changes in ADCs of lymph node metastases address the same issues as the management of lymphomas. Two recent papers investigate the changes in ADCs after chemoradiation of locally advanced rectal cancer [4,5]. Kim et al measured ADCs in rectal cancer before and after neoadjuvant chemoradiation.…”

“…Kim et al measured ADCs in rectal cancer before and after neoadjuvant chemoradiation. They show that post-chemoradiation ADC alone can reliably differentiate a pathologically complete response (pCR) from a non-pCR in locally advanced rectal cancer [4].Conversely, Lambregts et al show that DWI as a stand alone technique is not reliable, and recommend using preferably T2-weighted images to assess pCR [5]. The main gain from the addition of DWI would be an increase in the number of detected nodes and an improved PPV for identification of metastatic nodes.…”