Role of apparent diffusion coefficient as a biomarker in the evaluation of cervical cancer

Abstract

Background: Diffusion-weighted magnetic resonance imaging (DW-MRI) has evolved as a major diagnostic and prognostic tool in cervical cancer. The aim of our study was to compare the change in mean apparent diffusion coefficient (ADC) value before and after concurrent chemoradiation therapy (CCRT) in carcinoma cervix thereby establishing its role as a cancer biomarker. Materials and Methods: A hospital-based prospective study was conducted in 35 patients diagnosed with cervical cancer. All 35 patients underwent pelvic MRI before and after 6 months of CCRT. The study was done over a period of 12 months. Conventional axial and sagittal T2 imaging was followed by DW-MRI. In the axial DW/ADC images at “ b -value” of 800 s/mm 2 , a circular region of interest was drawn covering more than 60% of the tumor volume to calculate the ADC values. Statistical Package for the Social Sciences (version 21.0) was used for statistical evaluation. Chi-square test, independent samples t -test, and analysis of variance were used to analyze the data. The results are depicted as frequencies (number), proportion (percentages), and mean ± standard deviation. Results: Pre-CCRT mean ADC value was 0.814 × 10 −3 mm 2 /s. Post-CCRT mean ADC value was 1.294 × 10 −3 mm 2 /s. Mean ADC value of patients having lymph node involvement and parametrial extension was significantly lower when compared with those without lymph node involvement and parametrial extension ( P = 0.001). Nonresponders with residual lesion had lower ADC values than responders with no residual lesion. An interesting and unique observation was that pre-CCRT mean ADC value of responders was higher than nonresponders. Conclusion: An increase in mean ADC value of 0.480 × 10 −3 mm 2 /s after CCRT was found to be statistically significant ( P < 0.001) thereby proving its role as an imaging biomarker in cancer cervix.

Apparent Diffusion Coefficient Values Predict Response to Brachytherapy in Bulky Cervical Cancer

“…Despite mixed results as to whether lower ADC values portend a better or worse prognosis, [23,33] the literature in recent years has generally supported an association between higher ADC values and better outcomes. [24,25,31,32,[34][35][36] Our results are in line with this nding. Figure 3A illustrates an important bimodal distribution: while lower 90th percentile ADC values are spread between the CMR and non-CMR groups, the cohort of patients with high 90th percentile ADC values ( ≥ ~ 2.5 x 10 − 3 mm 2 /s) almost universally achieved a CMR.…”

“…1D, Patient B, black arrow in the ADC map), portending a favorable response to ISBT. [34] Despite consensus on the direction of this association, agreement has not yet been reached as to ADC cutoff values that could be used to risk-stratify cervical cancer patients. Ho, et al found a 90th percentile pretreatment ADC cutoff value of 1.917 x 10 − 3 mm 2 /s, with lower values associated with worsened outcomes, [25] while our data suggests a 90th percentile ADC cutoff value of 2.10 x 10 − 3 mm 2 /s.…”

Diffusion-weighted MRI to detect early response to chemoradiation in cervical cancer: A systematic review and meta-analysis

“…Members of this team produced one of the earliest studies that evaluated DWI as a biomarker of early response in cervical cancer ( Harry et al, 2008 ). Since then, DWI has been increasingly explored in the prediction and early assessment of treatment response in cervical carcinomas ( Chen et al, 2010 , Dashottar et al, 2019 , Hameeduddin and Sahdev, 2015 , Kuang et al, 2014 , Lee et al, 2014 , McVeigh et al, 2008 , Yang et al, 2018 , Zheng et al, 2020 ). Using the DW images, ADC maps have been generated and allow for the quantification of ADC before and during treatment, potentially offering a more individualized approach in treating these patients while reducing unnecessary toxicity.…”

Utility of the Diffusion Weighted Sequence in Gynecological Imaging: Review Article

“…Tumors with internal necrosis or cystic areas with higher ADC values indicate more hypoxic tumor tissue and are less responsive to chemoradiation. Tumors with low pretreatment ADC values are more responsive to chemoradiation [ 29 ]. Additionally, DWI is also helpful for determining tumor response to chemoradiation in cervical cancer when morphological changes are not apparent on other sequences, as tumors show an increase in ADC value from baseline.…”