Diffusion-Weighted Magnetic Resonance Application in Response Prediction before, during, and after Neoadjuvant Radiochemotherapy in Primary Rectal Cancer Carcinoma

Abstract

Introduction. Our interest was to monitor treatment response using ADC value to predict response of rectal tumour to preoperative radiochemotherapy. Materials and Methods. Twenty-two patients were treated with long course of radiochemotherapy, followed by surgery. Patients were examined by diffusion-weighted imaging MRI at three-time points (prior, during, and after radiochemotherapy) and were classified as responders and nonresponders. Results. A statistical significant correlation was found between preradiochemotherapy ADC values and during treatment ADC values, in responders (F = 21.50, P value <0.05). An increase in ADC value during treatment was predictive of at least a partial response. Discussion. Response of tumour to neoadjuvant therapy cannot be easily evaluated, and such capability might be of great importance in clinical practice, because the number of irradiated and operated patients may be superior to the number of who will really benefit from this multimodal treatment. A reliable prediction of the final clinical TN stage would allow radiotherapist to adapt multidisciplinary approach to a less invasive management, sparing surgical procedure in responder patients or even allowing an early surgery in nonresponders, which would significantly reduce radiochemotherapy related toxicity. Conclusion. Early evaluation of response during neoadjuvant radiochemotherapy treatment shows great promise to predict tumour response.

Locally advanced rectal cancer: Qualitative and quantitative evaluation of diffusion-weighted MR imaging in the response assessment after neoadjuvant chemo-radiotherapy

“…Second, we used 2 b-values (0 and 800 s/mm 2 ) for ADC calculations and did not investigate the possible influence of other b-values. Third, our study lacks an early follow-up MR examination that could allow an earlier and accurate prediction of the pathological tumor response during CRT treatment, thus enabling to guide modifications of the treatment protocol [24] .…”

Follow-Up in Head and Neck Cancer: A Management Dilemma

“…Diffusion weighted imaging (DWI) is an MR technique that has been suggested as noninvasive imaging biomarker to predict tumor response. The obvious advantage of DWI-MR, which uses water molecules motion in intracellular and extracellular space to reflect biological changes in tumour microenvironment, is that it is useful for accurately distinguishing recurrent disease from radiation-induced soft-tissue changes [5,26]. DWI-MR should detect the disease before the patient notices a return of any symptom.…”

Management of persistent anal canal carcinoma after combined-modality therapy: a clinical review

“…DW-MRI may directly measure the changes in tumour aggressiveness, evaluating tumour angiogenesis and cellularity. The treatment response using DW parameter – apparent diffusion coefficient (ADC) value – has been shown to be predictive of early therapeutic response in a large variety of tumours, including head and neck tumours, pancreatic tumours, cervical tumours, and rectal cancer, but its potentiality as imaging biomarker in anal canal carcinoma is not still tested [ 27 , 28 ]. Pre- and post-treatment ADC value should be considered to address the use of DW-MRI as an alternative approach to the management of persistent disease.…”