Joint application of diffusion-weighted imaging and perfusion-weighted imaging in radiotherapy effect evaluation on nasopharyngeal carcinoma

NIE Lin

Abstract：Objective To study the application of diffusion-weighted imaging and perfusion-weighted imaging in radiotherapy effect evaluation on nasopharyngeal carcinoma.Methods 48 patients with nasopharyngeal carcinoma (NPC), who all had no relevant medical history prior to admission underwent a routine MR, MR-DWI and MR-PWI check after admission and then, underwent a routine MR MR DWI and MR-PWI check once again after the completion of a radiotherapy cycle.Finally, the changes of nasopharyngeal mass before and after radiotherapy in different in MR imaging methods were compared.Results Before radiotherapy, the nasopharyngeal mass on DWI image was limited in diffuse, with higher values of ADC.The perfusion was rich on PWI image that the blood volume (BV) was higher.Images displayed on the diffusion limited area and the maximum level area of high perfusion.Compared with radiation enhanced T1WI before, the fat suppression sequence was smaller (P<0.05).High perfusion and diffusion limited area was slightly larger than area (P>0.05), with no statistical difference between the two.After radical radiotherapy, the nasopharyngeal mass diffusion limited regional perfusion area in the high sensitive group was significantly lower, Compared with enhanced T1W, theI fat suppression sequence was down more obvious (P<0.05).Tumor recurrence after radiotherapy was different from necrosis after radiotherapy or fibrosis.Recurrence of dispersion was limited in the increased BV.Necrosis and fibrosis of dispersion were not restricted The decrease in BV was significantly (P<0.05).Conclusion In terms of morphological and biological changes before and after reaction of nasopharyngeal carcinoma radiotherapy, combined with MR-DWI and MR-PWI can be more accurate.In evaluating the sensitivity of the nasopharyngeal carcinoma radiotherapy and identification of tumor recurrence after radiotherapy necrosis and fibrosis, the ADC dispersion values and BV parameters are of important reference value.