Clinical Study On The Timing Of Pseudoprogression After Glioma Chemoradiotherapy

Objectives:Glioma is the most common primary central nervous system malignant tumors.Surgery combined with postoperative radiotherapy and chemotherapy and other comprehensive treatment has become the current standard treatment in worldwide.Some patients come with pseudoprogression after the concurrent chemoradiotherapy and adjuvant chemotherapy.Nowadays,most of the literature reported pseudoprogression defined its occurrence within 3 months after the end of radiotherapy,and there were a few literatures reported that it could occur after 3 months or even 6 months later.There is no consensus on the time of occurrence of Pseudoprogression at present.The doctors became scrupulous about diagnosing of late Pseudoprogression in clinical work.It was recommended to review MRI 2 months later when suspected pseudoprogression.If the MRI review prompted the lesion began to reduce or remain stable,it would be determined as the pseudoprogression.Otherwise,if the review of MRI suggest that the lesion continues to increase,it may be determined as the recurrence of the tumor.There are two questions:(1)Whether the MRI showed enhanced lesions continue to increase is the recurrence of cancer?(2)Is the observation time of 2 months sufficient?This study aims to summarize the temporal distribution of pseudoprogression and to enrich the understanding of this phenomenon.Materials and Method:Collected glioma cases who received radiotherapy in Second Affiliated Hospital of Zhejiang University Medical College from January 2013 to May 2016.Patients received the s standardized treatment,including surgery,radiotherapy and chemotherapy.Dynamically evaluate the intracranial lesions changes in MRI.Pseudoprogression was diagnosed if the enhanced lesions increased or the emergence of new enhanced lesions after radiotherapy,and the follow-up MRI showed to be stable,reduced or disappeared without changing the treatment plan.Or surgical pathology confirmed as pseudoprogression.Clinical data such as sex,age,surgical resection,pathologic diagnosis,MGMT expression,IDH1 expression,radiotherapy regimen,chemotherapy regimen,changes in neurological status,and image data before and after radiotherapy and follow-up images were included in the study.Results:Among the 19 patients included in this study,the median follow-up time was 32.6 months(14-89 months).8 patients died and 11 survived(8 in the high grade and 3 in the low grade)at the last follow-up.Median survival time was 36.6 months,1 year survival rate was 100%,2-year survival rate was 78.0%,3-year survival rate was 58.5%.And in 16 patients with high grade glioma,the median survival time was 36.6 months,the 1-year survival rate was 100%,the 2-year survival rate was 73.7%,and the 3-year survival rate was 51.6%.Three cases of low grade gliomas survived at the end of follow-up.7 cases(36.8%)appeared PSP in 3 months after the end of radiotherapy;8 cases(42.1%)in 4-6 months after the end of radiotherapy,4 cases(21.1%)of the PSP appeared 6 months later after the end of radiotherapy.Pseudoprogression diagnosed by imaging cost 12 to 15 months(median,5.3 months).75%of the patients were followed up for more than 3 months and 25%Need to follow up for more than 6 months to make pseudoprogression diagnosis.62.5%of patients with suspected review the MRI twice or more.We also observed that pseudoprogression imaging had a longer duration,with a median duration of 11.7 months(5.1-1.25.7 months).Conclusion:Approximately 40%of pseudoprogression occurs within 3 months after concurrent radiotherapy and chemotherapy,and 40%occurs in 4-6 months and about 20%in 6 months later.It suggests that the incidence of late pseudoprogression may be higher.It should be paid more attention in clinical work.The method that found the early progress of imaging and then follow-up 2 months to make judgment of true progress or pseudoprogression was questionable.It should be treated differently based on the actual situation of patients.If the symptoms of patients with stable and disease progress is slow,it is recommended to extend the observation time.We observed that imaging abnormalities of pseudoprogression persisted for longer periods of time.