High-grade glioma is one of the tumors with the shortest survival time and most difficult to treat. The current initial treatment regimen for high-grade gliomas is radiation + temozolomide synchronized chemotherapy plus 6 courses of temozolomide adjuvant chemotherapy following radiation therapy after maximum tumor resection in a safe manner. All high-grade gliomas recur after initial treatment, and timely detection of small recurrent lesions can give patients the opportunity for further treatment. The current “gold standard” for glioma recurrence is an enhanced MRI of the head every 3 months. Having an MRI every three months is a significant financial and human burden for most patients and their families. However, high-grade gliomas are very fast-growing tumors, and a 3-month follow-up interval is not sufficient to detect recurrence in a timely manner. The ideal means of monitoring recurrence is based on serological examination, i.e., blood sampling to detect tumor recurrence. Research in this area is currently being conducted in our hospital, but it is a very complicated and lengthy process to move from laboratory findings to clinical application. Enhanced magnetic resonance imaging of the head is still the “gold standard” for the diagnosis of recurrence in the near future. However, enhanced MRI is not completely reliable. A significant number of patients with high-grade gliomas show MRI enhancement of the original lesions after radiation therapy, especially in the months following concurrent chemotherapy with temozolomide, which is not a tumor recurrence but a phenomenon called “pseudo-progression” that resolves on its own without further intervention and predicts a relatively This is not a recurrence of the tumor but a phenomenon called “pseudoprogression”. Misinterpretation of pseudoprogression can lead to treatment failure. The overall incidence of pseudoprogression has been reported in the literature to be around 20%, with an increased incidence of pseudoprogression following temozolomide as part of standard treatment for high-grade glioma and a 25%-40% incidence of pseudoprogression with simultaneous radiotherapy via temozolomide. Methylation of the MGMT promoter is currently an important prognostic factor in determining patient response to temozolomide therapy. Different authors have independently found that the incidence of pseudoprogression in patients with methylated MGMT promoter is significantly higher than in non-methylated patients, and some reports in the literature can reach more than 90%. The onset of pseudoprogression can occur from a few weeks to six months after the end of radiotherapy, with 60% occurring within 3 months. Usually the extent of MRI enhancement can be retracted within six months, but the T2/FLAIR changes continue until about 1 year after radiotherapy. In contrast, the onset of distant radiation brain necrosis, which has a clinical and imaging presentation very similar to pseudoprogression, is usually 18-24 months after the end of treatment. Recurrence of the tumor can occur at any time after treatment. The timing of imaging changes can be used as an aspect to empirically distinguish tumor recurrence, pseudoprogression, and radionecrosis. Tumor recurrence, pseudoprogression and radiation brain necrosis can all cause worsening of clinical symptoms or the appearance of new symptoms in patients, and therefore cannot be used as a basis for differentiating between the three. However, pseudoprogression has a lower incidence of clinical deterioration and will gradually decrease over several months, which can be used as a method of empirical determination. Currently, dynamic MRI enhancement is the only reliable noninvasive method to determine pseudoprogression, and the extent of enhancement usually diminishes within a few months, so dynamic observation of MRI enhancement is a more reliable way to identify the recurrence of pseudoprogression. The combined application of multiple imaging modalities can improve the accuracy of the determination of pseudoprogression. Magnetic resonance diffusion weighted imaging (DWI), magnetic resonance spectroscopy (MRS), perfusion weighted imaging (PWI), positron emitting tomography (PET), and magnetic resonance spectroscopy (MRI) can be used to identify pseudoprogression. positron emitting tomography (PET) are all helpful in identifying tumor recurrence and pseudo-progression. However, despite the use of the most advanced technology, the sensitivity and specificity of these tests need to be scientifically evaluated. The survival and progression-free survival of patients experiencing pseudoprogression is usually longer than that of patients without pseudoprogression. Therefore, patients with pseudoprogression should be treated aggressively based on a clear diagnosis, which usually leads to a relatively good outcome. For medical researchers, studying the detailed pathophysiological mechanisms of pseudoprogression can help identify new sensitizing factors for radiation therapy. Another type of condition that is more likely to be misdiagnosed and mistreated is an intensified lesion in the operative area after a longer period of time (usually more than 1 year) after treatment. Often these lesions have both a recurrent tumor component and a radiological brain injury component. A single or multi-point pathologic biopsy can easily result in a lopsided diagnosis. In other words, even pathological examination can easily result in misdiagnosis of tumor recurrence. There is no unified consensus on the treatment of these patients, and they must be evaluated in detail by experienced neurosurgeons and neuro-oncologists to develop the best treatment plan.