Diagnosis of progression is complex given the possibility of glioblastoma pseudoprogression. The Response Assessment in Neurooncology criteria increases the sensitivity for detecting progression.
Insufficient sensitivity and specificity of current imaging techniques based on non-specific vascular imaging agents lead to delays in the diagnosis of residual and/or recurrent disease.
The diagnosis of glioblastoma recurrence involves a combination of clinical evaluation, neuroimaging studies, and sometimes histopathological examination. Glioblastoma is an aggressive type of brain tumor, and recurrence is common despite initial treatment. Here are the key aspects involved in diagnosing glioblastoma recurrence:
Clinical Assessment:
Patient History: Detailed history regarding the patient's symptoms, previous treatments, and response to therapy.
Clinical Symptoms: Recurrent glioblastoma may present with symptoms such as worsening headaches, new-onset seizures, cognitive decline, or neurological deficits.
Neuroimaging Studies:
Positron Emission Tomography (PET): PET with Radiolabeled Amino Acids (e.g., FET-PET): Increased amino acid uptake in tumor cells may be detected.
Computed Tomography (CT): CT Perfusion Imaging: Measures blood flow within the brain, providing additional information.
Histopathological Examination:
Tissue Biopsy or Resection: In some cases, a repeat biopsy or resection of the suspected recurrent tumor may be performed for definitive diagnosis. This allows for histological analysis and molecular profiling.
Serial Imaging and Comparative Studies:
Comparing Current and Previous Scans: Serial imaging studies over time help assess changes in lesion characteristics and growth patterns.
Clinical and Radiological Criteria:
Response Assessment in Neuro-Oncology (RANO) Criteria: Guidelines developed for assessing treatment response and recurrence in neuro-oncology.
Glioblastoma recurrence is often diagnosed based on a combination of clinical and radiological criteria. The integration of various imaging modalities and close collaboration between neuro-oncologists, neurosurgeons, and neuroradiologists is crucial for accurate diagnosis and treatment planning. Despite advances in imaging techniques, the definitive diagnosis of glioblastoma recurrence may sometimes require histopathological confirmation. Early detection and accurate diagnosis play a crucial role in guiding further treatment decisions.