How Effective Is Chemotherapy for Glioblastoma?

Glioblastoma is the most malignant glioma of astrocytic tumors. Tumors are located in the subcortex, and most of them grow in various parts of the cerebral hemisphere above the curtain. Infiltrative growth, often invades several brain lobes, and invades deep structures, and can also spread to the contralateral cerebral hemisphere through the corpus callosum. Occurrence of the frontal lobe is most common.

Basic Information

English name

glioblastoma

Visiting department

Oncology, Neurology

Common locations

brain

Common symptoms

Headache, vomiting, etc.

Contagious

no

Causes of Glioblastoma

Studies have found that the molecular mechanisms of primary glioblastoma and secondary glioblastoma are different. The molecular changes of primary glioblastoma are mainly the amplification and overexpression of epidermal growth factor receptor (EGFR), while the primary glioblastoma is mainly the mutation of p53.

Clinical manifestations of glioblastoma

Glioblastoma grows rapidly, with 70% to 80% of patients having a disease course of 3 to 6 months, and only 10% of patients with a disease course exceeding 1 year. Those with a longer course may have evolved from less malignant astrocytomas. Due to rapid tumor growth, extensive cerebral edema, and increased intracranial pressure, all patients have symptoms of headache and vomiting. Optic edema has headaches, mental changes, limb weakness, vomiting, disturbance of consciousness, and speech disorders. Tumor invasion damages brain tissue, causing a series of focal symptoms. Patients have different degrees of hemiplegia, anaesthesia, aphasia, and hemiopia. Nervous system examinations can reveal hemiplegia, neurological damage to the brain, hemiplegia, and blindness. The incidence of epilepsy is less common than astrocytoma and oligodendroglioma, and some patients have seizures. Some patients showed mental symptoms such as apathy, dementia, and mental retardation.

Glioblastoma examination

Laboratory inspection

Multiple lumbar punctures indicate increased pressure, increased cerebrospinal fluid protein content, and increased counts. A few cases of special staining can sometimes reveal shed tumor cells.

2. Radionuclide inspection

The positive rate of diagnosis was higher than that of astrocytoma, and the lesion showed a radioactive area. The plain radiograph of the skull only shows increased intracranial pressure, occasional displacement after calcification of the pineal gland, and cerebral angiography shows vascular compression displacement. About half of them show pathological blood vessels, and the blood vessels at the lesion are uneven in thickness and distorted. Some are fine dots or filaments.

3.CT scan

The tumors were mixed-density lesions with unclear borders. Most of them had high-density manifestations due to intratumoral hemorrhage, but fewer were calcified. Intratumoral necrosis and cystic changes showed a low-density shadow, which made it morphological. Most of the brain edema around the lesion was heavier, and there was no obvious boundary between tumor and brain tissue. The ventricles are often compressed, deformed, or closed, and the midline structure is often displaced to the opposite side. Some of the enhanced tumors are unevenly enhanced, often with low-density central necrosis or irregular annular, island-shaped, or helical enhancement in the area surrounding the cystic hyperplasia area.

4.MRI examination

The tumor showed a low signal on the T ₁ weighted image, and the T ₂ weighted image was an unclear tumor shadow with a high signal boundary. If there is a large necrotic area in the tumor, the signal is lower, and if there is bleeding, the signal is higher. Carcasses are often affected, and midline structures, such as the longitudinal fissure pool, can deform, narrow, or shift. Tumors have mixed signals on T2-weighted images, with high signals predominate. After the injection of Gd-DTPA, the contrast of the tumor is significantly enhanced, which makes the tumor clearly demarcated from the adjacent structure, and it occurs in the deep brain, which is a characteristic manifestation.

Glioblastoma diagnosis

The diagnosis was confirmed based on medical history, clinical manifestations and imaging examination.

Glioblastoma Treatment

Glioblastoma is mainly treated with surgery, radiotherapy, chemotherapy and other comprehensive treatments.

Surgical treatment

Surgery should be done to remove as many tumors as possible without aggravating neurological dysfunction. Enlarging the scope of tumor resection can not only effectively decompress internally, but also reduce postoperative brain edema and reduce the incidence of neurological complications. If the tumor is located in an important functional area (language center or motor center), most of them can only be partially removed in order not to aggravate the impairment of brain function. For tumors located in the brainstem, basal ganglia and thalamus, the tumor can be strictly removed under the microscope. At the end of the operation, external decompression can be done.

2. Radiotherapy, chemotherapy and immunotherapy

Routine radiotherapy should be performed, and chemotherapy or immunotherapy can be combined. Recently, there are reports in the literature that radiotherapy is performed after surgery. Chemotherapy is performed every 2 months after radiotherapy, and immunotherapy is given at the same time, so that some patients can obtain a longer remission period.

Glioblastoma has a certain degree of radiotherapy tolerance. For residual tumors, high-dose segmental irradiation, intratumoral intratumor radiotherapy, and stereotactic radiosurgery are often used to achieve it. HFRT can increase the traditional external radiation dose to 70.2-72Gy. Without radioactive necrosis, the ability to suppress tumor recurrence is enhanced. ¹²⁵ I plasmid stereotactic implantation (interstitial radiotherapy) combined with HFRT can significantly improve the treatment effect, which is superior to the combination of traditional external radiotherapy and chemotherapy. Glioblastoma is susceptible to different chemotherapy rates of 40% to 80%. It is also feasible to reduce the side effects of chemotherapy by using autologous bone marrow transplantation in combination with high-dose multiple chemotherapeutics combined with shock therapy. Recently, there have been many reports on immunotherapy and gene therapy for glioblastoma, but the results are not very certain due to the inconsistency of treatment methods and evaluation criteria.