Gliomas are tumors that originate in brain tissue and do not usually metastasize to other parts of the body.
Etiology.
So far it is not clear. There is some relationship with genetics, trauma, and radiation, but it is not certain. Therefore there is also no special prevention method.
Hazards.
Due to tumor growth or invasion of normal neurovascular tissues causing headache, epilepsy, limb paralysis and numbness, vision loss, mental abnormalities, memory loss, nausea and vomiting, intracranial hemorrhage, death by coma, etc.
Grading.
There are four levels of clinicopathological grading (WHO grading, or World Health Organization grading), which are closely related to prognosis.
Grade 1 (I): It is a rare type, and the common ones are hairy cell astrocytoma, embryonic dysplastic neuroepithelioma, subventricular giant cell astrocytoma, and subventricular meningioma.
The prognosis is good and can be cured without recurrence if total excision is possible.
Grade 2 (Class II): mainly includes astrocytoma (astrocytic glioma), oligodendroglioma, oligodendrocytic-astrocytic glioma, ventricular meningioma, and mucinous hairy cell astrocytoma.
The average survival is about 5 years, with good recurrence at about 5 years after surgery.
Grade 3 (Class III): mesenchymal astrocytoma (astrocytic glioma), mesenchymal oligodendroglioma, mesenchymal oligodendroglioma-astrocytic glioma, mesenchymal ventricular meningioma.
The average survival is about 3 years, with good recurrence at about 3 years after surgery.
Grade 4 (Class IV): glioblastoma (also known as glioblastoma multiforme, glioblastoma, GBM), gliosarcoma
The average survival is 14 months, when recurrence is good.
Low-grade gliomas: including grade 1 and 2 gliomas
High-grade gliomas: including grade 3 and 4 gliomas
Diagnosis.
Cranial CT and cranial MRI scan + enhancement are the necessary and most basic tests to correctly diagnose glioma!
Magnetic resonance spectroscopy (MRS), diffusion imaging, water suppression imaging (Flair), etc. are necessary for differential diagnosis.
EEG, transcranial Doppler ultrasound cannot correctly diagnose glioma!
Treatment.
The main treatment is direct surgery to remove the tumor, with postoperative radiotherapy adjuvant.
(To use an analogy: surgery is equivalent to direct hoeing, radiotherapy is equivalent to hoeing and then playing herbicide.)
Surgery is the most basic treatment, the purpose is to.
1. Remove the tumor to the maximum extent. Under the condition of protecting the nerve function, remove the tumor as much as possible and delay the tumor recurrence.
2. Clarify the pathology. Obtain tumor classification and grading to guide subsequent radiotherapy treatment.
For deep brain tumors that cannot be removed directly, directional biopsy can be performed to clarify the nature of tumor and then radiotherapy treatment.
Radiotherapy is usually administered 3-4 weeks after surgery. Glioma must receive general radiotherapy after surgery, not just gamma knife radiotherapy (if local residual can be whole brain general radiotherapy + local gamma knife for residual tumor).
There is hope for complete cure after complete resection of grade 1 glioma. After complete resection, radiotherapy is not required, but regular MRI review is needed to monitor for recurrence. Incomplete resection requires adjuvant radiotherapy.
Grade 2-4 gliomas almost invariably recur sooner or later after complete surgical excision (as shown by imaging) and treatment with radiotherapy, etc.
The need for radiotherapy after total resection of grade 2 gliomas is controversial. postoperative radiotherapy should be given to those who fail to have total resection of grade 2 gliomas, and whether chemotherapy is given is controversial, but chemotherapy is currently favored.
The benefits of radiotherapy outweigh the disadvantages, although it has some side effects.
Other treatments such as anti-angiogenic targeted therapy and immunotherapy have uncertain effects.
Chinese medicine treatment: there is no definite and certain effect at present.
The key factors to determine the prognosis are
1. Tumor pathological classification and grading: oligodendroglioma and astrocytic glioma are both grade 2 gliomas, but oligodendroglioma generally has a better prognosis than astrocytic glioma. The higher the grade, the worse the prognosis;
2.Tumor growth site and thoroughness of resection: the more thorough the resection, the later the recurrence. However, due to the need to protect the normal nerve function, it is often difficult to completely resect. If the tumor is located in the central motor area of brain which manages limb activities, basal ganglia area, brainstem area, thalamus, etc., the prognosis is poor.
3. Whether the tumor received correct radiotherapy after surgery: correct radiotherapy after surgery can delay the recurrence.
Postoperative review
Regardless of the grade of glioma, regular postoperative review should be performed under the guidance of the doctor (usually every 3-6 months at the beginning and once a year thereafter).
The basic test for all glioma reviews is a plain cranial MRI + enhancement. Not just a CT scan!
Grade 2 gliomas should also be reviewed with a water suppression MRI (Flair).
Oligodendrogliomas require additional cranial CT.
In case of postoperative recurrence or necrosis by radiotherapy, magnetic resonance spectroscopy (MRS), magnetic resonance perfusion imaging (PWI), and PET-CT should be performed to identify the recurrence.
Treatment of recurrence after surgery
The principle remains that if surgery is possible, resection should be performed as much as possible, and postoperative radiotherapy should be performed according to the pathological classification and grading. Chemotherapy is generally not contraindicated. If you have received regular radiotherapy within 2 years, you should not receive radiotherapy again because it can lead to serious side effects of radiotherapy.
Difficulty of glioma surgery
Most of the glioma surgeries are hemispheric surgeries except for special sites (e.g. brainstem, thalamus), which are not difficult surgeries in neurosurgery. For gliomas in special areas, even the best neurosurgeons have difficulty in cutting the tumor completely due to the special location of the tumor, so the main purpose of surgery is to obtain pathological diagnosis and subsequent treatment mainly relies on radiotherapy.