Prof. Dr. Berrin PEHLIVAN
Different treatment options for brain tumors
Most convenient treatment is determined with consideration of tumor characteristics and patient medical condition. Tumor volume, cancer stage and the other factors has important role in decision making process of treatment type. It is also important to have multidisciplinary approach and case study of treatment planning.
Radiotherapy and Radio-surgery in the treatment of brain tumors
Radiotherapy (irradiation therapy)
This treatment method could be applied after surgery or as separated treatment method. Radiotherapy may be applied solely to tumor area as well as to the whole brain or spine.
What is Stereotactic Radiotherapy ?
Stereotactic radiotherapy is a method performed by targeting the tumor, radiation beams are applied from different angles to the head by targeting the area where the tumor is located. In this treatment method, the target is determined as a point shot and therefore it is important for the patient to remain in the same position during each beam delivery and remain still throughout the treatment seans.
For which diseases preferred Stereotactic Radiotherapy?
Listed articles are effective in selection of stereotactic radiotherapy method
-Secondary brain tumors
-Gliomas which relapsed after first treatment
-Small and low grade tumors with differentiated edges
Stereotactic treatment method is used in treatment of some nonmalignant brain tumors
-Acoustic neuroma
-Skull base meningioma / brain membrane tumor
-Pituitary gland adenoma
-Chordoma
Planning of Stereotactic Radiotherapy
-This method of treatment use CT or MRI screenings. Treatment planning process involve screening tests and studies for determine the rays that should be traced to target tumor directly. With this study, it is ensured that the radiation sent to the normal brain tissue located around the tumor is minimalized. As a result, the patient experiences much less side effects than normal radiotherapy.
Possible side effects:
Stereotactic radiotherapy in contrast to the traditional radiotherapy methods has less side effects, it may appear such side effects like fatigue and headache.
What is Radio-surgery?
Radio-surgery is not a surgical intervention, it is a type of stereotactic radiotherapy. Radio-surgery devices are used for treatments, due to this reason radio surgery may known as CyberKnife or Gamma Knife. Moreover, lineer accelerator could be used in treatment as well.
Tumor types that can be treated with radio-surgery
It is observed that this type of treatment is highly effective on some of brain tumors. If person has acoustic neuroma tumor which is under certain volume, radio-surgery is the method that applicable for treatment.
Radio-surgery could be used in treatments of tumors listed below:
-Small secondary brain tumors
-Small pituitary gland adenoma
-Post surgical recurrent hemangioblastoma cancer
-Some types of meningiomas
-Some types gliomas and recurrent gliomas
In cases of large brain tumors this method not preferred because it is not possible to send the same dose of radiation to the treatment area.
Chemotherapy and target therapy methods
Chemotherapy treatment of brain tumor
Recurrent or advanced stage brain tumors generally treated with chemotherapy. In some cases it could be combined with radiotherapy or applied before the main treatment. Chemotherapy used for destroy cancer cells with strong and effective pharmaceuticals. Single medicine or combination of medicines could be used related to tumor status. This medicines could be taken orally or intravenously. In general chemotherapy applied with courses. One course consist of treatment and period of recovery. Side effects may hardly tolerable for some persons. Such side effects like vomiting, nausea, loss of appetite, hair loss may minimized by usage of protective medicines which help patient spend more comfortable period. Frequency of treatment depends on pharmaceuticals and patient’s medical condition.
Target therapy methods for brain cancer treatment
Agent used in target therapy for treatment brain tumor diseases is Bevacizumab. This medical agent working with principal of blockage mechanism of tumor that produced angiogenesis and prevent this process from progressing. This medicine considered effective in treatment of recurrent glioblastoma or advanced stage glioblastoma.
Brain tumor treatment: Immunotherapy
There are many researches that has take place and continue to maintain treat core of brain tumor diseases. Some of jabs provoke response of immune system are just some of the strategies. Jabs as HPV that used for protect purpose, in contrast planned to be used in cancer, working with mechanism where immune cells fighting against cancer cells. As the result of phase studies relapsed glioblastoma cases determined good response of treatment by immunotherapy jabs. Vaccine named Rindopepimut block EGFRvIII genetic mutation that cause uncontrolled brain tumor progression.
Screening and surgical methods
Brain is one of the most important organ of our body and has very sensitive tissue, determine tumor size and location is very important stage in treatment process. Technological development make surgical interventions less risky, more safe and provide better treatment success rates. Fluorescent dye and endoscopy techniques take place in today’s approach. Before procedure patient take fluorescent ingredient dye which is attached to tumor that makes margins more actively determined. With endoscopy applicated treatments, locations that are hard to reach with via imaging level of fault minimized. In general this methods applied in ventricle and pituitary gland tumor surgeries.
Central nervous system diagnosis made by MRI (magnetic resonance imaging) screening, this method usually used for diagnosis. Functional MR, MR spectroscopy and MRI derivatives are the methods that used in medicine today. Functional MRI could determine by which functional area of the brain has tumor existence. MR spectroscopy enable to screen tumor’s important metabolites map. Malignant level of the formation could be determined with this screening method. MR screenings that take place before and after treatment makes possible to compare efficiency of applied procedures.
Radiotherapy:
IGRT is radiotherapy method that combined with screening, which make it better to direct radioactive rays to the target, during pre treatment process CT used for determination of radiotherapy application areas.
Chemotherapy:
The blood brain barrier is one of the biggest obstacles encountered in chemotherapy. This barrier normally protects nervous cells, hence it limits the transition of chemotherapy medicines to the target. At this point scientific studies continues, research investigate subject of chemotherapy medicines to pass this barrier. Chemical drugs needs to be attached to fat molecules or conjoin transitional molecules to be more effective. The other study is about to directly transition of drug to the tumor tissue, but it must be considered that this studies are ongoing and have not definitive results yet.