Types of Treatment for Brain Tumor

Executive Summary

The different types of standard treatments for brain tumor are explained in detail. Standard treatments are used along with the integration of effective treatment planning. Clinical trials are used as an innovative treatment approach that combines different therapies and drugs for treating brain tumors. Surgery can probably be the only treatment needed for a low-grade brain tumor, especially if all tumors are removed. Treatment begins typically with surgery for higher-grade tumors, followed by radiation therapy and chemotherapy. But certain breakthroughs in surgery for brain tumors have been also observed. In some cases, biopsy results are used to determine if cancer medications or radiation therapy will be helpful. Radiation therapy is used to treat brain tumors, mainly external-beam radiation therapy involving Conventional radiation therapy, 3-dimensional conformal radiation therapy (3D-CRT), and Intensity-modulated radiation therapy (IMRT), Proton Stereotactic radiosurgery, and Fractionated stereotactic radiation therapy. Chemotherapy involves the use of several effective drugs. Targeted therapy involving Bevacizumab (Avastin, Mvasi) and Larotrectinib (Vitrakvi) and entrectinib (Rozlytrek) are also used. Electric field therapy is used for hindering the activity of cells that help the tumor cells grow and increase. Palliative care is provided to the patients to cope with mental, physical or financial issues while involving medication, nutritional changes, emotional and spiritual support and other relaxation therapies. Brain metastasis is treated using surgery, radiation therapy, targeted therapy, and immunotherapy.

Treatment of Brain Tumors

“Standard to care” refers to the best-known Treatment for Brain Tumor. In cancer care, different doctors work together to bring out an overall treatment plan for the patient. It is called a multidisciplinary team. 

Treatments for Brain Tumor recommendations depend on many factors:

• The size, grade and type of tumor
• Whether the tumor is applying pressure on vital parts of the brain
• If the tumor has increased to other parts of the CNS or body
• Possible side effects
• The patient’s preferences and overall health

The types of treatments for Brain Tumor used for a brain tumor are explained below ^​1​. The care plan may also include treatment for symptoms and side effects, an essential part of your medical care.

It is crucial to have a care team specializing in caring for people with a brain tumor, which may mean talking with medical professionals beyond your local area to help with diagnosis and treatment planning.

Surgery can probably be the only treatment needed for a low-grade brain tumor, especially if all tumors are removed. If a visible tumor remains after surgery, radiation therapy and chemotherapy may be used ^​2​. 

Treatment begins typically with surgery for higher-grade tumors, followed by radiation therapy and chemotherapy. Your health care team develops your treatment plan.

The blood-brain barrier keeps the brain and spinal cord safe from harmful chemicals. But, this barrier also keeps out many types of chemotherapy. Surgery is complicated if the tumor is near a delicate part of the brain or spinal cord. Even when the surgeon can remove the original tumor, parts of the tumor can be present which are too small to be seen or removed during surgery. Radiation therapy can also lead to damage to healthy tissue.

Surgery

Surgery is the removal of a tumor and surrounding healthy tissue during an operation. A neurosurgeon specializes in treating a CNS tumor using surgery. It is usually the only treatment for Brain Tumor required for a low-grade brain tumor. Surgery to the brain needs the removal of part of the skull, and the process is called a craniotomy. After the surgeon removes the tumor, the patient’s bone will be used to cover the opening in the skull.

There have been breakthroughs in surgery for brain tumors. 

• Cortical mapping permits doctors to identify brain areas that control speech senses and motor skills.
• A fluorescent dye, named 5-aminolevulinic acid, can be given by mouth the morning before surgery. This particular dye is taken up by tumor cells. Doctors use a special microscope and light to see the cells that have taken up the dye during the surgery. 
• Computer-based techniques, such as image-guided surgery (IGS), help surgeons correctly map the tumor’s location. However, this is a specialized technique that may not be widely available.

In the case of a tumor located near the brain’s speech Centre, it is common to operate when the patient is awake. Then, special electrical stimulation techniques to find the particular part of the brain that controls speech. This approach can help in avoiding any damage while removing the tumor. 

The biopsy results can help determine if cancer medications or radiation therapy will be helpful for some tumour types. Even if it cannot be cured for a cancerous tumor, removing it can relieve symptoms from the tumor pressing on the brain.

Sometimes, surgery cannot be performed because the tumor is located where the surgeon cannot reach or near a vital structure. These tumors are called inoperable or unresectable. If the tumor is inoperable, the doctor will recommend other treatment options for Brain Tumor, including a biopsy or removal of a portion of the tumor.

Radiation therapy

Radiation therapy uses high-energy X-rays or particles to destroy cancer cells. Doctors use radiation therapy to slow or stop the growth of a brain tumor. It is typically given post-surgery and possibly along with chemotherapy.

The most common radiation treatment type is external-beam radiation therapy, in which radiation is given from the machine outside the body. A radiation therapy schedule consists typically of a specific number of treatments offered over a set period.

External-beam radiation therapy can be focused on a brain tumor in the following ways:

• Conventional radiation therapy – The treatment position is decided based on anatomic landmarks and x-rays. This technique is appropriate in specific situations, such as whole-brain radiation therapy for brain metastases. The quantity of radiation given depends on the tumor’s grade.
• 3-dimensional conformal radiation therapy (3D-CRT) – A 3-dimensional model of the tumor and healthy tissue surrounding the tumor is created on a computer using images from CT and MRI scans. This model can aim the radiation beams directly at the tumor, sparing the healthy tissue from high doses of radiation therapy.
• Intensity-modulated radiation therapy (IMRT) – IMRT is a type of 3D-CRT that can more directly target a tumor. It can deliver higher doses of radiation to the tumor while giving smaller amounts to the surrounding healthy tissue. In IMRT, the radiation beams are divided into smaller beams, and the intensity of each smaller beam can be changed. This means that the more intense beams, or the beams with more radiation, can be directed only at the tumor.
• Proton therapy – Proton therapy is a type of external-beam radiation therapy that uses protons rather than x-rays. At high energy, protons can destroy tumor cells. Proton beam therapy is typically used for tumors when less radiation is needed because of the location. This includes tumors that have grown into nearby bone, such as the base of the skull and those near the optic nerve.
• Stereotactic radiosurgery – Stereotactic radiosurgery uses a single, high dose of radiation given directly to the tumor and not healthy tissue. It works best for a tumor only in 1 area of the brain and certain noncancerous tumors. It is also used in a person who has more than one metastatic brain tumor. There are different types of stereotactic radiosurgery equipment:
  • A modified linear accelerator is a machine that creates high-energy radiation with the help of electricity to generate a stream of fast-moving subatomic particles.
  • A Gamma Knife is a form of radiation therapy that concentrates highly focused beams of gamma radiation on the tumor.
  • A CyberKnife is a robotic device used in radiation therapy to guide radiation to the tumor, particularly in the brain, head, and neck areas.
• Fractionated stereotactic radiation therapy –  Radiation therapy is delivered with stereotactic precision but spilt into small regular doses called fractions and given over several days or weeks, in contrast to the 1-day radiosurgery. This technique is used for tumors close to sensitive structures, such as the optic nerves or brain stem.

With the help of different procedures, doctors are trying to be more precise and reduce radiation exposure and damage to nearby healthy brain tissue. Depending upon the size and location of the Brain Tumor, the radiation oncologist may choose any of the above radiation techniques.

Short-term side effects from radiation therapy can include mild skin reactions, fatigue, upset stomach, hair loss, and neurologic symptoms, like memory problems. Most side effects diminish or go away soon after treatment for Brain Tumor ends. Radiation therapy usually is not recommended for children younger than five because of the high risk of damage to their developing brains.

Chemotherapy

Chemotherapy uses medicine to kill or stop the growth of cancerous cells. Depending upon the stage, different chemotherapy is given. The point that makes a difference is how the chemotherapy enters the body and which cells it affects.

Systemic chemotherapy enters the bloodstream to reach cancerous cells all over the body. 

Standard methods for chemotherapy include an intravenous (IV) tube placed into a vein using a needle or by capsule or pill taken orally.

A chemotherapy schedule usually consists of a certain number of cycles over a fixed period. A patient can be given one drug at a time or a combination of different medications given simultaneously.

Some drugs are used to pass through the blood-brain barrier. These are the drugs that are mainly used for a brain tumor.

• Gliadel wafers are a method to give the drug carmustine (BiCNU). These wafers are positioned where the tumor was removed during surgery.
• The latest standard of care for glioblastoma and high-grade glioma patients is radiation therapy with daily low-dose temozolomide (Temodar). Monthly doses of temozolomide follow this after radiation therapy for six months to a year.
• A combination of 3 drugs, lomustine (Gleostine), vincristine (Vincasacr) and procarbazine (Matulane), has been used along with radiation therapy. This approach has helped lengthen patients’ lives with grade III oligodendroglioma with a 1p/19q co-deletion when given before or right after radiation therapy. It has also been shown to prolong patients’ lives after radiation therapy for a low-grade tumor that surgery could not remove entirely. 

Patients are observed with a brain MRI every 2 to 3 months during active treatment. As we advance, the length of time between MRI scans increases depending on the tumor’s grade. Patients often have regular MRIs to observe their health after treatment, and the tumor has not grown. If the tumor grows during treatment, other treatment options can be considered.

The side effects of chemotherapy treatment depend on the patient and the dose used. Still, they can include fatigue, risk of infection, nausea and vomiting, hair loss, loss of appetite, and diarrhoea. These side effects usually go away after treatment is finished. Rarely, particular drugs can cause some hearing loss, while others may lead to kidney damage. Patients may be provided with extra fluid by IV to protect their kidneys.

Targeted therapy

Targeted therapy aims at any factor contributing to the growth and development of cancer cells. It can be a specific protein, gene or tissue environment. These treatments are typical and do not harm surrounding cells like those in chemotherapy or Radiotherapy.

All tumors do not have the same target; doctors may recommend testing to understand better changes in the individual tumor’s genes and proteins. 

Additionally, research studies continue to find out more about specific molecular targets and new treatments.

For a brain tumor, two types of targeted therapy may be used:

• Bevacizumab (Avastin, Mvasi) is an anti-angiogenesis therapy used in the treatment of glioblastoma multiforme in case the previous treatment has not worked. Anti-angiogenesis therapy focuses on stopping the process of making new blood vessels called angiogenesis. Because a tumor needs the nutrients delivered by blood vessels to grow and spread, the goal of anti-angiogenesis therapy is to “starve” the tumor.
• Larotrectinib (Vitrakvi) and entrectinib (Rozlytrek) are targeted therapies not specific to a particular type of tumor but focus on a genetic change called an NTRK fusion. This kind of gene change is found in tumors, including some brain tumors. These drugs are approved to treat some metastatic brain tumors or cannot be removed with surgery and have worsened with other treatments.

Various other targeted therapies are being studied in brain tumors that consist of other specific molecular changes, like IDH mutations, BRAF mutations, and FGFR fusions. 

Alternating Electric field therapy (tumor treating therapy)

This treatment uses noninvasive portable devices that hinder cells that help the tumor cells grow and increase. It is given by electrodes producing an electric field outside a person’s head. The device is called Optune.

Alternating electrical field therapy may be an alternative for people newly diagnosed with glioblastoma or for recurrent glioblastoma. Researchers have shown that people with recurrent glioblastoma who used the device lived as long as those who received chemotherapy. Additionally, they had lesser side effects. Other research shows that people recently diagnosed with glioblastoma lived longer and were less likely to worsen the disease when this treatment was used along with temozolomide after radiation therapy. 

Palliative Care

Cancer and its treatment for Brain Tumor have side effects that can be mental, physical or financial and managing the effects are palliative or supportive care.

Palliative care includes medication, nutritional changes, emotional and spiritual support and other relaxation therapies. 

Palliative care focuses on alleviating how you feel during treatment by managing symptoms and supporting patients and their families with other non-medical needs. Regardless of type and stage of Cancer age, any person may receive this type of care.

Remission and the chance of recurrence of Brain Tumor

When cancer can’t be detected in the body and there are no symptoms, this is known as remission. It may also be called having ‘no evidence of disease’ or ‘NED.’

A remission can be temporary or permanent. Many people worry about the recurrence of cancer.

For most primary brain tumors, despite imaging tests showing that the tumor growth is controlled or there are no visible signs, it is typical for a brain tumor to recur.

Patients often continue to receive regular MRI scans from watching for a recurrence. This uncertainty creates worry for people that the tumor will come back.

If the tumor returns after the original treatment, it is called a recurrent tumor. A recurrent brain tumor often comes again near where it initially started. But rarely, it may come back in another place which is called a multifocal recurrence.

The doctor performs another round of tests to know the extent of the recurrence.

The treatment plan for Brain Tumor mainly includes the treatments explained above, like surgery, chemotherapy, radiation therapy, and targeted therapy. Still, they are used in a different combinations or given at a different pace. Options can be:

• Temozolomide
• Bevacizumab
• Clinical trials studying new treatments
• Alternating electric field therapy for patients with recurrent high-grade glioma

There is no single approach to treating a recurrent brain tumor, and the treatment plan is generally based on many factors. Whichever treatment plan you go for, palliative care will be necessary for relieving symptoms and side effects.

Metastatic Cancer

When cancer starts spreading to other parts of the body, it is called metastatic cancer. Doctors can have different opinions regarding the best standard treatment plan. Clinical trials might also be an option. For many people, the diagnosis of metastatic cancer is very stressful and challenging. It is usually helpful to talk with other patients through support groups or peer support programs. The treatment plan can include a combination of surgery, targeted therapy, radiation therapy, and immunotherapy, which is a treatment created to boost the body’s natural defences to fight the tumor.

Treatment of Brain metastases

Presently, the following options are available for brain metastases:

• Surgery – Surgery is usually only an option for patients who have cancer in a single brain area. Radiation therapy is often given afterwards.
• Radiation therapy – Whole-brain radiation therapy is radiation therapy given to the entire brain. Sometimes, doctors can avoid damaging the hippocampus (a part of the brain). It helps lessen the cognitive side effects associated with radiation therapy. High-dose radiation therapy can be given using stereotactic techniques that focus the radiation only on the tumor in the brain, which can also help lessen the side effects.
• Targeted therapy – These include:
  • Osimertinib (Tagrisso) for non-small cell lung cancer (NSCLC) that has a genetic change in the EGFR gene
  • Alectinib (Alecensa) for NSCLC with a genetic modification on the ALK gene
  • Lapatinib (Tykerb) can be used for HER2-positive breast cancer
  • Dabrafenib (Tafinlar) either by itself or along with trametinib (Mekinist) and vemurafenib (Zelboraf) for melanoma
• Immunotherapy – Some types of immunotherapy have demonstrated promise in treating brain metastases from lung cancer and melanoma. These include ipilimumab (Yervoy), pembrolizumab (Keytruda) and nivolumab (Opdivo).  

Treatment of leptomeningeal metastases

If cancer spreads to the meninges or the Cerebrospinal fluid, it is known as leptomeningeal metastases. People with leptomeningeal metastases may receive chemotherapy that is given directly into the brain’s Cerebrospinal fluid. It can be done with a lumbar puncture and is called intrathecal chemotherapy. Or it may be delivered using a catheter with a reservoir called an Ommaya reservoir. Radiation therapy may also be an option.

If treatment doesn’t work

Recovery from bone sarcoma is not always possible. If cancer can’t be treated or controlled, it leads to advanced or terminal cancer. It is vital to have straightforward conversations with your health care team to express your feelings, preferences, and concerns. The health care team has unique skills, knowledge, and experience to assist patients and their families. Ensuring that a person is physically comfortable, free from pain, and emotionally supported is extremely important. 

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