” You may need brain surgery.” Hearing these words, some people picture a craniotomy — an operation in which part of the skull is temporarily opened to remove the lesion. It may feel as though this is the only path forward.

However, brain tumor treatment is not limited to a single approach. Even with the same diagnosis, the treatment actually considered can differ from patient to patient. In addition to surgical resection through a craniotomy, options may include radiation therapy, drug therapy, or careful monitoring without immediate treatment. Among radiation therapies, there is an approach called stereotactic radiosurgery (SRS), which concentrates radiation on the lesion without opening the skull. Gamma Knife is one system used for this type of treatment.

This article outlines the treatment options available for brain tumors in Japan and the role each one plays.

It’s important to note that no single option can be determined to be suitable based on general information alone. The final treatment approach is considered by a physician based on a comprehensive evaluation of the tumor’s characteristics and the patient’s condition, using MRI and other imaging along with clinical information.

Brain Tumor Treatment Options Available in Japan

The main treatments considered for brain tumors include observation, surgical resection, radiation therapy, and drug therapy. Supportive care to ease symptoms may also be provided. These approaches may be used alone or in combination. Which method is considered depends on the tumor’s type, characteristics, size, location, and symptoms.

Watchful Waiting — Choosing to Monitor Rather Than Treat Immediately

Finding a brain tumor does not always mean treatment begins right away. When growth is slow and no symptoms are present, physicians may choose not to begin treatment immediately, instead monitoring the tumor through regular checkups and imaging such as MRI. This approach is known as observation, or watchful waiting.

Watchful waiting does not mean “doing nothing.” Patients undergo testing at set intervals, and if changes in tumor size or symptoms are observed, a shift toward active treatment may be considered.

Surgical Resection via Craniotomy

A craniotomy is a surgical procedure in which part of the skull is temporarily removed to access the brain and remove the tumor.

This surgery serves two roles. The first is therapeutic: removing the tumor can relieve pressure on the surrounding brain tissue. The second is diagnostic: examining the removed tissue provides information to help diagnose the tumor’s type and characteristics. In some cases, a biopsy — in which only a small tissue sample is collected — may be performed to help identify the tumor type.

After surgical removal of a tumor, radiation therapy or drug therapy may be added to help reduce the likelihood of recurrence.

The length of hospitalization and recovery time following a craniotomy varies depending on the tumor’s location and size, the details of the surgery, and the patient’s condition.

Radiation Therapy and Stereotactic Radiosurgery

Radiation therapy uses radiation to act on tumor cells. In many cases, this involves directing radiation at the affected area from a device outside the body.

Within radiation therapy, there is a method called stereotactic radiosurgery (SRS). By directing radiation from multiple angles so that the beams converge at the lesion, a high dose can be concentrated on the lesion while keeping the dose to surrounding tissue low. Although the word “surgery” is used, this is not a procedure that opens the skull to remove the tumor. Gamma Knife is one system used to perform this type of stereotactic radiosurgery.

However, SRS is not suitable for every patient. The circumstances under which it may become an option are explained in the following section.

Drug Therapy and Supportive Care

Drug therapy includes chemotherapy and targeted therapy, among other approaches.

That said, not all brain tumors are treated with drug therapy. Brain tumors also include benign tumors, and whether drug therapy is used — and which drugs might be appropriate — depends on the tumor’s type and characteristics.

Separately, there are treatments aimed at easing symptoms themselves. This is known as supportive care, and may include treatment for seizures or brain swelling. Supportive care serves a different role from treatments that act on the tumor itself, and it may be provided alongside other treatments depending on the patient’s symptoms.

As this shows, there are multiple paths when it comes to brain tumor treatment. The next section looks more closely at craniotomy and Gamma Knife, one form of stereotactic radiosurgery.

Craniotomy and Gamma Knife — How Their Roles Differ

Craniotomy and stereotactic radiosurgery are often discussed as if choosing between the two were a simple either/or decision. In reality, the two approaches differ in how they act on the lesion and in the role each is expected to play. Here, we look at what each treatment is intended to achieve.

What Craniotomy Aims to Achieve

The goal of a craniotomy is to work directly on the lesion itself.

Its role can be divided into three main parts. The first is removing the lesion. The second is relieving pressure on the surrounding brain, which may help improve symptoms caused by that pressure. The third is collecting tissue to obtain information for diagnosing the tumor’s type and characteristics.

The ability to reach the lesion directly — allowing for removal and tissue sampling — is a defining feature of craniotomy. For this reason, it may be considered when relieving pressure by removing the lesion is necessary, or when tissue sampling is judged necessary for pathological diagnosis.

What Gamma Knife Aims to Achieve

Gamma Knife stereotactic radiosurgery concentrates radiation on the lesion without any skin incision or opening of the skull.

This treatment does not remove the lesion on the spot. Its main purpose is to concentrate radiation on the lesion in order to control its growth, and in some cases the lesion may shrink over time.

Because of this, the effects are not always apparent immediately after treatment. It takes time for the effects on the cells to become evident, and how the lesion changes is confirmed through follow-up imaging. The way changes appear also varies depending on the type and characteristics of the lesion. Regular follow-up after treatment is an essential part of this approach.

Details on how the radiation is delivered and what the treatment process involves can be found in how Gamma Knife stereotactic radiosurgery works.

Why It Can’t Simply Be Judged Which Is “Better”

Craniotomy and Gamma Knife act on the lesion in different ways, and the circumstances in which each is chosen vary. For this reason, the two cannot be compared in terms of simple superiority.

Cases where relieving pressure by removing the lesion is needed, and cases where controlling the lesion’s growth with Gamma Knife is considered, call for treatments with different intended roles. Neither approach is inherently superior to the other — which treatment is considered depends on the individual patient’s condition.

Both treatments also carry potential complications or side effects. Because the nature of these — and how they present — differs between treatments, a decision cannot be made by looking at just one option alone. Potential side effects of Gamma Knife treatment are discussed in a separate article.

Which treatment is actually considered depends on the tumor’s type and characteristics, size, location, symptoms, prior treatment history, and the patient’s overall condition.

When Multiple Treatments Are Combined

Treatment does not always mean choosing one approach over another.

For example, depending on the type and location of the lesion, radiation therapy — including Gamma Knife — may be considered for portions that remain after surgery or for a lesion that has recurred. In some cases, depending on the tumor type, radiation therapy may also be given after surgery to help reduce the likelihood of recurrence. However, whether radiation therapy is given after surgery, and whether Gamma Knife is chosen, depends on the type and characteristics of the lesion.

For some patients, both craniotomy and Gamma Knife may be included within a single treatment plan. Whether to combine treatments, and in what order or timing, is something the physician considers after evaluating the patient’s condition.

So how are these decisions actually made in practice?

How the Treatment Approach Is Determined

The treatment approach is not decided by diagnosis name alone. Here, we outline the kinds of information that inform this decision.

Tumor Type, Size, Location, and Number

Even within the category of “brain tumor,” the way a tumor grows and affects surrounding tissue varies by type and characteristics. Beyond size, where in the brain the tumor is located and whether there is a single lesion or multiple lesions also factor into the decision.

These factors are not evaluated in isolation; they are assessed together to determine which approaches may be considered.

Symptoms, Treatment History, and Overall Health

The decision involves not only information about the lesion itself but also the patient’s own condition. This includes whether symptoms are present and their severity, whether the course has been stable or changing, along with any prior surgery, the site of any previous radiation therapy, the course of any drug therapy, age, overall health, and any other medical conditions.

That said, no single factor alone determines whether a treatment can be used. Even with similar imaging findings, the treatment considered may differ depending on the patient’s condition.

Why Reviewing the Images Themselves Is Necessary

The diagnosis name or an imaging report alone may not provide enough information to determine what treatment options can be considered. For this reason, the MRI or CT images themselves are reviewed. Images make it possible to assess the lesion’s size, location, and relationship to surrounding tissue, and if prior images are available, changes over time can also be observed.

This assessment is not based on imaging alone; medical reports, pathology results, treatment history, and current symptoms are also reviewed together.

Why a Specialist’s Evaluation Is Needed to Determine Suitability

Because so many factors are involved in determining a treatment approach, it is difficult to identify the right treatment for a given individual from general information alone. That said, gathering information is still valuable — understanding the range of options can make a physician’s explanation easier to follow and help you organize your questions ahead of a consultation.

From there, consulting a specialist who can review your images and clinical information allows you to ask specifically what may be considered in your case. If you have already been advised to undergo surgery, you can find guidance on how to proceed in getting a second opinion when surgery has been recommended.

So what does the process look like for those living overseas who wish to consult a medical institution in Japan?

The Process for Consulting a Medical Institution in Japan From Overseas

Here is a general outline of the process.

Start With an Inquiry

The first step is to contact the medical institution you are considering. Providing a brief summary of your current diagnosis and treatment history at this stage can help the process move more smoothly.

The information required and the way consultations are handled vary by institution. Some accept inquiries directly from patients, while others require the inquiry to go through a referring physician or an intermediary organization. It’s important to note that suitability for treatment or acceptance as a patient is not determined at this stage.

Preparing MRI/CT Images, Medical Reports, and Treatment History

When moving forward with a consultation, the following information is generally prepared:

• MRI, CT, or other imaging data along with the accompanying findings
• Medical reports
• Pathology results, if a biopsy has been performed
• History of surgery, radiation therapy, drug therapy, or other treatments
• Current symptoms and medications

Required documents vary by institution, so please prepare materials according to the guidance provided by the institution you contact.

Consultation and Confirmation Before Traveling

Some medical institutions offer the option to consult based on images and clinical information before you travel to Japan. At this stage, you may be advised of any additional tests or documents that are needed.

However, a pre-travel consultation alone does not necessarily confirm a diagnosis or suitability for treatment. After arriving in Japan, you may be examined again and, if necessary, undergo additional testing before the treatment approach is considered.

Planning Treatment and Follow-Up Care

Based on the consultation, plans for travel and treatment are considered. It’s also important to confirm what imaging and follow-up appointments will be needed after treatment.

Where follow-up care takes place after returning home depends on the patient’s circumstances and the relationship between the Japanese medical institution and medical providers in your home country. How and where follow-up care will continue after treatment should also be confirmed during the consultation.

How to Consult Koto Memorial Hospital

Gamma Knife Treatment at Koto Memorial Hospital

Koto Memorial Hospital (Higashiomi City, Shiga Prefecture) is home to the Shiga Gamma Knife Center. Gamma Knife stereotactic radiosurgery is performed here.

Whether Gamma Knife treatment may be an option for you is considered by a physician after reviewing your images and clinical information.

Information about the physicians and facility involved can be found under about the physicians and facility. Details of what is included in the base treatment fee are summarized under what is included in the base fee.

How to Request a Consultation

If you would like to inquire about Gamma Knife treatment, please contact us through the consultation request form.

When you reach out, please let us know your current diagnosis and the course of treatment you have received so far. Please confirm what images and clinical information will be required when you contact us.

Please note that an initial inquiry alone does not confirm suitability for treatment or acceptance as a patient.

If you are considering Gamma Knife treatment in Japan, please start by contacting us about your current diagnosis and treatment history.

Request a Consultation

Frequently Asked Questions

If I am diagnosed with a brain tumor, is surgery always necessary?
No. Depending on the tumor’s type, characteristics, and symptoms, options such as observation, radiation therapy, or drug therapy may be considered. The treatment approach differs from patient to patient.

Can Gamma Knife replace craniotomy?
In some cases it can, but not in all. The two treatments are expected to play different roles, and a treatment plan may include both craniotomy and Gamma Knife.

How is it determined whether I am a candidate for Gamma Knife treatment?
This is assessed based on the tumor’s type, size, location, and number, as well as symptoms, treatment history, and overall health. A physician evaluates this comprehensively using MRI and other imaging along with clinical information.

What should I prepare when consulting a medical institution in Japan?
Generally, this includes MRI and CT imaging data, examination findings, medical reports, pathology results, treatment history, and current symptoms and medications. Please confirm the specific documents needed with the institution you contact.

What kind of follow-up is needed after Gamma Knife treatment?
Changes in the lesion are monitored through imaging and medical examinations. The specific tests, their frequency, and how follow-up care is handled after returning home vary by patient, so please discuss this with your physician before treatment.

If you would like to discuss your current diagnosis or treatment history, please contact us through the inquiry form. Please prepare any required images or clinical information according to the guidance provided.

Request a Consultation