Radiation Therapy
May 28,2024 Update
Radiation Therapy
With radiation therapy, there is an external irradiation treatment that emits radiation from outside the body, and brachytherapy, which irradiates from the inside. This is said to be one of the three major treatments for malignant tumors, along with surgery and drug therapy. Radiation therapy equipment has been progressing exponentially in recent years and it has become possible to minimize the adverse effects and be minimally invasive.
In our hospital, we perform stand-alone radiation therapy or concomitant therapy with surgery and chemotherapy. In addition, we cooperate closely with the attending doctor (or the referring original doctor) and perform the treatment.
Introduction to the treatment rooms
Our hospital performs treatment with two external irradiation treatment devices and one brachytherapy device.
External irradiation treatment
A linear accelerator (LINAC) is used to irradiate using high energy radiation (X-rays and electron beams) for medical radiation of the affected area. The outlet of the radiation is equipped with a mechanism called multi-leaf collimator (MLC), which can freely create a shape using lead blocks to form an irradiation field that matches the shape of the tumor.
| Treatment Room 1 | Treatment Room 2 | |
|---|---|---|
| Type | VARIAN TrueBeamSTx | VARIAN TrueBeam |
| Typical case | →Brain tumor, prostate cancer, etc. | →Lung cancer, breast cancer, etc |
(1) Stereotactic irradiation (pinpoint irradiation)
- "Brain Lesions"
-
The radiation is focused three-dimensionally from multiple directions for metastatic brain tumors and arteriovenous malformations (AVM) which can't be treated with surgery. There is little effect on the surrounding normal tissue and a treatment effect equivalent to surgery can be expected. MRI imaging is performed, head-fixing masks are prepared in advance, and CT imaging is used to make detailed plans in order to provide high-precision treatment.
The treatment period is from one day to several days, and one treatment time is about 30 minutes. - "Pulmonary tumors"
- This is an application of stereotactic radiation technology for lesions in the brain. This can also apply to lung cancer and metastatic lung tumors. In our hospital, we perform high-precision treatment by using a fixture for respiratory control.
(2) Brachytherapy
Brachytherapy allows radiation to be concentrated in the affected area by directly attaching it to the tumor site or piercing it with the radiation source, thereby minimizing the effect of radiation on normal tissues and delivering a high dose to the targeted lesion. These irradiation methods using brachytherapy are roughly divided into intracavity irradiation and interstitial irradiation. In our hospital, we use Iridium 192Ir as a radiation source to perform intracavity irradiation (cervical cancer) and interstitial irradiation (prostate cancer).
(3) Intensity modulated radiation therapy
High-precision radiotherapy is performed on the head and neck, lungs, and prostate, etc. of the body, organs according to the shape of the tumor and avoiding surrounding normal tissue.
Treatment Time (flow of treatment)
- ・Examination
- When a radiologist examines a patient referred from the hospital or from outside, they will explain the need for radiation therapy, such as the treatment policy (where the body will be irradiated, and how it will be irradiated) in an easy-to-understand manner. Please bring your referral letter and image examination film, etc. that are necessary for treatment to the initial consultation.
- ・ Orientation by a nurse
- After the doctor's examination, there will be an orientation by the nurse. In order to provide patients with a comfortable and anxiety-free treatment, we use videos and leaflets to explain about the treatment in a way that is easy to understand.
- ・Appointments
- After the medical examination and the description of the treatment have been completed by the radiologist, the specific treatment plan date and the treatment start date will be determined. The treatment will usually begin within one week after the examination. (However, the start of the irradiation may be one week or more after the examination, after the patient’s surgery or in combination with chemotherapy, etc.)
- ・Radiation therapy plan (simulation)
- Determination of how to actually irradiate with the radiation and marking the body (skin surface). Our hospital uses a CT simulator to create treatment plans, The target area is imaged by CT, and the necessary lines are drawn on the surface of the body with a specialized marker to align the treatment position.
The entire process up to this point takes approximately 20 minutes.
GE OPTIMA CT580W
Based on the CT images, the radiotherapist decides on the irradiation method, and calculations are performed by a 3D treatment planning system (Eclipse, iPLAN, etc.), and the data is sent to the treatment device.
- ・Treatment
- The treatment is basically performed from two days after the treatment planning. You will lie in a special bed for the treatment and we will accurately match the marks on the skin from the treatment plan. Since the LINAC records and matches the treatment method to the individual using computer management, we are able to do the same irradiation every time. The treatment time for 1 time is about 5-10 minutes.
- ・Return visits
- After the radiotherapy, we will examine the course of radiotherapy periodically and check whether there is any reaction.
