1. Field of the Invention
The present invention relates to an assisting technology for radiotherapy, particularly to an assisting method and apparatus for radiotherapy of a tumor adjacent to the diaphragm.
2. Description of the Related Art
Radiotherapy is a kind of treatment applying radioactive ray to tumors or other diseases and used for curing localized solid tumors, such as lung cancer, liver cancer, prostate cancer, colonic/rectal cancer, thyroid cancer, kidney cancer, adrenal cancer, pancreatic cancer, breast cancer, etc . . . The effect of radiotherapy has been raised now as the maximum permissible dose of radiation increased with improved radiotherapy.
A lung tumor or liver tumor appears at the upper or lower region of the diaphragm of a patient, such as the lower edge of the lobe or the upper border of the liver. When a patient breathes, the tumor in the lung or liver moves with the rise and down of the diaphragm. Such a problem causes inaccurate positioning at the tumor and decreases the effect of radiotherapy.
Accordingly, the present invention proposes an assisting method and apparatus for radiotherapy to decrease the safety margin of radiotherapy, reduce the radiation dosage applied on normal tissues, decrease side effects on normal tissues, and increase the maximum permissible dose of radiation on the cancerous tissues for improved control rate of cancer.
One objective of the present invention is to provide an assisting method and apparatus for radiotherapy, wherein the variations of the inspiratory and expiratory lung volumes are used to track the physical position of a tumor, and wherein the bedplate on which the patient leans is moved in a direction opposite to the direction of the tumor displacement to offset the tumor displacement caused by breathing, whereby the tumor is equivalently static or almost immobile with respect to the static radiotherapy apparatus, and whereby the radiation can be concentrated to attain a greater dose, wherefore higher control rate of cancer and better treatment effect on cancer are achieved.
To achieve the abovementioned objective, the present invention proposes an assisting method for radiotherapy, which can assist the radiotherapy of a tumor adjacent to the diaphragm, and which comprises steps: using a supporting means to support the patient; calculating the displacement (the direction and distance of movement) of the tumor according to the inspiratory and expiratory capacities of the patient; and moving the supporting means oppositely to the displacement of the tumor to offset the displacement of the tumor.
The present invention also proposes an assisting method for radiotherapy, which can assist the radiotherapy of a tumor adjacent to the diaphragm, and which comprises a driving mechanism coupled to a supporting means supporting the patient; a breathing sensor arranged on a breathing region of the patient to detect the inspiratory and expiratory capacities of the patient; a computer connected with the driving mechanism and the breathing sensor, calculating the direction and distance of the movement (the displacement) of the tumor according to the inspiratory and expiratory capacities of the patient of the patient, and controlling the driving mechanism to move the supporting means to offset the displacement of the tumor according to the direction and distance of the displacement of the tumor.
Refer to
Define the movement of the bedplate toward the head of the bed to be the upward displacement of the bedplate, and define the movement of the bedplate toward the tail of the bed to be the downward displacement of the bedplate. In step 16, the bedplate is moved in a direction opposite to the direction of the displacement of the tumor and in a distance equal to the distance of the displacement of the tumor. In other words, when the ascending of the diaphragm displaces the tumor upward, the bedplate together with the patient is driven to have a downward displacement opposite to the upward displacement of the tumor; when the descending of the diaphragm displaces the tumor downward, the bedplate together with the patient is driven to have an upper displacement opposite to the downward displacement of the tumor.
When a tumor is adjacent to the diaphragm, the upward and downward movements of the diaphragm will change the position of the tumor. The present invention tracks the physical position of the tumor according to the variations of the inspiratory and expiratory lung volumes of the patient. For a static radiotherapy apparatus, the displacement of the bedplate and the patient can offset the displacement of the tumor. In other words, the tumor is equivalently static or almost immobile for the radiotherapy apparatus. Thereby, the radiation can focus on the cancerous region more accurately with a lower dose thereof received by normal tissues. Therefore, the present invention can reduce the side effects on normal tissues and improve the effect of radiotherapy.
In the present invention, the upward or downward displacement of the bedplate can offset the tumor displacement caused by free breathing, whereby the tumor is equivalently static or almost immobile with respect to a static radiotherapy apparatus, wherefore the present invention can concentrate the radioactive ray to undertake a high dose radiotherapy to achieve high tumor control rate and better therapeutic effect.
The embodiments described above are only to demonstrate the technical contents and characteristics of the present invention to enable the persons skilled in the art to understand, make, and use the present invention. However, it is not intended to limit the scope of the present invention. Any equivalent modification or variation according to the spirit of the present invention is to be also included within the scope of the present invention.
Number | Date | Country | Kind |
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98113873 | Apr 2009 | TW | national |