Principle of Proton Heavy Ion Therapy for Tumor Treatment
In the process of Proton Heavy Ion Therapy for Tumor Treatment, special machines and appliances can be utilized to release only a very small amount of energy before it reaches the tumor, avoiding as much as possible the damage to the healthy tissues. Only when the body's heavy ions reach the tumor site will they release a large amount of energy for a concentrated blast, which is also known as the "Bragg peak" energy release trajectory.
The difference between proton and heavy ion therapy and conventional radiotherapy
Proton can disrupt the single-stranded DNA of tumor cells, and heavy ions are even more powerful, disrupting the double-stranded DNA of the tumor cells, which can destroy the tumor cells and prevent them from repairing. In particular, it can effectively "kill" tumors that are insensitive to conventional radiation, as well as recurrent tumors.
Compared with conventional radiotherapy (X-rays, gamma rays), heavy ion/proton therapy can focus the irradiation energy on the tumor lesion. This not only reduces the side effects of radiotherapy, but also reduces the number of treatments. In addition, it can also provide excellent results for tumors that are difficult to treat with conventional radiation therapy.
The proton beam radiates very little when it approaches the tumor, and the vast majority of the energy is deposited within the tumor tissue, with no dose at all around or behind the tumor.
Conventional X-ray therapy: radiation loses a large amount of energy within the first few centimeters of entering the tissue, and then damages normal tissue even more than tumor tissue.
Relief rate of proton and heavy ion therapy
In the treatment of various types of solid tumors, proton and heavy ion therapy is internationally recognized as a very good local treatment. According to the National Institute of Radiology, Japan, the 5-year survival rate of patients with early-stage tumors treated with proton therapy is more than 80%.
By the end of 2013, the number of patients who have received heavy ion therapy is close to 10,000 cases worldwide, and the number of patients who have received proton therapy is more than 100,000 cases.
The 5-year survival rate of prostate cancer used for proton therapy is 88%; for optic nerve glioma, treatment with proton therapy can be used with preservation of vision and no recurrence 3 years after treatment. For hepatocellular carcinoma treatment, the 7-year survival rate is reported to be 94%; for elderly tumors and pediatric tumors with poor physical condition, the treatment effect is clinically tested to be better. Ocular melanoma used to be treated by removing the eyeball, which is extremely painful for patients. And proton therapy can save more than 90% of the eyeball, and the 5-year local control rate is more than 96%.