Proton Therapy 質子放射治療

Proton therapy relies on the generation of high-energy proton beams (greater than 200 MeV). Its most important feature is that protons release the majority of their energy at a specific depth inside the body after entering the surface — a phenomenon known as the Bragg peak. This allows for the concentrated and precise delivery of radiation doses to the tumor site, significantly reducing damage to surrounding healthy tissues.

Advantages

Because protons can be precisely targeted, damage to adjacent normal tissues is minimized. As a result, many advanced medical centers around the world have invested heavily in building proton therapy facilities. In the coming years, Taiwan may become one of the countries with the highest concentration of proton therapy equipment worldwide.

According to current clinical literature, proton therapy is applicable for the following conditions:

1. Pediatric cancers:
   Compared to traditional radiation therapy, proton therapy reduces long-term side effects and the risk of secondary malignancies in children with cancer.

2. Tumors at the skull base and central nervous system:
   Proton therapy provides better protection for critical organs near the tumor, such as the brainstem, spinal cord, and optic nerves.

3. Prostate cancer:
   Studies show that proton therapy offers comparable disease control to conventional radiation therapy while reducing the incidence of urinary and rectal toxicity.

4. Thoracic or liver tumors:
   Some studies indicate that proton therapy causes less damage to lung or liver function, allowing for higher radiation doses and potentially better disease control.

5. Recurrent tumors:
   For tumors that recur after previous radiation or other treatments, proton re-irradiation can lower the risk of complications associated with a second course of radiation.

質子治療是依賴於高能質子束（>200MeV）的產生，質子束最重要的特性是在質子進入體表後在特定深度處釋放大部分能量，這種現象被稱為布拉格尖峰（Bragg peak）。這種特性使得質子能夠集中而且精確地傳遞放射劑量至腫瘤部位，從而減少對鄰近正常組織的損害。 

優勢： 由於質子能夠精準定位減少對周圍正常組織的損害。因此，許多國內外先進的醫療中心都投入了大量資金和資源來建立質子治療中心。在未來的幾年，臺灣有可能成為全球質子治療設備最集中的國家。

依目前現有文獻，質子可應用的臨床適應症如下：

 1. 兒童癌症：與傳統放射治療相比，質子治療能夠減少兒童癌症 患者的長期副作用和二次惡性腫瘤的風險。

 2. 顱底部和中樞神經系統腫瘤：質子治療對於貼近腫瘤的重要器官（如腦幹、脊柱和視神經等）可提供更好的保護效果。 

3. 前列腺癌：在研究報告，質子治療的疾病控制率與傳統放射治 療相當，並降低了泌尿道和直腸毒性的發生率。 

4. 胸部或肝臟腫瘤：部分文獻顯示質子治療對於肺部或肝臟功能損傷較少，因而可提高放射劑量，達到更好的疾病控制效果。 

5. 復發腫瘤：對於已經接受過放射治療和其他治療後復發的腫瘤，在適當情況下進行質子照射，能夠降低二次放射治療可能產生的併發症。