God said that if there is light, there will be light in this world. According to legend, God created the world in seven days, and on the first day he first created light. In ancient mythology, it is often a “light” that splits the chaos and darkness of the world. It can be said that light is the origin of all things. In modern humans, light has various applications, and it can even be used to treat cancer.
First, a beam of light kills tumors that are ineffective in conventional treatment
Guizhou’s 60-year-old grandpa has dark yellow skin, no appetite, Significant weight loss and discomfort such as lack of energy were admitted to the hospital. The examination revealed abnormal liver function accompanied by severe jaundice and severe bile duct obstruction, and was finally diagnosed as cholangiocarcinoma.
(Source: Sky Eye News)
The malignant degree of cholangiocarcinoma is very high, and the clinical treatment for cholangiocarcinoma is very important. Limited, radiochemotherapy drugs are not sensitive, and there is no targeted targeted drugs, generally only physical means such as stents and lasers can be used. The grandfather’s condition is very critical. After temporarily relieving the problem of bile duct obstruction, the doctor finally decided to use the latest technology “photodynamic” to kill tumor cells in the bile duct for him.
Through the joint efforts of many doctors, Uncle Gun’s tumor has been controlled, and the function of the biliary tract has returned to normal. Such a “magical” therapy is believed to be unheard of by many people. How exactly does it cure diseases?
Second, a new method for tumor treatment – photodynamics! How does it heal? 4000 years ago, Egyptians used to treat vitiligo by taking plants with photosensitizers and then irradiating them with sunlight. This is a very primitive application. The real origin of modern photodynamic therapy was in 1897, when Oscar Raab of Munich University School of Medicine in Germany accidentally discovered that acridine was stimulated by lightning while researching new antimalarial drugs. Paramecium can be killed quickly, while acridine or lightning alone does not kill paramecium.
He speculates that the effect is due to the transfer of light energy to chemicals, similar to the absorption of light by chlorophyll in plants. After that, Oscar Raab never published a paper on photodynamics, but his supervisor, Professor Tappeiner, has been engaged in this research, and he successfully applied this discovery to tumor therapy.
Nowadays, photodynamic therapy is relatively mature in foreign countries, but it is still in a new stage in my country, and its clinical application is relatively small. Everyone knows very little about photodynamic therapy. What kind of treatment is this?
Photodynamic therapy consists of photosensitizers, light and molecular oxygen, all of which interact with each other. The use of photodynamic therapy requires the photosensitizer to be injected into the human body first, so that the photosensitizer can fully enter the tumor tissue and stay there. After a period of time, the tumor tissue is irradiated with light of a specific wavelength, so that the photosensitizer produces reactive oxygen species and kills the tumor cells.
Photosensitizers are special anti-tumor drugs and will not threaten normal tissue cells in the body. In layman’s terms, tumor tissue’s ability to absorb photosensitizers is 30 times that of normal tissue, just like sun exposure. Normal people will not be harmful to health after exposure to the sun. And some people who are allergic to light themselves, once exposed to the sun will cause skin allergies, rashes and other uncomfortable symptoms.
The cancer tissue injected with photosensitizers is similar to photosensitizers. The photochemical effect can be produced by the light, and the tumor cells will be destroyed, and the blood vessels in the tumor will be destroyed. Embolism occurs and eventually the cancer cells gradually die.
Photodynamic therapy, as an emerging therapy in recent years, has many advantages in treatment. What are the specific ones? 3. What are the advantages of photodynamic therapy for cancer cells to die in the presence of light?
Photodynamic therapy was actually approved by the State Food and Drug Administration for tumor treatment in 2003. Professor Li Ruizhen of Peking University Shenzhen Hospital is the fifth most popular treatment for cancer after treatment. The advantages of photodynamic therapy are mainly reflected in three aspects.
1. Precise positioning without the pain of surgery
The therapy uses optical fibers, endoscopes and some other interventional techniques to guide the laser to the Treating patients in vivo can allow patients to avoid the pain caused by thoracotomy, laparotomy and other surgeries.
2. Small side effects and low toxicity
Photodynamic therapy is a local treatment method that only targets tumor cells in the body and will not give normal Damage to tissue cells will not affect hematopoietic function.
3. The treatment can be repeated or combined with other treatments. Cancer cells will not develop resistance to photosensitizing drugs. It will not increase toxic reactions due to multiple treatments, and patients can repeat the treatment multiple times or cooperate with some other treatments to improve the curative effect.
Since there are so many advantages of photodynamic therapy, and it will not bring some side effects to health, why is it not widely used in clinical practice? 4. Can photodynamic therapy cure all cancers?
Of course not. Photodynamic therapy is not a “universal” treatment method. It is mainly suitable for various solid malignant tumors, vascular tumors, and viral and bacterial inflammatory diseases. Malignant tumors, including skin tumors, digestive tumors, gynecological tumors, respiratory tumors, and urinary tumors et al.
For some solid tumors without fiber optic channels, photodynamic therapy is a bit “helpless”. In addition, photodynamic therapy also has certain drawbacks. Unlike other treatments such as radiotherapy and chemotherapy, photodynamic therapy has a shallower killing depth on tumors. In addition, patients who have undergone treatment need to be protected from light for nearly a month, which will have a certain impact on normal life.
In the future, the clinical application of photodynamic therapy will be more and more extensive, bringing new hope to more cancer patients. But we must also have a correct attitude towards this. The premise of using any treatment method is to be suitable for ourselves, and we must not blindly follow it.
References:
[1] “Origin and Development History of Photodynamic Therapy”. Chinese Medical Abstracts Dermatology. 2015.4
[2] “Tumor Cells “see the light to die” Guizhou Provincial People’s Hospital successfully carried out photodynamic therapy for bile duct cancer patients for the first time”. Tianyan News. 2022.4.8
[3] “Several Advantages of Tumor Photodynamic Therapy”. China Tumor Photodynamics.2022.3.19