Because of the late onset of symptoms of bile duct cancer, most patients are already in the middle and late stages of the disease and only a small percentage of patients are suitable for radical surgery,
Therefore, the prognosis of bile duct cancer is poor. Tumor spread along the biliary system will lead to intractable obstructive bile accumulation, cholangitis and liver failure. Patients who cannot be treated surgically can survive for an average of one month with conventional palliative treatment by placing an endobiliary prosthesis. If photodynamic therapy is applied in combination with a biliary stent, the average survival time can be extended to one month,
It also reduces the incidence of cholangitis and obstructive jaundice. Irradiation of tumor tissue with photosensitizers and lasers of certain wavelengths can produce tissue penetration that can destroy cancer cells,
Thus, most of the tumors can be eradicated. Compared with other palliative treatments, it is less expensive and can improve the quality of life of patients,
Therefore, it can be used as a conventional palliative treatment for cholangiocarcinoma. In this paper, we would like to give a brief review on the application in the treatment of cholangiocarcinoma. I. Background Cholangiocarcinoma is a rare malignant tumor, the incidence of which is high in China and Japan, and the mortality rate is almost as high as the incidence. This is mainly because the early growth of cholangiocarcinoma is mostly an asymptomatic process,
Moreover, most patients are diagnosed late or the early lesions cannot be detected with current diagnostic equipment. As a result, only one patient is suitable for surgical resection and palliative surgery is often difficult or impossible to perform at the site. The primary goal of palliative care for patients with inoperable cholangiocarcinoma is to relieve obstructive xanthogranuloma. Bile duct decompression can relieve dyspepsia, spasticity, and improve the patient’s physical status and quality of life. However,
Successful completion of drainage operations such as stent placement often does not result in good drainage serum bilirubin reduction. ‘I’.
. The prognosis of patients with cholangiocarcinoma treated with bile duct decompression did not improve significantly with a mean survival time of one,
Metastasis and spread of the tumor in the biliary system. Chemotherapy and radiation therapy have also been tried to inhibit the growth of cholangiocarcinoma and the survival time of patients with cholangiocarcinoma after radiation therapy can reach up to 1 year after radiation therapy and chemotherapy combined with stenting alone can significantly improve the survival time of patients [,
I. However, due to the serious side effects of both chemotherapy and radiation therapy, although it can prolong the survival time of patients, it cannot improve the quality of patients’ survival. It can prolong the survival time of patients,
It mainly consists of the injection of non-toxic photosensitizers, followed by laser irradiation at a certain wavelength to cause apoptosis of tumor cells,
It consists mainly of the injection of a toxic photosensitizer, followed by laser irradiation at a certain wavelength to cause apoptosis of tumor cells. The mechanism of action is a two-step process, starting with intravenous injection of a photosensitizer such as sodium Yefir, which is usually administered before laser irradiation. The photosensitizer can preferentially accumulate in tumor cells,
The concentration in normal tissues is low, and after a suitable interval,
After a suitable interval, the tumor tissue is exposed to a non-thermal laser when the drug concentration peaks in the tumor tissue. The laser should be tuned to the appropriate wavelength so that photosensitization of the photosensitizer occurs. After photosensitization, single linear oxygen radicals are generated in the cells,
This can damage the cell membrane or mitochondria of tumor cells,
The whole destruction process is a moderately selective process that preserves most of the normal membranes and almost all of the normal connective tissues.
. Significant tumor degradation can be achieved by applying sodium Yefir and exposing it to wavelengths of laser light, including malignant tumors of the skin, bronchial tree, esophagus, stomach, and bladder,
It has been approved for clinical antitumor treatment of esophageal cancer in the United States, and for lung and esophageal malignancies in some European countries and Japan. However,
However, it should be noted that the efficacy and safety vary depending on the type and location of the tumor, and caution should be exercised in areas involving important vascular structures such as the hepatic portal. The first type of photosensitizer is a hemophyllin derivative such as sodium Yefir and Yefimna, which are currently the most widely used photosensitizers. The depth of necrosis caused can be up to 1.5 mm,
The main side effect is photosensitivity,
The main side effect is photosensitivity, which usually lasts for one week. The intensity of the side effects depends on the photosensitizer used and the skin type of the patient’s white body. The second type of photosensitizer is the drug precursor aminoglycoside, which is different from other photodynamic therapies because it is the precursor of the photosensitizer protoleukin. Each nucleated cell can spontaneously produce precursors,
This is regulated by negative feedback inhibition. When an excessive amount of exogenous subs is injected, the body’s natural regulatory mechanism is disturbed. Ferrous protochlorine synthase catalyzes the chelation of ferrous ions onto protochlorine molecules,
In malignant or precancerous tissues, the amount of ferrous protochlorine synthase is reduced,
The most important advantage of protoferrin is that the photosensitization caused by protoferrin only lasts for a short period of time and can be applied orally or even topically. However, the selectivity of the tumor tissue is not strong enough,
Moreover, the deepest tissue penetration is only one. It can also cause systemic side effects, including liver dysfunction, hypotension and vomiting. The third photosensitizer is m-tetrakisbenzhydrol. It has a very high yield of single-linear oxygen radicals,
Therefore, only a low dose of laser irradiation is required to obtain the desired therapeutic effect, and the irradiation time can also be shortened. However, the deeper tissue penetration may damage some normal tissues, and the photoallergic reaction of the skin may last for a week.
The skin allergy can last for a week. IV. Design and introduction There are two more common methods of introduction. One is the common bile duct speculum and bile duct speculum introduction method such as’ , after the photosensitizer injection is completed, and after the drug accumulation interval has passed,
We put a tip with. An effective radiation length. A quartz fiber of the size of the worship was mounted on a flexible cylindrical diffuser probe. The tip of the diffusor is segmented, which makes it very flexible and resistant to breakage,
It does not cause trauma to the bile duct wall. After locating the stricture with the choledochoscope, a guidewire is first inserted and passed through the stricture,
The stricture and its adjacent tissues are radiated under the guidance of the cholangioscope and wire. After one month a drainage tube is inserted and placed in the recanalized bile duct as an indwelling catheter until the next follow-up chart. The other is the endoscopic retrograde cholangiopancreatography guide method III’
. It should be used to determine the proximal and distal ends of the cancer in the duct lumen. A cylindrical diffuse probe is inserted into a bile duct duct with a distal hole. This catheter has a lateral aperture at the distal end,
This lateral aperture allows for the passage of a single guidewire. A diffusor probe with an effective radiation length of or is selected depending on the length of the stricture. Once the guidewire is positioned at the biliary stenosis, a preloaded biliary catheter is passed along the guidewire to the stenosis,
The guide wire is then withdrawn, and the laser diffuser fiber inside the catheter is pushed out and positioned at the biliary stenosis to begin irradiation. The diffuser has an impermeable marker at the tip of the diffuser,
This makes positioning easier. A tunable dye laser is used to stabilize the laser wavelength. The absorption peak is the longest wavelength that exactly activates the photosensitizer sodium Yefir,
It also produces a tissue penetrating power of one. Applying a diffuse probe with an output power, the total energy dose is which . The output power is measured with an integrating sphere power meter before and after the ding,
To ensure the safety of the operation. The radiation time is between one and one, depending on the size of the bile duct lumen. After a or of plastic stent will be inserted into the main stenosis site. V. Determination of therapeutic efficacy For the determination of therapeutic efficacy, cholangioscopy was used at first, but later it was found that this method could not accurately determine the therapeutic efficacy of Ding. Although this method can determine the extent of cholangiocarcinoma in the duct lumen, it is not suitable for diffuse cholangiocarcinoma,
However, its ability to diagnose diffuse forms of bile duct cancer is limited. Significant changes on the surface of the bile duct can be detected by cholangioscopy, but it lacks the ability to determine the spread of tumor cells within the luminal wall.