Photodynamic therapy is different from the three conventional treatments of surgery, radiotherapy and chemotherapy in that it is selective in terms of target tissues and degree of damage, and can reduce the damage to normal tissues.
Compared with conventional treatments such as surgery, chemotherapy and radiotherapy, photodynamic therapy has the following important advantages.
1. Minimal trauma.
With the help of optical fiber, endoscope and other interventional techniques, the laser can be guided deep into the body for treatment, avoiding the trauma and pain caused by open-chest and open-abdomen surgery.
2.Low toxicity.
The photosensitive drug entering the tissue will trigger photodynamic reaction and kill tumor cells only when it reaches a certain concentration and is irradiated by sufficient amount of light, which is a local treatment method. The part of human body that is not irradiated by light does not produce such reaction, and the organs and tissues in other parts of human body are not damaged, nor does it affect the hematopoietic function, so the toxic side effects of photodynamic therapy are very low.
3.Good selectivity.
The main target of photodynamic therapy is the lesion tissue in the light area, and the damage to the normal tissues around the lesion is slight, and this selective killing effect is difficult to achieve by many other treatment means.
4.Good applicability.
Photodynamic therapy is effective for cancer tissues of different cell types and has a wide range of applicability, while the sensitivity of cancer tissues of different cell types to radiotherapy and chemotherapy can vary greatly and the application is restricted.
5.Repeatable treatment.
Cancer cells are not resistant to photosensitive drugs, and patients will not have increased toxic reactions due to multiple photodynamic treatments, so treatment can be repeated.
6.Can be palliative treatment.
For advanced tumor patients, or tumor patients who cannot receive surgery due to advanced age, cardiopulmonary, hepatic and renal insufficiency, hemophilia, photodynamic therapy is a kind of palliative that can effectively relieve pain, improve quality of life and prolong life.
7. It can improve the efficacy of treatment in cooperation with surgery.
For some tumors, surgical resection first and then applying photodynamic therapy can further destroy residual cancer cells, reduce the chance of recurrence and improve the thoroughness of surgery; for some other tumors, photodynamic therapy can be done first to make the tumor shrink before resection, expand the indications for surgery and improve the success rate of surgery.
8.It can eliminate occult cancer lesions.
Clinically, some tumors, such as bladder metastatic cell carcinoma, may have scattered tiny cancer nests invisible to the naked eye outside the main lesion, and conventional treatment means can only remove the main lesion and can do nothing for the hidden cancer nests, but using photodynamic therapy to adopt the method of surface irradiation after full bladder filling to eliminate all the tiny lesions that may exist can greatly reduce the chance of tumor recurrence.
9. It can protect the appearance and important organ functions.
For skin cancer of face, oral cancer, penile cancer, cervical cancer, retinoblastoma, etc., the application of photodynamic therapy may effectively kill the cancerous tissues and minimize the damage to the epithelial structure and collagen scaffold of the developing organs, so that the appearance will be less affected after the wound healing and the appearance of the organs and normal physiological functions will be kept intact.