Based on years of clinical observation, the main factors affect the efficacy of tumor radiotherapy include the following:
(1) early or late stage disease: the early blood supply, and easy to control; late blood supply is poor, poor efficacy.
Factors affect the efficacy of tumor radiotherapy (2) the manner of tumor growth: Where shallow invasion of cancer down effect; to the growth of deep infiltration is relatively poor.
(3) the site of tumor growth: tumor bed for a good part of the muscle and the blood circulation and easily cured; tumor blood supply is poor, where the parts can not tolerate high radiation doses are difficult to cure.
(4) The general situation: previous good health or not, a great impact on the efficacy, physical health, their resistance to strong, normal tissue repair capacity is good, the whole body radiation reaction, may be tolerated at higher doses it is effective, otherwise poor.
Factors affect the efficacy of tumor radiotherapy (5) complications: a complication of radiotherapy response are heavier, efficacy is poor, often do not amount to cure the cancer, radiation therapy should not be serious complications, complications to be controlled before starting treatment.
(6) local conditions: mainly secondary infection, inflammation caused by local congestion, worse blood supply to the tumor itself, and thus decreased sensitivity to radiation, poor efficacy.
Factors affect the efficacy of tumor radiotherapy (7) the sensitivity of tumors to radiation: the same type of tumor, differentiation of the better, the worse the radiosensitivity, the higher sensitivity and vice versa. However, the level of radiosensitivity and the effect is not proportional to the particularly sensitive tumors, often easier to transfer.
the high sensitivity of tumors: such as malignant lymphoma, kidney cancer, such as embryos, 20-40 Gy (2000-4000 rad that is) of radiation to kill these tumors, the effect is significant, but far from easy to appear early transfer, Guchang with chemotherapy or other therapies to be combined to achieve the desired effect.
moderately sensitive tumors: including a variety of epithelial cancers, such as nasopharyngeal cancer , cervical cancer, skin cancer and so on, these tumors often require 60 Gy to be effective, but relatively slow as the development of these tumors, there are more transfers night, so the sensitivity of tumor effect than good.
not sensitive or resistant tumors to radiation: mainly derived from the mesoderm osteosarcoma, fibrosarcoma and other soft tissue, because of its lethal dose far exceeds the tolerance dose of the surrounding tissues, so not suitable for radiotherapy.
- factors affacting efficacy of tumour