Invisible scalpel - tumor radiotherapy

Invisible scalpel - tumor radiotherapy

Radiotherapy is a treatment method that uses high-energy rays to kill cancer cells or inhibit their growth. It is one of the three main means of tumor treatment, and together with surgery and chemotherapy, it constitutes the cornerstone of comprehensive tumor treatment. So what is radiotherapy, what diseases can radiotherapy treat, and what is the process of radiotherapy?

What is radiotherapy?

The principle of radiotherapy is to use high-energy rays to destroy the DNA structure of cancer cells, making them lose the ability to grow and divide, thereby achieving the purpose of killing cancer cells. Commonly used radiotherapy rays include X-rays and gamma rays. The rays are like an invisible and intangible "scalpel". They do not cause wounds on the skin, but can kill tumor cells in the body.

The effect of radiotherapy

Radiotherapy is an economical and effective cancer treatment method. According to WHO statistics: 45% of malignant tumors are curable, and more than 70% of tumor patients need radiotherapy at different stages of the disease development. Among the currently curable cancers, the contribution of surgical treatment is 48.9%, chemotherapy is only 11%, and radiotherapy is 40%. The cure rate for early nasopharyngeal carcinoma is 100%, the cure rate for early prostate cancer is 99%, the cure rate for early laryngeal cancer is 90%, the cure rate for early cervical cancer is 93-100%, the cure rate for early NK/T cell lymphoma is 85-92%, and the cure rate for early oral cancer is 86%. The cure rate for early skin cancer is over 90%, and the use of SBRT for early lung cancer can achieve the same efficacy as surgery, and can achieve a five-year local control rate of >95%.

Indications for radiotherapy

Tumors suitable for radiotherapy:

1.Tumors sensitive to radiation: malignant lymphoma, testicular seminoma, nephroblastoma, cerebellar medulloblastoma, neuroblastoma, retinoblastoma, etc.;

2.Superficial tumors moderately sensitive to radiation and tumors located in physiological channels: such as nasopharyngeal carcinoma, oral cancer, skin cancer, maxillary sinus cancer, laryngeal cancer, hypopharyngeal cancer, cervical cancer, bladder cancer, etc. Although some of these tumors are also suitable for surgical treatment, radiotherapy causes less damage to the body;

3.Malignant tumors whose location makes it difficult to radically cure by surgery: such as cervical esophageal cancer, etc.

Tumors that require combined radiotherapy and surgery: breast cancer, lymph node metastasis, esophageal cancer, lung cancer, endometrial cancer, parotid cancer, rectal cancer, gastric cancer, brain tumor, cervical cancer, vulvar cancer, penile cancer, oral cancer, etc. Such tumors are often treated with preoperative or postoperative radiotherapy to reduce the local recurrence rate.

Palliative radiotherapy: radiotherapy for pain relief of cancer bone metastasis, radiotherapy for brain metastasis to reduce lesions and relieve symptoms. Radiotherapy can also control the development of distant metastases and relieve compression symptoms (digestive tract obstruction, superior vena cava syndrome).

Total body radiotherapy (TBI): It is an important part of pretreatment before hematopoietic stem cell transplantation. TBI in a broad sense includes the use of X (γ) rays or electron beams to irradiate the whole body, half body, whole spinal cord and whole lymph nodes. Total body radiotherapy combined with chemotherapy can suppress the body's immune response to the greatest extent, so that the transplant can be accepted by the recipient's body without causing too much rejection reaction; at the same time, it kills bone marrow cells and empties the bone marrow cavity, so as to facilitate the survival of transplanted healthy bone marrow cells; it can also remove the remaining malignant tumor stem cells in the body and reduce the risk of recurrence and metastasis.

Radiotherapy for benign diseases: Graves' ophthalmopathy, pterygium, scar hyperplasia, plantar warts, keratoacanthosis, hemangioma, tenosynovitis, bursitis, fibromatosis, eosinophilic lymphogranuloma, Dupuytren's contracture, heterotopic ossification, male breast hyperplasia, ovarian castration, parotid fistula, etc.

Radiotherapy process

1.Make molds and simulate CT positioning: technicians and doctors will make molds according to the patient's condition and location, and perform position fixation and scanning positioning.

2.Outline the target area and formulate a radiotherapy plan: After the doctor outlines the target area where the tumor is located and the organs at risk (normal tissue), he will prescribe a dose according to the condition and then hand it over to the physicist to design the irradiation plan. The physicist will design the radiotherapy plan based on the radiation range and required dose determined by the doctor, that is, the incident angle and intensity of the rays, so as to meet the doctor's radiotherapy plan requirements to the maximum extent, while ensuring that the dose of normal organs does not exceed the tolerance range, and finally the doctor will evaluate whether the requirements are met.

3.Treat according to the radiotherapy plan.

Is there radiation in the patient's body after radiotherapy?

Radiotherapy patients receive radiation therapy, so after the patient's treatment, there is no radiation in the body and it will not affect other people.

Radiotherapy has been in clinical practice for decades. The technology and means of radiotherapy are constantly improving, and people's level of using radiation to maintain health will continue to improve. These will bring more good news to cancer patients. Rational choice of treatment can help everyone better overcome the disease.