Cyber Knife for Treatment of Lung Cancer

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Lung Cancer

Lung cancer is the most common cause of death due to cancer in the world. This is a disease afflicting mostly old people over the age of 65, but has also surpassed breast cancer as the most common cause of death due to cancer in women.

Most common environmental causes attributed to lung cancer are exposure to cigarette smoke, asbestos, radon and air pollution. Familial predisposition and previous history of chronic obstructive disease may also contribute to the development of the malignancy.

Depending on the size, stage of the disease and the general health condition of the patient, treatment may consist of one or a combination of surgery, chemotherapy and radiotherapy. These modalities may be used to treat lung cancer by removing the tumor, decreasing its size and preventing spread of cells to other sites.

What is CyberKnife?

CyberKnife for treatment of lung cancer consists of delivering radiation therapy to the patient by a robotic system that ensures accuracy and precision even as the tumor moves while the patient is breathing. The system provides pain-free reduction of the tumor size without surgical incision or hospitalization. It is usually recommended for patients with inoperable tumor or those who have complex tumors that may be difficult to remove surgically. Otherwise it can also be an alternative choice to patients who do not want to undergo an invasive and potentially complicated procedure. CyberKnife technology has FDA approval and can also be used for other tumors like prostate, brain and spinal malignancies.

The process of treatment begins with careful planning and preparation of the set-up. This involves:

  • Determining the location and size of the tumor/s in the lung
  • Implantation of markers made up of tiny gold seeds into the tumor, if needed, to track its location while the patient breathes and lung moves
  • Fitting of a specialized body cradle where the patient will be positioned comfortably during treatment
  • Fitting of a special vest to be used during radiation, which will enable the CyberKnife robot to correlate the tumor location while the patient breathes
  • Use of CT scan, MRI and/or PET scan to create images of the tumor, to be downloaded into the CyberKnife treatment planning software
  • Treatment plan to be determined by the patient’s team of doctors, including a medical physicist; involves studying the tumor size, location and radiation dosage to be given

Actual radiation treatment will be given in one to five sessions, depending on the need. He will be asked to put on the custom vest and lie on his body cradle while relaxed. Then the CyberKnife computer-controlled robot will target the tumor even as the patient is awake and breathing and painlessly deliver radiation.

After each session the patient may be able to go home and continue with his normal activities. He will be given a schedule for succeeding treatments and follow-up appointments. Side effects will be discussed and these are usually minor (fatigue and nausea), lasting for one to two weeks after treatment.

The benefits this technology offers compared to conventional radiotherapy systems are greater accuracy of targeting, precision of dose delivery and sparing of healthy tissues that are not targets of radiation.

Although many patients respond well to this type of treatment, the patient must not expect a sudden disappearance of the tumor and that patient response differ from patient to patient. Regular monitoring of the effects of treatment to tumor reduction must be done to determine the outcome of the disease.

References

CyberKnife, “How Does CyberKnife Treat Lung Cancer?”, https://cyberknife.com/cyberknife-treatments/lung/how-used-treat-cancer.aspx

MedicineNet, “Lung Cancer”, https://www.medicinenet.com/lung_cancer/page2.htm