Stereotactic Body Therapy

Stereotactic body radiation therapy (SBRT) employs special equipment to deliver cancer-destroying doses of radiation while reducing exposure to normal tissue. Using special equipment to position the patient and localize the tumor allows precise delivery of radiation therapy to the tumor. This has been used for many years with benign and malignant brain tumors. Treatment is typically performed in one session, using rigid immobilization, and is called stereotactic radiosurgery (SRS).

Rigid immobilization has not been possible for tumors in the body. Recent advances in patient immobilization, in imaging, and in daily tumor localization and tracking now allow body treatment with nearly the same precision as brain treatments. These advances have enabled SBRT. This technique allows the treatment from many different points of entry, which allows for smaller doses to normal tissue, and much higher doses to the tumor during each treatment, increasing the likelihood of tumor control.

SBRT is most useful in situations in which we can clearly identify the tumor, use imaging to localize the tumor before and during treatment, and in tumors that are not too close to the skin surface or involve critical structures. Tumors in the lung frequently meet these criteria, and that is where we have the most experience and most mature results for SBRT. Other treatment sites have included liver metastases, spinal metastases or paraspinal tumors, solitary bone cancer metastases and primary tumors of the prostate and pancreas. Side effects are uncommon but are dependent on the size and location of the tumor.

SBRT advantages for lung cancer are rapid treatment completion with smaller volume of normal tissue treated, lower risks of complications and significantly better tumor control. Based on the results from treatment of primary lung cancer, liver metastases, bone cancer metastases and other sites, it is likely that SBRT will be used with increasing frequency in the coming months and years.