Body radiosurgery and stereotactic radiotherapy
The field of extracranial radiosurgery is rapidly expanding and is set to represent a revolution in the treatment of lung and prostate cancer as well as oligometastatic patients, just like radiosurgery has been for the treatment of brain metastases. Small peripheral lung cancers, as well as small prostate cancers can be treated curatively via a stereotactic approach.
Nowadays, treatments on either moving tumors or moving organs at risk are planned using four-dimensional CT scans (4DCT). Respiration-related motion can be accounted for in an individualized manner. The treatment delivery has become more complex, thus enabling the high-dose region to conform more tightly to the tumor and significantly shorten treatment time. Similarly, the development of image-guidance at point of delivery with cone-beam CT (CBCT) has improved the accuracy of treatment setups, which has spearheaded the hypofraction movement in extracerebral tumours: small-sized peripheral lung cancers, as well as prostate cancers can be treated curatively via a stereotactic approach.
The treatment paradigm would not be a legitimate approach, if there was no ongoing evaluation of the process and outcome of these novel methods.
A wealth of scientific information has evolved from the careful prospective monitoring of patients undergoing treatment with modern stereotactic techniques. A technique that expanded after the concept of evidence-based medicine was already well-entrenched, radiosurgery is probably the best documented treatment technique in clinical science. Data for mid- and long-term results in large patient cohorts are already being reported.