Stereotactic Body Radiation Therapy Treatment for Prostate Cancer: From Setup to Delivery Strategies.
Stereotactic Body Radiation Therapy of prostate cancer has garnered increasing attention owing to its proposed low a/b value, which is close to 1.5 Gy. Recent clinical data support the low value for a/b ratio as predicted by radiobiological models; hence, large doses per fraction should result in a higher probability of tumor control together with a reduced probability
of complications for healthy tissue.
In this paper, we focused on the technical parameters and treatment strategies adopted in the hypofractionation studies published in literature. The effect of geometric uncertainties is known to be one of the major concerns in radiation dose delivery in prostate cancer.
These uncertainties are mostly due to patient setup errors and extensive motion of the rectum and bladder that is dependent on organ filling. In this regard, an augmented impact of geometric uncertainties is expected when high doses per fractions are adopted.
This could occur because in HF treatments, any single targeting error causes a greater
biologic impact by consistently underdosing the target organ at greater expense of the organs at risks.
Several technological innovations have boosted the high-precision localization
of the prostate during treatment, allowing the delivery of highly conformed dose fractions to a well-defined
target with sharp dose fall-off towards the bladder and rectum.
However, multiple technical parameters and operational variables can affect the correct localization of the prostate
and the reproducibility of the procedures.
Radiol Open J. 2016; 1(2): 39-41. doi: 10.17140/ROJ-1-107