Stereotactic body radiation therapy for clinically localized prostate cancer

Background. In the last decade, we observed a significant increase in the number of patients undergoing radiotherapy for prostate cancer (PC). It became possible with the development of new equipment that can significantly increase radiation efficiency and reduce the frequency and severity of side effects. Active investigation of new fractionation regimens led to the development of stereotactic radiotherapy (StR) technique. In this article, we describe our own experience of using StR in patients with localized PC.Material and methods. The study included 48 patients treated with CyberKnife robotic radiosurgery system. The patients received a total dose of 36.25 Gy delivered in 5 fractions.Results. At a median follow-up of 24 months, the estimated four-year prostate-specific antigen (PSA) relapse-free survival rate was 95.8 %. The median PSA nadir was 0.48 ng/mL. We observed no grade III–IV side effects (either early or late).Conclusion. Our results suggest that the use of StR allows achieving good biochemical control comparable to that achieved by other methods and demonstrates comparable and sometimes even lower toxicity.

The Clinical Outcome of Hypofractionated Stereotactic Radiotherapy With CyberKnife Robotic Radiosurgery for Perioptic Pituitary Adenoma

Stereotactic radiation technique including single fraction radiosurgery and conventional fractionated stereotactic radiotherapy is widely reported as an effective treatment of pituitary adenomas. Because of the restricted radiation tolerance dose of the optic pathway, single fraction radiosurgery has been accepted for small tumor located far away from the optic apparatus, while fractionated stereotactic radiotherapy may be suitable for larger tumor located close to the optic pathway. More recently, hypofractionated stereotactic radiotherapy has become an alternative treatment option that provides high rate of tumor control and visual preservation for the perioptic lesions within 2 to 3 mm of the optic pathway. The objective of the study was to analyze the clinical outcomes of perioptic pituitary adenomas treated with hypofractionated stereotactic radiotherapy. From 2009 to 2012, 40 patients with perioptic pituitary adenoma were treated with CyberKnife robotic radiosurgery. The median tumor volume was 3.35 cm3 (range, 0.82-25.86 cm3). The median prescribed dose was 25 Gy (range, 20-28 Gy) in 5 fractions (range, 3-5). After the median follow-up time of 38.5 months (range, 14-71 months), 1 (2.5%) patient with prolactinoma had tumor enlargement, 31 (77.5%) were stable, and the remaining 8 (20%) tumors were smaller in size. No patient’s vision deteriorated after hypofractionated stereotactic radiotherapy. Hormone normalization was observed in 7 (54%) of 13 patients. No newly developed hypopituitarism was detected in our study. These data confirmed that hypofractionated stereotactic radiotherapy achieved high rates of tumor control and visual preservation. Because of the shorter duration of treatment, it may be preferable to use hypofractionated stereotactic radiotherapy over fractionated stereotactic radiotherapy for selected pituitary adenomas immediately adjacent to the optic apparatus.