Reproducibility and geometric accuracy of the fixster system during hypofractionated stereotactic radiotherapy

Peter Lindvall¹ , Per Bergström² , Per-Olov Löfroth² , Roger Henriksson² and A Tommy Bergenheim¹

¹Department of Neurosurgery, Umeå University Hospital, Umeå, Sweden

²Department of Radiation sciences, Umeå University Hospital, Umeå, Sweden

author email corresponding author email

Radiation Oncology 2008, 3:16doi:10.1186/1748-717X-3-16


Published:	28 May 2008

Abstract

Background

Hypofractionated radiotherapy has been used for the treatment of AVMs and brain metastases. Hypofractionation necessitates the use of a relocatable stereotactic frame that has to be applied on several occasions. The stereotactic frame needs to have a high degree of reproducibility, and patient positioning is crucial to achieve a high accuracy of the treatment.

Methods

In this study we have, by radiological means, evaluated the reproducibility of the isocenter in consecutive treatment sessions using the Fixster frame. Deviations in the X, Y and Z-axis were measured in 10 patients treated with hypofractionated radiotherapy.

Results

The mean deviation in the X-axis was 0.4 mm (range -2.1 – 2.1, median 0.7 mm) and in the Y-axis -0.3 mm (range -1.4 – 0.7, median -0.2 mm). The mean deviation in the Z-axis was -0.6 (range -1.4 – 1.4, median 0.0 mm).

Conclusion

There is a high degree of reproducibility of the isocenter during successive treatment sessions with HCSRT using the Fixster frame for stereotactic targeting. The high reducibility enables a safe treatment using hypofractionated stereotactic radiotherapy.