Initial clinical experience with a frameless and maskless stereotactic radiosurgery treatment

Laura I. Cerviño, Nicole Detorie, Matthew Taylor, Joshua D. Lawson, Taylor Harry, Kevin T. Murphy, Arno J. Mundt, Steve B. Jiang, Todd A. Pawlicki

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

Purpose: To evaluate the initial clinical experience with a frameless and maskless technique for stereotactic radiosurgery using minimal patient immobilization and real-time patient motion monitoring during treatment. We focus on the evaluation of the patient treatment process. Methods and Materials: The study considered the first 23 patients treated with this technique. Head positioning was achieved with a patient-specific head mold made out of expandable foam that conforms to the patient's head. The face of the patient is left open for maximal comfort and so that motion of a region of interest consisting of the forehead, nose, eyes, and temporal bones can be monitored during treatment using a video surface imaging system (VisionRT Inc, London, UK). Initial setup of the patient was performed with the surface imaging system using the surface of the patient obtained from the treatment planning computed tomographic (CT) scan. The initial setup was confirmed and finalized with cone-beam CT (CBCT) prior to treatment. The shifts for final setup based on the CBCT and the duration of all the steps in the treatment process were recorded. Patients were monitored during treatment with surface imaging, and a beam hold-off was initiated when the patient's motion exceeded a prespecified tolerance. Results: The average total setup time including surface imaging and CBCT was 26 minutes, while the portion corresponding to surface imaging was 14 minutes. The average treatment time from when the patient was placed on the treatment table until the last treatment beam was 40 minutes. Eight (35%) patients needed repositioning during the treatment. The average shifts identified from CBCT after initial setup with surface imaging were 1.85 mm in the anterior-posterior direction, and less than 1.0 mm in the lateral and superior-inferior directions. The longest treatment times (including beam hold-offs) happened for patients who fell asleep on the treatment table and were moving involuntarily. Conclusions: The frameless and maskless treatment using minimal immobilization and surface imaging has proven to be reasonably fast for routine clinical use. We observed that patient compliance is important. An additional degree of semi-rigid immobilization would be helpful for patients who fall asleep and involuntarily move during the procedure.

Original languageEnglish (US)
Pages (from-to)54-62
Number of pages9
JournalPractical Radiation Oncology
Volume2
Issue number1
DOIs
StatePublished - Jan 2012

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ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging

Cite this

Cerviño, L. I., Detorie, N., Taylor, M., Lawson, J. D., Harry, T., Murphy, K. T., Mundt, A. J., Jiang, S. B., & Pawlicki, T. A. (2012). Initial clinical experience with a frameless and maskless stereotactic radiosurgery treatment. Practical Radiation Oncology, 2(1), 54-62. https://doi.org/10.1016/j.prro.2011.04.005