Multi-institutional clinical experience with the Calypso System in localization and continuous, real-time monitoring of the prostate gland during external radiotherapy

Patrick Kupelian, Twyla Willoughby, Arul Mahadevan, Toufik Djemil, Geoffrey Weinstein, Shirish Jani, Charles Enke, Timothy Solberg, Nicholas Flores, David Liu, David Beyer, Lisa Levine

Research output: Contribution to journalArticle

350 Scopus citations

Abstract

Purpose: To report the clinical experience with an electromagnetic treatment target positioning and continuous monitoring system in patients with localized prostate cancer receiving external beam radiotherapy. Methods and Materials: The Calypso System is a target positioning device that continuously monitors the location of three implanted electromagnetic transponders at a rate of 10 Hz. The system was used at five centers to position 41 patients over a full course of therapy. Electromagnetic positioning was compared to setup using skin marks and to stereoscopic X-ray localization of the transponders. Continuous monitoring was performed in 35 patients. Results: The difference between skin mark vs. the Calypso System alignment was found to be >5 mm in vector length in more than 75% of fractions. Comparisons between the Calypso System and X-ray localization showed good agreement. Qualitatively, the continuous motion was unpredictable and varied from persistent drift to transient rapid movements. Displacements ≥3 and ≥5 mm for cumulative durations of at least 30 s were observed during 41% and 15% of sessions. In individual patients, the number of fractions with displacements ≥3 mm ranged from 3% to 87%; whereas the number of fractions with displacements ≥5 mm ranged from 0% to 56%. Conclusion: The Calypso System is a clinically efficient and objective localization method for positioning prostate patients undergoing radiotherapy. Initial treatment setup can be performed rapidly, accurately, and objectively before radiation delivery. The extent and frequency of prostate motion during radiotherapy delivery can be easily monitored and used for motion management.

Original languageEnglish (US)
Pages (from-to)1088-1098
Number of pages11
JournalInternational Journal of Radiation Oncology Biology Physics
Volume67
Issue number4
DOIs
StatePublished - Mar 15 2007

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Keywords

  • Localization
  • Motion
  • Prostate
  • Radiation
  • Tracking

ASJC Scopus subject areas

  • Radiation
  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research

Cite this

Kupelian, P., Willoughby, T., Mahadevan, A., Djemil, T., Weinstein, G., Jani, S., Enke, C., Solberg, T., Flores, N., Liu, D., Beyer, D., & Levine, L. (2007). Multi-institutional clinical experience with the Calypso System in localization and continuous, real-time monitoring of the prostate gland during external radiotherapy. International Journal of Radiation Oncology Biology Physics, 67(4), 1088-1098. https://doi.org/10.1016/j.ijrobp.2006.10.026