How many brain metastases can be treated with stereotactic radiosurgery before the radiation dose delivered to normal brain tissue rivals that associated with standard whole brain radiotherapy?

Stewart J. Becker, Evan J. Lipson, Gabor Jozsef, Jason K. Molitoris, Joshua S. Silverman, Joseph Presser, Douglas Kondziolka

Research output: Contribution to journalArticlepeer-review

Abstract

Introduction: Clinical trial data comparing outcomes after administration of stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT) to patients with brain metastases (BM) suggest that SRS better preserves cognitive function and quality of life without negatively impacting overall survival. Here, we estimate the maximum number of BM that can be treated using single and multi-session SRS while limiting the dose of radiation delivered to normal brain tissue to that associated with WBRT. Methods: Multiple-tumor SRS was simulated using a Monte Carlo – type approach and a pre-calculated dose kernel method. Tumors with diameters ≤36 mm were randomly placed throughout the contoured brain parenchyma until the brain mean dose reached 3 Gy, equivalent to the radiation dose delivered during a single fraction of a standard course of WBRT (a total dose of 30 Gy in 10 daily fractions of 3 Gy). Distribution of tumor sizes, dose coverage, selectivity, normalization, and maximum dose data used in the simulations were based on institutional clinical metastases data. Results: The mean number of tumors treated, mean volume of healthy brain tissue receiving > 12 Gy (V12) per tumor, and total tumor volume treated using mixed tumor size distributions were 12.7 ± 4.2, 2.2 cc, and 12.9 cc, respectively. Thus, we estimate that treating 12–13 tumors per day over 10 days would deliver the dose of radiation to healthy brain tissue typically associated with a standard course of WBRT. Conclusion: Although in clinical practice, treatment with SRS is often limited to patients with ≤15 BM, our findings suggest that many more lesions could be targeted while still minimizing the negative impacts on quality of life and neurocognition often associated with WBRT. Results from this in silico analysis require clinical validation.

Original languageEnglish (US)
Article numbere13856
JournalJournal of applied clinical medical physics
Volume24
Issue number3
DOIs
StatePublished - Mar 2023

Keywords

  • brain metastases
  • gamma knife
  • radiation toxicity
  • stereotactic radiosurgery
  • whole brain radiotherapy

ASJC Scopus subject areas

  • Instrumentation
  • Radiation
  • Radiology Nuclear Medicine and imaging

Fingerprint

Dive into the research topics of 'How many brain metastases can be treated with stereotactic radiosurgery before the radiation dose delivered to normal brain tissue rivals that associated with standard whole brain radiotherapy?'. Together they form a unique fingerprint.

Cite this