TY - JOUR
T1 - 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?
AU - Becker, Stewart J.
AU - Lipson, Evan J.
AU - Jozsef, Gabor
AU - Molitoris, Jason K.
AU - Silverman, Joshua S.
AU - Presser, Joseph
AU - Kondziolka, Douglas
N1 - Publisher Copyright:
© 2022 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.
PY - 2023/3
Y1 - 2023/3
N2 - 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.
AB - 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.
KW - brain metastases
KW - gamma knife
KW - radiation toxicity
KW - stereotactic radiosurgery
KW - whole brain radiotherapy
UR - http://www.scopus.com/inward/record.url?scp=85146184231&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85146184231&partnerID=8YFLogxK
U2 - 10.1002/acm2.13856
DO - 10.1002/acm2.13856
M3 - Article
C2 - 36628586
AN - SCOPUS:85146184231
SN - 1526-9914
VL - 24
JO - Journal of applied clinical medical physics
JF - Journal of applied clinical medical physics
IS - 3
M1 - e13856
ER -