Probabilities of Radiation Myelopathy Specific to Stereotactic Body Radiation Therapy to Guide Safe Practice

Journal Article · Fri Feb 01 04:00:00 EST 2013 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2012.05.007· OSTI ID:22149756

Sahgal, Arjun ^[1]; Weinberg, Vivian ^[2]; Ma, Lijun ^[3]; Chang, Eric ^[4]; Chao, Sam ^[5]; Muacevic, Alexander ^[6]; Gorgulho, Alessandra ^[7]; Soltys, Scott ^[8]; Gerszten, Peter C. ^[9]; Ryu, Sam ^[10]; Angelov, Lilyana ^[5]; Gibbs, Iris ^[8]; Wong, C. Shun ^[11]; Larson, David A. ^[3]

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1. Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, ON (Canada)
2. University of California San Francisco Helen Diller Family Comprehensive Cancer Center Biostatistics Core, San Francisco, California (United States)
3. Department of Radiation Oncology, University of California at San Francisco, San Francisco, California (United States)
4. Department of Radiation Oncology, University of Southern California and University of Texas MD Anderson Cancer Center, University of Texas, Houston, Texas (United States)
5. Department of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States)
6. European Cyberknife Center Munich in affiliation with University Hospitals of Munich, Munich (Germany)
7. Department of Neurosurgery, University of California at Los Angeles, Los Angeles, California (United States)
8. Department of Radiation Oncology, Stanford University, Stanford, California (United States)
9. Departments of Neurological Surgery and Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States)
10. Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan (United States)
11. Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada)

Purpose: Dose-volume histogram (DVH) results for 9 cases of post spine stereotactic body radiation therapy (SBRT) radiation myelopathy (RM) are reported and compared with a cohort of 66 spine SBRT patients without RM. Methods and Materials: DVH data were centrally analyzed according to the thecal sac point maximum (Pmax) volume, 0.1- to 1-cc volumes in increments of 0.1 cc, and to the 2 cc volume. 2-Gy biologically equivalent doses (nBED) were calculated using an {alpha}/{beta} = 2 Gy (units = Gy{sub 2/2}). For the 2 cohorts, the nBED means and distributions were compared using the t test and Mann-Whitney test, respectively. Significance (P<.05) was defined as concordance of both tests at each specified volume. A logistic regression model was developed to estimate the probability of RM using the dose distribution for a given volume. Results: Significant differences in both the means and distributions at the Pmax and up to the 0.8-cc volume were observed. Concordant significance was greatest for the Pmax volume. At the Pmax volume the fit of the logistic regression model, summarized by the area under the curve, was 0.87. A risk of RM of 5% or less was observed when limiting the thecal sac Pmax volume doses to 12.4 Gy in a single fraction, 17.0 Gy in 2 fractions, 20.3 Gy in 3 fractions, 23.0 Gy in 4 fractions, and 25.3 Gy in 5 fractions. Conclusion: We report the first logistic regression model yielding estimates for the probability of human RM specific to SBRT.

• OSTI ID: 22149756
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 2 Vol. 85; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
DOSE EQUIVALENTS
HEALTH HAZARDS
PATIENTS
PROBABILITY
RADIATION DOSE DISTRIBUTIONS
RADIATION DOSES
RADIOTHERAPY
VERTEBRAE