Pre-Operative Versus Post-Operative Radiosurgery of Brain Metastases—Volumetric and Dosimetric Impact of Treatment Sequence and Margin Concept
AbstractBackground: Pre-operative radiosurgery (SRS) preceding the resection of brain metastases promises to circumvent limitations of post-operative cavity SRS. It minimizes uncertainties regarding delineation and safety margins and could reduce dose exposure of the healthy brain (HB). Methods: We performed a systematic treatment plan comparison on 24 patients who received post-operative radiosurgery of the resection cavity at our institution. Comparative treatment plans were calculated for hypofractionated stereotactic radiotherapy (7 × 5 Gray (Gy)) in a hypothetical pre-operative (pre-op) and two post-operative scenarios, either with (extended field, post-op-E) or without the surgical tract (involved field, post-op-I). Detailed volumetric comparison of the resulting target volumes was performed, as well as dosimetric comparison focusing on targets and the HB. Results: The resection cavity was significantly smaller and different in morphology from the pre-operative lesion, yielding a low Dice Similarity Coefficient (DSC) of 53% (p = 0.019). Post-op-I and post-op-E targets showed high similarity (DSC = 93%), and including the surgical tract moderately enlarged resulting median target size (18.58 ccm vs. 22.89 ccm, p < 0.001). Dosimetric analysis favored the pre-operative treatment setting since it significantly decreased relevant dose exposure of the HB (Median volume receiving 28 Gy: 6.79 vs. 10.79 for pre-op vs. post-op-E, p < 0.001). Dosimetrically, pre-operative SRS is a promising alternative to post-operative cavity irradiation that could furthermore offer practical benefits regarding delineation and treatment planning. Comparative trials are required to evaluate potential clinical advantages of this approach. View Full-Text
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El Shafie, R.A.; Tonndorf-Martini, E.; Schmitt, D.; Weber, D.; Celik, A.; Dresel, T.; Bernhardt, D.; Lang, K.; Hoegen, P.; Adeberg, S.; Paul, A.; Debus, J.; Rieken, S. Pre-Operative Versus Post-Operative Radiosurgery of Brain Metastases—Volumetric and Dosimetric Impact of Treatment Sequence and Margin Concept. Cancers 2019, 11, 294.
El Shafie RA, Tonndorf-Martini E, Schmitt D, Weber D, Celik A, Dresel T, Bernhardt D, Lang K, Hoegen P, Adeberg S, Paul A, Debus J, Rieken S. Pre-Operative Versus Post-Operative Radiosurgery of Brain Metastases—Volumetric and Dosimetric Impact of Treatment Sequence and Margin Concept. Cancers. 2019; 11(3):294.Chicago/Turabian Style
El Shafie, Rami A.; Tonndorf-Martini, Eric; Schmitt, Daniela; Weber, Dorothea; Celik, Aylin; Dresel, Thorsten; Bernhardt, Denise; Lang, Kristin; Hoegen, Philipp; Adeberg, Sebastian; Paul, Angela; Debus, Jürgen; Rieken, Stefan. 2019. "Pre-Operative Versus Post-Operative Radiosurgery of Brain Metastases—Volumetric and Dosimetric Impact of Treatment Sequence and Margin Concept." Cancers 11, no. 3: 294.
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