| Autor: |
Berta, Luca, Mainardi, Hae Song, Brambilla, Maria Grazia, Monti, Angelo Filippo, Colombo, Paola Enrica, Torresin, Alberto, Leocata, Filippo, Picano, Marco, Pozza, Alessandro, Arienti, Virginia Maria, Palazzi, Mauro, La Camera, Alessandro |
| Předmět: |
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| Zdroj: |
Journal of Radiosurgery & SBRT; 2022 Supplement, Vol. 8, p85-86, 2p |
| Abstrakt: |
Purpose: to retrospectively analyse plans of patients with large brain metastasis (BM) treated with adaptive staged-dose gamma knife radiosurgery in two stages. Material and methods: since 2018, 76 patients with large BM (>10 cm³) has been treated with a two-stages radiosurgery protocol using a dose prescription of 12 Gy at 50% of maximum of the dose distribution and planned time interval of 1 months between the two stages. The plans were elaborated with Gammaplan v.11.1.1 treatment planning system and delivered on a Gamma knife Perfexion unit. MR T1 weighted images, dose distribution and structures were exported to MIM software v. 7.1.4 for subsequent analysis. A rigid deformation between MR images of the two stages was calculated and the two dose distributions of the two plans were linearly summed up on the MR image of the second sessions. The initial tumour volume, its change after the time interval Δt between the two stages (ΔVol%), and the volume of surrounding healthy tissues receiving 12Gy in the summed dose distribution (V12GyHTacc) were calculated. The volume of treated BM and the presence of side effects will be considered and analysed as follow-up parameters at 3, 6, and 12 months after the second stage. Results: Two distinct BM were treated simultaneously in 5 patients using the same prescription of 12 Gy in both stages. For 33 patients one or more smaller BM with higher dose prescription were treated during one of the two stages. The tumour volume at the first stage was (24.±15.4)cm³ and the shrinkage ΔVol% resulted in (-32±29)% after a Δt of (31.3±5.5) days. In only 9 patients out of 76 (11.8%) the tumour increased volume during the time interval between the two stages and in one of these cases (1.3%) ΔVol% was greater than 30%. The dose accumulated to the healthy tissues surrounding tumours resulted in V12HTGyacc of (48.7±31.5)cm³. No acute treatment-related toxicity was recorded between the two fractions. We reported the preliminary data about the volume of treated BM and the presence of side effects, collected and analysed as follow-up parameters at 3, 6, and 12 months after the second stage. Conclusions: adaptive staged-dose gamma knife radiosurgery in two session for brain metastases is highly effective on local control with a low rate of complications due to low dose irradiation to surrounding brain tissue. Further information will come from the analysis of followup data taking accumulated dose distribution into account. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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