Image guided SBRT for multiple liver metastases with ExacTrac Adaptive Gating

AimTo report the outcome and toxicity of sequential stereotactic body radiotherapy (SBRT) for multiple liver metastases in patients treated with ExacTrac Adaptive Gating.BackgroundIn selected patients with a limited number of liver metastases, SBRT has been evaluated as a safe and effective treatment, with minimal toxicity and high rates of local control.Materials and methodsFrom April 2008 to October 2013, 21 patients with multiple (3–14) liver metastases (n[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]101) were treated sequentially with SBRT at our institution. Maximum tumor diameter was 7.5[[ce:hsp sp="0.25"/]]cm. Prior to treatment, internal markers were placed inside or near the tumor. CT or PET-CT simulation was used for the definition of gross tumor volume (GTV). Median planning target volume was 32.3[[ce:hsp sp="0.25"/]]cc (3.6–139.3[[ce:hsp sp="0.25"/]]cc). Treatment consisted of 3 fractions (12–20[[ce:hsp sp="0.25"/]]Gy/fraction) or 5 fractions (10[[ce:hsp sp="0.25"/]]Gy/fraction), prescribed to the 90–95% of the PTV volume. Daily intra-fraction image guidance was performed with ExacTrac Adaptive Gating. Regular follow-up included CT or PET-CT imaging.ResultsAfter a median of 23.2 months, the estimated local control rate was 94.4%, 80.6%, 65% and 65% after 1, 2, 3 and 4 years; the median overall survival was 62 months (95% CI 49.12–74.87) and the actuarial survival reached at 60 months was 57.6%. The univariate data analysis revealed that only primary histology other than colorectal adenocarcinoma was shown as an independent significant prognostic factor for local control (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.022). Number of treated metastases did not modify significantly the overall survival (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.51). No toxicity higher than G3 (1 patient with chest wall pain) and no radiation-induced liver disease were observed.ConclusionsSequential SBRT with ExacTrac Adaptive Gating for multiple liver metastases can be considered an effective, safe therapeutic option, with a low treatment-related toxicity. Excellent rates of local control and survival were obtained

Local control rates in stereotactic body radiotherapy (SBRT) of lung metastases associated with the biologically effective dose

AimTo evaluate dose differences in lung metastases treated with stereotactic body radiotherapy (SBRT), and the correlation with local control, regarding the dose algorithm, target volume and tissue density.BackgroundSeveral studies showed excellent local control rates in SBRT for lung metastases, with different fractionation schemes depending on the tumour location or size. These results depend on the dose distributions received by the lesions in terms of the tissue heterogeneity corrections performed by the dose algorithms.Materials and methodsForty-seven lung metastases treated with SBRT, using intrafraction control and respiratory gating with internal fiducial markers as surrogates (ExacTrac, BrainLAB AG), were calculated using Pencil Beam (PB) and Monte Carlo (MC) (iPlan, BrainLAB AG).Dose differences between both algorithms were obtained for the dose received by 99% (D99%) and 50% (D50%) of the planning treatment volume (PTV). The biologically effective dose delivered to 99% (BED99%) and 50% (BED50%) of the PTV were estimated from the MC results. Local control was evaluated after 24 months of median follow-up (range: 3–52 months).ResultsThe greatest variations (40.0% in ΔD99% and 38.4% in ΔD50%) were found for the lower volume and density cases. The BED99% and BED50% were strongly correlated with observed local control rates: 100% and 61.5% for BED99%>85Gy an

Extreme Hypofractionation with SBRT in Localized Prostate Cancer

Prostate cancer is the most commonly diagnosed cancer among men around the world. Radiotherapy is a standard of care treatment option for men with localized prostate cancer. Over the years, radiation delivery modalities have contributed to increased precision of treatment, employing radiobiological insights to shorten the overall treatment time, improving the control of the disease without increasing toxicities. Stereotactic body radiation therapy (SBRT) represents an extreme form of hypofractionated radiotherapy in which treatment is usually delivered in 1–5 fractions. This review assesses the main efficacy and toxicity data of SBRT in non-metastatic prostate cancer and discusses the potential to implement this scheme in routine clinical practice.Sin financiación3.109 JCR (2021) Q3, 177/245 Oncology0.926 SJR (2021) Q3, 126/369 OncologyNo data IDR 2020UE