58 research outputs found

    Conformal stereotactic radiosurgery treatment: plan evaluation methods and results

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    The purpose of our study was the objective evaluation of micro-multileaf collimator (mMLC)-based stereotactic radiosurgery treatment plans. Forty-seven patients, 71 lesions received static beam conformal stereotactic radiosurgery treatment in our institute between November 2005 and June 2008. Target volume and organs at risk were outlined on a MRI-CT image fusion basis. BrainSCAN 5.31 system (BrainLAB AG, Heimstetten, Germany) was used for treatment planning, Elekta Presice TS linear accelerator (Elekta Oncology Systems Ltd, Crawley, UK) and BrainLAB m3 mMLC were used for treatment delivery. An invasive head frame, mounted to the treatment table, was used with four screws for patient head fixation. Treatment plans were analysed with objective parameters, such as conformal index (COIN), homogeneity index (HI), coverage index (CI) and healthy tissue relative overdose factor (HTOF) tools. x2 tests were performed between COIN, HI and the geometrical parameters of the target volume (lesion volume - LV, lesion-organ distance - LOD, lesion deformity index - LDI). Mean value of COIN, HI, HTOF and CI was 0.52 (SD 0.13), 1.16 (SD 0.1), 0.88 (SD 0.53), and 0.94 (SD 0.11), respectively. COIN significantly correlated with (p<0.001 in all three cases), while HI was independent of LV, LOD, LDI (p=0.94; 0.14 and 0.72). COIN is similar, HTOF is less than data from the literature. According to our results geometrical parameters of the target volume (size, location, deformation) significantly influence the COIN, but they have no effect on HI

    Clinical outcomes of 130 patients with primary and secondary lung tumors treated with Cyberknife robotic stereotactic body radiotherapy

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    Background: Authors report clinical outcomes of patients treated with robotic stereotactic body radiotherapy (SBRT) for primary, recurrent and metastatic lung lesions. Patients and methods: 130 patients with 160 lesions were treated with Cyberknife SBRT, including T1-3 primary lung cancers (54%), recurrent tumors (22%) and pulmonary metastases (24%). The mean biologically equivalent dose (BED10Gy) was 151 Gy (72–180 Gy). Median prescribed dose for peripheral and central lesions was 3x20 Gy and 3x15 Gy, respectively. Local control (LC), overall survival (OS), and cause-specific survival (CSS) rates, early and late toxicities are reported. Statistical analysis was performed to identify factors influencing local tumor control. Results: Median follow-up time was 21 months. In univariate analysis, higher dose was associated with better LC and a cut-off value was detected at BED10Gy ≤ 112.5 Gy, resulting in 1-, 2-, and 3-year actuarial LC rates of 93%, vs 73%, 80% vs 61%, and 63% vs 54%, for the high and low dose groups, respectively (p = 0.0061, HR = 0.384). In multivariate analysis, metastatic origin, histological confirmation and larger Planning Target Volume (PTV) were associated with higher risk of local failure. Actuarial OS and CSS rates at 1, 2, and 3 years were 85%, 74% and 62%, and 93%, 89% and 80%, respectively. Acute and late toxicities ≥ Gr 3 were observed in 3 (2%) and 6 patients (5%), respectively. Conclusions: Our favorable LC and survival rates after robotic SBRT, with low rates of severe toxicities, are coherent with the literature data in this mixed, non-selected study population

    Testing of membrane module for ultrafiltration

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    <div><p>ABSTRACT</p><p><b>Background.</b> To evaluate efficacy and toxicity of radio-chemotherapy (RCT) and MR-guided pulsed-dose-rate (PDR) adaptive brachytherapy (IGABT) for locally advanced cervical cancer (LACC).</p><p><b>Material and methods.</b> Between 2007 and 2014 85 patients with FIGO stage 1B1 N+ or ≥ 1B2 cervical cancer were treated with RCT+ IGABT. The treatment consisted of a pelvic± paraaortic external beam radiotherapy (EBRT) (45–50.4 Gy ± 10 Gy boost to primary tumor and/or to pathologic lymph nodes) with concurrent cisplatin followed by 25–35 Gy of PDR IGABT in 30–50 pulses. The ratio of 3D-CFRT/IMRT was 61/24 patients. Dose-volume parameters of high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume (IR-CTV) and D2cm<sup>3</sup> organs at risk (OARs) were reported. Local control (LC), cancer-specific survival (CCS) and overall survival (OS) were analyzed actuarially and morbidity crude rates were scored using CTCAEv4.0.</p><p><b>Results.</b> Mean follow-up was 36 months (range 6–94). The mean D90 and D98 for HR-CTV was 84.4 ± 9 Gy and 77 ± 8.1 Gy, while for IR-CTV was 69.1 ± 4.3 Gy and 64.8 ± 4.3 Gy, respectively. The mean D2cm<sup>3</sup> for OARs was the following: bladder: 77.3 ± 10.5 Gy, rectum: 65 ± 6.8 Gy, sigmoid: 63 ± 7.9 Gy and intestine: 64.0 ± 9.1 Gy. Three year LC, CSS and OS were: 94%, 85% and 81%. The three-year regional- and distant control rates were 95% and 74%. Node negative patients had significantly higher three-year CSS (100 vs. 72%, p = 0.016) and OS (92 vs. 72%, p = 0.001) compared to node positive ones. Three-year actuarial late Grade ≥ 3 morbidity was the following: GI: 8%, GU: 5%, Vaginal: 8%. The frequency of Grade ≥ 3 hematological toxicities including anemia/leukopenia/neutropenia/thrombocytopenia were 8.6%/34.7%/24.3%/24.3%, respectively.</p><p><b>Conclusion.</b> This large mono-institutional experience builds up further evidences that IGABT in conjunction with RCT should be the standard of care for patients suffering LACC.</p></div
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