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Automated multimodal volume registration based on supervised 3D anatomical landmark detection
We propose a new method for automatic 3D multimodal registration based on anatomical landmark detection. Landmark detectors are learned independantly in the two imaging modalities using Extremely Randomized Trees and multi-resolution voxel windows. A least-squares fitting algorithm is then used for rigid registration based on the landmark positions as predicted by these detectors in the two imaging modalities. Experiments are carried out with this method on a dataset of pelvis CT and CBCT scans related to 45 patients. On this dataset, our fully automatic approach yields results very competitive with respect to a manually assisted state-of-the-art rigid registration algorithm
Conformal stereotactic radiosurgery treatment: plan evaluation methods and results
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
Combined FiF+ Tangent-to-tangents VMAT breast SIB technique: Clinical introduction of an optimal class solution
peer reviewe
Clinical introduction of an all-in class solution for prone breast hypofractionated SIB with multibeam IMRT
Clinical outcomes of 130 patients with primary and secondary lung tumors treated with Cyberknife robotic stereotactic body radiotherapy
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
<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
Daily and accumulated dose based on residual errors for pancreas SABR using two different approaches.
0info:eu-repo/semantics/publishe
Interobserver variability in delineation of target volumes in head and neck cancer
BACKGROUND AND PURPOSE: In the last decade precision of radiotherapy treatment execution increased, demanding more accurate delineations to fully exploit these developments. The aim of this study was to identify the extent of interobserver variability in delineation of head and neck cancer (HNC). MATERIALS AND METHODS: In February 2017 all Belgian radiotherapy departments were invited to complete an online survey and submit clinical target volumes for five HNC reference cases. Clinical target volume of the primary tumour (CTVp) and elective nodal neck (CTVe) were submitted and compared between centres for CTVp and to the CTVe 'gold standard' (CTVeGS). Volume, DICE similarity coefficient (DSC) and median Hausdorff Distance (HD) were measured and calculated. RESULTS: Fourteen of 22 centres (64%) completed both survey and delineations. They all used delineation guidelines for CTVe and twelve confirmed the use of guidelines of Grégoire et al. Nine centres used CTVp guidelines, although none used the same ones. Median DSC for CTVe comparing centres with CTVeGS ranged between 0.67 and 0.82 and HD50 between 1.7 mm and 2.8 mm. Good agreement was shown for neck level II, III and IV, whilst worst consensus was observed for level Ib, V, VI, VIIa and VIIb. Improvement of DSC and HD50 was observed when the same levels as CTVeGS were selected. Median DSC and HD50 for CTVp ranged between 0.51 and 0.79 and 2.8 mm and 4.1 mm respectively, which both slightly improved when calculating it for only the centres using a 10 mm margin. CONCLUSION: Although nearly all participants used identical guidelines for CTVe there were large discrepancies in neck levels selected and volumes delineated. CTVp delineations were also heterogeneous although we expect improvement with implementation of recently published guidelines. Additional teaching in target volume delineation is necessary as this paper demonstrates that availability and implementation of guidelines alone is not enough to guarantee uniform delineation.status: publishe
139 DOES QUALITY OF RADIOTHERAPY PREDICT OUTCOMES OF MULTICENTRE CLINICAL TRIALS? THE EORTC RADIATION ONCOLOGY GROUP EXPERIENCE.
Patterns of difficult cases for breast irradiation: where multi-beam IMRT and SIB should be the primary choice
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