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Cost-Effective Technologies to Study the Arctic Ocean Environment †

Viviana Piermattei, Alice Madonia, Simone Bonamano, Riccardo Martellucci, Gabriele Bruzzone, Roberta Ferretti, Angelo Odetti, Maurizio Azzaro, Giuseppe Zappalà, Marco Marcelli
2018 Sensors  
The Arctic region is known to be severely affected by climate change, with evident alterations in both physical and biological processes. Monitoring the Arctic Ocean ecosystem is key to understanding the impact of natural and human-induced change on the environment. Large data sets are required to monitor the Arctic marine ecosystem and validate high-resolution satellite observations (e.g., Sentinel), which are necessary to feed climatic and biogeochemical forecasting models. However, the
more » ... Observing System needs to complete its geographic coverage, particularly for the harsh, extreme environment of the Arctic Region. In this scenario, autonomous systems are proving to be valuable tools for increasing the resolution of existing data. To this end, a low-cost, miniaturized and flexible probe, ArLoC (Arctic Low-Cost probe), was designed, built and installed on an innovative unmanned marine vehicle, the PROTEUS (Portable RObotic TEchnology for Unmanned Surveys), during a preliminary scientific campaign in the Svalbard Archipelago within the UVASS project. This study outlines the instrumentation used and its design features, its preliminary integration on PROTEUS and its test results.
doi:10.3390/s18072257 pmid:30011806 pmcid:PMC6069410 fatcat:5i7dvytlqndwvdr6tgqoxxomvu

Breast in vivo dosimetry by EPID

Andrea Fidanzio, Francesca Greco, Alessandra Mameli, Luigi Azario, Mario Balducci, Maria Antonietta Gambacorta, Vincenzo Frascino, Savino Cilla, Domenico Sabatino, Angelo Piermattei
2010 Journal of Applied Clinical Medical Physics  
An electronic portal imaging device (EPID) is an effective detector for in vivo transit dosimetry. In fact, it supplies two-dimensional information, does not require special efforts to be used during patient treatment, and can supply data in real time. In the present paper, a new procedure has been proposed to improve the EPID in vivo dosimetry accuracy by taking into account the patient setup variations. The procedure was applied to the breast tangential irradiation for the reconstruction of
more » ... e dose at the breast midpoint, Dm. In particular, the patient setup variations were accounted for by comparing EPID images versus digitally reconstructed radiographies. In this manner, EPID transit signals were obtained corresponding to the geometrical projections of the breast midpoint on the EPID for each therapy session. At the end, the ratios R between D(m) and the doses computed by the treatment planning system (TPS) at breast midpoints, D(m,TPS), were determined for 800 therapy sessions of 20 patients. Taking into account the method uncertainty, tolerance levels equal to ± 5% have been determined for the ratio R.The improvement of in vivo dosimetry results obtained (taking into account patient misalignment) has been pointed out comparing the R values obtained with and with-out considering patient setup variations. In particular, when patient misalignments were taken into account, the R values were within ± 5% for 93% of the checks; when patient setup variations were not taken into account, the R values were within ± 5% in 72% of the checks. This last result points out that the transit dosimetry method overestimates the dose discrepancies if patient setup variations are not taken into account for dose reconstruction. In this case, larger tolerance levels have to be adopted as a trade-off between workload and ability to detect errors, with the drawback being that some errors (such as the ones in TPS implementation or in beam calibration) cannot be detected, limiting the in vivo dosimetry efficacy.The paper also reports preliminary results about the possibility of reconstructing a dose profile perpendicular to the beam central axis reaching from the apex to the lung and passing through the middle point of the breast by an algorithm, similar to the one used for dose reconstruction at breast midpoint. In particular, the results have shown an accuracy within ± 3% for the dose profile reconstructed in the breast (excluding the interface regions) and an underestimation of the lung dose.
pmid:21081886 pmcid:PMC5720411 fatcat:piqlky2yqnghnnlpqushogeojm

Breast in vivo dosimetry by EPID

Andrea Fidanzio, Francesca Greco, Alessandra Mameli, Luigi Azario, Mario Balducci, Maria Antonietta Gambacorta, Vincenzo Frascino, Savino Cilla, Domenico Sabatino, Angelo Piermattei
2010 Journal of Applied Clinical Medical Physics  
An electronic portal imaging device (EPID) is an effective detector for in vivo transit dosimetry. In fact, it supplies two-dimensional information, does not require special efforts to be used during patient treatment, and can supply data in real time. In the present paper, a new procedure has been proposed to improve the EPID in vivo dosimetry accuracy by taking into account the patient setup variations. The procedure was applied to the breast tangential irradiation for the reconstruction of
more » ... e dose at the breast midpoint, D m . In particular, the patient setup variations were accounted for by comparing EPID images versus digitally reconstructed radiographies. In this manner, EPID transit signals were obtained corresponding to the geometrical projections of the breast midpoint on the EPID for each therapy session. At the end, the ratios R between D m and the doses computed by the treatment planning system (TPS) at breast midpoints, D m,TPS , were determined for 800 therapy sessions of 20 patients. Taking into account the method uncertainty, tolerance levels equal to ± 5% have been determined for the ratio R. PACS numbers: 87.55.Qr, 87.55.km, 87.53.Bn Key words: in vivo dosimetry, transit dosimetry, quality assurance in breast radiotherapy a
doi:10.1120/jacmp.v11i4.3275 fatcat:ibewrxpf3vgipf6zebvpefxucm

Correlation functions for Elekta aSi EPIDs used as transit dosimeter for open fields

Savino Cilla, Andrea Fidanzio, Francesca Greco, Domenico Sabatino, Aniello Russo, Laura Gargiulo, Luigi Azario, Angelo Piermattei
2010 Journal of Applied Clinical Medical Physics  
In-vivo dosimetry techniques are currently being applied only by a few Centers because they require time-consuming implementation measurements, and workload for detector positioning and data analysis. The transit in-vivo dosimetry performed by the electronic portal imaging device (EPID) avoids the problem of solid-state detector positioning on the patient. Moreover, the dosimetric characterization of the recent Elekta aSi EPIDs in terms of signal stability and linearity make these detectors
more » ... ul for the transit in-vivo dosimetry with 6, 10 and 15 MV photon beams. However, the implementation of the EPID transit dosimetry requires several measurements. Recently, the present authors have developed an in-vivo dosimetry method for 3D CRT based on correlation functions defined by the ratios between the transit signal, st (w,L), by the EPID and the phantom midplane dose, Dm(w,L), at the source to axis distance (SAD) as a function of the phantom thickness, w, and the square field dimensions, L. When the phantom midplane was positioned at distance, d, from the SAD, the ratios st(w,L)/s't(d,w,L) were used to take into account the variation of the scattered photon contributions on the EPID as a function of d and L.The aim of this paper is the implementation of a procedure that uses generalized correlation functions obtained by nine Elekta Precise linac beams. The procedure can be used by other Elekta Precise linacs equipped with the same aSi EPIDs, assuming the stabilities of the beam output factors and the EPID signals. The procedure here reported avoids measurements in solid water equivalent phantoms needed to implement the in-vivo dosimetry method in the radiotherapy department. A tolerance level ranging between ± 5% and ± 6% (depending on the type of tumor) was estimated for the comparison between the reconstructed isocenter dose, Diso, and the computed dose, Diso,TPS, by the treatment planning system (TPS).
pmid:21330974 pmcid:PMC5718589 fatcat:3jzkhtq6rjgahmbxyheqwreumu

Role of Homologous Recombination Repair (HRR) Genes in Uterine Leiomyosarcomas: A Retrospective Analysis

Francesca Ciccarone, Matteo Bruno, Elisa De Paolis, Alessia Piermattei, Maria De Bonis, Domenica Lorusso, Gian Franco Zannoni, Nicola Normanno, Angelo Minucci, Giovanni Scambia, Gabriella Ferrandina
2022 Cancers  
Uterine leiomyosarcomas (uLMS) is a very rare disease, and patients experience a dismal prognosis even when treated with chemotherapy. Therefore, a more in-depth molecular characterization of this disease could provide suitable data for the identification of potential target-based drugs. This retrospective, single institutional study aimed to define the frequencies of gene alterations in uLMS, especially regarding the somatic mutations of BRCA and Homologous Recombination Repair (HRR) genes,
more » ... the impact of molecular alterations on clinical outcomes. The 16-genes Next-Generation Sequencing (NGS) panel, Homologous Recombination Solution TM (HRS, Sophia Genetics, Saint Sulpice, Switzerland), was used for the molecular evaluation of samples. The majority of patients (66/105, 63%) carried at least one sequence alteration, with a prevalence of TP53 involvement followed by RAD51B, BRCA1/2, and FANCL. Patients with TP53 gene alterations experienced a significantly worse prognosis for progression free survival (PFS) and overall survival (OS) versus wild-type patients. Given the number of patients with the BRCA1/2 mutation (N = 12), we included them in the HRR patient group; there was no difference in clinical outcomes with HRR versus non-HRR. The Cox's multivariate analysis showed that stage and TP53 gene alterations resulted in a significantly worse OS. The integration of gene networking data, such as tumor mutation burdens and cancer driver gene identification, could show a clearer discrimination of gene distribution patterns, and lead to the implementation of therapeutic targets.
doi:10.3390/cancers14081934 pmid:35454841 pmcid:PMC9024785 fatcat:ze6zxb3kpnfq3ihdues3vax5rq

Correlation functions for Elekta aSi EPIDs used as transit dosimeter for open fields

Savino Cilla, Andrea Fidanzio, Francesca Greco, Domenico Sabatino, Aniello Russo, Laura Gargiulo, Luigi Azario, Angelo Piermattei
2010 Journal of Applied Clinical Medical Physics  
In-vivo dosimetry techniques are currently being applied only by a few Centers because they require time-consuming implementation measurements, and workload for detector positioning and data analysis. The transit in-vivo dosimetry performed by the electronic portal imaging device (EPID) avoids the problem of solid-state detector positioning on the patient. Moreover, the dosimetric characterization of the recent Elekta aSi EPIDs in terms of signal stability and linearity make these detectors
more » ... ul for the transit in-vivo dosimetry with 6, 10 and 15 MV photon beams. However, the implementation of the EPID transit dosimetry requires several measurements. Recently, the present authors have developed an in-vivo dosimetry method for 3D CRT based on correlation functions defined by the ratios between the transit signal, s t (w,L), by the EPID and the phantom midplane dose, D m (w,L), at the source to axis distance (SAD) as a function of the phantom thickness, w, and the square field dimensions, L. When the phantom midplane was positioned at distance, d, from the SAD, the ratios s t (w,L)/s' t (d,w,L) were used to take into account the variation of the scattered photon contributions on the EPID as a function of d and L. The aim of this paper is the implementation of a procedure that uses generalized correlation functions obtained by nine Elekta Precise linac beams. The procedure can be used by other Elekta Precise linacs equipped with the same aSi EPIDs, assuming the stabilities of the beam output factors and the EPID signals. The procedure here reported avoids measurements in solid water equivalent phantoms needed to implement the in-vivo dosimetry method in the radiotherapy department. A tolerance level ranging between ± 5% and ± 6% (depending on the type of tumor) was estimated for the comparison between the reconstructed isocenter dose, D iso , and the computed dose, D iso,TPS , by the treatment planning system (TPS). PACS number: 87.55.Qr; 87.56.Fc
doi:10.1120/jacmp.v12i1.3279 fatcat:wxoiff6plbctzpypbdyqsi26yy

Comparison of measured and computed portal dose for IMRT treatment

Savino Cilla, Pietro Viola, Luigi Azario, Luca Grimaldi, Maurizio Craus, Guido D'Onofrio, Andrea Fidanzio, Francesco Deodato, Gabriella Macchia, Cinzia Digesù, Alessio G. Morganti, Angelo Piermattei
2006 Journal of Applied Clinical Medical Physics  
A new 2D array Seven 29 TM model (PTW, Freiburg), equipped with 729 vented plane-parallel ion chambers, projected for pretreatment verification of radiotherapy plans, was used as a detector for the transmitted or portal dose measurements below a Rando phantom. The dosimetric qualities of the 2D array make it attractive for measuring transmitted dose maps from step-and-shoot intensity-modulated radiotherapy (IMRT). It is well known that for step-and-shoot IMRT beams that use a small number of
more » ... itor units (MUs) per sequence, the early and recent electronic portal imaging devices (EPIDs) present a different response at X-ray start-up that affects the accuracy of the measured transmitted dose. The comparison of portal doses measured to those calculated by a commercial treatment-planning system (TPS) can verify correct dose delivery during treatment. This direct validation was tested by irradiating a simulated head tumor in a Rando anthropomorphic phantom by step-and-shoot IMRT beams. The absolute transmitted doses on a plane orthogonal to the beam central axis below the phantom were measured by the 2D array calibrated in terms of dose to water and compared with the computed portal dose extracted by custom software. In a previous paper, the comparison between the IMRT portal doses, computed by a commercial TPS and measured by a linear array that supplied a 1 mm spatial dose resolution, was carried out. The γ-index analysis supplied an agreement of more than 95% of the dose point with acceptance criteria, in terms of dose difference, ∆D max , and distance agreement, ∆d max , equal to 4% and 4 mm, respectively. In this paper, we verify the possible use of the PTW 2D array for measurements of the transmitted doses during several fractions of head and neck tumor radiotherapy. There are two advantages in the use of this 2D array as a portal dose device for the IMRT quality assurance program: first is the ability to perform absolute dose comparisons for hundreds of measurement positions to verify the correct dose delivery in several fractions of the therapy; second is the efficiency in time to detect these kinds of dose distributions within the field of view area of the CT scanner. PACS number: 87.53.Xd
doi:10.1120/jacmp.v7i3.2281 pmid:17533343 pmcid:PMC5722422 fatcat:w7h4dyeyejd63fnqemj6yoqyt4

Large Discrepancies between Planned and Actually Delivere dose in Imrt of Head and Neck Cancer. A Case Report

Angelo Piermattei, Savino Cilla, Guido D'Onofrio, Luca Grimaldi, Cinzia Digesù, Gabriella Macchia, Francesco Deodato, Alessio G Morganti
2007 Tumori (Milano)  
Correspondence to: Prof Angelo Piermattei, UO Fisica Sanitaria, Università Cattolica del Sacro Cuore, Largo A. Gemelli 1, 86100 Campobasso, Italy.  ... 
doi:10.1177/030089160709300320 pmid:17679475 fatcat:v3znj4vqtrd6pilrangztfaazi

Intensity-Modulated Radiation Therapy with Simultaneous Integrated Boost in Unresected Left-Sided Pleural Mesothelioma: A Case Report

Savino Cilla, Cinzia Digesù, Giovanni Silvano, Gabriella Macchia, Mariangela Massaccesi, Francesco Deodato, Gilbert DA Padula, Andrea Fidanzio, Angelo Piermattei, Alessio G Morganti
2010 Tumori (Milano)  
A 77-year-old male patient with unresected malignant pleural mesothelioma, clinical stage T3N0M0 according to the New International Staging System for Diffuse Malignant Pleural Mesothelioma, received intensity-modulated radiotherapy (IMRT) with a simultaneous integrated boost (SIB) after 6 cycles of chemotherapy with cisplatin and pemetrexed. SIB-IMRT delivered 40.5 Gy (1.5 Gy/fraction) to the left pleura and 50 Gy (1.85 Gy/fraction) to the sites of macroscopic disease. Radiotherapy was well
more » ... erated. Two months after the end of radiotherapy the patient showed grade 2 lung toxicity (febrile episodes accompanied by dry cough) that was successfully treated with steroid therapy. Local control lasted for 2 years after SIB-IMRT. Then the tumor recurred marginally to the radiation field and the patient underwent chemotherapy with pemetrexed. Three years from the diagnosis, the patient is alive and in good general condition. He only takes prednisone 5 mg/daily for exertional dyspnea. To the best of our knowledge this is the first reported use of SIB-IMRT in unresected malignant pleural mesothelioma. Considering the dosimetric advantages of SIB-IMRT and the clinical results observed in our patient, additional evaluation of this technique seems justified. Free full text available at www.tumorionline.it Tumori, 96: 618-622, 2010
doi:10.1177/030089161009600417 pmid:20968144 fatcat:xo3ovuabibebzcdnsmasvr5qvu

Evaluation of interfraction setup variations for postmastectomy radiation therapy using EPID‐based in vivo dosimetry

Shengwei Kang, Jie Li, Jiabao Ma, Wei Zhang, Xiongfei Liao, Hou Qing, Tingqiang Tan, Xin Xin, Bin Tang, Angelo Piermattei, Lucia Clara Orlandini
2019 Journal of Applied Clinical Medical Physics  
Postmastectomy radiation therapy is technically difficult and can be considered one of the most complex techniques concerning patient setup reproducibility. Slight patient setup variations - particularly when high-conformal treatment techniques are used - can adversely affect the accuracy of the delivered dose and the patient outcome. This research aims to investigate the inter-fraction setup variations occurring in two different scenarios of clinical practice: at the reference and at the
more » ... t patient setups, when an image-guided system is used or not used, respectively. The results were used with the secondary aim of assessing the robustness of the patient setup procedure in use. Forty eight patients treated with volumetric modulated arc and intensity modulated therapies were included in this study. EPID-based in vivo dosimetry (IVD) was performed at the reference setup concomitantly with the weekly cone beam computed tomography acquisition and during the daily current setup. Three indices were analyzed: the ratio R between the reconstructed and planned isocenter doses, γ % and the mean value of γ from a transit dosimetry based on a two-dimensional γ -analysis of the electronic portal images using 5% and 5 mm as dose difference and distance to agreement gamma criteria; they were considered in tolerance if R was within 5%, γ % > 90% and γ mean < 0.4. One thousand and sixteen EPID-based IVD were analyzed and 6.3% resulted out of the tolerance level. Setup errors represented the main cause of this off tolerance with an occurrence rate of 72.2%. The percentage of results out of tolerance obtained at the current setup was three times greater (9.5% vs 3.1%) than the one obtained at the reference setup, indicating weaknesses in the setup procedure. This study highlights an EPID-based IVD system's utility in the radiotherapy routine as part of the patient's treatment quality controls and to optimize (or confirm) the performed setup procedures' accuracy.
doi:10.1002/acm2.12712 pmid:31541537 pmcid:PMC6806484 fatcat:66j3moqjenhn3hmfp6zpqlb3ue

Extracranial radiosurgery with volumetric modulated arc therapy: Feasibility evaluation of a phase I trial

FRANCESCO DEODATO, SAVINO CILLA, GABRIELLA MACCHIA, LUCIANA CARAVATTA, SAMANTHA MIGNOGNA, MARIANGELA MASSACCESI, VINCENZO PICARDI, CINZIA DIGESU, GIUSEPPINA SALLUSTIO, PIERLUIGI BONOMO, ANGELO PIERMATTEI, GABRIELLA FERRANDINA (+4 others)
2013 Oncology Letters  
The aim of this study was to report early clinical experience in stereotactic body radiosurgery (SBRS) delivered using volumetric intensity modulated arc therapy (VMAT) in patients with primary or metastatic tumors in various extracranial body sites. Each enrolled subject was included in a different phase I study arm, depending on the tumor site and the disease stage (lung, liver, bone, metastatic), and sequentially assigned to a particular dose level. Technical feasibility and dosimetric
more » ... s were investigated. The acute toxicity, tumor response and early local control were also studied. In total, 25 lesions in 20 consecutive patients (male/female, 11/9; median age, 67 years; age range, 47-86 years) were treated. Of these 25 lesions, 4 were primary or metastatic lung tumors, 6 were liver metastases, 8 were bone metastases and 7 were nodal metastases. The dose-volume constraints for organs at risk (OARs) were observed in 19 patients using a single-arc technique. Only in one patient were two arcs required. The treatment was performed without interruption or any other technical issues. The prescribed dose ranged from 12-26 Gy to the planning target volume (PTV). Delivery time ranged from 4 min to 9 min and 13 sec (median, 6 min and 6 sec). No incidence of grade 2-4 acute toxicity was recorded. The overall response rate was 48% (95% confidence interval (CI), 24.2-70.2) based on computed tomography (CT)/magnetic resonance imaging (MRI) and 89% (95% CI, 58.6-98.7) based on the positron emission tomography (PET) scan. SBRS delivered by means of VMAT allowed the required target coverage to be achieved while remaining within the normal tissue dose-volume constraints in the 20 consecutive patients. VMAT-SBRS resulted in adequate technical feasibility; the maximum tolerable dose has not yet been reached in any study arm.
doi:10.3892/ol.2013.1276 pmid:23833662 pmcid:PMC3700848 fatcat:gcs2avp4fzblzgsl2jcta6syie

aSi-EPID transit signal calibration for dynamic beams: a needful step for the IMRT in vivo dosimetry

Francesca Greco, Angelo Piermattei, Luigi Azario, Lorenzo Placidi, Savino Cilla, Rocchina Caivano, Vincenzo Fusco, Andrea Fidanzio
2013 Medical and Biological Engineering and Computing  
dosimetry procedure here presented is among the objectives of a National Project financially supported by the Istituto Nazionale di Fisica Nucleare for the development of in vivo dosimetry procedures (Piermattei  ... 
doi:10.1007/s11517-013-1094-x pmid:23835663 pmcid:PMC3751319 fatcat:qflks273brbphgmnrrq3ypuocy

A Feasibility Study for in vivo Dosimetry Procedure in Routine Clinical Practice

Maria D. Falco, Stefano Giancaterino, Andrea De Nicola, Nico Adorante, Ramon Gimenez De Lorenzo, Monica Di Tommaso, Annamaria Vinciguerra, Marianna Trignani, Francesca Perrotti, Albina Allajbej, Andrea Fidanzio, Francesca Greco (+3 others)
2018 Technology in Cancer Research and Treatment  
Purpose: The aim of the in vivo dosimetry, during the fractionated radiation therapy, is the verification of the correct dose delivery to patient. Nowadays, in vivo dosimetry procedures for photon beams are based on the use of the electronic portal imaging device and dedicated software to elaborate electronic portal imaging device images. Methods: In total, 8474 in vivo dosimetry tests were carried out for 386 patients treated with 3-dimensional conformal radiotherapy, intensity-modulated
more » ... herapy, and volumetric modulated arc therapy techniques, using the SOFTDISO. SOFTDISO is a dedicated software that uses electronic portal imaging device images in order to (1) calculate the R index, that is, the ratio between daily reconstructed dose and the planned one at isocenter and (2) perform a g-like analysis between the signals, S, of a reference electronic portal imaging device image and that obtained in a daily fraction. It supplies 2 indexes, the percentage g% of points with g < 1 and the mean g value, g mean . In g-like analysis, the pass criteria for the signals agreement DS% and distance to agreement Dd have been selected based on the clinical experience and technology used. The adopted tolerance levels for the 3 indexes were fixed in 0.95 R 1.05, g% ! 90%, and g mean 0.5. Results: The results of R ratio, g-like, and a visual inspection of these data reported on a monitor screen permitted to individuate 2 classes of errors (1) class 1 that included errors due to inadequate standard quality controls and (2) class 2, due to patient morphological changes. Depending on the technique and anatomical site, a maximum of 18% of tests had at least 1 index out of tolerance; once removed the causes of class-1 errors, almost all patients (except patients with 4 lung and 2 breast cancer treated with 3-dimensional conformal radiotherapy) presented mean indexes values ( R, g%, and g mean ) within tolerance at the end of treatment course. Class-2 errors were found in some patients. Conclusions: The in vivo dosimetry procedure with SOFTDISO resulted easily implementable, able to individuate errors with a limited workload.
doi:10.1177/1533033818779201 pmid:29871570 pmcid:PMC5992805 fatcat:67ma3rpesrdi5brhmcztkzsoz4

Adaptive optimization by 6 DOF robotic couch in prostate volumetric IMRT treatment: rototranslational shift and dosimetric consequences

Silvia Chiesa, Lorenzo Placidi, Luigi Azario, Gian Carlo Mattiucci, Francesca Greco, Andrea Damiani, Giovanna Mantini, Vincenzo Frascino, Angelo Piermattei, Vincenzo Valentini, Mario Balducci
2015 Journal of Applied Clinical Medical Physics  
The purpose of this study was to investigate the magnitude and dosimetric relevance of translational and rotational shifts on IGRT prostate volumetric-modulated arc therapy (VMAT) using Protura six degrees of freedom (DOF) Robotic Patient Positioning System. Patients with cT3aN0M0 prostate cancer, treated with VMAT simultaneous integrated boost (VMAT-SIB), were enrolled. PTV2 was obtained adding 0.7 cm margin to seminal vesicles base (CTV2), while PTV1 adding to prostate (CTV1) 0.7 cm margin in
more » ... all directions, except 1.2 cm, as caudal margin. A daily CBCT was acquired before dose delivery. The translational and rotational displacements were corrected through Protura Robotic Couch, collected and applied to the simulation CT to obtain a translated CT (tCT) and a rototranslated CT (rtCT) on which we recalculated the initial treatment plan (TP). We analyzed the correlation between dosimetric coverage, organs at risk (OAR) sparing, and translational or rotational displacements. The dosimetric impact of a rototranslational correction was calculated. From October 2012 to September 2013, a total of 263 CBCT scans from 12 patients were collected. Translational shifts were < 5 mm in 81% of patients and the rotational shifts were < 2° in 93% of patient scans. The dosimetric analysis was performed on 172 CBCT scans and calculating 344 VMAT-TP. Two significant linear correlations were observed between yaw and the V20 femoral heads and between pitch rotation and V50 rectum (p < 0.001); rototranslational correction seems to impact more on PTV2 than on PTV1, especially when margins are reduced. Rotational errors are of dosimetric significance in sparing OAR and in target coverage. This is relevant for femoral heads and rectum because of major distance from isocenter, and for seminal vesicles because of irregular shape. No correlation was observed between translational and rotational errors. A study considering the intrafractional error and the deformable registration is ongoing. PACS number: 87.55.de
doi:10.1120/jacmp.v16i5.5525 pmid:26699314 pmcid:PMC5690171 fatcat:kch5jth53rgijclcablon6d6be

Volumetric modulated arc therapy (VMAT) and simultaneous integrated boost in head-and-neck cancer: is there a place for critical swallowing structures dose sparing?

Savino Cilla, Francesco Deodato, Gabriella Macchia, Cinzia Digesù, Anna Ianiro, Angelo Piermattei, Vincenzo Valentini, Alessio G Morganti
2016 British Journal of Radiology  
doi:10.1259/bjr.20150764 pmid:26728543 pmcid:PMC4986495 fatcat:wgbrp7vhtrhj5mltlyjaexxkpy
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