Publications by authors named "Bucciolini M"

Purpose: Aim of this work is the assessment of build-up and superficial doses of different clinical Head&Neck plans delivered with Helical TomoTherapy (HT) (Accuray, Sunnyvale, CA). Depth dose profiles and superficial dose points were measured in order to evaluate the Treatment Planning System (TPS) capability of an accurate dose modeling in regions of disequilibrium. Geometries and scattering conditions were investigated, similar to the ones generally encountered in clinical treatments.

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Purpose: To evaluate EBT3 for pre-treatment patient specific quality assurance (QA). The method we propose combines the experience gained in our center with the guidelines of the protocol proposed by Lewis et al. in 2012.

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Aim: The aim of this study was to compare surface imaging, portal imaging, and skin marker set-up in radiotherapy of thoracic and pelvic regions, using cone beam computed tomography (CBCT) data as the gold standard.

Patients And Methods: Twenty patients were included in this study. CBCT, surface acquisition (SA), and two orthogonal portal images (PI) were acquired during the first four treatment sessions.

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Purpose: The aim of our study was to evaluate the usefulness of the four-dimensional computed tomography (4DCT) in accelerated partial breast irradiation (aPBI) planning.

Materials And Methods: At our Institute, we have been treating the index quadrant with external intensity-modulated radiation therapy in a phase III trial. For this study, we selected a sample of 10 patients with right- or left-sided breast cancer and surgical clips at the excision site.

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Linac-based stereotactic radiosurgery (SRS) has been widely used for treating small intracranial lesions. This technique allows conforming the dose distribution to the planning target volume (PTV), providing a steep dose gradient with the surrounding normal tissues. This is realized through dedicated collimation systems.

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Purpose: The aim of this work is to investigate the behavior of a single crystal diamond diode (SCDD) for volumetric modulated arc therapy (VMAT) dose verifications. This delivery technique is one of the most severe test of a dosimeter performance due to the modulation of the dose rate achieved by simultaneously changing the velocity of the gantry and the position of the collimator leaves. The performed measurements with VMAT photon beams can therefore contribute to an overall global validation of the device to be used in dose distribution verifications.

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Background: The use of adjuvant radiotherapy in ductal carcinoma in situ is accepted by most radiation oncologists worldwide; the role of a boost on the tumor bed is however more controversial.

Materials And Methods: We reviewed our Institute experience in DCIS treatment, focusing on main prognostic factors and impact of radiation boost on local relapse. A total of 389 patients treated between 1990 and 2007 were retrospectively analyzed.

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Purpose: The aim of this paper is to investigate the accuracy of a laser∕camera surface imaging system (Sentinel) when used on patients treated in the thorax or pelvic regions and to evaluate system employment conditions and patient setup procedures that provide more accurate results.

Methods: The system was tested on two groups of patients for whom different patient setup procedures and Sentinel employment conditions were considered. For the first group of 33 patients (FG) no changes to the usual setup procedures were made and a surface extension limited to the treated region was considered.

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Purpose: The aim of this study is to investigate the performance of Sentinel(™), a patient setup verification device based on a laser/camera system, when used on rigid-body phantoms.

Methods: The Sentinel system consists of a scanner unit, containing the laser and the camera, and surface-matching registration software. For the registration procedure, both a computed tomography (CT) and a Sentinel image can be used as a reference.

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In radiotherapy, treatment portal images and digitally reconstructed radiographs (DRRs) are used to monitor patient setup during clinical routine. The output of the registration between the portal image and the reference DRR indicates the patient displacement. If the registration is not reliable, the patient positioning will not be accurate.

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In radiotherapy treatment portal images and digitally reconstructed radiographs (DRRs) are the most frequently used image-guidance systems to monitor patient set-up during clinical routine. DRR is therefore a critical element in the process of virtual simulation and patient position verification in radiotherapy. The aim of this work was to assess the geometric reliability of the DRR generated by XiO, Pinnacle, Odyssey and Ocentra-Masterplan Treatment Planning Systems (TPS).

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Purpose: To evaluate with a randomized clinical trial the possibility of treating the index quadrant with external intensity-modulated radiotherapy (IMRT) in a selected group of patients with early-stage breast cancer and to analyze the acute toxicity.

Methods And Materials: From September 2005, a randomized Phase III clinical trial has been conducted to compare conventional (tangential field) fractionated whole breast treatment (Arm A) with accelerated partial breast irradiation plus intensity-modulated radiotherapy (Arm B). For intensity-modulated radiotherapy, the clinical target volume was drawn with a uniform 1-cm margin around the surgical clips in three dimensions.

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The aim of this paper is to present a new phantom for arc therapy, intensity-modulated radiation therapy (IMRT), and tomotherapy dose distribution measurement in pretreatment verification. The presented phantom is innovative for its use of water as the tissue equivalent material, together with a technical solution specifically designed to support radiographic or radiochromic film and ionization chambers in any desired position. The phantom comprise a Plexiglas container, whose present shape and dimensions offer the possibility to simulate a human torso or abdomen; the container can be filled with water by opening the upper cover.

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The evaluation of the agreement between measured and calculated dose plays an essential role in the quality assurance (QA) procedures for intensity modulated radiation therapy (IMRT). Film dosimetry has been widely adopted for this purpose due to excellent film characteristics in terms of spatial resolution; unfortunately, it is a time-consuming procedure and requires great care if film has to be used as an absolute dosimeter. If this is not the case, then an independent ionimetric measurement is mandatory to assess the absolute dose agreement.

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A commercial amorphous silicon electronic portal imaging device (EPID) has been studied to investigate its potential in the field of pretreatment verifications of step and shoot, intensity modulated radiation therapy (IMRT), 6 MV photon beams. The EPID was calibrated to measure absolute exit dose in a water-equivalent phantom at patient level, following an experimental approach, which does not require sophisticated calculation algorithms. The procedure presented was specifically intended to replace the time-consuming in-phantom film dosimetry.

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We used X-rays from a linear accelerator and from a low energy therapeutic source to calibrate the single cell gel electrophoresis (comet assay), a widely used method to measure DNA damage. Gamma-rays from 60Co, with known efficiency in inducing DNA breakage, were used as reference. Human lymphocytes and one murine tumour cell line, F10-M3 cells, were irradiated under different experimental conditions.

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The goal of this work was to compare the behaviour of a chemical vapour deposited (CVD) diamond sample, grown at the University of Florence using a local procedure, with that of a commercial CVD diamond. The comparison was performed exposing both systems to 25 MV photons and measuring the current response during irradiation. Properties of dosimetric interest such as stability of response, dose rate dependence and rise time were investigated.

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Segmentation and registration tools are commonly used in radiotherapy for target and at risk organs localisation. In this work the performances of three different segmentation tools and of a surface matching registration technique, used on computed tomography (CT) and magnetic resonance (MR) images for the treatment planning of conformal prostate carcinoma, are studied. The accuracy of the segmentation and registration tools was evaluated by phantom experiment and on patient data, respectively.

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Aims And Background: Treatment of local-regional recurrent rectal carcinoma is a challenging problem, and local control may be dose dependent; doses should probably exceed 60 Gy. Our aim was to verify the possibility to deliver 66 Gy to the target, but less than 35 Gy to the small bowel, comparing different 3D irradiation techniques, in a selected group of patients.

Methods: Five patients with local recurrent rectal carcinoma were selected as representative of different presentations of the disease.

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In intensity modulated radiation therapy (IMRT) the aim of an accurate conformal dose distribution is obtained through a complex process. This ranges from the calculation of the optimal distribution of fluence by the treatment planning system (TPS), to the dose delivery through a multilamellar collimator (MLC), with several segments per beam in the step and shoot approach. The above-mentioned consideration makes mandatory an accurate dosimetric verification of the IM beams.

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The aim of this work was to test the suitability of a PTW diamond detector for nonreference condition dosimetry in photon beams of different energy (6 and 25 MV) and field size (from 2.6 cm x 2.6 cm to 10 cm x 10 cm).

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Clinical benefits from neuronavigation are well established. However, the complexity of its technical environment requires a careful evaluation of different types of errors. In this work, a detailed phantom study which investigates the accuracy in a neuronavigation procedure is presented.

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The aim of this work was to investigate the use of TLD-100 detectors in the field of relative dosimetry in proton eye facilities. These dosemeters, of different sizes, were used to measure transverse and longitudinal distributions of 62 MeV unmodulated proton beams at INFN-LNS in Catania. Comparison with other detectors, such as ionisation chambers, GAF and radiographic film, is extensively discussed.

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A 6 MV photon beam from Linac SL75-5 has been collimated with a new micromultileaf device that is able to shape the field in the two orthogonal directions with four banks of leaves. This is the first clinical installation of the collimator and in this paper the dosimetric characterization of the system is reported. The dosimetric parameters required by the treatment planning system used for the dose calculation in the patient are: tissue maximum ratios, output factors, transmission and leakage of the leaves, penumbra values.

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The dosimetric properties of two PTW Riga diamond detectors type 60003 were studied in high-energy photon and electron therapy beam. Properties under study were current-voltage characteristic, polarization effect, time stability of response, dose response, dose-rate dependence, temperature stability, and beam quality dependence of the sensitivity factor. Differences were shown between the two detectors for most of the previous properties.

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