Papers by Antonella Stravato
Radiotherapy and Oncology, 2019
The re-irradiation of locally recurrent rectal cancer presents challenges due to the proximity of... more The re-irradiation of locally recurrent rectal cancer presents challenges due to the proximity of critical organs such as bowel. Ion beam therapy, specifically carbon ions radiotherapy (CIRT) have some advantages for the favorable relative biological effectiveness and physical dose distribution providing a highly conformal dose distribution while minimizing normal tissue damage. The aim of this study is to report our experience on feasibility and toxicity of carbon-ion radiotherapy (CIRT) in previously irradiated patients with locally recurrent rectal cancer. Material and Methods Between August 2014 and February 2017, a total of 10 patients (M:F= 8:2) were treated with CIRT as reirradiation for locally recurrent rectal cancer at National Centre of Oncological Hadrontherapy (CNAO). Patient ages ranged between 46 to 78 years (median 58.5 years). All patients had a history of surgery and pelvic radiotherapy. Specifically, the dose of previous radiotherapy ranged from 45 to 50.4 Gy in 9 patients one of which received a brachytherapy boost up to a total dose of 20Gy. One patient was irradiated with a total dose of 76 Gy for a prostatic cancer. One patient, at time of the first recurrence, underwent to re-irradiation with stereotactic radiotherapy (30 Gy in 6 fractions). They had 7 presacral, 1 perineal, 1 perianal and 1 pre-coccygeal relapses. Three patients received spacer implantation prior to CIRT to secure adequate distance between bowel and tumor. Toxicity was scored according CTCAE 4.0 scale. Results The median interval between the two courses of radiotherapy was 89.3 months (range: 13.8-138.2). Median total dose of CIRT was 60 GyRBE (range: 35-76.8) and was administered in a median number of 16 fractions (range: 15-20) over 4 weeks (from 3 to 4.8 Gy RBE/fraction). The GTV ranged from 7.21 to 300.8 cm 3 with a median of 28.42 cm 3. The PTV ranged from 53.55 to 742.64 cm 3. All patients completed the scheduled treatment course. Median follow-up was 13 months. Acute toxicity was mild and mainly neuropathic: grade 2 (G2) neuropathic pain in 1 (10%) and G1 in 2 (20%) patients. The major late toxicities were peripheral neuropathy (20%, G2). No G≥3 acute/late reaction nor pelvic infections were observed. Four patients were diagnosed with local progression after carbon ion radiotherapy with a median disease free survival of 11.4 months (range: 2.4-39.7). Three patients experienced systemic progression. The estimated 1-year-local control rate was 80%. Conclusion In our experience, CIRT for locally recurrent rectal cancer appears to be safe and effective with an acceptable rate of morbidity of normal tissue. More data and longer follow-up are required to investigate the long-term disease control and to determine late effects. EP-1457 Moderate hypofractionation and SIB with volumetric modulated arc therapy (RapidArc) for anal cancer
Biophysical Journal, 2004
This work deals with a dielectric study at radio frequencies of the influence at room temperature... more This work deals with a dielectric study at radio frequencies of the influence at room temperature of two organic molecules, known as cryo-protectants, ethylene-glycol and glycerol, on conformational and dynamic properties of two model proteins, lysozyme (lys) from chicken egg-white and ferricytochrome-c (cyt-c) from horse heart. Cyt-c is a compact globular protein whereas lys is composed of two structural domains, separated by the active site cleft. Measurements were carried out at the fixed temperature of 208C varying the concentration of the cosolvent up to 90% w/w. From the analysis of the dielectric relaxation of the protein solution, the effective hydrodynamic radius and the electric dipole moment of the protein were calculated as a function of the cosolvent concentration. The data show that glycerol does not modify significantly the conformation of both proteins and cyt-c is also stable in the presence of ethylene-glycol. On the contrary ethylene-glycol strongly affects the dielectric response of lysozyme denoting a specific effect on its conformation and dynamics. The data are coherently interpreted hypothesizing that glycol molecule wedges between and separates the two domains of lys making them rotationally independent.
This record contains raw data related to article "Critical Appraisal of the Risk of Secondar... more This record contains raw data related to article "Critical Appraisal of the Risk of Secondary Cancer Induction From Breast Radiation Therapy With Volumetric Modulated Arc Therapy Relative to 3D Conformal Therapy" PURPOSE: To evaluate the excess absolute risk (EAR) comparing volumetric modulated arc therapy (VMAT) and 3-dimensional (3D) conformal radiation therapy (CRT) in breast cancer radiation therapy treatment. METHODS AND MATERIALS: Two VMAT arrangements (VMAT_tang and VMAT_full, i.e. partial arcs with and without a sector of 0 Monitor Unit, respectively) and a 3D CRT (field-in-field [FinF]) plan were calculated with an accurate dose calculation algorithm, Acuros, in 20 patients presenting with early-stage breast cancer. The dose prescription was 40.05 Gy in 15 fractions. The planning aim was to maximize the dose reduction in the lungs, contralateral breast, heart, and coronary artery. EAR was estimated using different models: linear, linear-exponential, plateau, and f...
In-vivo dosimetry with Gafchromic films for multi-isocentric VMAT irradiation of total marrow lym... more In-vivo dosimetry with Gafchromic films for multi-isocentric VMAT irradiation of total marrow lymph-nodes: a feasibility study planned one for the TMI-TMLI protocol where partially overlapping arcs with different isocenters are required.
Radiotherapy and Oncology, 2017
Radiotherapy and Oncology, 2016
Purpose or Objective: To evaluate the patterns of recurrence and its value in target delineation ... more Purpose or Objective: To evaluate the patterns of recurrence and its value in target delineation for postoperative radiotherapy(PORT) in patients with stage III thoracic esophageal squmous cell carcinoma(ESCC) after esophagectomy. Material and Methods: 395 patients with stage III thoracic ESCC treated with radical esophagectomy from Jan, 2008 to Dec, 2011 were enrolled in this study. No patients has accepted preoperative adjuvant therapy. There were 302 males and 93 females; median ages was 60 years old (range 33-83). There were 33 patients located in upper-, 273 in middle-and 89 in low-segment. 375 patents has operated with two-field and 22 with three-field esophagectomy. The median number of dissected lymph nodes were 10 per case (range 1-34). There were 244 with stage IIIA, 106 with IIIB and 45 with IIIC. There were 97 patients received with surgery alone, 212 with postoperative chemotherapy(POCT), 86 with PORT(30 with POCT and PORT). Diagnosis of recurrence was parimarily based on CT images, some of which were biopsy-confirmed. The location and time of tumor recurrences were analyzed.
Radiotherapy and Oncology, 2015
3rd ESTRO Forum 2015 S39 adjacent structures. For these patients a mask was created from the GTV ... more 3rd ESTRO Forum 2015 S39 adjacent structures. For these patients a mask was created from the GTV by a 2cm expansion after which the GTV itself was removed (figure C,D), effectively registering the adjacent structures. This method was evaluated on five weekly fractions of 24 patients. The second method was applied on patients with a non-attached tumor. In this method the local rigid registration was expanded by a scaling factor such that the regressing tumor in the CBCT was magnified to the original size of the tumor of the reference CT-scan during the registration (figure G,H). This method was applied on 5 patients and also five weekly fractions were evaluated. Bland-Altman analysis was applied to quantify the limits of agreement between these registration methods and the clinically approved registrations. All automatic registrations were visually validated to assess the success rate. Results: The limits of agreement between the registration method for regressing tumors attached to surrounding structures showed limits of agreement with the clinical method of-2.6-2.9mm for the LR direction,-2.9-2.8mm for the CC direction and-3.1-3.2mm for the AP direction. The alignment differences between these two methods were 1.3 (LR), 1.4 (CC) and 1.4 mm (AP) systematically and 1.0, 1.1 and 1.2mm randomly. This automatic method had a success rate of 91%. The limits of agreement between the registration method for non-attached tumors and the clinical method were larger with-6.0-4.1mm (LR),-8.5-7.1mm (CC) and-3.3-4.3mm (AP). The alignment differences between these two methods were 4.0 (LR), 3.9 (CC) and 3.6mm (AP) systematically and 4.0, 3.3 and 2.4mm randomly. The success rate of these automatic registrations was 100%. Conclusions: The registration method developed for regressing tumors attached to surrounding structures proved to be a reliable method for automatic tumor registration. The registration method for regressing non-attached tumors is promising but needs further investigation on a larger patient cohort.
Radiotherapy and Oncology, 2015
Purpose/Objective: In the framework of the EMRP-funded project 'Metrology for radiotherapy using ... more Purpose/Objective: In the framework of the EMRP-funded project 'Metrology for radiotherapy using complex radiation fields' (MetrExtRT), ENEA-INMRI has developed a new graphite calorimeter which, positioned in a water-phantom, allows the realization of absorbed-dose-to-water unit (Dw) for mediumenergy x-ray beams. Materials and Methods: According to a nested design, the innermost graphite body, the disc-shaped core of 21 mm diameter, 2 mm thickness, and weighing 1.14 grams, is surrounded by a 0.5 mm-thick vacuum gap and then by a second graphite body, the jacket, having the same heat capacity as the core. The jacket is surrounded by an additional 0.5 mm-thick vacuum gap and then by a third graphite body (the shield) which acts as a thermal buffer to improve the core thermal insulation. Results: Repeated measurements of absorbed dose to water in filtered x-rays qualities put a preliminary estimate of the combined standard uncertainty to a value of 1.8% (k=1). Conclusions: The ENEA-INMRI calorimeter is the first Dw standard built for measurements in medium energy x-rays based on graphite calorimetry, and is therefore expected to improve the robustness of the existing Dw primary standards system. The calorimeter is participating in an EURAMET absorbed dose to water indirect comparison and, upon successful completion, it will become the Italian national standard for absorbed dose to water in medium-energy x-ray beams.
Radiotherapy and Oncology, 2015
shifts in AP and SI directions, both with the largest shift of ± 1.2 cm, while the corresponding ... more shifts in AP and SI directions, both with the largest shift of ± 1.2 cm, while the corresponding result for the relative shifts in the LR directions where +0.5 cm (Figure 1b). The number of shifts > ± 0.3 cm was 31 %, 28% and 12 % in the AP, SI and LR directions respectively. The systematic (∑) error based on the difference between the bony and soft tissue registration were 0.4 cm, 0.3 cm and 0.2 cm in the AP, SI and LR directions respectively. The corresponding random (σ) errors were 0.2 cm (AP), 0.2 cm (SI) and 0.1 cm (LR). Using bony structures as surrogate for the tumour (ITV) requires an AP margin of 1.1 cm, SI margin of 0.9 cm and LR margin of 0.5 cm (Table I), calculated according to the Van Herk formula (Seminars in Radiation and Oncology, 2004). Conclusions: Large differences between bony and soft tissue registrations were revealed, and the use of bony structures as a surrogate for the tumour would result in a setup margin of 1.1 cm, 0.9 cm and 0.5 cm in AP, SI and LR directions, respectively. We concluded that the bony structures in the spine seem to be inappropriate as a surrogate for the tumour in lung stereotactic radiotherapy treatments. EP-1670 Does the use of an endorectal balloon stabilise the rectum for patients receiving prostate radiotherapy?
Radiotherapy and Oncology, 2015
3rd ESTRO Forum 2015 S73 achieve 0.5% uncertainty in relative measurements are determined based o... more 3rd ESTRO Forum 2015 S73 achieve 0.5% uncertainty in relative measurements are determined based on uncertainty analysis including data covariance. Systematic errors are compared to the statistical behaviour of pixel dose. Results: Comparing single and multichannel methods demonstrate significant reduction of systematic errors (Figure 1). Uncertainties in determining output factors with the proposed procedure are 1.2% for single measurements and 0.4% for measurements repeated ten times. Consistency in determining dose distributions of known beams show systematic errors up to 10% with single channel analysis, while they are on average diminished by a factor up to three with the new multichannel method, leaving these errors well below statistical uncertainties. Conclusions: Results suggest that once a controlled experimental procedure and proper analysis are combined, radiochromic film has great potential for small photon field dosimetry. The proposed method allows uncertainties in quality correction factors comparable to previous film models. Future comparison between experiments and Monte Carlo simulations should validate the theoretical predictions reported herein by evaluating the energy dependence of the film response.
Radiotherapy and Oncology, 2017
Radiotherapy and Oncology, 2011
Metrologia, 2012
A chemical vapour deposition diamond detector fabricated at Rome 'Tor Vergata' University was inv... more A chemical vapour deposition diamond detector fabricated at Rome 'Tor Vergata' University was investigated for its applicability as transfer dosimeter in radiotherapy photon beams with small field sizes. The detector consists of a single crystal diamond with a very small sensitive volume (0.004 mm 3). The detector showed a measurement repeatability of 0.1% and a long term reproducibility of 0.4%. Monte Carlo simulations revealed a response dependence on the photon beam energy of about 2% from the 60 Co quality to 10 MV photon beam. The calculated detector response was found to be independent of field size within 0.5% from 10 cm × 10 cm to 2 cm × 2 cm beam size for both 6 MV and 10 MV photon beams, increasing in smaller field sizes. D w values obtained by the diamond detector were found to be in agreement with D w values obtained by a small volume ionization chamber in photon beams with field size down to 2 cm × 2 cm.
Radiotherapy and Oncology, 2020
Radiotherapy and Oncology, 2020
Radiotherapy and Oncology, 2019
Radiation Oncology, 2018
Background: Monte Carlo simulations were run to estimate the dose variations generated by thediff... more Background: Monte Carlo simulations were run to estimate the dose variations generated by thedifference arising from the chemical composition of the tissues. Methods: CT datasets of five breast cancer patients were selected. Mammary gland was delineated as clinical target volume CTV, as well as CTV_lob and CTV_fat, being the lobular and fat fractions of the entire mammary gland. Patients were planned for volumetric modulated arc therapy technique, optimized in the Varian Eclipse treatment planning system. CT, structures and plans were imported in PRIMO, based on Monte Carlo code Penelope, to run three simulations: AdiMus, where the adipose and muscle tissues were automatically assigned to fat and lobular fractions of the breast; Adi and Mus, where adipose and muscle, respectively were assigned to the whole mammary gland. The specific tissue density was kept identical from the CT dataset. Differences in mean doses in the CTV_lob and CTV_fat structures were evaluated for the different tissue assignments. Differences generated by the tissue composition and estimated by Acuros dose calculations in Eclipse were also analysed. Results: From Monte Carlo simulations, the dose in the lobular fraction of the breast, when adipose tissue is assigned in place of muscle, is overestimated by 1.25 ± 0.45%; the dose in the fat fraction of the breast with muscle tissue assignment is underestimated by 1.14 ± 0.51%. Acuros showed an overestimation of 0.98 ± 0.06% and an underestimation of 0.21 ± 0.14% in the lobular and fat portions, respectively. Reason of this dissimilarity resides in the fact that the two calculations, Monte Carlo and Acuros, differently manage the range of CT numbers and the material assignments, having Acuros an overlapping range, where two tissues are both present in defined proportions. Conclusion: Although not clinically significant, the dose deposition difference in the lobular and connective fat fraction of the breast tissue lead to an improved knowledge of the possible dose distribution and homogeneity in the breast radiation treatment.
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Papers by Antonella Stravato