•24 centres performed an autoplanning validation for whole breast radiotherapy.•Centers had large variations in case complexity and clinical practices.•A single autoplanning configuration was used ...for all patients and all centres.•Autoplanning was favorable compared to manual, but with large inter-centre variations.•Autoplanning configuration adaptation in some centres may enhance clinician satisfaction.
To present the results of the first multi-centre real-world validation of autoplanning for whole breast irradiation after breast-sparing surgery, encompassing high complexity cases (e.g. with a boost or regional lymph nodes) and a wide range of clinical practices.
The 24 participating centers each included 10 IMRT/VMAT/Tomotherapy patients, previously treated with a manually generated plan (‘manplan’). There were no restrictions regarding case complexity, planning aims, plan evaluation parameters and criteria, fractionation, treatment planning system or treatment machine/technique. In addition to dosimetric comparisons of autoplans with manplans, blinded plan scoring/ranking was conducted by a clinician from the treating center. Autoplanning was performed using a single configuration for all patients in all centres. Deliverability was verified through measurements at delivery units.
Target dosimetry showed comparability, while reductions in OAR dose parameters were 21.4 % for heart Dmean, 16.7 % for ipsilateral lung Dmean, and 101.9 %, 45.5 %, and 35.7 % for contralateral breast D0.03cc, D5% and Dmean, respectively (all p < 0.001). Among the 240 patients included, the clinicians preferred the autoplan for 119 patients, with manplans preferred for 96 cases (p = 0.01). Per centre there were on average 5.0 ± 2.9 (1SD) patients with a preferred autoplan (range 0–10), compared to 4.0 ± 2.7 with a preferred manplan (0,9). No differences were observed regarding deliverability.
The automation significantly reduced the hands-on planning workload compared to manual planning, while also achieving an overall superiority. However, fine-tuning of the autoplanning configuration prior to clinical implementation may be necessary in some centres to enhance clinicians’ satisfaction with the generated autoplans.
Abstract Purpose Triple channel algorithm and specific procedures make more reliable radiochromic dosimetry for treatment planning verification and quality assurance in radiation therapy. A tool to ...obtain radiochromic dose distributions and compare them with the ones resulting from a treatment planning system was developed and applied. Methods The tool was developed as Microsoft Excel macro; it builds dose calibration curves against net optical density of Gafchromic EBT3 film, produces axial, coronal and sagittal dose maps and allows to evaluate them against dose distributions calculated by the Varian treatment planning system Eclipse using gamma index and gamma angle. Results The net optical density standard errors of estimate of calibration curves at 6 MV Varian DBX600 linac energy were 0.2%, 0.4% and 0.2% for the red, green and blue channels. Tests of these curves by means of three independent eight dose points measurement series, at 15 MV and 6 MV Varian 2100C linac and at 6 MV DBX600 linac energies, showed less than 2% of dose errors for the red channel and less than 3% for the green channel in the range 100–450 cGy. The comparisons between dose distributions from Gafchromic EBT3 triple channel algorithm and the ones from Eclipse analytic anisotropic algorithm (AAA) showed values of gamma index 95th percentile between 0.6 and 1.0. Conclusion The obtained results encourage the application of this tool in radiation therapy quality assurance.
Staphylococcus aureus is a very common organism capable of producing several enterotoxins (SEs) that cause intoxication symptoms of varying intensity in humans when ingested through contaminated ...food. This paper reports the results of an investigation on the presence of Coagulase-Positive Staphylococci (CPS) and
S. aureus in several food products marketed in Italy and on food contact surface swabs sampled from the food industry. A total of 11,384 samples were examined and 1971 of them (17.3%) were found to contain CPS. The assays performed on 541 CPS strains led to the identification of 537
S. aureus strains on which characterization of type A, B, C and D staphylococcal enterotoxins (SEA, SEB, SEC and SED) was performed. A total of 298
S. aureus strains (55.5%) produced one or more SEs: 33.9% of the strains produced SEC, 26.5% SEA, 20.5% SEA+SED, 13.4% SED, 2.7% SEB, 1.7% SEA+SEB, 0.7% SEC+SED and 0.3% produced SEA+SEC and SEB+SEC.
The investigation highlighted that these organisms are very common and constitute a potential risk for consumers' health.
The calibration of the newly installed Philips Brilliance Big Bore CT scanner, finding the most appropriate curve (HU vs electron densities) for Varian Eclipse AAA algorithm. FOV dimensions, CT ...voltage, object dimensions and reconstruction filters are the major parameters that can affect the response curve, depending on the particular scanner model. They’ve been studied, and differences respect Varian default curve were evaluated.
The CIRS62M HEAD and BODY phantoms, equipped with low and high densities inserts, of known electron densities were used. Scans were made varying the position of inserts from the centre to the border of the test object, then varying separately CT voltage, FOV, test-object dimensions with respect to FOV, CT protocol (head vs body protocols), with particular attention to reconstruction filters. Test acquisitions regarded both allowed and not-allowed filters (Philips gives general indications about filters to be avoided for planning, cause their effect on HU is not negligible).
CT voltage and FOV dimensions have shown not to influence the response curve. Variability among allowed reconstruction filters is acceptable even for high HU (<2% at 1000 HU), while the not-allowed filters move the HU values till 3% and 12% (at 1000 HU, body and head respectively). With allowed filters, the factor mainly influencing the HU curve has proved to be the object dimension: the head phantom scanned with a body protocol, independently of FOV, (e.g head-and-neck or arm/leg scans) gives differences till 9% at 1000 HU: the head curve should be used.
Measures analysis suggests to create two different curves for planning purposes, with the average data of allowed filters: (1) head and (2) body curves. Varian default curve is much similar to the head one, while differences are not negligible with the body curve extrapolating at very high densities: titanium HU is evaluated 5200 against Varian 5600.▪
MR Open produced by Paramed is an open MRI total body scanner, with a static maximum field of 0,5 T, and a superconducting MgB2 coils system, not requiring a liquid helium bath. A recent installation ...in ASSL Sassari has permitted to investigate the performance of the scanner and a different approach to safety problems.
MGB2 is an intermetallic superconductor (Tc 39 K, instead of about 10 K for Nb-Ti classical magnets) recently used in MRI, through two cryocooling systems exploiting a small amount of helium gas in two closed-loops.
Our MR open has an open magnet, and is equipped with 10 different multichannel coils, addressed to patients’ multiposition and weight-bearing studies, while cardiac and breast studies are not permitted. The scanner is suitable for claustrophobic and wheelchair patients.
A specific quality assurance protocol has been assessed for each coil, according to EUROSPIN, NEMA, and AAPM guidelines. EUROSPIN phantoms have been used in general, but two ESAOTE (not PARAMED) phantoms have proved useful for the smaller coils.
The amount of helium was judged safe: even in case of total dispersion, oxygen level wouldn’t drop down 20,6%: unexpected quench problems are substantially fictitious, no quench line and oxygen sensor are needed. Magnetic fringe field is quite high. The possibility to quickly switch off the static field should be managed carefully, even in case of accident: the hazard of high induced currents should be considered.
The quality parameters resulted within AAPM tolerances for all the coils, SNR values were determined according to NEMA and kept as reference, maximum ghosting resulted in 2,5%, higher than usual.
Safety and QA protocols must be fit to the particular facility.
The comprehensive phantom set resulted quite appropriate, except for the spatial resolution with small coils (only 2 mm possible measure). Ghost is generally not negligible.
To evaluate and compare 2D images data coming from 4 identical digital mammography units, with the exception of the AEC (Automatic-Exposure-Control) calibration curve, and to verify the need to ...standardize the procedures.
In ASSL Sassari hospital, 3 Hologic Selenia Dimensions mammography units have been recently installed.
During acceptance tests, evaluating at first the dose and CNR at different thicknesses and minimum detectable diameter results, we chose the same calibration curves (appointed “4” by owner) for the new units (M1-M2-M3), while we had already entered another curve (appointed “0” by owner) for the fourth machine (M4 -AOU Sassari) installed in 2011.
We extracted patients’ data stored in PACS through OpenRem, a free software developed by NHS (National Health Institute). We analyzed more than 2600 patients’ data, making statistics on AGD, age, breast thickness and compression force.
You can see in the table below the ESAKs and CNRs calculated on the PMMA slabs. Even if the curve ”4” brings to higher doses for major than 60 mm breast thicknesses, these are well below achievable EUREF limits, and the gain in terms of CNR and detectability is high.
In the boxplot you can see the results on the AGD patients’ data calculated by the machine; the data shown concern the thickness of the patients’ breast over 60 mm to better highlight the differences in AGD between the three twin machines and M4.
The possible influence of different thicknesses distributions between the 4 machines has been evaluated through t-test, which results are compatible with the null hypothesis.
With the aim to improve image quality while keeping dose below EUREF limits, our next step will be to set the curve “4” on the M4 mammograph and indicate a minimum threshold for the compression force to further improve image quality. Display omitted
