Survey on the interest and commitment of AIFM members to scientific activities (SicAS) - The initiative of the FutuRuS working group.

PURPOSE: The "FutuRuS" working group of the Italian Association of Medical Physics and Health Physics (AIFM) designed a survey (SicAS) to get feedback from its members regarding their interests and their experience in taking part in scientific activities and events, with the objective of focusing future efforts of the AIFM towards increasing the scientific activity of the medical physics expert (MPE). METHODS: SicAS was sent out in March 2022 to all AIFM members by newsletter and official communication. SicAS was structured into three sections: personal information and institution of affiliation information, involvement in scientific activities, interest in and commitment to scientific activities. Responses were collected in a fully anonymised mode from the Google Forms platform and analysed with descriptive statistics. RESULTS: Out of 1289 members (active at the end of 2021), 467 responded to the Survey (response rate of 36%). The Survey results highlighted that AIFM members ranked the involvement of the MPE in scientific activities as highly relevant to the profession. However, 34.7% indicated devoting less than 10% of their working time to scientific activities. 67.5% of the respondents were dissatisfied with the time spent on scientific activities. The primary barrier was the lack of time (77%), followed by a lack of mentoring (32%). CONCLUSIONS: SicAS highlighted the need for AIFM initiatives to support members' scientific activities. National societies should help develop and support networks between members, create links among universities, hospitals, research institutions and industries, and provide guidelines and learning platforms for enhancing the MPEs' involvement in scientific activities.

Image quality and dose evaluation of MVCT TomoTherapy acquisitions: A phantom study.

BACKGROUND: The aim of this study is to evaluate the dose delivered and the image quality of pre-treatment MVCT images with Hi-Art TomoTherapy system, varying acquisition and reconstruction parameters. MATERIALS AND METHODS: Catphan 500 MVCT images were acquired with all acquisition pitch and reconstruction intervals; image quality was evaluated in terms of noise, uniformity, contrast linearity, contrast-to-noise ratio (CNR) and spatial resolution with the Modulation Transfer Function (MTF). Dose was evaluated as Multi Slice Average Dose (MSADw) and measurements were performed with the Standard TomoTherapy® Quality Assurance Kit composed by the TomoTherapy Phantom, the Exradin A1SL ion chamber and TomoElectrometer. For each pitch-reconstruction interval, acquisitions were repeated 5 times. RESULTS: Differences in noise and uniformity, though statistically significant in some cases, were very small: noise ranged from 2.3% for Coarse - 3 mm to 2.4% for Coarse - 6 mm, while uniformity passed from 99.5% for Coarse - 6 mm to 99.8% for Normal - 4 mm. No differences at all were found for CNR for high and low density inserts, while MTF was higher for pitch Coarse, even if no differences in spatial resolution were observed visually (spatial resolution was up to 4 lp/cm for all combinations of pitch and reconstruction interval). Dose was dependent on pitch, being 1.0 cGy for Coarse, 1.5 cGy for Normal and 2.85 cGy for Fine. CONCLUSIONS: We observed negligible differences in image quality among different pitch and reconstruction interval, thus, considerations regarding pre-treatment imaging modalities should be based only on dose delivered and on the desired resolution along the cranio-caudal axis for image-guided radiotherapy and adaptive radiotherapy purposes.

Impact of image guidance on toxicity and tumour outcome in moderately hypofractionated external-beam radiotherapy for prostate cancer.

To report toxicity and efficacy outcome of moderately hypofractionated image-guided external-beam radiotherapy in a large series of patients treated for prostate cancer (PCa). Between 10/2006 and 12/2015, 572 T1-T3N0M0 PCa patients received 70.2 Gy in 26 fractions at 2.7 Gy/fraction: 344 patients (60%) with three-dimensional conformal radiotherapy (3D-CRT) and 228 (40%) with intensity-modulated radiotherapy (IMRT). Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria and Houston definition (nadir + 2) were used for toxicity and biochemical failure evaluation, respectively. Median age was 74 years (interquartile range 69-77). Compared with 3D-CRT, in IMRT group more high-risk patients (29% vs 18%; P = 0.002) and more high-volume target (75% vs 60%; P < 0.001) were included. Acute gastro-intestinal (GI) toxicity G > 1 were registered in 8% and in 11% IMRT and 3D-CRT patients, respectively, whereas late GI G > 1 were observed in 2% and 16% IMRT and 3D-CRT patients, respectively. Acute genito-urinary (GU) toxicity G > 1 were registered in 26% and 40% IMRT and 3D-CRT patients, respectively, whereas late GU G > 1 occurred in 5% IMRT and 15% 3D-CRT patients. Multivariate proportional hazard Cox models confirmed significantly greater risk of late toxicity with 3D-CRT compared to IMRT for GU > 1 (P = 0.004) and for GI > 1 (P < 0.001). With a median 4-year follow-up, overall survival (OS), clinical progression-free survival (cPFS) and biochemical PFS (bPFS) for the whole series were 91%, 92% and 91%, respectively. cPFS and bPFS were significantly different by risk groups. Multivariate Cox models for bPFS and cPFS showed no difference between irradiation techniques and a significant impact of risk group and initial PSA. Moderately hypofractionated radiotherapy is a viable treatment option for localized PCa with excellent tumour control and satisfactory toxicity profile. IMRT seems associated with a reduction in toxicity, whereas tumour control was equal between IMRT and 3D-CRT patients and depended mainly on the risk category.

VERO® radiotherapy for low burden cancer: 789 patients with 957 lesions.

PURPOSE: The aim of this retrospective study is to evaluate patient profile, feasibility, and acute toxicity of RadioTherapy (RT) delivered by VERO® in the first 20 months of clinical activity. METHODS: Inclusion criteria: 1) adult patients; 2) limited volume cancer (M0 or oligometastatic); 3) small extracranial lesions; 4) treatment between April 2012 and December 2013 and 5) written informed consent. Two techniques were employed: intensity modulated radiotherapy (IMRT) and stereotactic body radiotherapy (SBRT). Toxicity was evaluated using Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer (RTOG/EORTC) criteria. RESULTS: Between April 2012 and December 2013, 789 consecutive patients (957 lesions) were treated. In 84% of them one lesion was treated and in 16% more than one lesion were treated synchronously/metachronously; first radiotherapy course in 85%, re-irradiation in 13%, and boost in 2% of cases. The treated region included pelvis 46%, thorax 38%, upper abdomen 15%, and neck 1%. Radiotherapy schedules included <5 and >5 fractions in 75% and 25% respectively. All patients completed the planned treatment and an acceptable acute toxicity was observed. CONCLUSIONS: RT delivered by VERO® was administrated predominantly to thoracic and pelvic lesions (lung and urologic tumours) using hypofractionation. It is a feasible approach for limited burden cancer offering short and well accepted treatment with favourable acute toxicity profile. Further investigation including dose escalation and other available VERO® functionalities such as real-time dynamic tumour tracking is warranted in order to fully evaluate this innovative radiotherapy system.

Salvage image-guided intensity modulated or stereotactic body reirradiation of local recurrence of prostate cancer.

OBJECTIVE: To retrospectively evaluate external beam reirradiation (re-EBRT) delivered to the prostate/prostatic bed for local recurrence, after radical or adjuvant/salvage radiotherapy (RT). METHODS: 32 patients received re-EBRT between February 2008 and October 2013. All patients had clinical/radiological local relapse in the prostate or prostatic bed and no distant metastasis. re-EBRT was delivered with selective RT technologies [stereotactic RT including CyberKnife(TM) (Accuray, Sunnyvale, CA); image-guidance and intensity-modulated RT etc.]. Toxicity was evaluated using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria. Biochemical control was assessed according to the Phoenix definition (NADIR + 2 ng ml(-1)). RESULTS: Acute urinary toxicity: G0, 24 patients; G1, 6 patients; G2, 2 patients. Acute rectal toxicity: G0, 28 patients; G1, 2 patients; and G2, 1 patient. Late urinary toxicity (evaluated in 30 cases): G0, 23 patients; G1, 6 patients; G2, 1 patient. Late renal toxicity: G0, 25 patients; G1, 5 patients. A mean follow-up of 21.3 months after re-EBRT showed that 13 patients were free of cancer, 3 were alive with biochemical relapse and 12 patients were alive with clinically evident disease. Four patients had died: two of disease progression and two of other causes. CONCLUSION: re-EBRT using modern technology is a feasible approach for local prostate cancer recurrence offering 2-year tumour control in about half of the patients. Toxicity of re-EBRT is low. Future studies are needed to identify the patients who would benefit most from this treatment. ADVANCES IN KNOWLEDGE: Our series, based on experience in one hospital alone, shows that re-EBRT for local relapse of prostate cancer is feasible and offers a 2-year cure in about half of the patients.

Intraprostatic fiducial markers: a potential application for ultrasound-guided radiotherapy in prostate cancer.

We report on a two-phase test performed to assess the ability of the ultrasound-based B-mode acquisition and targeting (BAT) trans-abdominal system to identify non-dedicated fiducial markers implanted into the prostate gland for subsequent image-guided radiotherapy.Although further investigation is warranted in order to identify the optimal echogenic marker and to define its potential use for image-guided radiotherapy in prostate cancer patients, we demonstrate the feasibility of the BAT system for the visualization of non-ultrasound-dedicated markers.

Genetic evolutionary taboo search for optimal marker placement in infrared patient setup.

In infrared patient setup adequate selection of the external fiducial configuration is required for compensating inner target displacements (target registration error, TRE). Genetic algorithms (GA) and taboo search (TS) were applied in a newly designed approach to optimal marker placement: the genetic evolutionary taboo search (GETS) algorithm. In the GETS paradigm, multiple solutions are simultaneously tested in a stochastic evolutionary scheme, where taboo-based decision making and adaptive memory guide the optimization process. The GETS algorithm was tested on a group of ten prostate patients, to be compared to standard optimization and to randomly selected configurations. The changes in the optimal marker configuration, when TRE is minimized for OARs, were specifically examined. Optimal GETS configurations ensured a 26.5% mean decrease in the TRE value, versus 19.4% for conventional quasi-Newton optimization. Common features in GETS marker configurations were highlighted in the dataset of ten patients, even when multiple runs of the stochastic algorithm were performed. Including OARs in TRE minimization did not considerably affect the spatial distribution of GETS marker configurations. In conclusion, the GETS algorithm proved to be highly effective in solving the optimal marker placement problem. Further work is needed to embed site-specific deformation models in the optimization process.

Irradiation with standard tangential breast fields in patients treated with conservative surgery and sentinel node biopsy: using a three-dimensional tool to evaluate the first level coverage of the axillary nodes.

Recent data show that axillary coverage can be obtained, but only through a selective CT-based treatment planning, as standard tangential fields are inadequate to deliver therapeutic doses. Currently, the replacement of axillary dissection with new techniques, such as sentinel node (SN) biopsy, makes it necessary to re-address the question about the real role of axillary irradiation, complicated by the differences in the anatomy of dissected and undissected axillary regions. The purpose of this paper is the dosimetric analysis of first axillary level coverage in standard irradiation of 15 breast-cancer patients treated with quadrantectomy and SN biopsy (negative finding). During surgery a clip on the site of the SN was positioned, marking the caudal margin of first axillary level. After the breast treatment plan was completed, the first axillary level was contoured on CT scans, from the site of the surgical clip up to the sternal manubrium, for coverage analysis with dose-volume histograms (DVHs) and three-dimensional isodose visualization. The maximum dose mean ranged from 5% to 80% of the prescribed dose (mean value 48.7%). The mean total dose received by the volume of interest was lower than 40 Gy in all but one patient. No patient had total irradiation of first nodal level; only one patient had 35% of the volume enclosed in the 100% isodose. Our analysis lead to the conclusion that therapeutic doses are not really delivered to first level axillary level nodes by a standard tangential field technique, and that specific treatment planning and beam arrangement are required when adequate coverage is necessary.

Intraoperative radiation therapy with electrons (ELIOT) in early-stage breast cancer.

Local recurrences after breast-conserving surgery occur mostly in the quadrant harbouring primary carcinoma. The main objective of postoperative radiotherapy should be the sterilisation of residual cancer cells in the operative area while irradiation of the whole breast may be avoided. We have developed a new technique of intraoperative radiotherapy of a breast quadrant after the removal of the primary carcinoma (ELIOT). A mobile linear accelerator with a robotic arm is utilised delivering electron beams able to produce energies from 3 to 9 MeV. Different dose levels were tested from 10 to 21 Gy without important side effects. A randomized trial is currently ongoing in order to compare conventional irradiation and ELIOT. More than 400 patients have been enrolled. In addition a new approach for nipple and areola complex conservation, including ELIOT, is under investigation.

Output ratios in a miniphantom for asymmetric fields shaped by a multileaf collimator.

The integrated GE multileaf collimator (MLC) provides the ability to achieve 'double' asymmetric fields: each of the 64 leaves allow an over-axis travel of 10 cm and the Y-jaws allow 20 cm. A formalism has recently been proposed by the authors to calculate the output ratio in a miniphantom for this type of MLC by the product of independent leaf and jaw correction factors. The original proposed formalism was restricted to regular or irregular fields including the collimator rotational axis. Introducing 'reduced coordinates' for the correction factors in the present work this formalism is extended to asymmetric fields where central leaves or jaws overlap the collimator axis. The extended formalism is applied to asymmetric square, rectangular and irregular fields. For all fields checked at a given off-axis position, measured and calculated output ratios agree within 1% for 6, 18 and 25 MV photon beams. To relate output ratios normalized to off-axis points with output ratios on-axis, off-axis ratios are derived from film and miniphantom measurements. Both off-axis ratios agree to within 1% for 6 and 25 MV photon beams; a maximum deviation of 1.3% is observed at 18 MV. Calculated products of output ratios and off-axis ratios derived from films are compared with measurements for asymmetric square, rectangular and irregular fields, and agree mostly within 1% for all energies checked; maximum deviations of 1.3 and 1.6% are observed for 6 and 18 MV photon beams.

Measurements of basic parameters in wedged high-energy photon beams using a mini-phantom.

Basic dosimetric quantities necessary to specify wedged beans (beam quality, wedge factors, output ratios) are obtained by measurements performed in a narrow coaxial mini-phantom for 6, 18 and 15 MV photon beams. To express beam quality, an attenuation coefficient mu is derived from measurements in a mini-phantom at 20 and 10 cm depth. Wedge factors and output ratios are measured as a function of field size at 10 cm water-equivalent depth. In open beams one observes beam softening with increasing distance from the collimator axis for all energies. With an inserted wedge a beam hardening is observed at 6 MV. This beam hardening decreases at 18 MV while at 25 MV a slight beam softening is detected. Larger variations of output ratios with field sizes are observed with a wedge than without a wedge. An equivalent square formula for head-scatter factors can be used with a good accuracy for rectangular wedged fields. For irregular wedged fields a method is proposed to calculate the product of the output ratio and the wedge factor. Measurements and calculations agree within 1% for all irregular wedged fields checked.

Thyroid hormones and atrial natriuretic hormone secretion: study in hyper- and hypothyroid patients.

Plasma atrial natriuretic hormone (ANH) values were evaluated in 28 hyperthyroid patients and in 11 hypothyroid patients and compared with 20 healthy subjects. In hyperthyroid patients plasma ANH basal levels were significantly (p less than 0.01) higher (14.2 +/- 1.6 pmol/l) than in controls (7.8 +/- 0.4 pmol/l) and in hypothyroid patients (6.4 +/- 0.3 pmol/l). No significant differences were found between controls and hypothyroid patients. The propranolol-induced decrease in heart rate in hyperthyroid patients did not significantly affect the plasma ANH values. Conversely, after the methimazole-induced euthyroidism a return within the normal range of ANH values was observed. The thyroxine replacement in hypothyroid patients determined a small but significant (p less than 0.05) increase in plasma ANH values. Observed data suggest that in humans thyroid hormones may influence plasma ANH concentrations independently of their effect on heart rate.

[Hormone profile of hypothyroidism in an area of the Central African Republic with endemic goiter]. / Quadri ormonologici dell'ipotiroidismo in un'area della Repubblica Centro Africana affetta da endemia gozzigena.

In the Ouham region of Centro African Republic, one of the present Authors (B.P.) described a severe goiter endemia due to marked iodine deficiency and high daily intake of manioc as staple food. In the present study serum TSH, T3 and T4 of 233 subjects were determined; 150 of them lived in rural villages (Group 1) and 83 lived in Bocaranga, chief town of the province (Group 2). The blood samples done contemporaneously to the epidemiological survey, were strictly randomized in the population examined. The subjects of each group were divided in 4 sub-groups: A) with TSH, T3 and T4 in normal range; B) with elevated TSH; C) with elevated TSH and sub-normal T4; D) with elevated TSH and sub-normal T3 and T4. An apparently euthyroid pattern of TSH, T3 and T4 was evident in only 60 subjects (19.3% from group 1; 37.35% from group 2); the remaining 173 (80.67% from group 1; 62.65% from group 2) were hypothyroid (subclinical in the sub-group B; mild in the sub-group C; overt in the sub-group D). The mean hormonal values of the apparently euthyroid subjects (sub-group A) in the villages and in the chief town, were significantly different (p less than 0.05) from the control values of our laboratory. More significant differences were clearly evident between the control values and the mean values of sub-groups B, C and D in each of the two groups (1 villages; 2 chief town).(ABSTRACT TRUNCATED AT 250 WORDS)

[Thyroid hormone profiles in goitrous and non-goitrous subjects seen in an endemic goiter area of the Central African Republic]. / Quadri ormonali tiroidei di soggetti gozzuti e non gozzuti osservati in un' area di endemia gozzigena della Repubblica Centro Africana.

In the present study T3, T4, TSH serum concentrations were measured in 166 subjects whose goiter grading was ascertained according to WHO classification; 39 of them had no goiter (grading 0), 127 were goitrous with a grading comprised between 1a and 4. The two samples were composed by Males and Females of various ages whose choice was strictly predetermined by random numbers. The median ages of 127 goitrous and 39 non goitrous subjects were respectively 23.5 years and 33.5 years; 30 Males and 5 Females were in the first group; 58 Males and 69 Females in the second. They lived in the Ouham region of Centro African Republic where some of the Authors ascertained a severe goiter endemia due to iodine deficiency and manioc consumption as staple food. All the values of T4 and TSH of the two group of subjects, were significantly different from the control values (p less than 0.01) excepting T3. Goitrous subjects had T4 value lower than non goitrous subjects (p less than 0.05). The subjects of each group were distributed in the four subsequent subgroups: A) with T3, T4, TSH in the normal range; B) with elevated TSH and T3 and T4 in normal range; C) with elevated TSH, subnormal T4, and T3 in normal range; D) with elevated TSH and subnormal T3 and T4. From fig. 1 it can be seen that the 79.5% of goitrous subjects had a supranormal TSH (subgroups B + C + D) and 40.7% of them had a subnormal T4 (subgroups C + D).(ABSTRACT TRUNCATED AT 250 WORDS)