Search

Purpose: Contrast-enhanced mammography (CEM) is an innovative imaging tool for breast cancer detection, involving intravenous injection of a contrast medium and the assessment of lesion enhancement in two phases: early and delayed. The aim of the study was to analyze the topographic concordance of lesions detected in the early- versus delayed phase acquisitions. Materials and methods: Approved by the Ethics Committee (No. 118/20), this prospective study included 100 women with histopathological confirmed breast neoplasia (B6) at the Radiodiagnostics Department of the Maggiore della Carità Hospital of Novara, Italy from May 1, 2021, to October 17, 2022. Participants underwent CEM examinations using a complete protocol, encompassing both early- and delayed image acquisitions. Three experienced radiologists blindly analyzed the CEM images for contrast enhancement to determine the topographic concordance of the identified lesions. Two readers assessed the complete study (protocol A), while one reader assessed the protocol without the delayed phase (protocol B). The average glandular dose (AGD) of the entire procedure was also evaluated. Results: The analysis demonstrated high concordance among the three readers in the topographical identification of lesions within individual quadrants of both breasts, with a Cohen's κ > 0.75, except for the lower inner quadrant of the right breast and the retro-areolar region of the left breast. The mean whole AGD was 29.2 mGy. The mean AGD due to CEM amounted to 73% of the whole AGD (21.2 mGy). The AGD attributable to the delayed phase of CEM contributed to 36% of the whole AGD (10.5 mGy). Conclusions: As we found no significant discrepancy between the readings of the two protocols, we conclude that delayed-phase image acquisition in CEM does not provide essential diagnostic benefits for effective disease management. Instead, it contributes to unnecessary radiation exposure. [ABSTRACT FROM AUTHOR]

• Factors for deriving effective and organ doses from P KA has been established in neurointerventional procedures. • Conversion factors were determined by considering different centres and angiographic equipment. • The conversion factors provide accurate estimates of effective and organ doses in neurointerventional procedures. • Significant reduction of patient exposure has been made possible thanks to the new technology. Radiation doses to adult patients submitted to cerebral angiography and intracranial aneurysms treatments were assessed by using DICOM Radiation Dose Structured Reports (RDSR) and Monte Carlo simulations. Conversion factors to estimate effective and organ doses from Kerma-Area Product (P KA) values were determined. 77 cerebral procedures performed with five angiographic equipment installed in three Italian centres were analyzed. Local settings and acquisition protocols were considered. The geometrical, technical and dosimetric data of 16,244 irradiation events (13305 fluoroscopy, 2811 digital subtraction angiography, 128 cone-beam CT) were extracted from RDSRs by local dose monitoring systems and were input in MonteCarlo PCXMC software to calculate effective and organ doses. Finally, conversion factors to determine effective and organ doses from P KA were determined. Differences between centres were assessed through statistical analysis and accuracy of dose calculation method based on conversion factors was assessed through Bland-Altman analysis. Large variations in P KA (14–561 Gycm2) and effective dose (1.2–73.5 mSv) were observed due to different degrees of complexity in the procedures and angiographic system technology. The most exposed organs were brain, salivary glands, oral mucosa, thyroid and skeleton. The study highlights the importance of recent technology in reducing patient exposure (about fourfold, even more in DSA). No statistically significant difference was observed in conversion factors between centres, except for some organs. A conversion factor of 0.09 ± 0.02 mSv/Gycm2 was obtained for effective dose. Organ and effective doses were assessed for neuro-interventional procedures. Conversion factors for calculating effective and organ doses from P KA were provided. [ABSTRACT FROM AUTHOR]

Abstract Background FDG-PET/CT imaging has an emerging role in staging and treatment planning of various tumor locations and a number of literature studies show that also the carcinoma of the anal canal may benefit from this diagnostic approach. We analyzed the potential impact of FDG-PET/CT in stage definition and target volume delineation of patients affected by carcinoma of the anal canal and candidates for curative radiotherapy. Methods Twenty seven patients with biopsy proven anal carcinoma were enrolled. Pathology was squamous cell carcinoma in 20 cases, cloacogenic carcinoma in 3, adenocarcinoma in 2, and basal cell carcinoma in 2. Simulation was performed by PET/CT imaging with patient in treatment position. Gross Tumor Volume (GTV) and Clinical Target Volume (CTV) were drawn on CT and on PET/CT fused images. PET-GTV and PET-CTV were respectively compared to CT-GTV and CT-CTV by Wilcoxon rank test for paired data. Results PET/CT fused images led to change the stage in 5/27 cases (18.5%): 3 cases from N0 to N2 and 2 from M0 to M1 leading to change the treatment intent from curative to palliative in a case. Based on PET/CT imaging, GTV and CTV contours changed in 15/27 (55.6%) and in 10/27 cases (37.0%) respectively. PET-GTV and PET-CTV resulted significantly smaller than CT-GTV (p = 1.2 × 10-4) and CT-CTV (p = 2.9 × 10-4). PET/CT-GTV and PET/CT-CTV, that were used for clinical purposes, were significantly greater than CT-GTV (p = 6 × 10-5) and CT-CTV (p = 6 × 10-5). Conclusions FDG-PET/CT has a potential relevant impact in staging and target volume delineation of the carcinoma of the anal canal. Clinical stage variation occurred in 18.5% of cases with change of treatment intent in 3.7%. The GTV and the CTV changed in shape and in size based on PET/CT imaging.

Objective: To assess the cumulated exposure to radiation due to imaging in Hodgkin (HL) and diffuse large B‐cell (DLBCL) lymphoma patients who were not submitted to radiotherapy. Methods: The study population included 51 and 83 adult patients with HL and DLBCL, with a follow‐up duration >1 year. The cumulated exposure was expressed using patient‐specific data as cumulated effective dose (CED). Results: Fifty‐one HL patients (median age 47 years) were followed for a median of 3.5 years. The median total CED per subject was 104 mSv. CT and PET/CT examinations accounted for 75 and 25% of the total CED, respectively. 26 patients (49%) had a total CED ≥ 100 mSv and the maximum CED was 302 mSv. Eighty‐three DLBCL patients (median age 66 years) were followed for a median of 3.7 years. The median total CED per subject over the study period was 134 mSv. CT and PET/CT for 86% and 13% of the total CED, respectively. 56 patients (67%) had a total CED ≥100 mSv. The maximum CED was 557 mSv. Conclusion: Our study demonstrated the large number of imaging procedures performed for patients with lymphoma. Overall, 61% of the patients accrued a CED ≥ 100 mSv. Imaging policies were only in a partial agreement with current international guidelines. Advances in knowledge: The cumulated exposure radiation exposure may be of concern in HL patients and the contribution of CT procedures to the total CED is significant. The standardisation of clinical guidelines for managing patients with lymphoma is warranted. [ABSTRACT FROM AUTHOR]

Background: FDG-PET/CT imaging has an emerging role in staging and treatment planning of various tumor locations and a number of literature studies show that also the carcinoma of the anal canal may benefit from this diagnostic approach. We analyzed the potential impact of FDG-PET/CT in stage definition and target volume delineation of patients affected by carcinoma of the anal canal and candidates for curative radiotherapy. Methods: Twenty seven patients with biopsy proven anal carcinoma were enrolled. Pathology was squamous cell carcinoma in 20 cases, cloacogenic carcinoma in 3, adenocarcinoma in 2, and basal cell carcinoma in 2. Simulation was performed by PET/CT imaging with patient in treatment position. Gross Tumor Volume (GTV) and Clinical Target Volume (CTV) were drawn on CT and on PET/CT fused images. PET-GTV and PET-CTV were respectively compared to CT-GTV and CT-CTV by Wilcoxon rank test for paired data. Results: PET/CT fused images led to change the stage in 5/27 cases (18.5%): 3 cases from N0 to N2 and 2 from M0 to M1 leading to change the treatment intent from curative to palliative in a case. Based on PET/CT imaging, GTV and CTV contours changed in 15/27 (55.6%) and in 10/27 cases (37.0%) respectively. PET-GTV and PET-CTV resulted significantly smaller than CT-GTV (p = 1.2 ×10-4) and CT-CTV (p = 2.9 ×10-4). PET/ CT-GTV and PET/CT-CTV, that were used for clinical purposes, were significantly greater than CT-GTV (p = 6 × 10-5) and CT-CTV (p = 6 ×10-5). Conclusions: FDG-PET/CT has a potential relevant impact in staging and target volume delineation of the carcinoma of the anal canal. Clinical stage variation occurred in 18.5% of cases with change of treatment intent in 3.7%. The GTV and the CTV changed in shape and in size based on PET/CT imaging. [ABSTRACT FROM AUTHOR]

Purpose: To characterize ordered-subset expectation maximization algorithm with a fixed 3D Gauss post-reconstruction filtering (OSEM) in 99mTc SPECT as for noise, contrast and spatial resolution with varying number of subset and iteration and to compare OSEM with an optimized set of parameters, with filtered backprojection (FBP) with filter parameters typical of brain and myocardial SPECT, both with and without Chang's method of attenuation correction (AC).Methods: SPECT images of a Jaszczak phantom with cold rod inserts, hot and cold spheres and capillary line sources were acquired. Different background activity concentrations of the phantom were simulated as well as different lesion-to-background activity ratios. OSEM reconstructions were halted after 5, 10 and 15 iterations using 4, 8 and 16 subsets.Results: The effect of subset and iteration number over noise is additive: thus, it is possible to define an EM-equivalent iteration number that indicates the product between the subset and the iteration numbers. Noise increases linearly with increasing EM-equivalent iteration number. For each level of nominal contrast, the measured contrast after OSEM shows a little increase with increasing iteration number and saturates after 80 EM-equivalent iterations. The application of AC leads to diminished contrast values both in FBP and OSEM. The contrast of cold lesions after OSEM increases with increasing number of EM-equivalent iteration number: after 80 iterations the contrast values with OSEM overtake the ones obtained with FBP; contrast values diminished as background concentration raised. Resolution values did not change with increasing EM-equivalent iteration number and were higher than those obtained with FBP.Conclusion: The major findings of the present work are the demonstration of additivity of subset and iteration in OSEM over noise, with the possibility of defining an EM equivalent iteration number, and the superiority of OSEM with respect to FBP in terms of spatial resolution. [ABSTRACT FROM AUTHOR]

Purpose According to the EU directive 2013/59, the equipment used for computed tomography (CT) shall be able to inform the practitioner of relevant parameters for assessing the patient dose. Among them, the radiation output is usually displayed in terms of computed tomography dose index – CTDI [mGy]. The aim of this study was to measure the accuracy of the displayed CTDI100 for different manufacturers or models of CT and to assess the impact of acquisition parameters on CTDI100 accuracy. Methods 10 CT from 4 different manufacturers (16-slices n = 6, 32-slices n = 1, 64-slices n = 3) were included in the study. The accuracy of the displayed CTDI100 was checked with a dosimeter with traceable calibration. Reference values for the displayed CTDI100 were derived from the equipment’s manual. The impact of the CT model (16, 64, 128 slices), phantom size (head or body), kVp (80, 100, 120, 140 kVp) and primary collimation (from 1.25 to 40 mm, grouped in four level ⩽ 3, from 3 to ⩽ 10, from 10 to ⩽ 20, > 20 mm) on the accuracy of the displayed CTDI100, was assessed by a four-way factorial ANOVA. CT model, phantom size, kVp and primary collimation, were considered as independent variables (factors) and CTDI accuracy as the dependent variable. Results All the factors had a statistically significant impact on CTDI100 accuracy (p  <  0,05). In a head to head comparison, the lower accuracies were found on average for sixteen channels CT (10  ±  5%), for 80 KV (15  ±  11%) and for thick collimations (13  ±  7%), whilst no significant differences were found between head and body phantoms. Conclusions For sixteen channels CT and acquisition protocols involving the use of head phantom with low KV and thick primary collimation, the inaccuracies of the displayed CTDI can be higher than 20%, which is the suspension level indicated in the EC RP N.162 Publication for the accuracy of indicated dose parameters. This suggests the need of individual calibration of CT X-ray tubes by the manufacters and the necessity of including this check in the quality control programs for CT. [ABSTRACT FROM AUTHOR]

Purpose Internal contamination may occur when unsealed radioactive substances are manipulated for radiopharmaceutical preparation. This work shows the results of internal contamination routine monitoring of workers in a Nuclear Medicine department manipulating Tc99m, I123, I131, In111, F18, Cr51, in a 12-months period. F18 dose preparation was performed through and automatic dose partitioner. Methods Every week and specifically on Friday morning, the most exposed workers to the risk of internal contamination, namely the technician (TEC) working in the hot-lab and the nuclear medicine physician (NMP) devoted to patient injection provided urine samples. Samples were measured for 3600 ″ with a NaI(Tl) scintillation detector, previously calibrated in efficiency. Minimum detectable activities (MDA) were: 1.0, 1.0, 1.7, 2.3, 3.6 and 13.7 Bq for Tc99m, I123, I131, In111, F18 and Cr51, respectively. The intake at the time of contamination was derived from the activity in the urine sample by using biological models in the hypothesis that the contamination happened two days before. The committed effective dose was evaluated by using ICRP coefficients for ingestion. The annual workload of manipulated activity was: 8462, 17, 22, 3, 9600 and 0.3 GBq of Tc99m, I123, I131, In111, F18 and Cr51, respectively. Results For the monitored period, the evaluated intakes were the following: 1.2 10 6 (1.1 10 6 ) Bq, 2.5 10 4 (1.5 10 3 ) Bq, 1.4 10 3 (1.2 10 3 ) Bq, 3.0 10 3 (0) Bq and 1.2 10 3 (2.3 10 2 ) Bq for TEC and (NMP) respectively, corresponding to committed effective doses of 25.3 (24.7) μ Sv, 5.2 (0.3) μ Sv, 31.5 (27.4) μ Sv, 0.9 (

Nowadays interventional cardiac procedures are of concern for the relatively high doses delivered to patients. To estimate the effective dose (E), the organ doses (H t) and the related risk for cancer induction in terms of radiation exposure-induced death (REID) in patients undergoing coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) procedures with radial access. 65 patients underwent CA and PTCA interventions on a Philips Allura XPer FD10 angiographic equipment. For each patient, Xray tube voltage, projection, filtration, field dimensions and DAP were obtained by filming the monitor of the workstation during the entire procedure. E and H t were evaluated by means of the MonteCarlo code PCXMC that models radiation beam and transport in an anthropomorphic phantom, allowing also the evaluation of REID. Mean fluoroscopy time, DAP and E were: 3.1 min, 29.9 Gyxcm2, 9.1 mSv and 8.9 min, 60.9 Gyxcm2, 20.3 mSv for CA and PTCA, respectively; the correlation with DAP was very good in CA (r = 0.99) and in PTCA (r = 0.93). For both CA and PTCA, the most irradiated organs were lungs, oesophagus and red marrow, whose mean H t were 32.5 mSv, 30.7 mSv, 11.6 mSv for CA and 58.5 mSv, 66.7 mSv, 24.9 mSv for PTCA; the highest REIDs were for induction of leukemia (0.04% and 0.08%) and lung cancer (0.14% and 0.20%). Cardiac interventional procedures with radial access improves patient compliance, reduces haemorrhagic complications compared to femoral access with comparable E and Ht values. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to investigate the in vivo drainage of lymphatic spread by using the sentinel node (SN) technique and single-photon emission computed tomography (SPECT)-computed tomography (CT) image fusion, and to analyze the impact of such information on conformal pelvic irradiation. Methods and Materials: Twenty-three prostate cancer patients, candidates for radical prostatectomy already included in a trial studying the SN technique, were enrolled. CT and SPECT images were obtained after intraprostate injection of 115 MBq of 99mTc-nanocolloid, allowing identification of SN and other pelvic lymph nodes. Target and nontarget structures, including lymph nodes identified by SPECT, were drawn on SPECT-CT fusion images. A three-dimensional conformal treatment plan was performed for each patient. Results: Single-photon emission computed tomography lymph nodal uptake was detected in 20 of 23 cases (87%). The SN was inside the pelvic clinical target volume (CTV2) in 16 of 20 cases (80%) and received no less than the prescribed dose in 17 of 20 cases (85%). The most frequent locations of SN outside the CTV2 were the common iliac and presacral lymph nodes. Sixteen of the 32 other lymph nodes (50%) identified by SPECT were found outside the CTV2. Overall, the SN and other intrapelvic lymph nodes identified by SPECT were not included in the CTV2 in 5 of 20 (25%) patients. Conclusions: The study of lymphatic drainage can contribute to a better knowledge of the in vivo potential pattern of lymph node metastasis in prostate cancer and can lead to a modification of treatment volume with consequent optimization of pelvic irradiation. [Copyright &y& Elsevier]

Purpose: To investigate the potential impact of using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) on staging and target volume delineation for patients affected by rectal cancer and candidates for preoperative conformal radiotherapy. Methods and Materials: Twenty-five patients diagnosed with rectal cancer T3–4 N0–1 M0–1 and candidates for preoperative radiotherapy underwent PET/CT simulation after injection of 5.18 MBq/kg of FDG. Clinical stage was reassessed on the basis of FDG-PET/CT findings. The gross tumor volume (GTV) and the clinical target volume (CTV) were delineated first on CT and then on PET/CT images. The PET/CT-GTV and PET/CT-CTV were analyzed and compared with CT-GTV and CT-CTV, respectively. Results: In 4 of 25 cases (24%), PET/CT affected tumor staging or the treatment purpose. In 3 of 25 cases (12%) staged N0 M0, PET/CT showed FDG uptake in regional lymph nodes and in a case also in the liver. In a patient with a single liver metastasis PET/CT detected multiple lesions, changing the treatment intent from curative to palliative. The PET/CT-GTV and PET/CT-CTV were significantly greater than the CT-GTV (p = 0.00013) and CT-CTV (p = 0.00002), respectively. The mean difference between PET/CT-GTV and CT-GTV was 25.4% and between PET/CT-CTV and CT-CTV was 4.1%. Conclusions: Imaging with PET/CT for preoperative radiotherapy of rectal cancer may lead to a change in staging and target volume delineation. Stage variation was observed in 12% of cases and a change of treatment intent in 4%. The GTV and CTV changed significantly, with a mean increase in size of 25% and 4%, respectively. [Copyright &y& Elsevier]