Implementation of a computed tomography dose management program across a multinational healthcare organization.

OBJECTIVES: Radiation dose index monitoring (RDIM) systems may help identify CT dose reduction opportunities, but variability and complexity of imaging procedures make consistent dose optimization and standardization a challenge. This study aimed to investigate the feasibility to standardize and optimize CT protocols through the implementation of a Dose Excellence Program within a European healthcare network. METHODS: The Dose Excellence Program consisted of a multidisciplinary team that developed standardized organizational adult CT protocols and thresholds for relevant radiation dose indices (RDIs). Baseline data were collected retrospectively from the RDIM (Phase I, 2015). Organization's protocols were implemented and monitored from the RDIM for deviations (Phase II, 2016). Following standardization, radiation dose optimization was initiated (Phase III, 2017). Data from the three most used protocols were retrospectively extracted and grouped by country for all phases. The mean number of series (RS) and RDIs were compared between phases and with organizational reference levels. A Mann-Whitney test was conducted; p < .05 was considered as significant. RESULTS: Data from 9588, 12638, and 6093 examinations were analyzed from General Chest, General Head, and Thorax/Abdomen/Pelvis (TAP) multiphase respectively. Overall, after Phase III, mean RS and CTDIvol p75 were below the organizational reference levels in all countries for the three protocols. The CTDIvol decreased by 45% in Switzerland (p < .00001), 32% in Turkey (p < .00001), and 28% in Switzerland (p = .0027) for General Chest, General Head, and TAP multiphase respectively. CONCLUSIONS: The implementation of a Dose Excellence Program within a large-scale healthcare organization allowed unifying protocols and optimizing radiation dose across countries. KEY POINTS: • Engaging a multidisciplinary team can enhance the use of an RDIM system for CT dose management in a multinational healthcare environment. • Deep dive of baseline data and standardization of CT practices by defining organizational clinical indication CT protocols with RPIDs is an essential step before optimization of radiation dose. • Following the implementation of the program, the mean RS and CTDIvol were below or equal to the organizational reference levels in all countries.

Artificial intelligence for reduced dose 18F-FDG PET examinations: a real-world deployment through a standardized framework and business case assessment.

BACKGROUND: To determine whether artificial intelligence (AI) processed PET/CT images of reduced by one-third of 18-F-FDG activity compared to the standard injected dose, were non-inferior to native scans and if so to assess the potential impact of commercialization. MATERIALS AND METHODS: SubtlePET™ AI was introduced in a PET/CT center in Italy. Eligible patients referred for 18F-FDG PET/CT were prospectively enrolled. Administered 18F-FDG was reduced to two-thirds of standard dose. Patients underwent one low-dose CT and two sequential PET scans; "PET-processed" with reduced dose and standard acquisition time, and "PET-native" with an elapsed time to simulate standard acquisition time and dose. PET-processed images were reconstructed using SubtlePET™. PET-native images were defined as the standard of reference. The datasets were anonymized and independently evaluated in random order by four blinded readers. The evaluation included subjective image quality (IQ) assessment, lesion detectability, and assessment of business benefits. RESULTS: From February to April 2020, 61 patients were prospectively enrolled. Subjective IQ was not significantly different between datasets (4.62±0.23, p=0.237) for all scanner models, with "almost perfect" inter-reader agreement. There was no significant difference between datasets in lesions' detectability, target lesion mean SUVmax value, and liver mean SUVmean value (182.75/181.75 [SD:0.71], 9.8/11.4 [SD:1.13], 2.1/1.9 [SD:0.14] respectively). No false-positive lesions were reported in PET-processed examinations. Agreed SubtlePET™ price per examination was 15-20% of FDG savings. CONCLUSION: This is the first real-world study to demonstrate the non-inferiority of AI processed 18F-FDG PET/CT examinations obtained with 66% standard dose and a methodology to define the AI solution price.

Lead exposure in clinical imaging - The elephant in the room.

PURPOSE: Radiation Protection Apparel (RPA) is used during diagnostic imaging and interventional procedures to minimise incidental radiation exposure. The majority of RPA in use are lead-containing, which has until now been considered safe. A recent single-centre study has demonstrated that the external surface of 63 % of RPA was contaminated with lead dust. The purpose of this study was to reproduce this investigation with a larger sample size across Europe and assess whether decontamination procedures were possible. METHOD: The routine RPA Quality Control (QC) process was adapted to include lead dust contamination tests and decontamination if present. The presence of lead dust was determined using a commercially available colorimetric method. RPA that failed initial QC or could not be decontaminated were removed from use. RESULTS: From June to October 2019, 728 RPA from 85 imaging centres from five countries underwent initial QC. Of these, 712 were tested for lead dust contamination which was present on 162 (23 %). Following cleaning, 85 (12 %) remained contaminated and were removed from use. Linear regression analysis shows a significant correlation between type of RPA and contamination, (p = 0.0015). There was no correlation between contamination and imaging department, year of manufacture, country and RPA condition (p-values 0.98, 0.90, 0.94 and 0.14 respectively). CONCLUSIONS: Lead dust contamination is present on 23 % of RPA that would pass routine QC procedures. Approximately half were not amenable to decontamination and were removed from use. Procedures were introduced for the routine handling of RPA, and updated QC steps for assessment and cleaning. Lead-free RPA should be considered.

Effect of Hepatic Perfusion on Microwave Ablation Zones in an Ex Vivo Porcine Liver Model.

PURPOSE: To compare the size of ablation zones derived from nonperfused ex vivo livers with ablation zones created using an ex vivo perfused porcine liver model. MATERIALS AND METHODS: Six fresh porcine livers were used to evaluate microwave ablation (MWA). Perfused (n = 3) and nonperfused (n = 3) livers were warmed to 37°C by oxygenated, O-positive human blood reconstituted with Ringer solution, using an organ perfusion circuit. During MWA, perfusion was discontinued in the nonperfused group and maintained in the perfused group. After MWA (140 watts × 2 min at 2.45 GHz) with the Acculis MTA System (AngioDynamics, Latham, New York), ablation zones were bisected sagittally. Sections were stained with nicotinamide adenine dinucleotide (NADH) and hematoxylin-eosin to assess viability of cells in ablation and marginal zones. RESULTS: Comparison of 22 MWA zones (9 in perfused group, 13 in nonperfused group) was performed. Ablation zones demonstrated a central "white" and peripheral "red" zone. Cells in the white zone were nonviable with no NADH staining. The red zone showed progressive NADH staining toward the periphery, suggesting incomplete cell death. White and red zones of the perfused group were significantly smaller compared with the nonperfused group (short axis, 17.8 mm ± 2.7 vs 21.1 mm ± 3.2, P = .003; long axis, 40.69 mm ± 3.9 vs 39.63 mm ± 5.2, P = .44; intermediate zone,1.33 mm ± 0.04 vs 2.7 mm ± 0.14, P < .0001; mean ± SD). CONCLUSIONS: MWA algorithms provided by this manufacturer are based on nonperfused organ data, which overestimate ablation zone size. Data from perfused liver models may be required for more accurate dosimetry guidelines.

Lung carcinoma with hypertrophic osteoarthropathy in a teenager.

Hypertrophic osteoarthropathy (HOA) characterised by arthralgia, clubbing and periosteal proliferation of long bones, is rarely encountered in children and adolescents. Whereas in adults over 80% of cases are associated with malignancy, in children the majority of cases are due to non-neoplastic causes such as cystic fibrosis, bilary atresia and congenital heart disease. Up to 5% of adults with lung cancer demonstrate signs of HOA. However, lung cancer is extremely uncommon in children and young people. Here we report a case of lung adenocarcinoma in an 18 year old male associated with HOA present both at diagnosis and at subsequent disease progression.

MR imaging of nonmalignant penile lesions.

Magnetic resonance (MR) imaging is potentially useful in the assessment of many benign penile diseases. When T1- and T2-weighted sequences are used, MR imaging can clearly delineate the tunica albuginea and can be used to diagnose penile fracture and Peyronie disease; in both conditions, MR imaging may help refine the surgical approach. It is also useful in cases of priapism; in these cases, intravenously administered contrast material can help assess the viability of the corpora cavernosa and the presence of penile fibrosis. In the assessment of a penile prosthesis, MR imaging provides excellent anatomic information and is the investigation of choice. In the evaluation of erectile dysfunction, MR imaging has limited value, and for urethral stricture, it has not yet proved adequately superior to other modalities to justify its routine use.

MR imaging of prostate after treatment with high-intensity focused ultrasound.

PURPOSE: To prospectively evaluate magnetic resonance (MR) imaging findings after high-intensity focused ultrasound (HIFU) treatment of the prostate and to correlate them with clinical and histologic findings. MATERIALS AND METHODS: Local ethics committee approval and informed consent were obtained. Fifteen consecutive men aged 46-70 years with organ-confined prostate cancer underwent ultrasonographically guided ablation of the whole prostate. Postoperative MR images were obtained within 1 month (12 patients), at 1-3 months (five patients), and in all patients at 6 months. Prostate volume was measured on T2-weighted images, and enhancing tissue was measured on dynamic images after intravenous administration of gadopentetate dimeglumine. Prostate-specific antigen (PSA) level was measured at regular intervals, and transrectal biopsy was performed in each patient at 6 months after treatment. RESULTS: Initial post-HIFU images showed a central nonenhancing area, surrounded by an enhancing rim. At 6 months, the prostate was small (median volume reduction, 61%) and was of predominantly low signal intensity on T2-weighted images. The volume of prostate enhancing on the initial posttreatment image correlated well with serum PSA level nadir (Spearman r = 0.90, P < .001) and with volume at 6 months (Pearson r = 0.80, P = .001). The three patients with the highest volume of enhancing prostate at the initial posttreatment acquisition had persistent cancer at 6-month biopsy. CONCLUSION: MR imaging results of the prostate show a consistent sequence of changes after treatment with HIFU and can provide information to the operator about completeness of treatment.

The incidence of chronic scrotal pain after vasectomy: a prospective audit.

OBJECTIVE: To assess the extent of scrotal pain in men before and after vasectomy, to produce accurate data for the benefit of men considering this procedure, and hence improved informed consent about the outcomes, as chronic scrotal pain after vasectomy is a poorly quantified clinical problem. PATIENTS AND METHODS: Between November 2004 and January 2006 nine surgeons carried out vasectomies in 625 men (mean age 39.9 years, sd 5.6) under local anaesthesia. A questionnaire was devised to establish the presence of any scrotal or testicular pain, and to characterize this discomfort; 6 months after the procedure a modified version of the same questionnaire was administered. RESULTS: In all, 593 (94.7%) men returned the preoperative questionnaires and were entered into the study; 488 (82.2%) of these completed the follow-up questionnaire, giving a mean (sd) follow-up of 6.8 (1.6) months. In all, 65 men reported new-onset scrotal pain at 7 months (14.7%). The mean visual analogue score for this pain was 3.4/10. Four men (0.9%) in the responding group described pain after vasectomy as 'quite severe and noticeably affecting their quality of life'. CONCLUSION: At 7 months after vasectomy about 15% of previously asymptomatic men have some degree of scrotal discomfort. These early data indicate that chronic scrotal pain after vasectomy is a genuine entity, but a longer-term follow-up in this group will be important to allow further evaluation of how this pain develops with time.

Visually directed high-intensity focused ultrasound for organ-confined prostate cancer: A proposed standard for the conduct of therapy.

OBJECTIVE: To propose a standard for the conduct of visually directed transrectal high-intensity focused ultrasound (HIFU) and to offer a formal description of the changes observed on B-mode ultrasonography (US) during this procedure. We describe our early experience of using two different treatment methods; algorithm-based HIFU and visually directed HIFU for the treatment of organ-confined prostate cancer. PATIENTS AND METHODS: Between November 2004 and October 2005, 34 men were treated using the Sonablate-500 (Focus Surgery, Indianapolis, IN, USA) as primary therapy for T1 or T2 prostate cancer. None had had previous hormone therapy and all had > or = 3-month PSA nadirs recorded at the follow-up. Nine men were treated using an algorithm-based protocol (group 1) and 25 using visually directed therapy (group 2). The conduct of visually directed treatment was described and changes seen using B-mode US were categorized using three 'Uchida' grades. RESULTS The mean PSA nadir achieved in group 2 was 0.15 ng/mL, vs 1.51 ng/mL in group 1 (P < 0.005). In group 2, 21 of 25 men achieved PSA nadirs of < or = 0.2 ng/mL 3 months after treatment. Seven men achieved undetectable PSA values. The occurrence rate of treatment-related toxicity was similar in both groups. CONCLUSION: Visually directed, transrectal HIFU enables clinically important and statistically significantly lower PSA nadirs to be achieved than algorithm-based HIFU. This is the first reported experience of visually directed HIFU for the treatment of organ-confined prostate cancer. We think that this is the first attempt to standardize the conduct of therapy; such standardization facilitates teaching it, and makes it possible to derive quality standards. The standardization of the conduct of therapy is a key step in the process of health technology assessment.

The effect of neoadjuvant androgen suppression on prostate cancer-related outcomes after high-intensity focused ultrasound therapy.

OBJECTIVE: To explore the effect of neoadjuvant androgen suppression (AS) compared to no AS on cancer-related outcomes after radical high-intensity focused ultrasound (HIFU) therapy for men with presumed organ-confined prostate cancer. PATIENTS AND METHODS: Between January 1999 and January 2005, 250 patients underwent HIFU for presumed localized adenocarcinoma of the prostate; 154 had received neoadjuvant hormonal therapy and 96 had not. The primary outcome measure was treatment failure, as defined by the presence of prostate cancer on the biopsy taken 6 months after HIFU. Multiple logistic regression was used to examine relationships between the use of HIFU with and with no neoadjuvant AS and treatment failure. RESULTS: The treatment failure rate was slightly lower in patients receiving neoadjuvant AS (31% vs 34%), but this was not statistically significant (P = 0.119). CONCLUSION: In this unrandomized comparison between neoadjuvant or no AS before HIFU for men with presumed organ-confined prostate cancer, there appeared to be little if any benefit associated with the previous administration of AS.

To what extent does the prostate-specific antigen nadir predict subsequent treatment failure after transrectal high-intensity focused ultrasound therapy for presumed localized adenocarcinoma of the prostate?

OBJECTIVE: To explore the association between the prostate-specific antigen (PSA) nadir after transrectal high-intensity focused ultrasound (HIFU) therapy for organ-confined prostate cancer and subsequent treatment failure, as defined by the presence of residual disease at biopsy 6 months after treatment. PATIENTS AND METHODS: Between January 1999 and January 2005, 115 patients in a Japanese hospital were treated using a transrectal HIFU system (Sonablate, Focus Surgery, IN, USA) for presumed localized adenocarcinoma of the prostate. All treatments were primary and none of the patients had received hormone therapy. The PSA level was measured at 2-monthly intervals and all patients had a transrectal prostate biopsy taken at 6 months. Multiple logistic regression was used to examine the relationship between PSA nadir and treatment failure, as defined by the presence of disease at biopsy. RESULTS: The PSA nadir was strongly associated with treatment failure (P < 0.001). Patients with a PSA nadir of 0.0-0.2 ng/mL had a treatment failure rate of only 11% (four of 36), compared to 46% (17 of 37) in patients with a PSA nadir of 0.21-1.00 ng/mL and 48% (20 of 42) with a PSA nadir of >1.0 ng/mL. In addition, the PSA nadir was strongly associated with both preoperative PSA level and residual prostate volume. CONCLUSION: There is a clear and intuitive association between the PSA nadir and the risk of treatment failure after HIFU. These data can be used to predict the risk of residual disease in patients with prostate cancer undergoing HIFU therapy. They can also be used to inform where the target PSA nadir should be set for this novel therapy.