Typical values of z-resolution for different Digital Breast Tomosynthesis systems evaluated in a multicenter study

PURPOSE

The aim of the present study, conducted by a working group of the Italian Association of Medical Physics (AIFM), was to define typical z-resolution values for different digital breast tomosynthesis (DBT) models to be used as a reference for quality control (QC). Currently, there are no typical values published in internationally agreed QC protocols.

METHODS

To characterize the z-resolution of the DBT models, the full width at half maximum (FWHM) of the artifact spread function (ASF), a technical parameter that quantifies the signal intensity of a detail along reconstructed planes, was analyzed. Five different commercial phantoms, CIRS Model 011, CIRS Model 015, Modular DBT phantom, Pixmam 3-D, and Tomophan, were evaluated on reconstructed DBT images and 82 DBT systems (6 vendors, 9 models) in use at 39 centers in Italy were involved.

RESULTS

The ASF was found to be dependent on the detail size, the DBT angular acquisition range, the reconstruction algorithm and applied image processing. In particular, a progressively greater signal spread was observed as the detail size increased and the acquisition angle decreased. However, a clear correlation between signal spread and angular range width was not observed due to the different signal reconstruction and image processing strategies implemented in the algorithms developed by the vendors studied.

CONCLUSIONS

The analysis led to the identification of typical z-resolution values for different DBT model-phantom configurations that could be used as a reference during a QC program.

Providing high-quality care remotely to patients with rare bone diseases during COVID-19 pandemic

During the COVID-19 outbreak, the European Reference Network on Rare Bone Diseases (ERN BOND) coordination team and Italian rare bone diseases healthcare professionals created the "COVID-19 Helpline for Rare Bone Diseases" in an attempt to provide high-quality information and expertise on rare bone diseases remotely to patients and healthcare professionals. The present position statement describes the key characteristics of the Helpline initiative, along with the main aspects and topics that recurrently emerged as central for rare bone diseases patients and professionals. The main topics highlighted are general recommendations, pulmonary complications, drug treatment, trauma, pregnancy, children and elderly people, and patient associations role. The successful experience of the "COVID-19 Helpline for Rare Bone Diseases" launched in Italy could serve as a primer of gold-standard remote care for rare bone diseases for the other European countries and globally. Furthermore, similar COVID-19 helplines could be considered and applied for other rare diseases in order to implement remote patients' care.

[Epidemiology of chronic kidney disease in a population: residents in the territory of Umbria "Gubbio - Gualdese"]

The incidence of chronic kidney disease (CKD) has clearly increased in recent years. It is likely to be correlated with the aging population and with the growing association with vascular diseases. In Italy, there are different registers of dialysis and transplantation, providing an excellent means of monitoring patients in substitution treatment. On the contrary, few material is in our possession regarding CKD patients on conservative therapy. Therefore it lacks a necessary mean to implement mechanisms of prevention and programming for a disease that increasingly shows significant social - health consequences.

Effect of sodium hyaluronate on mucociliary clearance after functional endoscopic sinus surgery

BACKGROUND

To determine the effect of intranasal sodium hyaluronate on mucociliary clearance time following functional endoscopic sinus surgery in patients with nasal polyposis.

STUDY DESIGN

Randomized, controlled, blinded study.

METHODS

Thirty-six patients with grade II nasal polyposis undergoing functional endoscopic sinus surgery received intranasal sodium hyaluronate 9 mg twice daily or saline for 30 days commencing on the second day after surgery. Ciliary mucous transport time was assessed using charcoal powder and saccharin administered during rhinoscopy. Other outcomes included changes in symptoms, endoscopic appearance of the nasal mucosa, and tolerability.

RESULTS

Patients receiving sodium hyaluronate had a significantly faster mucociliary clearance time at 1 month compared with controls (14.3 +/- 2.5 vs. 23.6 +/- 3.3 minutes; p = 0.000). Furthermore, sodium hyaluronate recipients experienced a lower incidence of rhinorrhea, less nasal obstruction and a lower incidence of exudate on endoscopy than control subjects at 1 month (all p < 0.05). Sodium hyaluronate was well tolerated in patients following functional endoscopic sinus surgery.

CONCLUSION

The use of intranasal sodium hyaluronate in patients undergoing functional endoscopic sinus surgery for nasal polyposis augmented the improvement in mucociliary clearance observed following this procedure and improved several clinical and endoscopic parameters. These data provide encouraging evidence of the beneficial effects of sodium hyaluronate in the care of patients undergoing functional endoscopic sinus surgery with which to continue the development of the product for this indication.

Excision of the primary tumour in patients with metastatic breast cancer: a clinical dilemma

BACKGROUND

Approximately 10% of new breast cancer patients will present with overt synchronous metastatic disease. The optimal local management of those patients is controversial. Several series suggest that removal of the primary tumour is associated with a survival benefit, but the retrospective nature of those studies raises considerable methodologic challenges. We evaluated our clinical experience with the management of such patients and, more specifically, the impact of surgery in patients with synchronous metastasis.

METHODS

We reviewed patients with primary breast cancer and concurrent distant metastases seen at our centre between 2005 and 2007. Demographic and treatment data were collected. Study endpoints included overall survival and symptomatic local progression rates.

RESULTS

The 111 patients identified had a median follow-up of 40 months (range: 0.6-71 months). We allocated the patients to one ot two groups: a nonsurgical group (those who did not have breast surgery, n = 63) and a surgical group (those who did have surgery, n = 48, 29 of whom had surgery before the metastatic diagnosis). When compared with patients in the nonsurgical group, patients in the surgical group were less likely to present with T4 tumours (23% vs. 35%), N3 nodal disease (8% vs. 19%), and visceral metastasis (67% vs. 73%). Patients in the surgical group experienced longer overall survival (49 months vs. 33 months, p = 0.01) and lower rates of symptomatic local progression (14% vs. 44%, p < 0.001).

CONCLUSIONS

In our study, improved overall survival and symptomatic local control were demonstrated in the surgically treated patients; however, this group had less aggressive disease at presentation. The optimal local management of patients with metastatic breast cancer remains unknown. An ongoing phase iii trial, E2108, has been designed to assess the effect of breast surgery in metastatic patients responding to first-line systemic therapy. If excision of the primary tumour is associated with a survival benefit, then the preselected subgroup of patients who have responded to initial systemic therapy is the desired population in which to put this hypothesis to the test.

P2-15-05: Excision of the Primary Tumour in Patients with Metastatic Breast Cancer – Will E2108 Provide the Definitive Answer?

Background: Approximately 10% of new breast cancer patients will present with overt synchronous metastatic disease. Controversy exists about the optimal local management of these patients. While several series suggest that removal of primary tumour is associated with a survival benefit, the retrospective nature of these studies raises considerable methodological challenges. We decided to evaluate the experience at our centre around the impact of surgery in patients with synchronous metastasis.

Method: Case records of all patients seen with primary breast cancer and concurrent distant metastases between 2005 to 2007 were reviewed. Demographic and treatment data was collected. The study endpoints compared both overall survival and symptomatic local progression rates between patients who had breast surgery and those who did not.

RESULTS: 111 patients were identified. Median follow-up 40 months (0.6-71 months). Patients were divided into two groups: those patients who underwent breast surgery (n=48; 29/48 had surgery immediate prior to metastatic diagnosis) and those that did not have surgery(n = 63). The surgical group were less likely to present with T4 tumours (20% vs 36%), N3 nodal disease (8% vs 19%) and visceral metastasis (67% vs 73%)when compared with non-surgical group. Improved overall survival (49 months vs 33 months; p=0.01) and less symptomatic local progression rates ( 15% vs 43%, p &lt; 0.001 ) were seen in the surgical group compared to the non-surgical group.

CONCLUSIONS: The optimal local management of patients with metastatic breast cancer is unknown. Despite the surgery group demonstrating an improved overall survival and symptomatic local control, this group had less aggressive disease at presentation. These results confirm the need for prospective randomized studies. E2108, an ongoing Phase III Trial, was designed to assess the effect of breast surgery in metastatic patients responding to first line systemic therapy. If excision of the primary tumour is associated with a survival benefit, then the pre-selected subgroup of patients that have responded to initial systemic therapy is the desired population to put this hypothesis to test.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-15-05.

Functional links between transcription, DNA repair and apoptosis

DNA damage initiates damage response pathways, cell cycle arrest and apoptosis. These processes act in a concerted fashion and remain functionally linked through mechanisms not completely understood. Programmed cell death, referred to as apoptosis, is a tightly regulated phenomenon ensuring that cells that accumulate irreversible DNA damage do not replicate. Interestingly, hyperacetylation of histone proteins, which alters transcription patterns and appears linked to DNA repair, also induces apoptosis, suggesting that aspects of chromatin modification link these very distinct processes. Modulating chromatin structure in the absence of any DNA lesions also activates key DNA damage-signalling proteins, further supporting the role of higher-order chromatin structure in mediating stress responses. This review will present an overview of the epigenetic control of eukaryotic genomes by chromatin remodelling as it pertains to DNA damage and highlight the potential role of the ING PHD proteins in linking apoptosis and DNA repair to gene transcription.

[Performance assessment of mammographic diagnostic systems: evolution of methods and their application to a digital image study]

INTRODUCTION

"Receiver Operating Characteristic" (ROC) curves are one of the most efficient analysis tools for the complete evaluation of a diagnostic system performance. However this method is limited in visualizing and locating abnormal structures, such as clusters of microcalcifications on mammographic images. Other more refined and complex techniques have also been suggested, where particular statistical hypotheses are assumed, namely the "Free-response ROC" (FROC), the "Alternative FROC" (AFROC) and the "Free-response Forced Error" (FFE) analyses. We studied the theoretical bases of these different methods and their experimental applications to assess the correctness of the hypothetical statistical distributions.

MATERIAL AND METHODS

We considered two statistical hypotheses: first, that the false-positive response distribution follows the Poissonian statistics; second, that "signal" and "noise" distributions have a Gaussian trend with different means and variances. Thus, we applied the different methods to the responses given by 8 observers (5 radiologists and 3 medical physicists) who independently evaluated 3 digital mammographic samples. Every sample consisted of 39 images, with 1-15 clusters each (total: 100 clusters). The samples were obtained from 39 images available in an Internet database (sample 1); 2 different digital filters were applied to each image (samples 2 and 3). To collects responses, we provided for two phases: first, every observer visualized and located the clusters at a given confidence level; second, when a false-positive response was given, spontaneously or after forcing, the responses were ordered by decreasing conspicuity. Finally, data were analyzed with a "home-made" software by applying the FROC and AFROC analyses to the data collected in phase 1 and the FFE analysis to those collected in phase 2.

RESULTS

We considered the area under the AFROC curve as the most important parameter: the values obtained with the 3 types of analysis are well in agreement within their uncertainties. In particular, the FROC-AFROC agreement did not exceed 5.9% (10 of 14 cases within 2.5%), while the FFE analysis had higher standard deviations associated with the area value (about 10%). The interpolated curves from both FROC and AFROC data were very similar. The three methods had various advantages: the FFE is very simple to calculate and makes the most of the information given by the observer; FROC and AFROC can provide true-positive and false-positive responses on the same image, which permits to optimize the evaluation of a diagnostic system performance. The statistical tools used in the simplest methods are usually integrated with the completeness characteristics of the location of multiple signals on mammograms.

CONCLUSIONS

In theory, every method is necessary because it provides additional information to validate the statistical hypotheses under investigation. In fact, when the methods are used to evaluate and compare several diagnostic systems, the results of the three techniques are equivalent. Therefore, choosing a specific technique depends on both available resources and response type all the hypothetical statistical distributions in our study proved correct.

[Development and use of quality control program in magnetic resonance]

In 1992, two identical 0.5 Magnetic Resonance units were installed in Policlinico S. Orsola-Malpighi in Bologna. A Quality Assurance (QA) protocol was designed by the Medical Physics Department to monitor both systems as of Acceptance Test. Our main goals in drawing up the QA protocol were: 1) Completeness--to check all the most significant physical parameters; 2) Efficiency--to reduce examination time of the QC Protocol; 3) Reliability--to achieve good repeatability of results. The QA protocol consists of two QC programs: 1) Daily check of Variable Echo image SNR of a homogeneous phantom, Eddy Current compensation, laser printer test; 2) Monthly check of SNR of Spin Echo and Fast Scan images, integral uniformity, B0 uniformity, B1 uniformity, T2 stability, ghosts, slice thickness, slice profile, geometrical distortion, resolution power. SNR dependence on FOV, NEX, matrix and slice thickness, and resolution dependence on slice thickness and position were tested as Acceptance test. The daily checks provide continual monitoring of the performance of both systems and laser printer and have shown: 1) strong fluctuations in image reproduction probably due to film emulsion instability; 2) a "warning" of imminent malfunction. The monthly checks were in line with acceptance test data and have shown: 1) different behavior of the two systems that should perform analogously; 2) greater result stability in one system with better results also in terms of diagnostic images. The main aim of our QA protocol is to optimize diagnostic accuracy by checking several physical parameters that act as good "indicators" for possible malfunctioning. We believe this can be done with simple but useful daily QC supporting a routine more complex QC program and can be achieved through continual application of both protocols.

[Applications of the quality control program in diagnostic radiology. Confirmation of results, clinical and managerial benefits]

The Health Physics Department developed and implemented a QA program to test the X-ray equipment in Policlinico S. Orsola-Malpighi, Bologna, Italy. The program was aimed at achieving "total quality" in diagnostic radiology. To this purpose, suggestions were taken from: the code of practice of the leading international committees; our personal experience over several years in measuring and evaluating radiologic equipment and finally data relative to the maintenance procedures for radiologic equipment. The Integrated Quality Assurance Program (IQAP) manages two different quality control sub-procedures: the first one (QF) monitors equipment performance with a view to providing more pieces of diagnostic information and to reducing both patient and staff dose; the other one (QG) plans maintenance service to reduce running costs. QF included: i) practical tests for X-ray equipment; ii) analysis, interpretation and comparison of results; iii) tolerance limits. QG provided information on: i) inventory; ii) user-service relationship; iii) suitability of any corrective actions. The data relative to the last four years are reported in the text. The regular and correct use of this integrated protocol is very useful to monitor the factors affecting image quality and to improve diagnostic radiology. Finally, the protocol allowed us to plan our "yearly maintenance contracts" better and to save money on running costs.

Chordoma with multiple skin metastases

We report a case of sacral chordoma with numerous skin metastases. Histologically they show the typical 'physaliform cells' expressing simultaneously cytokeratin, S-100 protein, epithelial membrane antigen and vimentin immunoreactivity.

[Psychoacoustic tests: effects of atropine]

The efferent pathways exert a control action on the function of the cochlear nucleus and hair cells. Acetylcholine is the neurotransmitter of the centrifugal system and its action can be blocked by atropine. In order to give a contribution to the knowledge of the function of the efferent bundle and of the cochlea efficiency we examined 10 young normal subjects before and after infusion of 1 mg of atropine i.v. a battery of three psychoacoustical tests (Remote Masking, Critical Ratio and Brief Tone Audiometry). After infusion of atropine we have shown an increase of 0.25 Hz hearing threshold, an increase of RC values and a decrease of RM values. It can be concluded that the pharmacological block of the olivo-cochlear bundle determines a stiffness of outer hair cells and basilar membrane; this finding means that the atropine can inhibit the facilitating activity of the efferent system on the cochlear performance.

The tape stripping toluidine blue (TSTB) method in the diagnosis of malignant melanoma: an investigator-blind study

The cytological investigation of the skin surface with the simple, non-invasive tape-stripping toluidine blue (TSTB) method has been proposed to improve the clinical diagnosis of many dermatological disorders. We carried out an investigator-blind study to estimate the sensitivity and specificity of the procedure for the diagnosis of malignant melanoma. One hundred and fifty pigmented lesions were tested. Positive results were obtained in 22 out of 32 malignant melanomas (sensitivity 68.7%), with three false negatives (two cases of lentigo maligna in premalignant phase and one early melanoma in situ) and seven non-significant findings. Negative results were found in 88 out of 118 non-melanoma conditions (specificity 74.5%), with three false positives (two Spitz's naevi and one dysplastic naevus) and 27 non-significant findings. Thus the TSTB method may be a helpful diagnostic tool, in addition to the ABCDE rule, for the early detection of malignant melanoma.

[Evaluation of the quality of screen-film radiographic systems: physical principles and methods of measurement]

Comparative evaluation of radiographic film-screen systems presents several problems from both the theoretical and the experimental point of view. From the theoretical point of view the main difficulties are related to the choice of the parameters best suited to express the "overall quality" of a system. From the practical point of view the main problem is that to measure some basic quantities (resolution and noise) sophisticated and expensive instruments are required. This paper deals with both these problems. To express image quality we have assumed the signal-to-noise power ratio: this index depends in a explicit way on contrast, resolution and noise of the system. The dependence on sensitivity is implicit and was derived using literature data. From a knowledge of the dependence of image quality on sensitivity it is possible to develop an "overall quality" index which is considered to express the "technological level" of the system. This index can be used in the comparative evaluation of the different systems. In this work some basic physical quantities (characteristic curve, sensitivity) were evaluated using standard instruments. To measure spatial resolution and noise an inexpensive, PC-based, TV-digitizer system was developed. As an example, both image and overall quality indices were evaluated on three mammographic systems which are typical of the three different "phases" of the development of this technique.