Dose exposure in the ITALUNG trial of lung cancer screening with low-dose CT.

Few data are available on the effective dose received by participants in lung cancer screening programmes with low-dose CT (LDCT). We report the collective effective dose delivered to 1406 current or former smokers enrolled in the ITALUNG trial who completed 4 annual LDCT examinations and related further investigations including follow-up LDCT, 2-[(18)F]flu-2-deoxy-d-glucose positron emission tomography (FDG-PET) or CT-guided fine needle aspiration biopsy (FNAB). Using the air CT dose index and Monte Carlo simulations on an anthropomorphic phantom, the whole-body effective dose associated with LDCT was determined for the eight CT scanners used in the trial. A value of 7 mSv was assigned to FDG-PET while the measured mean effective dose of CT-guided FNAB was 1.5 mSv. The mean collective effective dose in the 1406 subjects ranged between 8.75 and 9.36 Sv and the mean effective dose to the single subject over 4 years was between 6.2 and 6.8 mSv (range 1.7-21.5 mSv) according to the cranial-caudal length of the LDCT volume. 77.4% of the dose was owing to annual LDCT and 22.6% to further investigations. Considering the nominal risk coefficients for stochastic effects after exposure to low-dose radiation according to the National Radiological Protection Board, International Commission on Radiological Protection (ICRP) 60, ICRP103 and Biological Effects of Ionizing Radiation VII, the mean number of radiation-induced cancers ranged between 0.12 and 0.33 per 1000 subjects. The individual effective dose to participants in a 4-year lung cancer screening programme with annual LDCT is very low and about one-third of the effective dose that is associated with natural background radiation and diagnostic radiology in the same time period.

CT colonography before colonoscopy in subjects with positive faecal occult blood test. Preliminary experience.

PURPOSE: We report a preliminary evaluation of the performance of computed tomography colonography (CTC) systematically obtained before optical colonoscopy (OC) in subjects with positive faecal occult blood test (FOBT) within a population-based screening programme for colorectal cancer (CRC). MATERIALS AND METHODS: Seventy-nine subjects with positive FOBT from a regional screening programme were invited to perform same day CTC and OC. CTC was performed with standard bowel preparation. OC with segmental unblinding was the reference standard. A per-patient per-adenoma analysis was performed. RESULTS: Forty-nine of 79 subjects (62%) with positive FOBT adhered to the study and completed both examinations. Twenty-two (44.9%) of the 49 had a cancer or an adenoma ≥6 mm. Per-patient sensitivity, specificity, negative predictive value and positive predictive value for cancer or adenoma ≥6 mm were 95.5% (95%CI:77.2%-99.9%), 51.9% (95%CI:32.0%-71.3%), 93.3% (95%CI:68.1%-99.8%) and 61.8% (95%CI:43.6%-77.8%). CONCLUSIONS: In the setting of a FOBT-based screening programme for CRC, CTC showed a high sensitivity, but relatively low specificity and positive predictive value, for cancer and adenoma ≥6 mm. Probably performing CTC without faecal tagging as second line test after a positive FOBT is not a cost-effective strategy.

3-D segmentation algorithm of small lung nodules in spiral CT images.

Computed tomography (CT) is the most sensitive imaging technique for detecting lung nodules, and is now being evaluated as a screening tool for lung cancer in several large samples studies all over the world. In this report, we describe a semiautomatic method for 3-D segmentation of lung nodules in CT images for subsequent volume assessment. The distinguishing features of our algorithm are the following. 1) The user interaction process. It allows the introduction of the knowledge of the expert in a simple and reproducible manner. 2) The adoption of the geodesic distance in a multithreshold image representation. It allows the definition of a fusion--segregation process based on both gray-level similarity and objects shape. The algorithm was validated on low-dose CT scans of small nodule phantoms (mean diameter 5.3--11 mm) and in vivo lung nodules (mean diameter 5--9.8 mm) detected in the Italung-CT screening program for lung cancer. A further test on small lung nodules of Lung Image Database Consortium (LIDC) first data set was also performed. We observed a RMS error less than 6.6% in phantoms, and the correct outlining of the nodule contour was obtained in 82/95 lung nodules of Italung-CT and in 10/12 lung nodules of LIDC first data set. The achieved results support the use of the proposed algorithm for volume measurements of lung nodules examined with low-dose CT scanning technique.

[Genetic anomalies of pancreatic carcinoma and clinical applications]. / Le anomalie genetiche del carcinoma pancreatico e le applicazioni cliniche.

Pancreatic cancer is a dismal disease. The 5-years overall survival ranges from 1% to 5%. Surgery is the only curative treatment available. Survival of selected patients with small lesion (< 2 cm) confined to the pancreas is improved to 19-41%. Presently the major effort is on studies of the cancer development phenomena to improve detection of patients with early lesions. The analysis of oncogene and tumor-suppressor gene activation may enable us to better define and cure this disease. Molecular genetic new tecnquiques performed on pancreatic juice, duodenal juice and stool, probably are the most promising new approach for early diagnosis of pancreatic cancer. This could be the right path to diagnose pancreatic malignant lesions at a curable stage, and to discriminate patients with a more favourable prognosis candidates to be submitted to adjuvant therapy with a curative intent, and also to discriminate real pancreatic cancer from patients with chronic pancreatitis.

[Ultrasonography of pancreatic neoplasms]. / L'ecografia del carcinoma pancreatico.

Pancreatic tumors are the fourth cause of death in Occident: the 5-year-survival rate is less than 5% because of diagnostic difficulties, low clinical expression at early stage, and complexity of the surgical treatment. The role of ultrasound (US) is in early diagnosis, because also in early cancer there could be lymphatic spread or peritoneal involvement. There are multiple modalities to study the pancreas with US: abdominal US, "contact" US (endosonography and intra-operative or laparoscopic US). The first is not invasive, cheap but limited by extrinsic and intrinsic factors, the latter are respectively characterized by high cost, and need of endoscopic specialists for endosonography, the complementarity to laparoscopy or surgery for the laparoscopic/intraoperative US. Abdominal US is the first diagnostic step for the pancreas, but it is not affordable in 15-25% of patients, because of meteorism. In all the other cases, it represents the pancreas with a good contrast between the normal parenchyma and tumoral tissues. Abdominal US, together with biopsy, can define the resectability. Ecoendoscopy is actually dedicated to small tumors staging, but recent studies demonstrate the same results achieved by spiral TC. Laparoscopic US is a second step imaging in patients already selected for surgery. The first finality in US evaluation of tumor masses is early diagnosis of pancreatic cancer; it can give to some of these patients the opportunity of undergoing to surgical treatment. This could be achieved by a proper use of the moititude of ultrasonic abdominal explorations that are requested in daily practice. US, together with CT and MR, can define the resectability of the tumor, with further supplementar evaluation by mean of laparoscopic US. Intraoperative US is now indicated for planning and guiding the surgeon in resection of the pancreatic cancer.

[Neural network based detection of pulmonary nodules on chest radiographs]. / Identificazione mediante reti neurali dei noduli polmonari nel radiogramma del torace.

PURPOSE: We investigated the capabilities of an artificial neural network-based Computer-Aided Diagnosis (CAD) system in improving early detection of pulmonary nodules on chest radiographs. MATERIAL AND METHODS: We used a data-set of 145 digitized chest films. Two different radiologists read the radiographs to detect the sites of possible nodules. The system uses two neural networks trained on a training-set of 100 radiographs selected from the data-set. The first network is used to focus attention on the sites of potential nodules while the second calculates the likeliness of nodule presence in ROIs. The clinical test was performed on 45 more radiographs from the training-set, but different from those in the data-set, which were positive for both benign and malignant nodules. These latter plain films showed 65 nodular lesions which differed by shape and acquisition technique. RESULTS: Sensitivity was 89% in all radiographs while specificity, evaluated by ROI, and accuracy, were 98%. CONCLUSIONS: There are potential limitations in nodule detection on plain radiographs. Some of them are operator-dependent, such as nonsystematic investigation, lesion underestimation, and poor reading, and some are technique-dependent, such as X-ray beam/tube, low voltage, patient positioning, focus-film distance and development process. CADs may contribute to improving detection of pulmonary nodules because the false-negative rate is decreased and sensitivity consequently increased. The high sensitivity and specificity rates of neural networks encourage further trials on wider data-sets to help the radiologist in the early detection of pulmonary nodules.

Recovery of functional status after stroke. A postrehabilitation follow-up study.

BACKGROUND AND PURPOSE: Information on predictors of long-term change in functional capacity after a rehabilitation program in stroke patients is scant. This study describes the long-term evolution of self-reported functional ability after discharge from rehabilitation and its relation with age, level of neural impairment at discharge, and changes in neural impairment during follow-up. METHODS: Fifty patients (31 men and 19 women; mean +/- SD age, 66.0 +/- 9.9 years; range, 47-86 years) with a first unilateral stroke and no severe cognitive impairment were consecutively enrolled. Self-reported disability in activities of daily living and neural impairment measured by the Fugl-Meyer Scale were evaluated after discharge from a rehabilitation program and 3 and 6 months later. RESULTS: Functional disability was significantly reduced after 3 and 6 months. Attenuation of disability occurred mainly among those patients with more severe baseline neural impairment. In this group, patients aged > or = 65 years were more disabled at baseline than younger individuals, but they had the same rate of improvement. In patients aged < 65 years, changes in disability over time could be attributed to changes in neural function, whereas older patients' functional recovery was greater than that expected from their improvement in neural impairment alone. CONCLUSIONS: These results suggest that in stroke patients with severe neural damage further functional improvement occurs even after completion of a rehabilitation program. There is evidence that older patients may be more likely to employ compensatory strategies to overcome some of the neural impairment that remains after stroke.

Gastric juice immunoreactive epidermal growth factor levels in patients with peptic ulcer disease.

Immunoreactive epidermal growth factor (IR-EGF) was measured by a highly sensitive and specific radioimmunoassay in gastric juice samples obtained during endoscopy from 26 control subjects, 44 patients with duodenal ulcers, and 18 with benign gastric ulcers. In the active stage, the concentrations of the peptide were consistently reduced, compared with those found in control subjects (592.7 +/- 55.8 pg/ml), in both duodenal (262.6 +/- 21.4 pg/ml) and gastric ulcer patients (320.2 +/- 34.1 pg/ml) (p less than 0.001 and 0.01, respectively). Mean IR-EGF values distinctly lower than in the controls were still present in the gastric juice of patients with inactive duodenal ulcers (349.7 +/- 35.9 pg/ml; p less than 0.001), whereas no difference was observed in patients with healed gastric ulcers (502.2 +/- 132.3 pg/ml). Although these findings suggest a possible role for EGF deficiency in the pathogenesis of peptic ulcer disease, the pathophysiological significance of our results (if any) remains to be elucidated.

Enzyme immunoassay of gastric luminal prostaglandin E2 in duodenal ulcer disease.

A highly sensitive enzyme immunoassay was used to determine gastric juice prostaglandin E2 (PGE2) levels in control subjects with or without gastritis and in both active or inactive duodenal ulcer patients. Mean pentagastrin-stimulated PGE2 concentration was significantly lower in patients with duodenal ulcer than in control subjects considered as a whole group (with or without gastritis). However, no such difference was found between duodenal ulcer patients and controls showing histologically normal gastric mucosa. On the other hand, controls with chronic superficial gastritis had PGE2 levels significantly higher than those of histologically normal subjects and duodenal ulcer patients. Therefore, it seems unlikely that an absolute gastric PGE2 deficiency is involved in the pathogenesis of duodenal ulcer disease. However, the possibility that PGE2 synthesis could be deficient in relation to the prevailing level of mucosal inflammation cannot be excluded.