An Adaptive Thresholding Method for BTV Estimation Incorporating PET Reconstruction Parameters: A Multicenter Study of the Robustness and the Reliability.

OBJECTIVE: The aim of this work was to assess robustness and reliability of an adaptive thresholding algorithm for the biological target volume estimation incorporating reconstruction parameters. METHOD: In a multicenter study, a phantom with spheres of different diameters (6.5-57.4 mm) was filled with (18)F-FDG at different target-to-background ratios (TBR: 2.5-70) and scanned for different acquisition periods (2-5 min). Image reconstruction algorithms were used varying number of iterations and postreconstruction transaxial smoothing. Optimal thresholds (TS) for volume estimation were determined as percentage of the maximum intensity in the cross section area of the spheres. Multiple regression techniques were used to identify relevant predictors of TS. RESULTS: The goodness of the model fit was high (R(2): 0.74-0.92). TBR was the most significant predictor of TS. For all scanners, except the Gemini scanners, FWHM was an independent predictor of TS. Significant differences were observed between scanners of different models, but not between different scanners of the same model. The shrinkage on cross validation was small and indicative of excellent reliability of model estimation. CONCLUSIONS: Incorporation of postreconstruction filtering FWHM in an adaptive thresholding algorithm for the BTV estimation allows obtaining a robust and reliable method to be applied to a variety of different scanners, without scanner-specific individual calibration.

Idiopathic recurrent acute pericarditis: familial Mediterranean fever mutations and disease evolution in a large cohort of Caucasian patients.

Idiopathic recurrent acute pericarditis (IRAP) is suspected to be an autoimmune phenomenon. We studied 46 consecutive patients. We looked for: 1) the occurrence of new diagnoses of autoimmune diseases during our follow up; 2) HLA typing; and 3) the presence of the most frequent mutations linked to familial Mediterranean fever (FMF gene or MEFV). HLA typing was done in 21 patients at loci B, DRB1, DQA1 and DQB1. MEFV gene was looked in 23 patients using specific primers. During the follow-up we made a new diagnosis of primary Sjögren's syndrome in four patients (8.7%) and of rheumatoid arthritis in one patient (2.2%). HLA B14, DRB1*01 and DQB1*0202 were significantly more prevalent, but we did not find a typical HLA typing. MEFV gene was searched: exon 10 was checked by sequence and the E148Q mutation by restriction site analysis. No mutations were found. In conclusion, the prevalence of definite immunorheumatological diseases and the absence of the mutations linked to FMF reinforce the notion that idiopathic acute recurrent pericarditis is an autoimmune condition.

Adult brain low-grade astrocytomas: survival after surgery and radiotherapy.

In order to identify prognostic factors of survival, twelve elements of disease and treatment have been evaluated for a population of 49 patients with diffuse low-grade astrocytoma treated with surgical resection and radiotherapy. The survival values were inversely correlated with age and major residual portion. On the other hand, KPS, lobar site, grade II Daumas-Duport lesions, protoplasmatic variant, early epilepsy, hyperfractionated radiotherapy and extent of exeresis were prognostic factors correlated with survival. Tumor extent and radiation total dose were not correlated in a meaningful way. Only KPS was statistically significant when compared to all the prognostic factors. We believe that patient selection according to age, lesion site and histological features are not sufficient to generate a homogeneous tumoral population. The most appropriate therapy for treating low-grade astrocytomas is still an open subject. However, recent studies have shown that the prognostic value of a group of factors is useful to plan controlled studies that compare differentiated treatment protocols.

Long-term effects of angiotensin-converting enzyme inhibitors and calcium antagonists on the right and left ventricles in essential hypertension.

To compare the effects of chronic antihypertensive treatment on left and right ventricular structure and function, 24 patients with mild to moderate, never-treated hypertension were randomized to receive fosinopril (20 mg daily) or amlodipine (10 mg daily) for 12 months. At baseline and subsequently at the end of third, sixth, and twelfth months, each patient underwent an integrated echocardiographic study and noninvasive ambulatory blood pressure monitoring. Both drugs significantly reduced blood pressure, casual or monitored (p < 0.01), and left ventricular mass index (from 125 +/- 32 to 100 +/- 12 gm/m2 [p < 0.02] with amlodipine and from 106 +/- 18 to 89 +/- 10 gm/m2 [p < 0.02] with fosinopril). The decrease in left ventricular mass was essentially caused by a reduction of ventricular thickness. Free right ventricular wall thickness was also lowered in both groups, more consistently with amlodipine (from 8.0 +/- 2.1 to 6.4 +/- 0.8 mm; p < 0.01), without an increase in plasma natriuretic peptide and insulin concentrations or heart rate. With both treatments, the decrease in ventricular mass was not associated with impairment of systolic function, whereas a trend toward an improvement of Doppler echocardiographic indexes of biventricular diastolic function was observed. In conclusion, both amlodipine and fosinopril induced similar qualitative effects on anatomy and function of both ventricles. The clinical meaning of these observations must be defined further by means of adequately sized prospective trials.

Albuminuria and transferrinuria in essential hypertension. Effects of antihypertensive therapy.

The objectives of this study were to evaluate the effects of an ACE inhibitor (fosinopril) and a calcium antagonist (amlodipine) on the urinary albumin and transferrin excretion and their relationship to the blood pressure in essential hypertension. Twenty-four never-treated patients (mean age, 46.4 +/- 8.9 years) with a diastolic blood pressure between 90 and 114 mm Hg and normal renal function, randomly received amlodipine or fosinopril and, if the diastolic blood pressure was not normalized, doxazosin was added to the therapy. Twenty-four-hour ambulatory blood pressure monitoring and 24-h urine collection for albumin and transferrin measurements were performed before and after 3 and 6 months of therapy. Diastolic blood pressure was normalized in 23 patients (96%). Before treatment, microalbuminuria was present in 50% of patients. In the amlodipine and fosinopril group, antihypertensive therapy significantly decreased blood pressure and, only in the fosinopril group, albuminuria. Transferrinuria did not change significantly in both groups. Fosinopril lowered albuminuria in all patients, whereas amlodipine only in half of patients. Albuminuria, but not transferrinuria, was significantly correlated to the ambulatory blood pressure. This correlation was more pronounced for systolic than for diastolic pressure. In essential hypertensive patients with normal renal function, a high prevalence of microalbuminuria can be observed. Albuminuria appears to correlate with ambulatory blood pressure, particularly with systolic pressure. Intrarenal hemodynamic changes seem to play a more important role than systemic blood pressure decrease in the reduction of albuminuria. Transferrinuria does not seem a useful marker to follow-up nondiabetic hypertensive patients with early signs of glomerular dysfunction.

[Drug therapy with disodium clodronate combined with radiotherapy of bone metastasis of solid tumors]. / Integrazione farmacologica con disodioclodronato alla radioterapia delle metastasi ossee di tumori solidi.

The largest portion of a radiation oncologist's practice is aimed at the palliative treatment of bone metastases. This trial investigated the impact of disodiumclodronate on radiation therapy results. Two groups of patients with bone metastases were compared: one (176 patients) treated by radiation therapy alone, the other (242 patients) by combined radiotherapy and disodiumclodronate. The evaluated parameters were changes in the volume of bone destruction, pain rating, performance status scale, and percentage of disease progression, as they appeared on pre and post-irradiation CT scans. In the disodiumclodronate group, a significant improvement was observed in the bone metastases from breast, prostate, and non-small cell lung cancers. As for bone metastases from urinary and gastro-intestinal cancers, disodiumclodronate did not prove to be much effective in improving radiation therapy results. Independent of primary tumor location, disodiumclodronate had a marked protective effect on both local disease progression and appearance of new lytic areas. In our experience, response duration was directly correlated with the actual time of disodiumclodronate administration. Toxicity was minimal, which makes it probable for disodiumclodronate to become an important adjunct to bone radiation therapy.

[Echocardiographic evaluation of mitral valve calcification]. / Valutazione ecocardiografica delle calcificazioni valvolari mitraliche.

Preoperative assessment of calcifications is important in order to choose the correct surgical approach for mitral valve disease. To test the accuracy of echocardiography (ECHO) in the semiquantitative analysis of mitral valve (MV) calcifications we preoperatively echo-studied 66 patients, who were to undergo MV replacement of rheumatic disease. Echocardiograms were performed using a standardized method, recorded on videotape and analyzed by two independent observers. Areas of calcification were identified as dense conglomerate echoes which were brighter than those of adjacent internal structures. After removal, the MVs were evaluated by means of inspection (I), direct radiography (X-ray) and quantitative calcium extraction--EDTA spectrophotometry--(QCa). In the three methods ECHO, I and X-ray, MV calcifications were graded as absent (group 1), mild (group 2) nodular (group 3) and diffuse (group 4). Using the chi square test, no significant differences were found between the three methods, or between ECHO and X-ray, or between ECHO and I, while I grading was slightly lower than X-ray grading (P less than 0.002). Using variance analysis, no significant differences were found in QCa in the three methods within group 1 and 4, whereas significant differences were present within group 2 (P less than 0.002) and group 3 (P less than 0.001), due to the lower sensitivity of I. On the base of the observed distribution of QCa in the removed MVs, the following QCa values: a) less than 20 mg, b) 20-80 mg, c) greater than 80 mg, were considered as the selection criteria for a) absent or mild, b) nodular and c) diffuse calcifications respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone loss in prednisone treated sarcoidosis: a two-year follow-up.

We followed up 35 sarcoid patients treated with prednisone for two years in order to evaluate bone mineral loss over time. Vertebral cancellous mineral content was detected by quantitative computed tomography and calibration phantom before beginning prednisone therapy and monitored two more times at yearly intervals. The percent mineral loss (ML%) averaged -13.9 +/- 2.1 at the end of the first year and -15.3 +/- 2.6 at the end of second year. We conclude first, that the time course of mineral loss in prednisone treated sarcoidosis is similar to that of other diseases such as asthma and rheumatoid arthritis. In a separate group of 10 early postmenopausal females, we observed a greater ML% averaging -21.9 +/- 16.6 and -26.2 +/- 18.5, at the end of the first and second year respectively. Our second conclusion was thus that the synergic effect of postmenopausal status and prednisone therapy results in an ML% far more significant than expected from the two single conditions.

Prednisone-induced bone loss in sarcoidosis: a risk especially frequent in postmenopausal women.

The incidence of glucocorticoid-induced osteoporosis is reported in about 40 to 50% of treated patients, but it has never been extensively studied in sarcoidosis. We have studied Vertebral Cancellous Mineral Content (VCMC) of the lumbar spine by Quantitative Computed Tomography (QCT) in 190 normal subjects, 7 patients with sarcoid on no treatment and 64 patients with sarcoid on treatment with prednisone. As compared to the 190 normal subjects and the 7 untreated patients, VCMC was reduced in 46 of 64 patients with sarcoid on treatment with prednisone. Loss of VCMC in the patients varied directly with dose and duration of prednisone treatment. It is concluded that - in sarcoid patients and especially in postmenopausal females - long-term prednisone therapy results in bone mineral loss more frequently than elsewhere reported for other groups of patients. It is not clear if this difference is due to the sarcoidosis itself or to the better sensitivity of Computed Tomography compared to former techniques.

Bone protection with salmon calcitonin (sCT) in the long-term steroid therapy of chronic sarcoidosis.

Prednisone-induced osteoporosis is very frequent in the long-term treatment of sarcoidosis (sarcoidosis 4:45-48, 1987). The aim of this work is to evaluate if salmon Calcitonin (sCT) is able to prevent osteopenia in the long-term. We have studied 53 patients with chronic histologically-proven sarcoidosis, all needing steroids, in a follow-up of 15 months; 20 of them were protected with sCT (100 I.U. i.m. daily for one month, then every two days for all the time of the study), 33 were unprotected. The two groups were matched for age, sex and total dose of prednisone. In order to overcome the differences of Vertebral Cancellous Mineral Content (VCMC) due to age and sex, we express VCMC in terms of Z score, i.e. the number of standard deviations above or below our normal means: initial Z score was -1.77 +/- 0.16 in the sCT group and -0.99 +/- 0.17 in the other group (P less than .05). For each subject we calculated the Mineral Loss (ML) in % of the initial value. At the end of the study ML% averaged -2.15(+/- 2.27) in the sCT protected group, and -14.11(+/- 2.08) in the unprotected group (P less than .001). We have also analysed the results limited to pts with initial Z score under -1 (19 sCT protected pts vs 18 unprotected). In these subgroups the ML% after 15 months averaged -13.62(+/- 2.9) in the unprotected group and -2.80(+/- 2.29) in the protected one (P less than .01). Finally we have studied another subgroup, i.e. 21 postmenopausal females: 9 were sCT protected, 12 were unprotected.(ABSTRACT TRUNCATED AT 250 WORDS)

Researching osteoporosis in prednisone treated sarcoid patients.

Eighty-four normal subjects, 5 untreated sarcoid patients and 32 sarcoid patients under chronic prednisone therapy were submitted to Quantitative Computed Tomography (QCT) for Vertebral Cancellous Mineral Content (VCMC) evaluation. In the five untreated and in the 84 normal subjects, VCMC (given in mg/cm3) fell in the normal range found elsewhere. 22 of the 32 treated patients had lower than normal values. Osteoporosis (expressed through cancellous mineral loss) increased significantly (P less than .01) with increasing dose x time of prednisone therapy. We conclude that the bone loss is far more frequent than suspected in prednisone treated patients with sarcoidosis; yearly QCT could be a good tool for monitoring patients under chronic therapy.

[Chernobyl accident: dosimetric evaluation and estimation of risks]. / Incidente di Chernobyl. Valutazioni dosimetriche e stime dei rischi.

The results of dosimetric evaluations carried out after Chernobyl accident in the Health Physics Department of Niguarda Ca' Granda Hospital (Milan) on air, rain and ground contamination are presented. The results obtained show that the incidence of stochastic late effects, both somatic and genetic, will be so low that practically will not be distinguishable from "natural" incidence.