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Biomedical subjects

G Garavaglia

Publications and source records attributed to G Garavaglia.

At least 19 recordsLinked to original sources
PubMed2005

COX-1 and COX-2 inhibition in horse blood by phenylbutazone, flunixin, carprofen and meloxicam: an in vitro analysis.

We report on the inhibitory activity of the NSAIDs meloxicam, carprofen, phenylbutazone and flunixin, on blood cyclooxygenases in the horse using in vitro enzyme-linked assays. As expected, comparison of IC50 indicated that meloxicam and carprofen are more selective inhibitors of COX-2 than phenylbutazone and flunixin; meloxicam was the most advantageous for horses of four NSAIDs examined. However at IC80, phenylbutazone (+134.4%) and flunixin (+29.7%) had greater COX-2 selectivity than at IC50, and meloxicam (-41.2%) and carprofen (-12.9%) had lower COX-2 selectivity than at IC50. We therefore propose that the selectivity of NSAIDs should be assessed at the 80% as well as 50% inhibition level.

Animals↗
PubMed2005

Diagnosis of occult scaphoid fracture with high-spatial-resolution sonography: a prospective blind study.

BACKGROUND: Evaluation of diagnostic accuracy of high-spatial-resolution sonography (HSR-S) in occult scaphoid fractures. PATIENTS AND METHODS: HSR-S was performed in 24 patients with clinically suspected fracture and normal radiographs. Three levels of clinical suspicion were considered (high, intermediate, and low). Three levels of sonographic suspicion were defined on the basis of cortical interruption, radiocarpal effusion, and scapho-trapezium-trapezoid effusion. Three positive criteria were interpreted as being highly indicative of fracture. Data from sonograms were compared with computed tomography (CT) scans. RESULTS: CT scanning demonstrated a fracture of the scaphoid in five patients. The global sensitivity of HSR-S for detection of occult scaphoid fracture was 100% and the specificity 79%. All patients with demonstrated occult fracture had a high sonography index of suspicion. A high sonography index of suspicion was correlated with 100% sensitivity, specificity, positive predictive value, and negative predictive value. CONCLUSION: HSR-S is a reliable, available, and cost-effective method in early diagnosis of occult fractures of the scaphoid. The presence of three defined criteria is required to assess the diagnosis.

Adolescent↗
PubMed2003

The Quality Assurance programme of the Radiotherapy Group of the European Organization for Research and Treatment of Cancer (EORTC): a critical appraisal of 20 years of continuous efforts.

In 1982, the European Organization for Research and Treatment of Cancer (EORTC) Radiotherapy Group established the Quality Assurance (QA) programme. During the past 20 years, QA procedures have become a major part of the activities of the group. The methodology and steps of the QA programme over the past 20 years are briefly described. Problems and conclusions arising from the results of the long-lasting QA programme in the EORTC radiotherapy group are discussed and emphasised. The EORTC radiotherapy group continues to lead QA in the European radiotherapy community. Future challenges and perspectives are proposed.

Clinical Trials as Topic↗
PubMed2000

Clinical impact of dosimetry quality assurance programmes assessed by radiobiological modelling of data from the thermoluminescent dosimetry study of the European Organization for Research and Treatment of Cancer.

The European Organization for Research and Treatment of Cancer (EORTC) Radiotherapy Group initiated its mailed thermoluminescence dosimetry (TLD) programme in 1986. The aim of the present study was to evaluate the clinical relevance of variations in beam output detected in the period 1993 to 1996. A total of 140 beam outputs were checked (26 for cobalt-60 units and 114 for linear accelerators) in 35 centres. Clinical dose-response data for tumour control and normal tissue morbidity were used to assess the variation in clinical outcome resulting from variability in beam output. For 75 checked beams with nominal accelerating potentials (n. a.p.) of 6 MV or less the mean ratio, +/- standard deviation (S.D.) of measured to stated output was 1.004+/-0.020. For 65 beams with n. a.p. of 8 MV or more, the ratio was 1.009+/-0.021. Even with this relatively high level of precision, broad distributions of estimated tumour control or normal tissue morbidity were found. In the 10% of the beams with the most pronounced underdosage, the loss in tumour control probability was estimated at 7-8 percentage points. Likewise, in the 10% of the beams with the most pronounced overdosage, the increase in mild/moderate morbidity was 19-22 percentage points. For severe morbidity the same beams raised the estimated incidence of severe complications from 5% to 9-10%. An estimation of the loss of uncomplicated cure probability was about 1% for both high and low energy beams. Sequential mailings considerably improved the uniformity of clinical outcome. We conclude that small deviations in beam output may lead to clinically important variations in outcome. Substantial reductions in the variation between measured and stated output can be achieved by sequential mailings. Mailed TLD checks should be an integral part of a continuously ongoing quality assurance activity in radiotherapy.

Dose-Response Relationship, Radiation↗
PubMed1998

Quality assurance of the EORTC radiotherapy trial 22931 for head and neck carcinomas: the dummy run.

PURPOSE: A dummy run was organized to test the compliance of participating centres with the guidelines of EORTC protocol 22931, which compares high dose radiotherapy with concomitant radiochemotherapy in a postoperative setting for patients presenting with locally advanced head and neck carcinomas. METHODS: In a first step the participants (seven centres, six replies) were asked to define the planning target volume (PTV) in a given patient on the basis of clinical, surgical and radiological (CT-images) data-sets and according to the protocol guidelines. In a second phase a series of CT-reconstructed slices with on- and off-axis PTV outlines were sent to 11 centres (10 replies), which were asked to plan a treatment following the recommendations made in the frame of the trial. RESULTS: The first step of this dummy run emphasized wide intercentre variations in PTV extensions. This fact raises the question of the reproducibility when pooling patients in multicentric trials. The second step indicated a large variability in the field arrangements which was left to the discretion of the investigators. Only three out of 10 of the institutions followed the ICRU 50 recommendations for dose reporting. Moreover, protocol requirements were not met for dose distribution homogeneity in any centre. CONCLUSIONS: In order to reduce intercentre treatment heterogeneities, several actions have been taken by the EORTC Radiotherapy Group, e.g. amendments have been brought to protocol 22931 regarding a better definition of clinical and planning target volumes. Furthermore, a stricter application of the ICRU 50 recommendations for dose reporting has been sought.

Carcinoma, Squamous Cell↗
PubMed1996

Wedge factors: dependence on depth and field size.

Wedge factor (WF) variation with field size and depth has been analysed for 6 and 15 MV X-ray beams. The measured field size effect is 1.4% in the worst case, whereas the WF shows a linear dependence with depth giving a maximum variation of 0.22%/cm (60 degrees wedge, 6 MV beam). An empirical correction for WF depth dependence on wedge thickness is proposed.

Absorption↗
PubMed1996

Quality assurance in radiotherapy: the importance of medical physics staffing levels. Recommendations from an ESTRO/EFOMP joint task group.

The safe application of ionising radiation for diagnosis and therapy requires a high level of knowledge of the underlying processes and of quality assurance. Sophisticated modern equipment can be used effectively for complicated diagnostic and therapeutic techniques only with adequate physics support. In the light of recent analyses and recommendations by national and international societies a joint working group of representatives from ESTRO (European Society for Therapeutic Radiology and Oncology) and from EFOMP (European Federation of Organisations for Medical Physics) was set up to assess the necessary staffing levels for physics support to radiotherapy. The method used to assess the staffing levels, the resulting recommendations and examples of their practical application are described.

Europe↗
PubMed1995

EORTC guidelines for writing protocols for clinical trials of radiotherapy.

The concept of a Master Protocol for phase III studies was raised at the Steering Committee of the EORTC Radiotherapy Group, in order to make the work of the study coordinators easier, when writing protocols and to give them more homogeneity. The Master Protocol defines and clarifies in a logical order the different steps which must be taken when designing a randomized trial--from the rationale to the references. It pays particular attention to eligibility criteria, volumes of interest defined in agreement with ICRU Report 50 (gross tumor volume, clinical target volume, planning target volume and organs at risk), simulation procedure, treatment technique, normal tissue sparing, dose computation, equipment, dose specification (also in agreement with ICRU Report 50). Last but not least, the different procedures of quality assurance for protocols and patients are also defined (site visits, dummy run procedure, in vivo dosimetry, individual case review) to allow working plans to be made in advance. We are aware that this work is not exhaustive, but hope that the contents will be of help to those who are writing a protocol.

Clinical Trials as Topic↗
PubMed1995

Quality assurance of the EORTC radiotherapy trial 22863 for prostatic cancer: the dummy run.

The results of a dummy run involving nine centers participating in a study comparing radiotherapy alone with radiotherapy plus hormone therapy in patients with high metastatic risk prostatic cancer (EORTC protocol 22863) show that, in all centers but one, patients are treated in the same way. However, they have also indicated that protocol compliance could be improved by a better assessment of the target volume, by taking into account of the use of protective shields and of variations in radiological density, by determining beam position on a large number of slices, and by the use of CT scan images for treatment planning.

Clinical Protocols↗
PubMed1991

Improved dose distribution homogeneity in conservative breast cancer irradiation.

At the occasion of recent meetings of the radiation oncology community, the description of a whole breast irradiation technique making use of cranio-caudal oriented wedge filters to compensate for dose distribution inhomogeneity in this direction has given rise to some discussions and misunderstandings. It is the scope of this presentation to describe the technique and its possible use for other localizations.

Breast Neoplasms↗
PubMed1991

Quality assurance in conservative treatment of early breast cancer. Report on a consensus meeting of the EORTC Radiotherapy and Breast Cancer Cooperative Groups and the EUSOMA (European Society of Mastology).

A consensus on a quality assurance programme of the treatment of early breast cancer was reached in a multidisciplinary meeting of surgeons, pathologists, radiotherapists, physicists and radiographers. Guidelines for treatment preparation and execution have been set up, including careful location and excision with marking of the primary tumour. The target volumes for irradiation of the whole breast and boost area have been defined. Radiation dose prescription rules, specification and checking procedures are given, together with measures to achieve a homogeneous dose within the target volume. The rules for a quality assurance programme in each clinic are designed for checking equipment and treatment method.

Axilla↗
PubMed1991

[Echographic screening for autosomal dominant polycystic kidney disease from intrauterine life to adult life].

ADPKD is the most widespread genetic nephropathy. Only twenty-five per cent of patients are symptomatic. In order to prevent the disease it is important early screening by ultrasonography that shows a typical picture only in adults. Familiar history is determinant for diagnosis in intrauterine age, in newborns and in infants. Ultrasonographic diagnosis is certain only after twenty-five weeks of pregnancy.

Adolescent↗
PubMed1990

Glomerular hyperfiltration indicates early target organ damage in essential hypertension.

In 111 patients with essential hypertension (World Health Organization stage I or II), we examined the relationship between renal hemodynamics and left ventricular hypertrophy. Left ventricular structure was determined by two-dimensional guided M-mode echocardiography, renal blood flow by iodine I 131 aminohippuric acid clearance, and glomerular filtration rate by creatinine clearance. The glomerular filtration rate correlated with left ventricular mass (r = .52) and left ventricular cross-sectional area (r = .21). Conversely, at a similar age, body mass index, body surface area, and arterial pressure, hypertensive patients with left ventricular hypertrophy disclosed a higher glomerular filtration rate and filtration fraction than those without left ventricular hypertrophy, whereas renal blood flow and renal vascular resistance measurements were not significantly different. Thus, at similar levels of arterial pressure and renal blood flow, glomerular hyperfiltration was linked to early cardiac structural changes in essential hypertension. We conclude that, in a hypertensive patient with normal renal function, a high glomerular filtration rate may be an indicator for early target organ damage in essential hypertension.

Adult↗
PubMed1990

Treatment of autonomous thyroid nodules with percutaneous ethanol injection: preliminary results. Work in progress.

Eight patients with autonomous thyroid nodules 2.4-4.3 cm in diameter received percutaneous ethanol injections (PEIs) under guidance by means of ultrasound (US). Sterile ethanol at 95% was injected with a 22-gauge needle and a 7.5-MHz probe with a guide device. Each patient received one or two treatments, with 1-3 mL of alcohol (depending on the nodule size) per treatment, each week for a total of three to six injections per lesion. After a total of 36 injections in all eight patients, there were no complications. Follow-up ranged from 2 to 10 months. After therapy, symptoms subsided and hormonal levels became normal or reached the range of subclinical hypothyroidism. Scintigrams showed that the previously suppressed thyroid tissue had resumed functioning. At US, all nodules had shrunk. PEI was risk free and easy to perform. If these preliminary results are confirmed in a larger study with longer follow-up, the new treatment may become an alternative to surgical or radioiodine ablation of autonomous thyroid nodules.

Adult↗