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Biomedical subjects

M Ciocca

Publications and source records attributed to M Ciocca.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Clinical and methodological aspects of quality assurance in external radiotherapy: optimization of radiotherapy in early cancer of the breast].

Since 1988, a specific physical and clinical quality assurance program for external whole breast irradiation has been activated in our department. Three areas of clinical investigation and related audit loops are analyzed to show our policy to improve the quality of patient care. Quality control procedures deal with (a) the evaluation of the adequacy of conventional methods of clinical target volume (CTV) localization, (b) the evaluation of the adequacy of the conventional method of determining the planning target volume (PTV) and (c) the systematic and objective assessment of acute and late side-effects. Corrective actions to maintain or meet the standards are also reported. The localization of residual mammary gland using conventional methods (anatomy and/or palpation) was compared in 100 patients with US localization: conventional methods were often inadequate and thus the use of US in PTV determination is necessary. Portal film analysis helped reduce ideal margins from 20 mm to 11 mm. The amount of irradiated ispilateral lung, retrospectively calculated in 88 consecutive patients, appeared adequate to the chosen reference standard. The systematic study of late skin reactions had shown in some patients telangectasia regions outside the boost area: since 1991, a corrective action, decreasing the thickness of the customized immobilization cast inside the treatment area, from 2 mm to 0.2 mm, has been adopted. These examples show that the routine application of quality assurance procedures can help optimize radiation treatment.

Breast Neoplasms↗
PubMed1996

[Histologic factors as elements of prognostic value in biliary atresia].

Biliary atresia (BA) is one of the biliary tree anomaly more frequent. Occurs in about 0.8 to 1/10.000 live births. BA is defined as a progressive biliary tree. The prognosis depends on the age of the diagnosis and precocity surgery. We present the results of a retrospective analysis of 71 RA carried out at the Garrahan Hospital from 1987 to 1993. 47 were female and 24 were male. Age ranged from 45 to 120 days of life. This study involved a consecutive series of 58 patients with histopathologic study of Porta-hepatis (PH) and liver biopsy obtained during the Kasai. The purpose of this study was to determine the value of histological factors as type of PH and hepatocytic giant cell transformation (GCT). 82.8% had favorable type of PH and the CCT was mild in 84.5%. 72.4% had bad outcome and was independent of the type of PH. Neither of them were statistically significant with survive and evolution. In our service neither PH non CGT were predictors of a bad outcome. There were good outcome in 27.5%, died 37.9% and 10.3% undergo liver transplantation. The precocity in a diagnosis and surgical procedure before two months of age are the most important factors in correlation with survival. Others immunomorphologic factors must be studied in BA that explained the etiopathogenic process. Orthotopic liver transplantation is the successful therapy in children with BA.

Biliary Atresia↗
PubMed1994

Chronic active autoimmune hepatitis in children. Strong association with a particular HLA-DR6 (DRB1*1301) haplotype.

The association of HLA antigens and type I or "lupoid" CAH-C was investigated in a population of 52 Argentinian Caucasoid patients. When compared with a population of normal individuals of the same ethnic group (n = 197), a significant increase of HLA-DR6 was observed (68.6% in patients vs 17.3% in controls; RR = 12.3, chi 2 = 52.4, pc = 0.00001). DNA typing showed that the HLA-DRB1*1301 allele was present in 32 out of 33 HLA-DR6 patients (66.6% of all the C-CAH patients vs 10.5% in controls; RR = 16.2, chi 2 = 111.3, pc = 0.00001). Analysis of HLA-DQB1 alleles also showed a significant increase of DQB1*0603 (RR = 15.4, chi 2 = 106.5, pc = 0.00001), an allele found in strong linkage disequilibrium with DRB1*1301. The association of CAH-C with this particular HLA-DR6 haplotype has not been previously described for the adult onset CAH. This different HLA predisposition, together with the fact that extrahepatic autoimmune diseases occur frequently only in the adult form of the disease, suggest that the immunopathogenic mechanisms involved in the development of these diseases may be different.

Adolescent↗
PubMed1992

He et al. reply.

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Journal Article↗
PubMed1992

Beam modifying devices in the treatment of early breast cancer: 3-D stepped compensating technique.

A 3-D compensating technique utilizing stepped brass filters to ensure an adequate dose distribution in the breast after conservative surgery is described. No compensation for lung inhomogeneity is applied. These compensators are part of a procedure which also involves the use of a rotatable half-beam block (HBB) and of an individualized immobilization cast. Results of patient dosimetry show a good agreement with dose prescription in the target volume (measured dose/prescribed dose = 100.9% +/- 1.8% at the reference point). Phantom dosimetry is discussed.

Breast Neoplasms↗
PubMed1992

[Comparison of acceptance tests of 5 linear electron accelerators for radiotherapy].

The acceptance tests of five electron linear accelerators have been analyzed to compare their completeness, the standards specified by the manufacturers and the measured deviations. Involved tests were relative to geometrical and mechanical parameters, photon and electron beam characteristics, dose monitoring systems, treatment table and safety systems. The comparison of acceptance tests has shown a significant nonuniformity, also due to the absence of a specific legislation; anyway, the measured deviations generally appeared to be within internationally recommended values.

Particle Accelerators↗
PubMed1991

Quality control in the conservative treatment of breast cancer: patient dosimetry using silicon detectors.

Twenty patients with early breast cancer were treated with external irradiation, delivered with two tangential beams (6 MV X-rays) using a half-beam block (HBB) and 3-D compensating filters. All patients were immobilized with individualized cellulose acetate casts. Patient dosimetry was performed using p-type silicon detectors. Midline doses were calculated by combined entrance and exit dose measurements. The mean ratio of the measured and the prescribed doses was 96.6 +/- 3.8% at the reference point, 96.8 +/- 4.3% at off-axis points on the central plane and 96.8 +/- 7.6% at off-plane points.

Breast Neoplasms↗
PubMed1990

[Personalized low-melting alloy shield for high-energy electrons in the treatment of superficial neoplasms of critical or esthetically important regions].

Individualized Cerrobend beam shapings for high-energy electrons have been utilized in the treatment of superficial tumours located in aesthetic or critical regions. Individualized cellulose acetate masks have been used as immobilization device. Measured transmissions through Cerrobend ranged from 0.5% at 4 MeV to 8.5% at 18 MeV. Phantom dosimetry showed a poor influence of Cerrobend on PDD (percentage depth doses). Output factor variations appeared to depend on electron energy and shielded area. It is very important to perform either empirical measurements or to adopt semiempirical models in order to exactly calculate those output factors. Three clinical examples are presented: the utilization of immobilization device and field shaping are illustrated with the main aim of sparing the dose to critical organs.

Electrons↗
PubMed1990

[Verification of 3 computerized systems for drafting a plan for treatment with electrons].

The electron beam treatment planning systems, with the availability of more and more developed hardware for complex calculation algorithms, need quality controls of accuracy and comparability of treatment plans from different systems. In this paper three systems have been evaluated; their similar computation algorithms (pencil beam) have been used but in some conditions (beam reconstruction, oblique incidence and dishomogeneity) different results have been drawn. The basic data (PDD, dose profile, etc.) were the same for every system, therefore it has been observed that different results are mainly due to differences in: a) input of parameter values, b) calculation algorithm approximations, c) image acquisitions and elaboration.

Electrons↗