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G M Cattaneo

Publications and source records attributed to G M Cattaneo.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Skin dose measurements for head and neck radiotherapy.

The use of immobilization plastic masks in head and neck radiotherapy can partially eliminate skin benefits derived from the utilization of megavoltage photon beams. Filters and blocks between the patient and the accelerator can further increase the skin dose value. In this study, the increase in surface dose due to 2 and 3.2 mm of plastic material utilized for patient immobilization was measured. Then, the effect of blocking trays, wedges, and blocks on skin dose in typical conditions for head and neck irradiation was evaluated. The measurements were obtained with a NE2534 chamber (Markus type) on a perspex phantom for 6 MeV x-rays from an accelerator.

Head and Neck Neoplasms↗
PubMedDate not supplied

The role of intraoperative therapy by electron beam and combination of adjuvant chemotherapy and external radiotherapy in carcinoma of the pancreas.

AIMS AND BACKGROUND: In the treatment of pancreatic carcinomas, one modality is intraoperative radiotherapy (IORT). A study was carried out to assess the feasibility of IORT alone or in a multimodality approach with postoperative adjuvant chemotherapy and external radiotherapy and to compare local control and survival of patients. Another objective of this retrospective study was to verify prognostic factors in resected patients treated with IORT. METHODS: From January 1985 through September 1992, 54 adenocarcinomas of the pancreas (unresectable and resected patients) were treated with IORT by electron beam at the San Raffaele Hospital and then analyzed. Comparison was also carried out between IORT-treated resected patients and a non-randomized control group of resected patients treated without IORT in the same period. RESULTS: In unresectable patients treated by laparotomy bypass and IORT, overall median survival was 6 months and 8 months in non-metastatic patients. Relief of severe pain present in 14 patients was observed in 85% within 12 days of IORT. As regards resected patients, the most important finding was that significantly better local control resulted from IORT. In fact, overall, local relapses were 25% in the IORT group and 55.8% in the non-IORT group (control group); instead, survival of the IORT group was not significantly longer than that of the control group. From a statistical analysis of resected patients treated with IORT and performed on prognostic factors on the basis of available data, survival was significantly influenced by tumor pathologic grading and diameter; postoperative adjuvant therapy was not a significant prognosis factor. CONCLUSIONS: IORT has a role in local control of unresectable pancreatic carcinomas and in control of resultant severe pain. In resected patients, IORT is effective in decreasing local recurrences but has little impact on survival. To obtain more satisfactory results, new and more effective adjuvant therapies and better abdominal prophylaxis should be tested.

Adenocarcinoma↗
PubMedDate not supplied

Quality control by portal film analysis in radiotherapy for prostate cancer: a comparison between two different institutions and treatment techniques.

AIMS AND BACKGROUND: Accuracy and reproducibility of patient setup during radiotherapy for prostate cancer were investigated in two different Institutions (A and B), within their Quality Assurance programs. The purpose of the study was to evaluate and compare setup accuracy and reproducibility in Institutions A and B, which adopt different patient positioning and treatment techniques for prostate irradiation. MATERIALS AND METHODS: A retrospective analysis of portal localization films taken during the treatment course was performed: 30 and 21 patients in Institutes A and B, respectively, entered the study. In Institute A, patients were treated in a prone position, utilizing an individualized immobilization cast (either an alpha cradle or a heat and vacuum-formed cellulose acetate cast) with an open table top and individual abdominal wall compressor to minimize small bowel irradiation; a 5-field conformal technique was used. In Institute B, patients were treated in a supine position without any immobilization device; a 6-field BEV-based technique (conformal only for patients treated with a radical aim) was adopted. A total of 598 portal films (420 from Institute A and 178 from Institute B) were analyzed. The mean number of films per patient was 12 (range, 4-29). Systematic and random setup errors were estimated utilizing the statistical method suggested by Bijhold et al. (1992). RESULTS: When patients with a mean (systematic) error larger than 5, 8 and 10 mm in craniocaudal, lateral and posterior-anterior directions, respectively, were compared, no statistically significant difference between the two groups was observed. Similarly, when comparing portal films, a significant difference (P <0.01) appeared only in the craniocaudal direction (errors > 5 mm: Institute A = 24%; Institute B = 11%). In both Institutes, the SD of random and systematic error distribution ranged from 1.8 to 4.2 mm, with a small prevalence of systematic errors. Only for craniocaudal shifts in Institute A was the random error larger than the systematic error, and it was significantly worse than in Institute B (1 SD, 4.2 mm in Institute A vs 1.8 mm in Institute B). CONCLUSIONS: Setup errors observed in Institutes A and B were similar and in accord with data reported in the literature. In Institute B, satisfactory geometrical treatment quality was achieved without patient immobilization. In Institute A, the goal of minimizing small bowel irradiation and prostate motion through the aforementioned technique, which makes patient position less comfortable, did not seem to considerably increase daily setup uncertainty.

Aged↗
PubMedDate not supplied

[The accuracy and reproducibility of the measurement of bone mineral content by single-photon absorptiometry (125I). The effect of source strength].

This study was aimed at verifying whether accuracy and reproducibility of mineral content measurements of bone phantoms by single-photon absorptiometry change as a function of source strength, and whether these changes depend on the phantom's width. To these purposes, the Norland 2780 bone mineralometer was used. With this unit, the mineral contents of two cylindrical phantoms of different diameter and of known mineral content were measured every week, 5 times on the whole, up to exhaustion of the source. Both accuracy and reproducibility decreased as source strength decreased. The lowest reproducibility was observed for the measurement of the smaller phantom with low source strength. It was therefore concluded that when source strength reaches the threshold value of 2000 cps, the measurement is so much affected as to jeopardize the reliability of short-term longitudinal studies of bone mineral content in patients.

Absorptiometry, Photon↗