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Biomedical subjects

A Nicolato

Publications and source records attributed to A Nicolato.

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

Familial cavernous hemangioma with atypical neuroimaging.

Three members of the same family were studied, all of whom had multiple intracerebral cavernous angiomas for which a dominant autosomal inheritance was hypothesised. The proband suffered from headaches, and physical examination revealed evident right hemiparesis. The second case started with a hemorrhagic cerebral stroke and the third was asymptomatic on neurological examination. Nuclear magnetic resonance (NMR), performed in two of the three cases, showed lesions whose number and extent were not radiologically characteristic of cavernous angioma. A cerebral biopsy of the proband enabled the diagnosis to be made. Despite the recent introduction of NMR, the nosological classification of familial forms can be difficult when the radiological lesions are atypical. In such cases, cerebral biopsy is not only a valid diagnostic aid, but is also indispensable for obtaining adequate genetic information.

Brain↗
PubMed1996

Gamma Knife radiosurgery in skull base meningiomas. Preliminary experience with 50 cases.

Gamma Knife radiosurgery was performed on 50 patients (10 males and 40 females) with skull base meningiomas (SBMs) between February 1993 and September 1995. The patients ranged in age from 25 to 78 years (mean age 56 years). The location of the tumors was anterior fossa (n = 4), sphenoorbital (n = 2), sellar region (n = 5), cavernous sinus (n = 26), petroclival (n = 12), and occipital foramen (n = 1). The tumor volume ranged from 0.6 to 20 cm3 (mean 8.6 cm3). The mean values for dose planning were edge isodose (EI) 46.7%, edge dose (ED) 18.0 Gy, maximum dose 39.8 Gy, average dose (AD) 25.4 Gy, and average number of isocentres 5.7. The patients were analyzed for five parameters: tumor volume (< 7.5 vs. > or = 7.5 cm3); EI (< 50 vs. > or = 50%); ED (< 18 vs. > or = 18 Gy); AD (< 25 vs. > or = 25 Gy), and primary versus residual or recurrent tumors. The overall frequency of tumor growth control (TGC) was 98%, with 1- and 2-year TGC rates of 97% and 100%, respectively. The most favorable neurological results were obtained with a tumor volume < 7.5 cm3 (p < 0.05), EI > or = 50% (NS), ED > or = 18 Gy (NS) and with primary SBMs (p < 0.01). A favorable TGC was demonstrated at follow-up imaging examinations when the tumor volume was > or = 7.5 cm3 (100% TGC rate), EI < 50% (100%), ED > or = 18 Gy (100%), AD > 25 Gy (100%), in both primary SBMs (100%) and residual or recurrent SBMs (96.5%). To date, only 3 (6%) of the 50 patients have presented signs of neurological worsening related to the Gamma Knife radiosurgery. While no early complications were noted, neuroradiological follow-up did show delayed transient imaging complications (3 edema and 1 radionecrosis; 8% of all patients). In conclusion, our preliminary results seem to confirm that Gamma Knife radiosurgery is an effective and safe adjuvant or a feasible alternative primary treatment in controlling or preventing SBM progression.

Adult↗
PubMed1996

Gamma Knife radiosurgery for intracranial metastases: from local tumor control to increased survival.

We have analyzed a series of 225 patients with intracranial metastases (343 lesions), treated in our department by Gamma Knife radiosurgery over a 30-month period. We have used a modified Pittsburgh protocol and performed 242 procedures on 164 single/78 multiple lesions. Primary tumors were mostly carcinomas of the lung (52%) and breast (11.6%). Neuroradiological localization of the target was usually performed by stereotactic computed tomography. Magnetic resonance imaging was only used in special circumstances. Routine dose planning was assisted by three-dimensional reconstruction programs. Mean tumor volume was larger than expected (5.7 ml). Mean prescription dose and average dose were 21.1 and 29.9 Gy, respectively. Middle- and long-term results were evaluated in a subset of 152 patients (236 lesions) with adequate (> 4 months) follow-up. Mean follow-up was 53.1 weeks with 61/152 patients still living. There was a predominance of retrospectively classified 'not fully eligible cases' among the survivors, mainly because of uncontrolled primary tumor. The 1-year local tumor control rate was 88.2%. Treatment-related radiological (3.9%) and clinical (1.6%) sequelae were minimal. Overall mean survival in these patients (40 weeks) turned out to be higher than that commonly reported after conventional surgical-radiation treatments. It was encouraging that the mean survival of 'fully' eligible patients was 51 weeks. Karnofsky performance status and neurological (Order Grading) performance scores were consistently high for most of the follow-up period. Functional Independence and the Palliative Index were not far from the value of mean survival. The main cause of death remains uncontrolled systemic disease (64.8%). On the other hand, the relative incidence of intracranial tumor progression was considerably decreased. This indicated that these patients should perhaps be treated more aggressively and underlines the need for randomized trials to determine the optimal treatment.

Adult↗
PubMed1995

Prognostic factors in low-grade supratentorial astrocytomas: a uni-multivariate statistical analysis in 76 surgically treated adult patients.

A retrospective uni-multivariate statistical analysis was performed on 32 prognostic factors to investigate their importance in predicting survival in a series of 76 adult patients with low-grade supratentorial astrocytomas treated over a 13-year period. The end point used for this study was the length of survival. The median survival time was 40 months. Overall actuarial survival at 2, 5, and 10 years was 69%, 38%, and 22%, respectively. Radical resection of the neoformation, a higher preoperative Karnofsky performance status (KPS) score, and an age younger than 50 years are strongly correlated with survival; postoperative radiotherapy appears to be associated with increased survival only in patients under 50 years of age.

Actuarial Analysis↗
PubMed1995

Gamma Knife radiosurgery in AIDS-related primary central nervous system lymphoma.

The frequency of AIDS-associated primary central nervous system (PCNS) lymphoma is rapidly increasing in adults and children. In AIDS-related PCNS lymphoma, different authors have reported an overall poorer response rate to conventional radiation compared with immunocompetent patients. This poorer response consists of a significantly positive, although transient effect on survival following radiotherapy (XRT), with a poor toleration for prolonged whole-brain RT (WBR) and with radiation-induced changes within the normal CNS tissue on autopsy examinations after a course of XRT. These observations led us to consider highly focused single-session radiosurgical treatments as a potentially useful therapeutic modality for AIDS-associated PCNS lymphomas. A multi-institutional diagnostic and therapeutic protocol for the evaluation and treatment of AIDS patients with high-risk intracerebral space-occupying lesions has been developed at the University Hospital of Verona. Therapy is based on tumor biopsy. Tumors < or = 3.5 cm in diameter are subjected to Gamma Knife radiosurgery, whereas tumors < or = 4.5 cm are treated with stereotactic brachytherapy. At the Department of Neurosurgery, Verona, Italy, Gamma Knife treatment was performed in 2 cases of deep-seated histologically verified malignant non-Hodgkin's lymphoma. A short-term cliniconeuroradiological follow-up (2 months later) showed neurologic improvement and virtually complete disappearance of the tumor in both patients. The excellent local control and the well-tolerated single-session treatment and absence of brain toxicity signs on CT scan indicate a putative role for Gamma Knife radiosurgery in the treatment of these patients.

Adult↗
PubMed1995

Gamma Knife radiosurgery of primary and metastatic malignant brain tumors, a preliminary report.

Between February 1993 and March 1994, 75 metastases, 16 gliomas and 2 AIDS-related malignant lymphomas were treated with Gamma Knife radiosurgery. Metastatic brain tumors (54% lung cancer, 14% breast cancer, 13.5% melanoma) were the most frequent and clinically rewarding cases. So-called local control was achieved in almost all patients, the vast majority showing neurological improvement associated with radiological disappearance or dramatic shrinkage of the tumor within 9-12 weeks from treatment. According to our modified 'Pittsburgh' protocol, we have treated up to four distinct intracranial lesions, up to a total maximum volume of 20 cm3, with an average surface dose of 25 Gy, with or without additional whole brain radiotherapy (WBR). Preliminary follow-up data seem to confirm increased quality of life and survival rates. The results were particularly striking whenever primary tumors were under control, and were poorly influenced by associated WBR. Gamma Knife treatment was also performed in a selected group of patients with small-to-medium-sized, well-defined, histologically proven, cerebral gliomas. The main indications for radiosurgery were high-risk surgery, multifocal disease, ventricular seeding and unresected or recurrent tumor. The prescription doses ranged from 18 to 30 Gy, with a mean of 27 Gy. Low-grade astrocytomas (9/16 cases) showed the better clinical and radiological response to treatment, with neurological recovery and significant reduction in tumor volume within 3-5 months in 5 of the 9 patients. In 4 of 7 high-grade gliomas, there was little or no response. However, an impressive radiological regression with full clinical recovery was observed in 2 high-grade cases with small tumor volumes: a recurrent, anaplastic 'mixed glioma' of the pineal region and a double ventricular seeding of a previously operated anaplastic astrocytoma.

Brain Neoplasms↗
PubMed1995

Gamma Knife stereotactic radiosurgery of ocular metastases: a case report.

A case of a choroidal metastasis treated with Gamma Knife stereotactic radiosurgery is reported. A 48-year-old Caucasian man afflicted with lung cancer (adenocarcinoma) was referred to the University Hospital of Verona, Italy, for loss of vision in his left eye due to a choroidal mass with exudative retinal detachment. Clinical investigation was conclusive of a well-defined, bilobed choroidal metastasis located in the temporal and inferior portion of the posterior pole of the eye. The lesion was characterized by a maximum thickness of 5.2 mm and a maximum lateral extension of 14 mm. The staging was negative for other metastatic localizations. Using the Gamma Knife technique, a surface dose of 25 Gy was administered at the 50% isodose line using the 8-mm collimator (5 shots) with equally weighted fields. After a 3-month follow-up period, a marked reduction in the lesion size as well as in the exudative retinal detachment was observed. This improvement was unchanged 6 months after the treatment, and the lesion appeared completely controlled. To the best of our knowledge, this is the first case report of an ocular metastasis treated with stereotactic Gamma Knife radiosurgery.

Adenocarcinoma↗
PubMed1995

Stereotactic radiosurgery of uveal melanomas: preliminary results with Gamma Knife treatment.

Twelve cases of uveal melanoma (T3N0M0:11 patients, T4N0M0:1 patient) treated with Gamma Knife stereotactic radiosurgery are reported. Our protocol includes preoperative ocular and systemic assessments with complete ocular examination, ophthalmoscopy, fundus photography, fluorangiography, standardized echography, CT and MRI, chest X-rays, liver echography and blood tests. The follow-up program is mainly based on echographic evaluation of tumor thickness and size. The procedures include fixation of the eye, application of the stereotactic Leksell frame G, CT/MRI localization of the melanoma, dose planning and treatment with the Gamma Knife (B type). A mean surface dose of 55 +/- 10 Gy was administered at the 60-90% isodose curve using 4- to 14-mm collimators and a number of shots ranging from 1 to 6. A significant reduction (10-41%) in echographic thickness of the tumor was shown in 6 cases with a follow-up of 3-12 months. In 4 patients, the tumor size was still unchanged after 1-10 months. The single high-dose radiation delivered to the target and the high spatial accuracy are the main advantages of stereotactic radiosurgery for the treatment of posterior uveal melanomas. A longer followup is needed to further validate this new application of Gamma Knife radiosurgery.

Adult↗
PubMed1995

A euristic approach to the volume reconstruction of arteriovenous malformations from biplane angiography.

Three-dimensional (3D) volume reconstruction is easily feasible with axial, coronal or sagittal CT and MRI scans. On the other hand, radiosurgical treatment of arteriovenous malformations (AVMs) is exclusively based on two orthogonal stereotactic projections, obtained with angiographic procedures. Most commonly AVM volumes have been calculated by assimilating the nidus volume to a prolate ellipsoid. We present an algorithm dedicated to 3D volume reconstruction starting from two stereotactic orthogonal projections. This has been achieved using a euristic approach which has been widely adopted in the artificial intelligence domain. Tests on phantoms of different complexity have shown excellent results. The importance of the algorithm is considerable. Firstly, it allows calculations of complex structures far removed from a regular ellipsoid. Secondly, it permits shape recovery. Thirdly, it provides AVM visualization on axial planes.

Algorithms↗
PubMed1995

Quality assessment of magnetic resonance stereotactic localization for Gamma Knife radiosurgery.

Artifacts in magnetic resonance imaging (MRI) may lead to anatomical distortion and inaccurate stereotactic coordinates. A special phantom for MRI and computed tomography (CT) was built to test the quality and precision of the two neuroradiological procedures. The phantom is fixed with the Leksell frame, and it has 15 orthogonal markers visible by CT and MRI techniques. The coordinates of the markers were calculated first on the CT scans and then on MR images. Two groups of different distortions were analysed: artifacts depending on the frame and its components and artifacts depending on the MR unit and image characteristics. A good target-coordinate correlation was found between CT and MRI in the axial plane, while in the coronal plane there was always a small error. This error is not constant, but changes from test to test, consequently it is hard to reform the image.

Artifacts↗
PubMed1994

p53 protein in low-grade astrocytomas: a study with long-term follow-up.

The immunohistochemical expression of p53 protein (p53) was examined in 52 patients out of a series of 66 patients with low-grade astrocytomas with long-term follow-up. All patients were also evaluated for several clinical and histological features, among which only preoperative Karnofsky score and the extent of surgery were statistically significant parameters to predict outcome on multivariate analysis. p53 accumulation was seen in 46.1% of patients, with a wide range of percentage of positive cells. Median survival for p53-positive and p53-negative patients was 41 and 37 months respectively. The survival curves of p53-positive and -negative patients were not statistically different. However, the curves showed a trend towards a more aggressive course in p53-positive patients beginning 3-4 years after surgery. Five years after diagnosis the survival estimate with the Kaplan-Meier method was 21.2% for patients with p53-positive tumours and 45.9% for patients with p53-negative tumours. This trend is not due to different distribution of major clinical prognostic factors (age, incomplete resection or Karnofsky status). The trend could be related to the time needed by the p53-positive clone to outgrow the rest of the p53-negative neoplastic cell population. This hypothesis is further supported by the fact that the five recurrences which were surgically removed (one anaplastic astrocytoma and four glioblastomas) derived from p53-positive tumours and were themselves intensely p53 positive.

Adolescent↗
PubMed1992

High calcitonin levels in unconscious polytrauma patients.

We measured levels of calcitonin and other markers of calcium and phosphorus metabolism in both unconscious and conscious patients after multiple trauma. We found dramatic increases in calcitonin levels in unconscious patients, and smaller increases in conscious patients. In two cases, very high levels, more than 100 x normal, appeared to be related to more rapid healing of bone. Calcitonin levels were highest immediately after admission and decreased over the ensuing two weeks. The possible relationship between unconsciousness and the increased rate of healing of fractures is discussed.

Adolescent↗
PubMed1991

[High resolution tridimensional study of the blood vessels of the neck and the intracranial circulation with magnetic resonance angiography].

Magnetic Resonance Angiography (MRA) is a modern vascular imaging technique which allows the noninvasive and direct imaging of vessels. The authors aimed at evaluating the diagnostic accuracy of MRA in the study of pathologic conditions in the neck and intracranial vessels; spatial resolution of the technique was also investigated. Twenty-four healthy volunteers and 82 patients suffering from various diseases of the head and neck vessels were included in the study. First of all, MRA capabilities were investigated in visualizing normal vessels of both neck and intracranial circle. The diagnostic accuracy of the method was then evaluated in the study of vascular diseases, and the results compared with conventional/digital angiographic findings. The comparison demonstrated how stenoses and atherosclerotic plaques tend to be overestimated by MRA because of technical artifacts inherent to the technique itself, whereas vascular ulcerations and aneurysms are frequently underestimated. However, this data was steady and therefore evaluable--the exact knowledge of the artifacts making diagnosis reliable. The diagnostic and technical problems relative to the various vascular diseases are discussed. Finally, several hypotheses of diagnostic iter are suggested.

Angiography, Digital Subtraction↗
PubMed1990

[Intra-arterial regional chemotherapy and intensive loco-regional radiotherapy in the treatment of locally advanced cancer of the breast].

A multimodal treatment combining intra-arterial chemotherapy and intensive loco-regional radiotherapy was administered to 55 patients with locally advanced breast cancer. Adjuvant polychemotherapy followed, and eventually endocrino-therapy. Combined intra-arterial chemotherapy and intensive radiotherapy gave excellent results in both primary and lymph node lesions, with 90.9% and 92.2% complete/partial response rates. Three-year and 5-year actuarial survival rates were 69% and 59%, respectively. Patients showing better local responses to combined intra-arterial chemotherapy and intensive radiotherapy had longer survival and less frequent local recurrences. Combined intra-arterial chemotherapy and intensive loco-regional radiotherapy seems to be an effective modality for the treatment of locally advanced breast cancer.

Adult↗
PubMed1990

[Electron beam radiotherapy for loco-regional recurrence of breast cancer].

125 cases of recurrent breast carcinoma (skin nodules or regional lymphnodes) after the primary radical treatment have been treated from 1975 to 1980. Most of these patients were irradiated with 6 MeV electron beams at 50-65 Gy; some of them with 20 MeV electrons. A complete response followed in 68% of lesions, a partial response in 23.2%. The survival at 5 and 10 years was respectively 25.6% and 8.8%. Low energy electron beam therapy is therefore an efficient way of treating loco-regional recurrences of breast carcinoma, after the failure of a radical primary treatment.

Adult↗
PubMed1983

[Cardiac damage during radiotherapy of the mediastinum].

Two cases of patients with neoplasias who were given radiotherapy on the mediastinum are reported. Serious and fully documented ECG alterations were observed in these patients, but the cause is not easy to ascertain, since the results were neither identical nor clinically attributable to a common pathogenetic factor.

Adenocarcinoma, Scirrhous↗