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R Foroni

Publications and source records attributed to R Foroni.

At least 19 recordsLinked to original sources
PubMed2005

Gamma knife radiosurgery in skull base meningiomas: a possible relationship between somatostatin receptor decrease and early neurological improvement without tumour shrinkage at short-term imaging follow-up.

BACKGROUND: This study investigates a possible relationship between the effects of gamma knife (GK) on meningioma somatostatin receptors (SRs) and the high rate of early neurological improvement without tumour reduction at short-term imaging follow-up. METHODS: From December 1997 to December 2002, somatostatin receptor scintigraphy (SRS) using an 111Indium-labelled somatostatin analogue, Octreotide, was performed both before and 7-12 months after radiosurgery in 20 patients with intracranial meningiomas. Semiquantitative data were calculated as an SRS index. FINDINGS: The pre-GK SRS index was always > 1, averaging 4.44 +/- 3.20. There were no statistically significant differences between the pre-GK average values of primary (4.80 +/- 3.65) and residual (3.75 +/- 1.93) meningiomas. At the first clinical/MRI follow-up, the neurological examination had improved in 15/20 (75%) and had not changed in 5/20 patients. A corresponding slight tumour shrinkage on high-resolution MRI was documented in 3/20 cases only. The post-GK average SRS index was lower than pre-GK values both in primary (3.87 +/- 3.19) and in adjuvant (2.52 +/- 1.14) treatments, but the differences were not significant. However, the subgroup of patients with early neurological improvement showed a higher pre-GK average SRS index (5.21 +/- 3.33) and a more substantial post-GK average SRS index decrease (3.86 +/- 3.00) than the patients whose clinical condition remained stable (2.10 +/- 0.59 and 1.99 +/- 0.55, respectively). The difference between the two subgroups of patients proved to be statistically significant (P < 0.05). CONCLUSIONS: Our preliminary findings suggest a possible relationship between a decrease in the concentration of SRs on meningioma cells at short-term functional imaging follow-up after radiosurgery and early neurological improvement.

Adult↗
PubMed2005

Gamma knife radiosurgery in brain metastases from testicular tumors.

To our knowledge, there are no published reports on the effectiveness of radiosurgery in the management of brain metastases from testicular nonseminomatous germ cell tumor. The authors evaluate the results of gamma knife (GK) treatment in three patients with these unusual intracranial lesions. Between April 1995 and July 2001, three patients with brain metastasis from testicular nonseminomatous germ cell tumor underwent adjuvant radiosurgery at our department. The primary tumor had been surgically removed in all cases. At diagnosis, one patient was stage IB and two were stage III poor risk. Chemotherapy and whole brain radiotherapy were administered before radiosurgery in all cases. Pre-GK radiotherapy was administered with a daily fraction dosage of 1.8-2.0 Gy. The indications for radiosurgery were tumor volume <20 cm3, microsurgery too risky, refusal of surgery. All the lesions were located in eloquent brain areas. Post-GK high-dose chemotherapy with autologous peripheral-blood stem-cell rescue was administered in two cases due to systemic recurrence of the disease. All patients are still alive with a median and mean follow-up period after radiosurgery of 63 and 68.3 mo, respectively. They had no neurological deficits at the latest examination. Neuroradiological follow-up invariably showed tumor growth control (complete response in two cases and partial response in one) with typically delayed post-radiosurgical imaging changes (transient in two cases and long-lasting in one). In conclusion, GK seems to be highly effective and safe in brain metastases from testicular nonseminomatous germ cell tumor. In cases with diffuse metastatic brain involvement, the whole brain radiotherapy preceding radiosurgery should be delivered with 1.8 Gy daily fraction to prevent the risk of long-lasting post-radiosurgical imaging changes.

Adolescent↗
PubMed2004

Multimodality stereotactic approach to the treatment of cystic craniopharyngiomas.

OBJECTIVES: To present the therapeutic reliability of a multimodality stereotactic approach (MSA) to cystic craniopharyngiomas (CPs), combining neuroendoscopy, intracavitary bleomycin and gamma knife (GK) radiosurgery. METHODS: 8 patients with mono- or multicystic CP (7/8 regrowths/recurrence) underwent stereotactic neuroendoscopy and subsequently treatment with intracavitary bleomycin and GK. They were clinically characterized by hypopituitarism (7 cases), visual impairment (7), endocranial hypertension (7), cognitive and behavioral disturbances (3), and cranial nerve deficits or focal signs (3). Concomitant hydrocephalus was observed in 3/8 patients. According to Backlund's classification, the treated CPs were classified as type A (3 cases), type Cc (4 cases) and type Dc (1 case). In all 8 patients, neuroendoscopy allowed evacuation of the cyst and, in multi-cystic CPs, fenestration of the interposed septa so as to create a single communicating cavity. Thus, a single catheter and Ommaya reservoir system was sufficient both for subsequent aspirations and for bleomycin injection (doses of 1.5-3 mg, usually repeated every 7-8 days, with total doses ranging from 3-35 mg). GK radiosurgery was carried out at a later stage on the collapsed cyst in type A forms, while in types Cc and Dc, it was used on the solid nodule on the same day as the neuroendoscopy. RESULTS: The median follow-up period was 42.5 months. Neurological improvement was observed in 8/8 patients. A complete response (reduction of the entire tumor volume > 90 %) was observed in 3/8 cases (type A), a subtotal response (reduction > 50 %) in 4/8 cases (types Cc and Dc), and a partial response (reduction < 50 %) in 1/8 cases (type Cc). Treatment of CP alone led to normalization of the ventricular morphology in the 3 patients with associated hydrocephalus. Transient GK-related visual worsening was recorded in one case only. One patient died because of ventriculitis after repeated shunt replacements. CONCLUSIONS: This MSA seems to be an effective and safe treatment alternative to microsurgery, above all in patients with regrowing/recurrent cystic CPs.

Adolescent↗
PubMed2002

Gamma knife radiosurgery in the management of arteriovenous malformations of the Basal Ganglia region of the brain.

OBJECTIVES: The authors report the results of gamma knife (GK) radiosurgery on a clinical series of selected patients with basal ganglia arteriovenous malformations (BGAVMs) in the brain. Clinical, epidemiological, anatomical and functional characteristics of BGAVMs and of supratentorial cortical AVMs are comparatively analyzed, and their influence on radiosurgical outcome is discussed. METHODS: At our Department, 33 BGAVMs (21 with FU > 2 years) and 209 cortical AVMs (110 with FU > 2 years) with a radiosurgical volume </= 10 cc were treated with GK between February 1993 and July 2001. Mean age, male/female ratio (M/F), and incidence of haemorrhagic onset in the two subgroups of patients were as follows: 25.5 years (5 - 62 years), 16 M/17 F, and 30/33 (91%) in BGAVMs; 34.4 years (8 - 74 years), 124 M/85 F, and 107/209 (51%) in cortical AVMs. Statistical analysis performed using the contingency table method and deviance analysis according to generalized linear models showed that the differences in age and incidence of haemorrhagic onset were highly significant. RESULTS: The rates of complete obliteration, permanent morbidity, bleeding/rebleeding during the latency period, and unsuccessful embolisation attempts in the two subgroups of patients were as follows: 81%, 4%, 8%, and 41.7%, respectively, in BGAVMs; 85.5%, 2%, 2%, and 2% in cortical AVMs. Statistical analysis did not show any significant difference between the two subgroups of patients in the rates of complete obliteration, permanent morbidity, or latency period bleeding/rebleeding, while difference in failed embolization rates resulted to be highly significant (P = 0.00003). CONCLUSIONS: In our experience, the different clinical, epidemiological and anatomico-functional characteristics of BGAVMs and cortical AVMs do not seem to influence the radiosurgical outcome, since complete obliteration and permanent neurological sequelae rates were very similar in these two subgroups of patients. GK may be considered the first choice treatment modality for BGAVMs with < 10 cc volume, since it offers a very high cure rate, very low permanent morbidity, and zero mortality. Although haemorrhagic onset is much more frequent in BGAVMs than in cortical AVMs, the difference between the bleeding/rebleeding rates in the two subgroups of patients during the latency period is not statistically significant, and seems to be limited to the first year after GK.

Adolescent↗
PubMed2001

Gamma knife radiosurgery in meningiomas of the posterior fossa. Experience with 62 treated lesions.

OBJECTIVES: This study was undertaken to assess the role of the gamma knife (GK) in the treatment of meningiomas of the posterior cranial fossa (PCF) and to statistically analyze the predictability of arbitrarily-selected prognostic factors in such treatment. METHODS: From February 1993 to November 1998, 57 patients underwent GK treatment for 62 meningiomas of the PCF (19 M/38 F; average age, 57.5 years, ranging from 25 - 82 years). Tumor sites included: foramen jugular-petrous bone (26/62), petroclival (23/62), cerebellar convexity (6/62), tentorium (6/62), and foramen magnum (1/62). Single lesions were treated in 44/62 cases while meningiomatosis was treated in the remaining 18. Post-operative residual or recurrent tumor was found in 27/62 patients and, in 7/27, histology documented characteristics of biological aggressiveness (GII/III). Indications for radiosurgery included: advanced age, high operative risk, tumor volume < 20 ml, inoperable or refused for additional surgery. The prognostic factors statistically analyzed included: meningiomatosis (yes/no), radiosurgery as primary or adjuvant treatment, GI vs. GII/III histology, and tumor volume (< or = 5 ml vs. > 5 ml). RESULTS: The observation periods varied from 6 to 64.3 months (median 28.7 months). At the end of the study, 53/57 patients were alive and reported to be in stable or improved neurological condition. The cause of death for the remaining 4 patients included: 2 deaths associated with tumor progression, while 2 died due to causes unrelated to the disease. Neuroradiological evaluation documented the disappearance or reduction of the meningioma mass in 34/62 (55 %) cases, a stable imaging picture in 25/62 (40 %), and a progression only in 3/62 (5 %). To date, there have been no reported cases of post-GK permanent morbidity or mortality. Side effects observed were of a transient nature due to post-radiosurgical edema (6.5 %). With regard to statistical analysis, the only factor to appear to significantly influence efficacy of radiosurgery for tumor growth control (TGC) was the biological nature of the meningioma (chi(2) = 2.708). The presence of meningiomatosis, SR as a primary or adjuvant treatment nor tumor volume were shown to statistically influence tumor behavior after GK. CONCLUSIONS: The excellent results obtained for TGC with minimal associated side effects suggest that GK is an effective therapeutic tool also for treatment of PCF meningiomas.

Adult↗
PubMed2000

An objective method for detecting time-dependent effects in graft survival.

The proportional hazards model has become increasingly important in the analysis of censored survival data after transplantation. Neverthless, in clinical transplantation it is still undefined how the influence of covariates changes over time. The additive regression model is an alternative (or extension) to the Cox model. It results in plots (Aalen plots) that may give information on the effect of covariates over time by way of the cumulative regression function plots. A total of 386 primary cadaveric kidney transplants performed between 1984 and 1996 were included in our analysis. The follow-up period ranged from 24 to 156 months. According to Aalen, an additive regression model was used and plots for the detection of time-dependent effects of covariates were determined. Patients dying with functioning grafts were classed as graft failures. Factors potentially affecting graft outcome, such as sex, donor and recipient's age, HLA A-B match, cold ischaemia time (CIT), delayed graft function (DGF), serum creatinine at 1 month (Cr1), rejection episodes within 3 months (R3), and type of brain death (BD), were considered. The slopes of the plots by donor age, DGF, HLA A-B match, R3, Cr1 and BD appear to have a significant influence throughout the observation period, with different time-dependent effects on graft survival. Slopes for DGF, Cr1, and age of donor are positive (increased hazard), while slopes for HLA match and BD are negative (decreased hazard). Estimated regression functions for DGF, donor age and Cr1 show a prompt slope (within 3 months); the covariate R3 has a clear influence for about 5 years, and then seems to disappear; and BD appears to have a consistent effect over the entire period. The additive regression model with Aalen plots represents a useful technique in the analysis of survival data after kidney transplantation. Some covariates, such as R3, may often lose their effects on graft survival, with a relevant clinical impact. Others have a clear and additive influence over the entire period (BD), while the effects of donor age, DGF and CR1 each appear to have a prompt effect in the outcome.

Adult↗
PubMed2000

Forecasting the growth of multicell tumour spheroids: implications for the dynamic growth of solid tumours.

The growth dynamics of multicell tumour spheroids (MTS) were analysed by means of mathematical techniques derived from signal processing theory. Volume vs. time trajectories of individual spheroids were fitted with the Gompertz growth equation and the residuals (i.e. experimental volume determinations minus calculated values by fitting) were analysed by fast fourier transform and power spectrum. Residuals were not randomly distributed around calculated growth trajectories demonstrating that the Gompertz model partially approximates the growth kinetics of three-dimensional tumour cell aggregates. Power spectra decreased with increasing frequency following a 1/f(delta) power-law. Our findings suggest the existence of a source of 'internal' variability driving the time-evolution of MTS growth. Based on these observations, a new stochastic Gompertzian-like mathematical model was developed which allowed us to forecast the growth of MTS. In this model, white noise is additively superimposed to the trend described by the Gompertz growth equation and integrated to mimic the observed intrinsic variability of MTS growth. A correlation was found between the intensity of the added noise and the particular upper limit of volume size reached by each spheroid within two MTS populations obtained with two different cell lines. The dynamic forces generating the growth variability of three-dimensional tumour cell aggregates also determine the fate of spheroid growth with a strong predictive significance. These findings suggest a new approach to measure tumour growth potential.

Animals↗
PubMed2000

Gamma knife radiosurgery as a primary treatment for prolactinomas.

OBJECT: The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas. METHODS: Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6-72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases. Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children. There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed. CONCLUSIONS: Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (> or = 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.

Humans↗
PubMed1999

A non-parametric method for the analysis of experimental tumour growth data.

Analysis of tumour growth is required to investigate the biology of tumours and to determine the effects of new anti-tumour therapies. A non-parametric mathematical method for the analysis of a set of experimental tumour growth data is described. The method is based on the similarity between time series of tumour size measurements (e.g. tumour volume), similarity being defined as the Euclidean distance between data measured for each tumour at the same time. Subsets of similar time series are found for a given population of tumours. A biologically meaningful parameter H has been derived which is a measure of the scattering of experimental volume samples. The method has been applied to the analysis of the growth of (i) untreated multicellular tumour spheroids obtained with different cell lines and (ii) spheroids treated with cytotoxic drugs (immunotoxins). Results are compared with those previously obtained by applying the classical Gompertz growth model to the analysis of treated and untreated spheroids.

Animals↗
PubMed1999

Oscillating growth patterns of multicellular tumour spheroids.

The growth kinetics of 9L (rat glioblastoma cell line) and U118 (human glioblastoma cell line) multicellular tumour spheroids (MTS) have been investigated by non-linear least square fitting of individual growth curves with the Gompertz growth equation and power spectrum analysis of residuals. Residuals were not randomly distributed around calculated growth trajectories. At least one main frequency was found for all analysed MTS growth curves, demonstrating the existence of time-dependent periodic fluctuations of MTS volume dimensions. Similar periodic oscillations of MTS volume dimensions were also observed for MTS generated using cloned 9L cells. However, we found significant differences in the growth kinetics of MTS obtained with cloned cells if compared to the growth kinetics of MTS obtained with polyclonal cells. Our findings demonstrate that the growth patterns of three-dimensional tumour cell cultures are more complex than has been previously predicted using traditional continuous growth models.

Animals↗
PubMed1996

Shape recovery and volume calculation from biplane angiography in the stereotactic radiosurgical treatment of arteriovenous malformations.

PURPOSE: A model for calculating the three-dimensional volume of arteriovenous malformations from biplane angiography. METHODS AND MATERIAL: Three-dimensional (3D) volume reconstruction is easily feasible with axial, coronal, or sagittal computer tomography (CT) and nuclear magnetic resonance (NMR) scans. On the other hand, radiosurgical treatment of arteriovenous malformations (AVM) 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 structure reconstruction starting from two orthogonal stereotactic projections. This has been achieved using a heuristic approach, which has been widely adopted in the artificial intelligence domain. RESULTS: Tests on phantom of different complexity have shown excellent results. CONCLUSION: The importance of the algorithm is considerable. As a matter of fact: (a) it allows calculations of complex structures far away from regular ellipsoid; (b) it permits shape recovery; (c) it provides AVM visualization on axial planes.

Adolescent↗
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

Digital subtraction angiography for arteriovenous malformations in stereotactic radiosurgery.

Images coming from digital subtraction angiography (DSA) are affected by a perspective distortion due to the use of image intensifiers. As a result, DSA cannot be used for the accurate definition of stereotactic coordinates. A correction method has been developed to enable the use of DSA for the radiosurgery of arteriovnous malformations. A software program and a special phantom tool were employed. The phantom is made by a computer-controlled drilling machine which makes holes in a Plexiglas plate. It has 865 calibration steel spheres with coordinates determined with a precision of 0.01 mm. A calibration image is acquired by a personal computer, and the software calculates the transformation algorithm to superimpose the image on the known positions of the phantom. This algorithm is saved and then recalled to transform the diagnostic images.

Angiography, Digital Subtraction↗
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

Heterogeneous response of individual multicellular tumour spheroids to immunotoxins and ricin toxin.

The cytoreductive effects of anti-transferrin receptor (anti-TfnR) immunotoxins (ITs) and of ricin toxin against tumour micromasses have been evaluated in a multicellular tumour spheroid (MTS) model. More than 600 (656) MTSs obtained with human breast carcinoma (MCF7) or rat glioblastoma (9L) cell lines were treated individually with ITs or toxin and the effects induced by the treatment were measured for each MTS as volume variation vs time by applying the Gompertz growth model. Two dose-dependent patterns of MTS growth were observed in MTSs of both cell lines in response to IT or toxin treatment: (1) complete inhibition of MTS growth ('sterilisation'); and (2) partial/complete inhibition ('heterogeneous response'). Within the range of IT or toxin concentrations resulting in partial inhibition of MTS growth, the sensitivity of treated MTSs was extremely heterogeneous (the cytoreductive effects varying between 0.1 and 4 logs of cells killed for a given IT or toxin concentration). Analysis of the post-treatment regrowth kinetics indicated that treated non-sterilised and control MTSs reached the same final limiting volumes. However, the doubling time estimated for the surviving cells of treated MCF7 and 9L MTSs ranged between 15 and 50 h, indicating that each MTS had individual growing potential. In conclusion, our results indicate that at substerilising IT concentrations individual heterogenicity of MTSs may greatly influence the cytoreductive potential of ITs. An implication of our study is that the efficacy of an IT treatment in eradicating disseminated micrometastases may not be predictable a priori. The MTS model that we describe in this paper may help in dissecting out factors limiting the effect of ITs in three-dimensional tumours.

Animals↗
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↗