ABSTRACT Lesion volume delineation of Positron Emission Tomography images is challenging because ... more ABSTRACT Lesion volume delineation of Positron Emission Tomography images is challenging because of the low spatial resolution and high noise level. Aim of this work is the development of an operator independent segmentation method of metabolic images. For this purpose, an algorithm for the biological tumor volume delineation based on random walks on graphs has been used. Twenty-four cerebral tumors are segmented to evaluate the functional follow-up after Gamma Knife radiotherapy treatment. Experimental results show that the segmentation algorithm is accurate and has real-time performance. In addition, it can reflect metabolic changes useful to evaluate radiotherapy response in treated patients.
The potential impact of High Intensity Focused Ultrasound (HIFU) into General Medicine and Oncolo... more The potential impact of High Intensity Focused Ultrasound (HIFU) into General Medicine and Oncology seems very high. But, while in the research area, the development of this technique is very rapid and unchallenged, the direct application of HIFU to the human tumour therapy it's hampered by various technical difficulties, which may confine its role to a marginal device in the surgery armamentarium. To deploy the full potential of Focused Ultrasound in Oncology, it seems necessary to review the basic relationship between HIFU and External Beam Radiotherapy (EBRT). This is the aim of the present work.
The quarterly journal of nuclear medicine and molecular imaging: official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of...
In this paper the clinical value of PET for early prediction of tumor response to Erlotinib in pa... more In this paper the clinical value of PET for early prediction of tumor response to Erlotinib in patients with advanced or metastatic nonsmall cell lung cancer (NSCLC) after failure of at least one prior chemotherapy regimen is evaluated. The aim was to compare the early metabolic treatment response using European Organization for Research and Treatment of Cancer (EORTC) 1999 recommendations and PET Response Criteria in Solid Tumors (PERCIST), and the standard treatment response using Response Evaluation Criteria in Solid Tumors (RECIST). Twenty patients with stage IV NSCLC were enrolled prospectively. PET/CT studies were performed before, then 48 h, and 45 days after the initiation of Erlotinib treatment. The lesion with the highest uptake in each patient was evaluated according to EORTC 1999 recommendations, PERCIST and RECIST to assess metabolic and anatomic response. Response classifications were compared statistically using Wilcoxon signedrank test. Disease-Free Survival (DFS) an...
ABSTRACT This study evaluates Operator-Dependent (OD) and Operator-Independent (OI) methods for P... more ABSTRACT This study evaluates Operator-Dependent (OD) and Operator-Independent (OI) methods for Partial Volume effect Correction (PVC) in PET-CT oncological studies. The proposed PVC methods are based on curves of Recovery Coefficients (RC) versus Measured Lesion-to-Background ratios (M-L/B). NEMA IQ phantom PET-CT measurements were performed for RC curves estimation, for M-L/B from 2 to 30. Validation of the PVC methods was performed by 18F-FDG PET-CT studies of a Breast Oncological Phantom, miming from 1cm to 1.56 cm lesions in breasts, for prepared L/B from 14 to 54. An OI PVC method based on a threshold-technique for the estimation of lesion uptake was found the most accurate method (accuracy >80%). PVC methods were applied to the SUV quantification of 11 18F-FDG PET-CT oncological studies. Results prove PV strongly affects lesion quantification and needs to be corrected. When a decrement in the PET lesion volume is observed, PVC-SUV always decreased well fitting the clinical assessment, as from diagnostic report. When an increment in the PET lesion volume is observed, results suggest PVC-SUV should be used together with the PET lesion volume for a better characterization or therapy response of oncological lesions. KeywordsPET-CT-quantification-PV-RC
Partial volume effect (PVE) in positron emission tomography (PET), as a consequence of the PET li... more Partial volume effect (PVE) in positron emission tomography (PET), as a consequence of the PET limited spatial resolution, causes underestimation of radiotracer uptake in oncological lesions and needs to be corrected. Aim of this work was to develop a method for PVE correction of PET-CT oncological studies, based on curves of recovery coefficients (RC) as a function of measured Lesion-to-Background
The existence of dual inner ear pathology such as unilateral Meniere's disease (MD) with a co... more The existence of dual inner ear pathology such as unilateral Meniere's disease (MD) with a contralateral vestibular schwannoma (VS) is very rare, but provides the otologist with a significant management dilemma. In this study, we present 5 cases of unilateral disabling MD with a contralateral VS in the better hearing ear. Conservative management of the VS is mandated unless there are impending complications, with management directed toward controlling the vertigo attributed to MD. If and when the VS requires intervention, or the hearing in that ear deteriorates to unserviceable levels, cochlear implant of the ear affected by MD prior to addressing the VS provides optimal management.
Description of a technique of middle ear obliteration (MEO) with blind sac closure of the externa... more Description of a technique of middle ear obliteration (MEO) with blind sac closure of the external auditory canal with discussion of the indications for its use in cases of recalcitrant chronic otitis and in far advanced disease. All patients underwent otologic examination and audiologic and radiologic assessments in a quaternary center. Fifty-three cases of MEO were analyzed. For 9 patients, primary surgery was performed. One case of residual disease was identified. The minimum follow-up was 2 years. The decision to perform a MEO is one that is made only rarely. However, this is a technique that should be part of every otologist's armamentarium. Whereas the indications for its use are more straightforward in an ear with unserviceable hearing, a MEO is occasionally required in an ear with good cochlear reserve due the severity of disease. All of our patients managed by MEO have had an improvement in their quality of life and a high rate of successful eradication of disease.
Partial Volume Effect (PVE) in PET-CT oncological studies affects the estimation of quantitative ... more Partial Volume Effect (PVE) in PET-CT oncological studies affects the estimation of quantitative parameters useful for lesion malignancy differentiation and for monitoring disease and response to therapy. The aim of this work was to investigate the clinical feasibility and accuracy of PVE correction methods based on Recovery Coefficients (RC) as function of measured Le- sion-to-Background ratio and measured lesion volume
The aim of this study was to verify the efficacy and the safety of transtympanic dexamethasone to... more The aim of this study was to verify the efficacy and the safety of transtympanic dexamethasone to treat sudden sensorineural hearing loss as first and single drug method. Considering ethical implication of performing a mininvasive procedure on middle ear, we matched such proposed treatment with systemic prednisone administration that represents the widest adopted protocol. Randomized prospective study was conducted. The inclusion criterion was a sudden sensorineural hearing loss of at least 30 dB across three contiguous frequencies over a period of 24 h. Group A received transtympanic steroid injections; Group B received oral administration of steroids. 25 patients were treated with transtympanic therapy whereas 21 underwent systemic treatment. The mean of initial PTA was 59 dB for the whole series: 65 dB for group A and 51 dB for group B. The recovery better than 10 dB was obtained in 80% of patients of group A and in 17 81% of patients of group B, with a total of 80.5%. The mean relative gain in PTA was 41.16% in the group A and 44.7% in the group B. In the frequencies tested (0.5, 1, 2, and 4 kHz) PTA improvements after transtympanic treatment were higher than after systemic treatment, but these differences were not statistically significant (P = 0.61). Both transtympanic and systemic treatment had similar clinical recovery times. This prospective randomized clinical study showed good result in terms of hearing recovery, better than the expected results of the simple observation without treatment. We can consider transtympanic administration as a first line treatment, because of the statistical analysis confirmed similar results with systemic therapy, reducing possible side effects of systemic drug administration. The delay of treatment does not influence the outcome, allowing treating patients within 10 days of onset.
ABSTRACT Lesion volume delineation of Positron Emission Tomography images is challenging because ... more ABSTRACT Lesion volume delineation of Positron Emission Tomography images is challenging because of the low spatial resolution and high noise level. Aim of this work is the development of an operator independent segmentation method of metabolic images. For this purpose, an algorithm for the biological tumor volume delineation based on random walks on graphs has been used. Twenty-four cerebral tumors are segmented to evaluate the functional follow-up after Gamma Knife radiotherapy treatment. Experimental results show that the segmentation algorithm is accurate and has real-time performance. In addition, it can reflect metabolic changes useful to evaluate radiotherapy response in treated patients.
The potential impact of High Intensity Focused Ultrasound (HIFU) into General Medicine and Oncolo... more The potential impact of High Intensity Focused Ultrasound (HIFU) into General Medicine and Oncology seems very high. But, while in the research area, the development of this technique is very rapid and unchallenged, the direct application of HIFU to the human tumour therapy it's hampered by various technical difficulties, which may confine its role to a marginal device in the surgery armamentarium. To deploy the full potential of Focused Ultrasound in Oncology, it seems necessary to review the basic relationship between HIFU and External Beam Radiotherapy (EBRT). This is the aim of the present work.
The quarterly journal of nuclear medicine and molecular imaging: official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of...
In this paper the clinical value of PET for early prediction of tumor response to Erlotinib in pa... more In this paper the clinical value of PET for early prediction of tumor response to Erlotinib in patients with advanced or metastatic nonsmall cell lung cancer (NSCLC) after failure of at least one prior chemotherapy regimen is evaluated. The aim was to compare the early metabolic treatment response using European Organization for Research and Treatment of Cancer (EORTC) 1999 recommendations and PET Response Criteria in Solid Tumors (PERCIST), and the standard treatment response using Response Evaluation Criteria in Solid Tumors (RECIST). Twenty patients with stage IV NSCLC were enrolled prospectively. PET/CT studies were performed before, then 48 h, and 45 days after the initiation of Erlotinib treatment. The lesion with the highest uptake in each patient was evaluated according to EORTC 1999 recommendations, PERCIST and RECIST to assess metabolic and anatomic response. Response classifications were compared statistically using Wilcoxon signedrank test. Disease-Free Survival (DFS) an...
ABSTRACT This study evaluates Operator-Dependent (OD) and Operator-Independent (OI) methods for P... more ABSTRACT This study evaluates Operator-Dependent (OD) and Operator-Independent (OI) methods for Partial Volume effect Correction (PVC) in PET-CT oncological studies. The proposed PVC methods are based on curves of Recovery Coefficients (RC) versus Measured Lesion-to-Background ratios (M-L/B). NEMA IQ phantom PET-CT measurements were performed for RC curves estimation, for M-L/B from 2 to 30. Validation of the PVC methods was performed by 18F-FDG PET-CT studies of a Breast Oncological Phantom, miming from 1cm to 1.56 cm lesions in breasts, for prepared L/B from 14 to 54. An OI PVC method based on a threshold-technique for the estimation of lesion uptake was found the most accurate method (accuracy >80%). PVC methods were applied to the SUV quantification of 11 18F-FDG PET-CT oncological studies. Results prove PV strongly affects lesion quantification and needs to be corrected. When a decrement in the PET lesion volume is observed, PVC-SUV always decreased well fitting the clinical assessment, as from diagnostic report. When an increment in the PET lesion volume is observed, results suggest PVC-SUV should be used together with the PET lesion volume for a better characterization or therapy response of oncological lesions. KeywordsPET-CT-quantification-PV-RC
Partial volume effect (PVE) in positron emission tomography (PET), as a consequence of the PET li... more Partial volume effect (PVE) in positron emission tomography (PET), as a consequence of the PET limited spatial resolution, causes underestimation of radiotracer uptake in oncological lesions and needs to be corrected. Aim of this work was to develop a method for PVE correction of PET-CT oncological studies, based on curves of recovery coefficients (RC) as a function of measured Lesion-to-Background
The existence of dual inner ear pathology such as unilateral Meniere's disease (MD) with a co... more The existence of dual inner ear pathology such as unilateral Meniere's disease (MD) with a contralateral vestibular schwannoma (VS) is very rare, but provides the otologist with a significant management dilemma. In this study, we present 5 cases of unilateral disabling MD with a contralateral VS in the better hearing ear. Conservative management of the VS is mandated unless there are impending complications, with management directed toward controlling the vertigo attributed to MD. If and when the VS requires intervention, or the hearing in that ear deteriorates to unserviceable levels, cochlear implant of the ear affected by MD prior to addressing the VS provides optimal management.
Description of a technique of middle ear obliteration (MEO) with blind sac closure of the externa... more Description of a technique of middle ear obliteration (MEO) with blind sac closure of the external auditory canal with discussion of the indications for its use in cases of recalcitrant chronic otitis and in far advanced disease. All patients underwent otologic examination and audiologic and radiologic assessments in a quaternary center. Fifty-three cases of MEO were analyzed. For 9 patients, primary surgery was performed. One case of residual disease was identified. The minimum follow-up was 2 years. The decision to perform a MEO is one that is made only rarely. However, this is a technique that should be part of every otologist's armamentarium. Whereas the indications for its use are more straightforward in an ear with unserviceable hearing, a MEO is occasionally required in an ear with good cochlear reserve due the severity of disease. All of our patients managed by MEO have had an improvement in their quality of life and a high rate of successful eradication of disease.
Partial Volume Effect (PVE) in PET-CT oncological studies affects the estimation of quantitative ... more Partial Volume Effect (PVE) in PET-CT oncological studies affects the estimation of quantitative parameters useful for lesion malignancy differentiation and for monitoring disease and response to therapy. The aim of this work was to investigate the clinical feasibility and accuracy of PVE correction methods based on Recovery Coefficients (RC) as function of measured Le- sion-to-Background ratio and measured lesion volume
The aim of this study was to verify the efficacy and the safety of transtympanic dexamethasone to... more The aim of this study was to verify the efficacy and the safety of transtympanic dexamethasone to treat sudden sensorineural hearing loss as first and single drug method. Considering ethical implication of performing a mininvasive procedure on middle ear, we matched such proposed treatment with systemic prednisone administration that represents the widest adopted protocol. Randomized prospective study was conducted. The inclusion criterion was a sudden sensorineural hearing loss of at least 30 dB across three contiguous frequencies over a period of 24 h. Group A received transtympanic steroid injections; Group B received oral administration of steroids. 25 patients were treated with transtympanic therapy whereas 21 underwent systemic treatment. The mean of initial PTA was 59 dB for the whole series: 65 dB for group A and 51 dB for group B. The recovery better than 10 dB was obtained in 80% of patients of group A and in 17 81% of patients of group B, with a total of 80.5%. The mean relative gain in PTA was 41.16% in the group A and 44.7% in the group B. In the frequencies tested (0.5, 1, 2, and 4 kHz) PTA improvements after transtympanic treatment were higher than after systemic treatment, but these differences were not statistically significant (P = 0.61). Both transtympanic and systemic treatment had similar clinical recovery times. This prospective randomized clinical study showed good result in terms of hearing recovery, better than the expected results of the simple observation without treatment. We can consider transtympanic administration as a first line treatment, because of the statistical analysis confirmed similar results with systemic therapy, reducing possible side effects of systemic drug administration. The delay of treatment does not influence the outcome, allowing treating patients within 10 days of onset.
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Papers by Alessandro Stefano