Egesta Lopci

Comparison of 18F-dopa PET/CT and 123I-MIBG scintigraphy in stage 3 and 4 neuroblastoma: a pilot study

Purpose18F-Dopa positron emission tomography (PET)/CT has proved a valuable tool for the assessment of neuroendocrine tumours. So far no data are available on 18F-dopa utilization in neuroblastoma (NB). Our aim was to evaluate the role of 18F-dopa PET/CT in NB and compare its diagnostic value with that of 123I-metaiodobenzylguanidine (MIBG) scintigraphy in patients affected by stage 3–4 NB.MethodsWe prospectively evaluated 28 paired 123I-MIBG and 18F-dopa PET/CT scans in 19 patients: 4 at the time of the NB diagnosis and 15 when NB relapse was suspected. For both imaging modalities we performed a scan-based and a lesion-based analysis and calculated sensitivity, specificity and accuracy. The standard of reference was based on clinical, imaging and histological data.ResultsNB localizations were confirmed in 17 of 19 patients. 18F-Dopa PET/CT and 123I-MIBG scintigraphy properly detected disease in 16 (94%) and 11 (65%), respectively. On scan-based analysis, 18F-dopa PET/CT showed a sensitivity and accuracy of 95 and 96%, respectively, while 123I-MIBG scanning showed a sensitivity and accuracy of 68 and 64%, respectively (p < 0.05). No significant difference in terms of specificity was found. In 9 of 28 paired scans (32%) PET/CT results influenced the patient management. We identified 156 NB localizations, 141 of which were correctly detected by 18F-dopa PET/CT and 88 by MIBG. On lesion-based analysis, 18F-dopa PET/CT showed a sensitivity and accuracy of 90% whereas 123I-MIBG scintigraphy showed a sensitivity and accuracy of 56 and 57%, respectively (p < 0.001). No significant difference in terms of specificity was found.ConclusionIn our NB population 18F-dopa PET/CT displayed higher overall accuracy than 123I-MIBG scintigraphy. Consequently, we suggest 18F-dopa PET/CT as a new opportunity for NB assessment.

The role of Fluorine-18-Fluorodeoxyglucose positron emission tomography in staging and restaging of patients with osteosarcoma.

Background. The objective of this study is to systematically review the role of positron emission tomography (PET) and PET/computed tomography (PET/CT) with Fluorine-18-Fluorodeoxyglucose (FDG) in patients with osteosarcoma (OS). Methods. A comprehensive literature search of published studies through October 10th, 2012 in PubMed/MEDLINE, Embase and Scopus databases regarding whole-body FDG-PET and FDG-PET/CT in patients with OS was performed. Results. We identified 13 studies including 289 patients with OS. With regard to the staging and restaging of OS, the diagnostic performance of FDG-PET and PET/CT seem to be high; FDG-PET and PET/CT seem to be superior to bone scintigraphy and conventional imaging methods in detecting bone metastases; conversely, spiral CT seems to be superior to FDG-PET in detecting pulmonary metastases from OS Conclusions. Metabolic imaging may provide additional information in the evaluation of OS patients. The combination of FDG-PET or FDG-PET/CT with conventional imaging methods seems to be a valuable tool in the staging and restaging of OS and may have a relevant impact on the treatment planning.

Salvage therapy of intraprostatic failure after radical external-beam radiotherapy for prostate cancer: A review

Radical external-beam radiotherapy (EBRT) is a standard treatment for prostate cancer (PC) patients. Despite this, the rate of intraprostatic relapses after primary EBRT is still not negligible. There is no consensus on the most appropriate management of these patients after EBRT failure. Treatment strategies after PC relapse are strongly influenced by the effective site of the tumor recurrence, and thus the instrumental evaluation with different imaging techniques becomes crucial. In cases of demonstrated intraprostatic failure, several systemic (androgen deprivation therapy) or local (salvage prostatectomy, cryotherapy, high-intensity focused ultrasound, brachytherapy, stereotactic EBRT) treatment options could be proposed and are currently delivered by clinicians with a variety of results. In this review we analyze the correct definition of intraprostatic relapse after radiotherapy, focusing on the recent developments in imaging to detect intraprostatic recurrence. Furthermore, all available salvage treatment options after a radiation therapy local failure are presented and thoroughly discussed.

18F-DOPA PET/CT in neuroblastoma: comparison of conventional imaging with CT/MR.

Aim: Role of 18F-DOPA PET/CT in neuroblastoma (NB) compared with CT/MR. Materials and Methods: In all, 21 patients (M:F = 14:7; mean age, 7.4 years) affected by advanced stage NB (III-IV) were prospectively enrolled. Overall, 37 paired 18F-DOPA PET and CT/MR scans were performed, and for each, we identified site and number of lesions. Standard of reference was based on a multidisciplinary assessment, including 123I-MIBG, selective biopsy, and clinical-instrumental monitoring. Both scan-based and a lesion-based analysis was performed, and for each modality, we calculated sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy. Results: On the scan-based analysis, 18F-DOPA PET and CT/MR showed the following rates: sensitivity, specificity, NPV, PPV, and accuracy were 100%, 92.3%, 100%, 96%, and 97.3% versus 91.7%, 61.5%, 80%, 81.5%, and 81.1%, respectively (P = 0.014). Overall 179 findings were reported at imaging, of which 139 (77.7%) resulted true sites of disease at final outcome. On the lesion-based analysis, the 2 imaging modalities showed the following sensitivity, specificity, NPV, PPV, and accuracy rates: 90.6%, 90%, 73.5%, 96.9%, and 90.5% versus 47.5%, 27.5%, 13.1%, 69.5%, and 43% (P < 0.00001). Conclusions: In our study, 18F-DOPA PET/CT results more accurate than CT/MR in advanced stage NB therefore should be taken into consideration for the diagnostic workup of these patients.

The role of 18F-FDG PET/CT in the metabolic characterization of lung nodules in pediatric patients with bone sarcoma†‡

The principal aim of this study was to identify the lowest nodule diameter and the SUVmax capable of characterizing lung nodules in pediatric patients with bone sarcoma.

MACOP-B regimen in the treatment of adult Langerhans cell histiocytosis: experience on seven patients

BACKGROUND Adult Langerhans cell histiocytosis (LCH) is a rare disease. The combination of vinblastine and prednisone, given in a 6-month course, is the standard of care but prospective randomized trials are lacking. PATIENTS AND METHODS We report our monocentric experience in the treatment of seven adult patients with multisystem (MS) LCH (n = 3) or single-system multifocal (SS-m) LCH (n = 4) with the short-course intensive chemotherapy regimen methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone and bleomicin (MACOP-B). RESULTS The overall response rate was 100% [five complete response (CR), two partial response (PR)]. After a median follow-up of 6.5 years, four patients are in first continuous CR and three patients relapsed after 5, 8 and 62 months, respectively. Four patients were evaluated with positron emission tomography (PET) scan: all three PET-negative patients at the end of treatment had a long-lasting response with only one patient relapsing after 5 years. PET scan detected additional bone lesions at diagnosis in two of four patients, changing the treatment program in one of them. CONCLUSIONS MACOP-B regimen seems to be very active in the treatment of adult MS or SS-m LCH, with long-lasting responses in five of seven patients. PET scan merits further evaluation in the initial staging and in the evaluation of the response to chemotherapy.

FDG–PET in the assessment of patients with follicular lymphoma treated by ibritumomab tiuxetan Y 90: multicentric study

BACKGROUND The aim of this study is the 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) evaluation following radioimmunotherapy (RIT) with ibritumomab tiuxetan Y 90 in patients with non-Hodgkins follicular lymphoma (FL). MATERIALS AND METHODS We retrospectively analyzed data from 59 relapsed or refractory FL patients treated with ibritumomab tiuxetan Y 90 in four different PET centers who had a PET scan carried out before and after RIT. Possible predictive factors of progression-free survival (PFS) were studied through univariate and multivariate analysis. RESULTS The post-RIT PET documented 45.8% complete responders (CR), 25.4% partial responders (PR) and 28.8% nonresponders [stable disease + progressive disease], with an overall survival of 71.2% (range 59.5%-90.9%). With a median follow-up period of 23 months, the univariate analysis documented a statistically significant relation between disease extent before RIT and response to treatment with respect to PFS (P = 0.015), while all the other prognostic factors showed no significant correlation. When carrying out the multivariate analysis, post-RIT PET resulted as the lonely independent predictor of PFS (P < 0.00001). CONCLUSIONS RIT is an effective therapy in FL patients, as confirmed in our study too. Disease extension before treatment and response to RIT, as assessed by FDG-PET, result as main predictors of PFS, with the post-RIT PET result being the only independent predictive factor.

Matched pairs dosimetry: 124I/131I metaiodobenzylguanidine and 124I/131I and 86Y/90Y antibodies

The technological advances in imaging and production of radiopharmaceuticals are driving an innovative way of evaluating the targets for antineoplastic therapies. Besides the use of imaging to better delineate the volume of external beam radiation therapy in oncology, modern imaging techniques are able to identify targets for highly specific medical therapies, using chemotherapeutic drugs and antiangiogenesis molecules. Moreover, radionuclide imaging is able to select targets for radionuclide therapy and to give the way to in vivo dose calculation to target tissues and to critical organs. This contribution reports the main studies published on matched pairs dosimetry with 124I/131I- and 86Y/90Y-labelled radiopharmaceuticals, with an emphasis on metaiodobenzylguanidine (MIBG) and monoclonal antibodies.

Usefulness of 64Cu-ATSM in head and neck cancer: a preliminary prospective study.

Aims 64Cu-diacetyl-bis(N4-methylthiosemicarbazone) (64Cu-ATSM) is a hypoxia-avid, positron emitter radiotracer. The primary aim of this study is to assess the efficacy of pretherapy 64Cu-ATSM PET/CT as a prognostic factor of response to therapy. The secondary aims are to investigate if there is a difference between early and late PET/CT scans and if there is a difference between the biologic tumor volume (BTV) in radiotherapy treatment planning calculated between 64Cu-ATSM and 18F-FDG, and to assess if 64Cu-ATSM is a prognostic marker of disease progression. Methods Eleven patients with head and neck cancer treated with chemoradiotherapy were enrolled prospectively; both 64Cu-ATSM and 18F-FDG PET/CT scans before and after treatment were obtained. The 64Cu-ATSM scans were performed after 1 hour (early) and 16 hours (late). Results All patients had stage III or IV squamous cell head and neck cancer; 7 of 11 patients had nodal metastasis, and 22 cancer foci were detected with 64Cu-ATSM. SUVmax was 16.2 ± 7.9, and there was no significant SUVmax difference between early and late imaging. 18F-FDG SUVmax before therapy was 15.6 ± 9.4, whereas 18F-FDG SUVmax after therapy was 1.5 ± 1.2. Sensitivity and specificity values of 64Cu-ATSM calculated with receiver operating characteristic curves were 100% and 50% considering the SUVmax and 100% and 33% considering the volume, respectively. No difference has been found between the BTV contoured with 64Cu-ATSM and 18F-FDG. Conclusions The 64Cu-ATSM scans showed high sensitivity but low specificity in predicting neoadjuvant chemoradiotherapy response. No difference was noted between early and late scans. 18F-FDG and 64Cu-ATSM provided similar results about delineation of BTV.

Investigation on the role of integrated PET/MRI for target volume definition and radiotherapy planning in patients with high grade glioma

PURPOSE To evaluate the impact of fluid-attenuated-inversion-recovery MRI (FLAIR/MRI) and Carbon-11-labeled-methionine PET (11C-MET-PET) on high grade glioma (HGG) tumor volume delineation for radiotherapy planning. MATERIAL AND METHODS Sixty-nine patients with HGG were evaluated. The clinical target volumes (CTV1, generated by adding a 10mm margin to FLAIRMRI area, CTV2 by adding a 20mm margin to enhanced T1MRI) and biological target volume (BTV) were delineated on pre-operative MRI images and 11CMETPET respectively. RESULTS The overlap between CTV1 and CTV2 showed a low correlation between the two volumes with CTV1 not always fully included into the CTV2. In all cases the whole BTV was included into the CTV1, while in 35/69 patients (50%) part of BTV was outside the CTV2 despite larger margins were added. In all cases recurrences were within the CTV1 volume and in 19/38 (50%) partially outside the CTV2. In all patients relapse corresponded to the BTV area. CONCLUSIONS Our data suggest that the target volume definition using FLAIR-MRI is more adequate compared to enhanced T1MRI. 11C-METPET uptake could help identify microscopic residual areas.