Giovanni Bosio

F-18 FDG-PET/CT evaluation of patients with differentiated thyroid cancer with negative I-131 total body scan and high thyroglobulin level.

Purpose: The aim was to evaluate the incremental diagnostic rate of F-18 fluoro-fluorodeoxygulose positron emission tomography/computed tomography (F-18 FDG-PET/CT) in patients with negative I-131 whole body scans and high Tg levels. The secondary end points were correlations between F-18 FDG-PET/CT positive results and Tg levels and comparison between F-18 FDG-PET/CT accuracy in patients “on-therapy” with suppressed thyroid stimulating hormone (TSH) and those with high TSH levels. Methods: We studied 52 patients who had undergone total thyroidectomy and remnant ablation; they had high Tg levels (average = 156 ng/mL; SD ± 274) after 3 weeks of levothyroxine withdrawal and negative I-131 total body scans after therapeutic doses. Results: We noted a statistically significant positive correlation between F-18 FDG-PET/CT positive results and Tg levels, irrespective of levothyroxine therapy regimen. Tg levels between F-18 FDG-PET/CT positive/negative groups were significantly different and we did not note any statistically significant correlation between F-18 FDG-PET/CT results and TSH levels, tumor size, and combination of Tg/TSH levels. Conclusions: Our results indicate that F-18 FDG-PET/CT is a useful diagnostic tool in patients with differentiated thyroid carcinoma and with negative I-131 total body scans and high Tg levels. The levothyroxine therapy regimen does not influence F-18 FDG-PET/CT results and the rate of F-18 FDG-PET/CT positive results appears to correlate with the Tg levels. The highest accuracy is reached when the study is performed for patients with Tg levels higher than 21 ng/mL.

Possible role of F18-FDG-PET/CT in the diagnosis of endocarditis: preliminary evidence from a review of the literature

Infective endocarditis (IE) is a particular disease which presents with a variety of clinical, aetiological forms and is lethal if not aggressively treated with antibiotics alone or in combination with surgery. This review tries to analyse the possible role of F18-FDG-PET/CT in the diagnosis of IE based on the state of art in literature.

Role of 11C-choline positron emission tomography/computed tomography in evaluating patients affected by prostate cancer with suspected relapse due to prostate-specific antigen elevation

PurposeThe aim of this study was to evaluate the accuracy of 11C-choline positron emission tomography/computed tomography (PET/CT) in restaging patients affected by prostate cancer and suspected relapse due to prostate-specific antigen (PSA) increase. We also aimed to determine a PSA cutoff that is most suited to the study in terms of best compromise between sensitivity and specificity. Secondary endpoints were a comparison between 11C-choline PET/CT and histological results, clinical findings, and radiological imaging (CT and magnetic resonance imaging).Materials and methodsWe retrospectively evaluated 210 patients (median ± SD age 70 ± 7 years) affected by prostate cancer who underwent 11C-choline PET/CT.Results11C-choline PET/CT imaging was positive in 116 (55.2%) patients and negative in 94 (44.8%). Receiver operating characteristic (ROC) analysis showed that the highest accuracy (sensitivity 76.8%, specificity 92.5%) for the whole population was achieved when the PSA level of 1.26 ng/ml level was used as the cutoff value for interpreting the results (P = 0.0001 and the area under the ROC curve AUC 0.897). For patients treated with surgery or surgery plus radiotherapy the cutoff was 0.81 ng/ml (sensitivity 73.2%, specificity 86.1%). For patients treated with radiotherapy alone, the cutoff was 2.0 ng/ml (sensitivity 81.8%, specificity 92.9%).ConclusionOur results indicate that 11C-choline PET/CT is a useful diagnostic tool in patients affected by prostate cancer and a relapsed PSA level. The highest accuracy for all patients is obtained with a PSA cutoff level of 1.26 ng/ml, above which the imaging study is performed (0.81 ng/ml for patients treated with surgery or surgery plus radiotherapy and 2.0 ng/ml for patients treated with radiotherapy alone).

Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography for therapy evaluation of patients with large-vessel vasculitis

PurposeSystemic vasculitis is a multisystem disease characterized by inflammation of blood vessels. Diagnosing extension of the disease and evaluating the response to therapy are cornerstones in the clinical management of vasculitis, and imaging has a pivotal role in this field.Materials and methodsWe have evaluated nine patients with large-vessel vasculitis by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) before and after treatment with corticosteroid.ResultsThe evaluation of eight patients was negative at follow-up studies after therapy, and one was unchanged.Conclusions18F-FDG-PET/CT is a useful, accurate tool for establishing the diagnosis of large-vessel vasculitis and for evaluating disease extension in these patients. Despite the small number of patients enrolled, our study confirms this statement and offers preliminary evidence that it could also be a reliable, accurate tool for monitoring therapy in conjunction with clinical and biochemical findings.

Role of F18-FDG-PET/CT in restaging patients affected by renal carcinoma.

BACKGROUND Renalcancers account for around 3% of all cancers and the most common type of (90%) is renal cell carcinoma Five-year survival rate in renal cancer patients is 68.4%. AIM The aim of our study was to establish the role of F18-FDG-PET/CT in restaging patients with renal carcinoma who underwent partial or radical nephrectomy. Secondary aim of the study was to identify histological characteristics of the primary tumour that may be responsible for the metabolic behaviour of neoplastic lesions. MATERIALS AND METHODS We retrospectively evaluated 68 patients with renal carcinoma in whom F18-FDG-PET/CT was performed. RESULTS Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of F18-FDG PET/CT were 82%, 100%, 100%, 66.7% and 86.8%, respectively. CONCLUSIONS The results of our study suggest that F18-FDG PET/CT is characterised by high specificity and positive predictive value and can be useful in restaging patients affected by renal carcinoma. However, due to low negative predictive value, this method cannot be recommended for definitely ruling out suspected disease relapse.

18F-FDG PET/CT Follow-up of Rosai-Dorfman Disease.

Rosai-Dorfman disease (RDD) or sinus histiocytosis is a rare histiocytic disorder characterized by massive lymphadenopathy and with extranodal involvement in 25% to 43% of cases. The clinical course of RDD is unpredictable with episodes of exacerbation and remissions that can last many years, and treatment strategies can be different according to organ involvement. We report a case of a 42-year-old woman with extranodal disease followed for almost 10 years from the diagnosis who underwent seven (18)F-FDG PET/CT. PET/CT has proven to be a useful method for the management of this patient, mainly for the staging, follow-up, and evaluation of treatment results.

Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients affected by differentiated thyroid carcinoma, high thyroglobulin level, and negative 131I scan : review of the literature

Differentiated thyroid carcinoma (DTC) is a slow-growing tumor that represents 1% of all malignant tumors and is the most frequent endocrine cancer. 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) imaging is an increasingly important imaging tool in oncology and is still under investigation in numerous studies looking into its efficacy and cost-effectiveness. Despite the fact that 18F-FDG-PET/CT has been shown to be a powerful and accurate diagnostic tool in patients affected by DTC with high serum thyroglobulin (Tg) levels and negative radioiodine (131I) total body scan, its definitive role is not completely clear, in particular regarding the role of thyroid stimulating hormone (TSH) and Tg value “cutoff” over which is better to perform the study. In this review, these issues are analyzed to clarify controversial aspects and identify established cornerstones. In particular, the literature analysis suggests that levothyroxine withdrawal is preferable in cases of relatively low Tg levels (<10 ng/ml) and good clinical compliance to hypothyroidism. Moreover, recombinant thyrotropin stimulating hor mone (rTSH) could be a preferable alternative in patients clinically unable to tolerate therapy withdrawal. A Tg cutoff level over which to perform the study seems to be 10 ng/ml, a reasonable value maintaining high accuracy in terms of a good compromise between sensitivity and specificity.

Final results of a phase 2A study for the treatment of metastatic neuroendocrine tumors with a fixed activity of 90Y‐DOTA‐D‐Phe1‐Tyr3 octreotide

The objective of this study was to assess the efficacy of 90Y‐DOTA‐D‐Phe1‐Tyr3 octreotide (90Y‐DOTATOC) therapy with a fixed activity of 2.56 GigaBequerels bimonthly in patients with advanced stage, well differentiated neuroendocrine carcinomas.

Incidental 11C-choline PET/CT brain uptake due to meningioma in a patient studied for prostate cancer: correlation with MRI and imaging fusion.

We report a case of a 75-year-old male patient treated with radiotherapy in 1999 for prostate cancer. Due to a rise in prostate-specific antigen, he underwent (11)C-choline PET/CT. The study was negative for secondary lesions but revealed an incidental pathologic focal brain uptake. A subsequent magnetic resonance examination confirmed the presence of a brain lesion typical for meningioma.

[18F]FDG-PET/CT in patients affected by retroperitoneal fibrosis: a bicentric experience

PurposeThe aim of our study was to assess the feasibility and usefulness of 2-[18F]-fluoro-2-deoxy-d-glucose positron emission tomography computed tomography ([18F]FDG-PET/CT) in patients affected by retroperitoneal fibrosis.Materials and methodsWe retrospectively evaluated 25 patients studied in two centers: 18 underwent [18F]FDG-PET/CT as initial evaluation, three during follow-up, three during steroid therapy, and one to re-evaluate the disease. Among the group who underwent initial evaluation, ten underwent a second [18F]FDG-PET/CT after steroid therapy.Results[18F]FDG-PET/CT was positive in 18 patients and negative in seven. Among the ten patients who underwent a second study after steroid therapy, six showed complete metabolic response, three partial response, and one no significant maximum standardized uptake value (SUVmax) reduction.ConclusionOur preliminary results show that [18F]FDG-PET/CT is feasible and suitable for evaluating retroperitoneal fibrosis and is useful in assessing therapy response. Larger studies are desirable to confirm these findings and to determine the appropriate position of [18F]FDG-PET/CT in the diagnostic flow chart for this disease.