Mattia Bertoli

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 in gastric MALT lymphoma: a bicentric experience

PurposeThe role of 18F-FDG-PET/CT in evaluating gastric MALT lymphoma is still controversial. In the literature the detection rate of 18F-FDG-PET/CT in patients with gastric MALT lymphoma is variable, and the reason for this heterogeneity is not still clear. Our aim was to investigate the particular metabolic behavior of these lymphoma.Materials and methodsSixty-nine patients (26 female, 43 male) with histologically confirmed gastric MALT lymphoma who underwent a 18F-FDG-PET/CT for initial staging from two centers were included. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio and compared with Ann Arbor stage, epidemiological (age, sex), histological (presence of gastritis, ulcer, H. pylori infection, plasmacytic differentiation, Ki-67 index), and morphological (tumor size, superficial lesions or mass-forming) characteristics.ResultsThirty-six patients (52 %) had positive PET/CT (average SUVmax was 9±6.7; lesion-to-liver SUVmax ratio 3.7±2.6, lesion-to-blood pool SUVmax ratio 4.8±3.3) at the corresponding gastric lesion; the remaining 33 were not 18F-FDG-avid. In the univariate analysis, 18F-FDG avidity was significantly associated with morphological features (mass forming p<0.001 and high maximum diameter p<0.001), Ann Arbor stage (p=0.010), and Ki67 index (p<0.001) and not correlated with age, sex, presence of gastritis, ulcer, Helicobacter pylori infection, and plasmacytic differentiation. In the multivariate analysis, the correlations with gross morphological appearance, Ann Arbor stage, and Ki-67 score were confirmed. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio correlated significantly only with Ki67 index (p=0.047; p=0.012; p=0.042).Conclusions18F-FDG avidity was noted in 52 % of gastric MALT lymphoma and this avidity is correlated with gross morphological characteristics, tumor stage, and Ki-67 index. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio are correlated only with Ki-67 index, and only lesion-to-liver SUVmax ratio was independently associated with Ki-67 score.

Incidental 11C-choline PET/CT uptake due to esophageal carcinoma in a patient studied for prostate cancer.

A 75-years-old patient with a history of prostate cancer, previously treated with radical prostatectomy, underwent C-choline PET/CT for restaging due to a rise in the prostate-specific antigen level. The study revealed a focal uptake of C-choline in the esophagus. A subsequent endoscopic examination showed the presence of an esophageal lesion, and after surgery, the histologic diagnosis was mildly differentiated squamous cell carcinoma. In our case, the incidental esophageal uptake revealed by C-choline PET/CT allowed the early diagnosis of an unsuspected esophageal carcinoma.

Hepatosplenic Candidiasis Detected by 18F-FDG-PET/CT

Hepatosplenic candidiasis is a fungal infection, which mostly affects patients with hematologic malignancies such as leukemia. The pathogenesis of this infection is not clear yet, and the liver is the most commonly affected organ. Diagnosis of hepatosplenic candidiasis can be only established via biopsy, since computed tomography (CT) scan, ultrasonography, and magnetic resonance imaging (MRI) yield non-specific results. The role of fluorine-18 fluorodeoxyglucose positron emission tomography /computed tomography (18F-FDG PET/CT) in diagnosis of hepatosplenic candidiasis remains undetermined, considering a few evidences in the literature. In this case report, we present the case of a 47-year-old patient, affected by acute myeloid leukemia, which was treated with three cycles of chemotherapy, resulting in the development of neutropenia and fever following the last cycle. The 18F-FDG PET/CT scan showed some foci of intense FDG uptake in the liver and spleen. The subsequent diagnostic investigations (i.e., abdominal CT scan and biopsy) were suggestive of hepatosplenic candidiasis. The patient was started on antifungal treatment with fluconazole. After one month, the clinical conditions were resolved, and the subsequent abdominal CT scan was negative.

18F-FDG PET/CT in primary brain lymphoma

The actual role of 18F-FDG PET/CT in evaluating primary brain lymphoma is still an open issue. Brain lymphoma usually show elevated 18F-FDG uptake, often higher than other brain tumors or inflammatory processes, but the metabolic behavior of this lymphoma is not still understood. Our aim was to investigate the particular metabolic behavior of this lymphoma. Forty six patients (21 female, 25 male) with histologically-confirmed brain lymphoma who underwent 18F-FDG PET/CT from vertex to the mid-thigh for initial staging were retrospectively evaluated. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, lesion-to-blood pool SUVmax ratio and the tumor to normal brain uptake ratio (T/N ratio) and compared with epidemiological (age, sex, HIV infection) and morphological (tumor size, MRI appearance) characteristics. Thirty-eight patients (83%) had positive 18F-FDG PET/CT (average SUVmax was 15.6 ± 9.2; lesion-to-liver SUVmax ratio 5.8 ± 2.8; lesion-to-blood pool SUVmax ratio 7.1 ± 3.8, T/N ratio 3.1 ± 1.7) at the corresponding brain lesion; the remaining 8 (17%) were not 18F-FDG avid. 18F-FDG avidity was significantly associated with morphological appearance and tumor size and not correlated with other features. 18F-FDG PET/CT detected extracranial disease in two cases (4%) with negative bone marrow biopsies and CT. In conclusion, brain lymphomas are 18F-FDG avid in 83% of cases showing high 18F-FDG uptake and 18F-FDG avidity is correlated with tumor size and morphological appearance of the lesion. PET/CT helped to recognize extracranial disease in two patients.

Pulmonary mucosa-associated lymphoid tissue lymphoma: 18F-FDG PET/CT and CT findings in 28 patients

OBJECTIVE The aim of the study was to evaluate the CT and fluorine-18-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) imaging findings of lung mucosa associated lymphoid tissue (MALT) lymphoma. METHODS 28 patients with histologically confirmed pulmonary MALT lymphoma who underwent a chest CT and 18F-FDG PET/CT for staging were retrospectively analysed. The CT images were evaluated to determine morphological pattern of appearance, laterality, localization, number, size, presence of thoracic lymphadenopaties and secondary/combined findings. PET images were analysed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio and lesion-to-blood pool SUVmax ratio. The relationship between qualitative and semi-quantitative features at 18F-FDG PET/CT and CT findings were also analysed. RESULTS A total of 57 pulmonary lesions were identified by CT: 37 areas of consolidation, 4 masses, 12 nodules and 4 ground-glass opacities. Solitary and multiple lesions were detected in 10 and 18 patients, respectively; among patients with multiple lesions, 16 were bilateral and 2 unilateral. 18F-FDG PET/CT revealed increased 18F-FDG uptake in 47/57 lesions, in 26/28 patients. 18F-FDG avidity was significantly associated only with tumour size. CONCLUSIONS Pulmonary MALT lymphoma is 18F-FDG avid in most cases and 18F-FDG avidity is correlated with tumour size. Consolidation is the most frequent morphological pattern of disease presentation. Advances in knowledge: This study demonstrated that lung MALT lymphoma are 18F-FDG avid in most cases depending on tumour size. Single or multiple areas of consolidation are the most common pattern of presentation of lung MALT lymphoma at CT.

Diagnostic and Prognostic Value of 18F-FDG PET/CT in Male Breast Cancer: Results From a Bicentric Population

PURPOSE We aim to assess the diagnostic and prognostic values of 18Ffluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in a small population with male breast cancer (MBC). MATERIALS AND METHODS From May 2005 to Jul 2013, we retrospectively reinterpreted 31 FDG PET/CT scans of 25 men (mean age: 67 years; range: 51-81 years) with a proven breast cancer diagnosis, from two Italian centers. In the majority of patients, an invasive ductal cancer was present (68%). PET/CT scan was performed for initial staging in 5 (16%), restaging in 18 (58%), restaging for the increase of tumor markers in 4 (13%), response to therapy in 2 (6%) and during follow-up in 2 cases (6%). The prognostic impact of PET/CT in this male breast cancer population was assessed by using Kaplan-Meier analysis. RESULTS Nuclear medicine imaging was negative in 10 subjects while it resulted positive in the residual 15 patients (60%). At initial staging, in four out of five cases, PET/CT showed a significant uptake in the primary cancer and of those three had also a loco-regional lymphatic and distant metastatic involvement. In restaging setting, PET/CT was more accurate than conventional imaging for detection of distant metastases, resolving two false-positive findings. Finally, a positive PET/CT scan was demonstrated to be prognostically unfavorable as compared to a negative exam. CONCLUSIONS MBC is a rare tumor with similar biological and metabolic characteristics of female breast cancer. FDG PET/CT seems to be useful, particularly in the restaging setting, to delineate the correct therapeutic approach and to predict the prognosis.

Multicentric study on 18F-FDG-PET/CT breast incidental uptake in patients studied for non-breast malignant purposes

AIM Our study has aimed to establish the prevalence and pathological nature of fluorine-18-fluorodeoxyglucose ((18)F-FDG) breast incidental uptake (BIU) in patients studied for non-malignant breast tumours and then to compare our data obtained in three Italian nuclear medicine centres with those available in literature. MATERIAL AND METHODS We retrospectively evaluated 42,927 (18)F-FDG-PET/CT scans performed on patients studied in three Italian Nuclear Medicine Centres. All patients underwent (18)F-FDG-PET/CT for oncologic purposes not related to breast disease. RESULTS Among 42,927 scans, a BIU was identified in 79 (0.18%) patients, 75 (95%) female and 4 (5%) male with an average age of 62 ± 17 years. Twenty-five out of 35 (71.5%) BIUs were malignant and 10/35 (28.5%) benign. Among the 25/35 incidentalomas that were malignant, 12/25 (48%) were infiltrating ductal carcinoma, 5/25 (20%) ductal carcinoma (infiltrating and in situ), 4/25 (16%) lobular carcinoma, 2/25 (8%) ductal carcinoma in situ and 2/25 (8%) were metastases from the primary tumour under investigation. Of the 10 BIUs that were benign in the histological examination, after further investigations it was found that 9/10 (90%) were fibroadenomas and 1/10 (10%) was a benign lesion not better specified. The lesion to liver or to blood-pool SUVmax ratio in malignant lesions is significantly higher than in benign ones. CONCLUSIONS Our multicenter study demonstrates that, although they are uncommon, BIUs show a high percentage of malignancy and therefore requires further research.

Incidental 18F-FDG PET/CT bilateral breast uptake due to carcinoma

We report a case of 71-year-old female patient, previously treated with chemotherapy and surgical resection of sigmoid tract of the large bowel for adenocarcinoma (pT3N1M0), who underwent a 18F-FDG PET/CT for a suspicious hepatic lesion detected at CT scan during follow-up. 18F-FDG PET/CT showed no abnormal uptake in the liver both at 60 minutes and 120 minutes after injection but revealed a pathological uptake in two breast nodules, (one localized in upper-internal-quadrant of the right breast and the other in the upper-external-quadrant of the left breast). The patient underwent breast MRI, which confirmed the suspicious nature of both lesions; subsequently she underwent a trucut biopsy of both lesions witch demonstrated a bilateral localization of papillary carcinoma (both lesion were classified as pT1c). The patient underwent bilateral mastectomy and the final biopsy confirmed the presence of breast cancer, while bilateral sentinel nodes biopsy showed no lymph-nodes metastases.

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

BACKGROUND: Renal cancers 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