Arianna Massaro

PET/CT imaging in different types of lung cancer: An overview

Lung cancer (LC) still represents one of the most common tumours in both women and men. PET/CT is a whole-body non-invasive imaging procedure that has been increasingly used for the assessment of LC patients. In particular, PET/CT added value to CT is mainly related to a more accurate staging of nodal and metastatic sites and to the evaluation of the response to therapy. Although the most common PET tracer for LC evaluation is 18F-FDG, new tracers have been proposed for the evaluation of lung neuroendocrine tumours (68Ga-DOTA-peptides, 18F-DOPA) and for the assessment of central nervous system metastasis (11C-methionine). This review focuses on the main clinical applications and accuracy of PET/CT for the detection of non-small cells lung cancer (NSCLC), broncho-alveolar carcinoma (BAC), small cells lung cancer (SCLC), lung neuroendocrine tumours (NET) and solitary pulmonary nodules (SPN).

Role of 18F-choline PET/CT in biochemically relapsed prostate cancer after radical prostatectomy: correlation with trigger PSA, PSA velocity, PSA doubling time, and metastatic distribution.

Purpose The aim of this study was to evaluate the efficacy of 18F-choline PET/CT (18FCH-PET/CT) in restaging patients previously treated by radical prostatectomy for a prostate cancer, presenting with biochemical relapse during follow-up (FU). Patients and Methods Three hundred thirty-one patients referred to us from January 2009 to April 2011 to perform 18FCH PET/CT were evaluated: 233 of them (mean age 69.7 years) met the inclusion criteria of the study: (1) biochemical relapse after radical prostatectomy (trigger PSA >0.2 ng/mL) (n = 224) and (2) high risk for relapse (elevated Gleason score ≥8) in spite PSA <0.1 ng/mL during FU (n = 9). Trigger PSA was available for all patients (mean 8 ng/mL) and in 44 of them also PSA kinetic (PSA velocity—PSAvel; PSA doubling time—PSAdt). Correlation between 18FCH PET/CT detection rate and trigger PSA, PSAvel, PSAdt, and tumoral spread distribution were evaluated by univariate and multivariate analysis. Subsequent minimum FU was 1 year (mean 26 months, range 12–40). Results Overall detection rate of 18FCH PET/CT was 54%, which significantly increased when the trigger PSA increases (P < 0.001). PET-positive patients presented a “fast” PSA kinetic (mean PSAdt = 6 months and mean PSAvel = 9.3 ng/mL/yr), while PET-negative patients presented a “slow” PSA kinetic (mean PSAdt = 15.4 months and mean PSAvel = 0.9 ng/mL/yr). Disease relapse was local in 17% of cases, distant in 66%, and combined in 17%. Conclusions Overall 18FCH PET/CT detection rate was 54% (ie, similar to that reported in literature with 11C-choline), which increases with the increase in trigger PSA: this condition was particularly true in patients with accelerated PSA kinetic. In about 20% of patients, 18FCH PET/CT demonstrated local relapses early enough to offer locoregional radiation therapy.

Diagnosis of infected total knee arthroplasty with anti-granulocyte scintigraphy: the importance of a dual-time acquisition protocol.

ObjectiveTo evaluate clinical efficacy of a dual-time acquisition protocol consisting of early 4 h and delayed 20–24 h imaging with anti-granulocyte scintigraphy (LeukoScan) in the diagnosis of infection in painful total knee arthroplasty (TKA). Materials and methodsSeventy-eight consecutive patients with TKA (12 bilateral) were prospectively enrolled in the study from August 2004 to July 2005. All the patients had clinical and biochemical suspicious of infection, except for the 12 patients with bilateral painless prosthesis who had no signs and symptoms of loosening and/or infection and were considered as controls. TKA prostheses had been implanted 4 months to 9.5 years before our studies. Forty-three patients were on antibiotic therapy at the moment of scintigraphic examination, and treatment was not discontinued. All patients underwent LeukoScan examination by performing both early 4 h and delayed 20–24 h imaging. In addition to planar imaging SPECT was performed in 18 cases. A decrease in radiotracer uptake from early to delayed LeukoScan imaging was interpreted as an unspecific finding (negative for infection), while an increasing uptake was interpreted as a positive finding for the presence of infection. Three-phase 99mTc-MDP bone scan was also routinely performed by standard technique. Sensitivity and specificity of early and delayed LeukoScan imaging were calculated. ResultsSensitivity for early and delayed imaging were 92.7%, while specificity was 78.4% for early imaging and 100% for delayed imaging approach. SPECT imaging did not add any significant information as regard to specificity in our experience. Eight false positive early scans were correctly diagnosed as negative at delayed imaging. Three false negative results were recorded. Sensitivity and specificity were similar when patients were on or off antibiotic therapy. Imaging was negative in all 12 controls. ConclusionsOur results, based on a large group of patients, suggest that delayed LeukoScan imaging is important in identifying false positive results detect at early imaging. Thus, a dual-time, 4 h early and 20–24 h delayed LeukoScan imaging approach should be recommended to increase the diagnostic accuracy of the scintigraphy, with the exception of patients with a negative early LeukoScan examination, in whom the acquisition of delayed imaging appears unnecessary. In our experience, concomitant antibiotic therapy did not influence the diagnostic value of LeukoScan.

18F-DOPA PET/CT biodistribution consideration in 107 consecutive patients with neuroendocrine tumours.

ObjectiveL-6-Fluoro 3,4-dihydroxyphenylalanine (18F-DOPA), an amino acid-based radiopharmaceutical, is increasingly being used in the detection and management of neuroendocrine tumours. Knowledge of the normal biodistribution of this radiopharmaceutical is essential for the proper interpretation of such studies, but the literature available is scanty due to the rarity of these tumours. The aim of this study is to evaluate the biodistribution pattern and normal variants of 18F-DOPA in a cohort of patients with neuroendocrine tumours using semiquantitative analysis (maximum standardized uptake value). MethodsWe analysed 107 consecutive 18F-DOPA PET/CT studies of patients referred with medullary carcinoma of the thyroid (43), phaeochromocytoma including cases of Von Hippel Lindau syndrome and multiple endocrine neoplasia type IIA cases (34), paraganglioma (14) and other neuroendocrine tumours (16). The study population were divided into two groups: those with negative 18F-DOPA PET/CT scans (32) and those with positive scans (75). The biodistribution of 18F-DOPA in each group was measured and compared between the two groups. ResultsThe physiological biodistribution in the basal ganglia and liver parenchyma showed no variability between the two groups. Conversely, uptake in the pancreas (particularly the uncinate process) and adrenals showed considerable variability between the groups. However, these differences were found not to be significant on statistical analysis. ConclusionThe data presented may provide useful information in understanding the physiologic biodistribution of DOPA and its variants, for the purpose of improving the interpretation of 18F-DOPA PET/CT.

New acquisition protocol of 18F-choline PET/CT in prostate cancer patients: review of the literature about methodology and proposal of standardization.

Purpose. (1) To evaluate a new acquisition protocol of 18F-choline (FCH) PET/CT for prostate cancer patients (PC), (2) to review acquisition 18F-choline PET/CT methodology, and (3) to propose a standardized acquisition protocol on FCH PET/CT in PC patients. Materials. 100 consecutive PC patients (mean age 70.5 years, mean PSA 21.35 ng/mL) were prospectively evaluated. New protocol consisted of an early scan of the pelvis immediately after the injection of the tracer (1 bed position of 4 min) followed by a whole body scan at one 1 hour. Early and 1 hour images were compared for interfering activity and pathologic findings. Results. The overall detection rate of FCH PET/CT was 64%. The early static images of the pelvis showed absence of radioactive urine in ureters, bladder, or urethra which allowed a clean evaluation of the prostatic fossae. Uptake in the prostatic region was better visualized in the early phase in 26% (7/30) of cases. Other pelvic pathologic findings (bone and lymph nodes) were visualized in both early and late images. Conclusion. Early 18F-choline images improve visualization of abnormal uptake in prostate fossae. All pathologic pelvic deposits (prostate, lymph nodes, and bone) were visualized in both early and late images.

Colorectal cancer: prognostic role of 18F-FDG-PET/CT.

of F-FDG-PET/CT Gaia Grassetto, Carlo Capirci, Maria Cristina Marzola, Lucia Rampin, Sotirios Chondrogiannis, Alessandra Musto, Giorgio Crepaldi, Anna Maria Minicozzi, Arianna Massaro, Domenico Rubello Department of Nuclear Medicine—PET/CT Centre, Santa Maria della Misericordia Hospital, Via Tre Martiri 89, 45100 Rovigo, Italy Radiotherapy Unit, Santa Maria della Misericordia Hospital, Rovigo, Italy Oncology Unit, Santa Maria della Misericordia Hospital, Rovigo, Italy Clinical Surgery, University of Verona, Verona, Italy

Minimally invasive radio-guided surgery for primary hyperparathyroidism: From preoperative to intraoperative localization imaging.

The introduction and successful implementation of minimally invasive radio-guided parathyroidectomy (MIRP) has revolutionized the surgical approach to remove parathyroid adenomas. A prerequisite for such success is an accurate localization of the offending adenoma. To achieve this goal, a multimodality approach is commonly employed using a combination of anatomical and functional imaging. Of the anatomical cross-sectional techniques, ultrasonography is the most widely available but is operator-dependent and has reduced sensitivity, specially in the presence of thyroid nodules. Similarly, computed tomography and magnetic resonance imaging have low sensitivities but provide value in detecting retrotracheal, retro-oesophageal and mediastinal adenomas. Functional imaging with ⁹⁹(m)Tc-Sestamibi is currently the most vital imaging procedure in this respect with variable protocols including dual-phase and dual isotope imaging. The sensitivity and specificity can improve by acquiring in single photon emission tomography (SPECT) mode and using co-registration with low dose CT to provide anatomical data (SPECT/CT). The current recommended approach is the combination of functional imaging with ⁹⁹(m)Tc-Sestamibi and high-resolution ultrasound (US), supplemented with intraoperative gamma probe in certain cases and quick persurgical measurement of parathyroid hormone. This review aims to explore the utility of various imaging modalities, alone and in combination, in detecting parathyroid adenoma and facilitating the current approach of MIRP.

Positron-emission tomography in gynaecologic malignancies

IntroductionThe role of 18F-FDG PET in the management of gynaecologic malignancies remains unclear mainly due to the failure of clinicians to appreciate the significance of this imaging tool. However, this under utilisation is being actively re-addressed with a large number of reviews and studies, particularly in the last few years.Methods and ResultsPET has been shown to have high sensitivity and specificity in the evaluation of relapse and nodal disease in cervical cancer, while other uses such as staging and monitoring response to therapies being under further investigation. Similarly, promising results have been published in the use of PET in patients affected by endometrial cancer and uterine sarcomas for detecting lymph nodes metastasis and recurrent disease. In ovarian cancer, PET appears to have a great potential in staging and assessment of disease relapse. An important utility of PET in gynaecologic tumours, which is shared with a large number of other malignancies, is its value in positively changing the patients’ management.Conclusion The surge in studies using PET in gynaecological malignancies is in its early stages, and further studies are required to optimise the role of PET in these conditions.

Optimized protocol for (18)F-choline PET/CT in patients with biochemically relapsed prostate cancer: experiences on 250 consecutive cases.

Purpose We review acquisition 18F-choline PET/CT methodology, evaluate a new 18F-choline acquisition protocol for prostate cancer (PC), and propose a standardized acquisition protocol on 18F-choline in PC patients. Materials Two hundred fifty consecutive PC patients (mean age 72 years, mean PSA 7.9 ng/mL) were prospectively evaluated with 18F-choline PET/CT. An early scan of the pelvis (1 bed position of 4 minutes) was followed by a whole-body scan at 1 hour. Early and 1 delayed hour images of the pelvis were compared. Results Twenty-one percent of patients (n = 57) with positive 18F-choline demonstrated abnormal local uptake; 18% of patients (n = 45) showed distant localization only; 23% of patients (n = 53) had both local and distant localization; 38% of patients (n = 38) did not show any pathological uptake. All early images showed absence of radioactive urine in ureters, bladder, or urethra with satisfactory visualization of the prostatic region. Considering the group of patients with local uptake only, the prostatic region uptake, confirmed by late images, was better visualized in the early phase in 32/57 cases (SUVmax 12.4 ± 3.2 vs. 7.3 ± 5.2, P <0.01). Instead distant lesions were visualized on both early and late images with similar uptakes values (SUVmax 9.8 ± 4.1 vs. 10.3 ± 4.5, P = N.S.). Conclusion Early 18F-choline images improve pelvic prostate cancer lesion clarity. All pathologic pelvic deposits (prostate, lymph nodes, bone) were visualized both in the early and late images.

Antigranulocyte scintigraphy in infected hip prosthesis: the diagnostic importance of delayed 20-24-h imaging and semiquantitative analysis.

AimTo evaluate clinical efficacy of a dual-time acquisition protocol, which included 4 and 20/24-h imaging with antigranulocyte antibody scintigraphy (LeukoScan) combined with semiquantitative analysis in the diagnosis of infection in painful hip prosthesis. MethodsSixty-seven consecutive patients with hip prosthesis were enrolled in this research project: 35 females, 32 males, mean age of 56.3 years. All patients had clinical and biochemical suspicious of infection. Each prosthesis had been implanted 3 months to 12 years before enrollment in this study. Twenty-four patients were on antibiotic therapy at the time of scintigraphy. Seven patients had bilateral hip prosthesis, one painful and the other painless: the seven painless prostheses were considered controls. LeukoScan examination was performed both at early (4 h) and delayed (20/24 h) times. The scintigraphic data were assessed both by visual and semiquantitative methods by three experienced nuclear medicine physicians blinded to clinical, laboratory and radiographic results. The uptake was graded visually by a 4-point scale: intense=3, moderate=2, mild=1 and absent=0. The semiquantitative analysis was obtained by a region of interest (ROI) analysis used in the anterior views to measure the ratio between the mean radioactivity in the prosthesis and the background radioactivity in the early and delayed images. An increase in the intensity of uptake of at least one scale-step at visual analysis and 20% at semiquantitative ROI analysis at the dual-time (early vs. delayed) LeukoScan was considered consistent with infection, whereas a stable or decreasing pattern was judged a negative result. Three-phase 99mTc-hydroxymethane diphosphonate bone scan was also performed routinely. Final diagnosis was determined at surgery and/or long-term clinical and imaging follow-up. ResultsAt visual analysis, sensitivity for both early and delayed imaging was 94%, whereas specificity was 71% for early imaging and 83% for early and delayed imaging approach. At semiquantitative ROI analysis, sensitivity remained 94%, whereas specificity rose slightly to 73% for early imaging and to 90% for early and delayed imaging combined. Of note, four false-positive early scans were diagnosed correctly as negative on delayed imaging showing a decreasing pattern in uptake intensity. Sensitivity and specificity were similar whether patients were on or off antibiotic therapy. ConclusionOur data show that early imaging LeukoScan is highly sensitive in evaluating septic prosthesis, but it is not optimally specific. Although the dual-time LeukoScan is capable of significantly increasing specificity for detecting infection. The semiquantitative ROI analysis further increased the specificity. Concomitant antibiotic treatment did not seem to influence the diagnostic efficacy of LeukoScan scintigraphy in detecting infected hip prosthesis.