P18.11.A Active beam scanning proton therapy for large skull base benign meningiomas: long-term results

Purpose

To report long-term results of active beam scanning proton therapy (PT) for large skull base benign meningiomas

Material and Methods

Eighty-two patients (pts) with large skull base meningiomas were treated with PT between April 2015 and December 2021. Median age was 62 years (range, 48-82) while KPS ranged between 60 and 100 (median 90); 60 were female (73%), and 22 were male (27%). Thirty-two pts (39%) had histologically proven World Health Organization (WHO) Grade I tumors. In remaining pts diagnosis was based on the typical imaging appearance of benign meningioma. All patients received PT for residual, progressive or non-operable lesions. Newly diagnosed tumors received total dose of 50 GyRBE (RBE: relative biologic effectiveness) while progressing meningiomas 54 GyRBE. All the treatments were delivered at 2 GyRBE per fraction. All pts were treated with active beam scanning PT using 3 fields with single field optimization technique. Treatment planning was based on morphological magnetic resonance imaging (MRI) with contrast enhancement medium administration. All pts received also 68-Ga-DOTATOC-PET. Gross tumor volume ranged from 21 to 64 cc. Toxicity was assessed according to Common Terminology Criteria for Adverse Events version 4.0. Median follow-up time was 40 months (range, 3-83).

Results

All pts completed the treatment without breaks. Registered acute side effects include grade 1 (19%) and grade 2 (8%) skin erythema, grade 1 (5%) and grade 2 (5%) alopecia, grade 1 (40%) fatigue, grade 1 (5%) and grade 2 (10%) conjunctivitis, grade 1 (10%) pain, grade 1 (5%) blurred vision, grade 1 (10%) headache, and grade 2 (5%) skin hyperpigmentation. One pts (1%) experienced grade 3 pain. There were no further grade 3 or higher acute toxicities. Registered late side effects include grade 1 (2%) and grade 2 (5%) alopecia, grade 1 (21%) fatigue, grade 1 (5%) and grade 2 (5%) headache, grade 1 (6%) dizziness, grade 1 (3%) blurred vision, grade 1 (3%) and grade 2 (6%) pain, grade 1 (2%) dry eye, and grade 1 (5%) skin hyperpigmentation. Two pts (2%) experienced grade 3 pain. Two further pts (2%) experienced grade 3 optic neuropathy. There were no further grade 3 or higher late toxicities. During follow-up one pts (1%) with cavernous sinus meningioma experienced complete obstruction of intracavernous carotid artery with mild transient symptoms that resolved in few days and brain tissue ischemia detected at MRI (grade 2). Before irradiation this pts already had a meningioma-related near-complete obstruction of the intracavernous carotid artery and received a vascular surgery evaluation. Currently, absolute tumor control is 99%. Moreover, relief of symptoms recorded before irradiation occurred in 40% of pts.

Conclusion

PT is safe and effective treatment for pts with large skull base benign meningiomas.

Therapeutic strategies for gastroenteropancreatic neuroendocrine neoplasms: State-of-the-art and future perspectives

Although gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have always been considered rare tumors, their incidence has risen over the past few decades. They represent a highly heterogeneous group of neoplasms with several prognostic factors, including disease stage, proliferative index (Ki67), and tumor differentiation. Most of these neoplasms express somatostatin receptors on the cell surface, a feature that has important implications in terms of prognosis, diagnosis, and therapy. Although International Guidelines propose algorithms aimed at guiding therapeutic strategies, GEP-NEN patients are still very different from one another, and the need for personalized treatment continues to increase. Radical surgery is always the best option when feasible; however, up to 80% of cases are metastatic upon diagnosis. Regarding medical treatments, as GEP-NENs are characterized by relatively long overall survival, multiple therapy lines are adopted during the lifetime of these patients, but the optimum sequence to be followed has never been clearly defined. Furthermore, although new molecular markers aimed at predicting the response to therapy, as well as prognostic scores, are currently being studied, their application is still far from being part of daily clinical practice. As they represent a complex disease, with therapeutic protocols that are not completely standardized, GEP-NENs require a multidisciplinary approach. This review will provide an overview of the available therapeutic options for GEP-NENs and attempts to clarify the possible approaches for the management of these patients and to discuss future perspectives in this field.

Detection rate of 18F-Choline positron emission tomography/computed tomography in patients with non-metastatic hormone sensitive and castrate resistant prostate cancer

AIM

To assess the detection rate of 18F-choline PET/CT in non-metastatic hormone-sensitive prostate cancer (hsPCa) and non-metastatic castrate resistant prostate cancer (CRPCa), based on the criteria proposed in the phase III SPARTAN trial and with high Gleason Score (GS).

METHODS

Between October 2008 and September 2019, data from a retrospective multicenter study (n=4 centers), involving patients undergoing 18F-choline PET/CT scans for a biochemical recurrence of PCa, were collected. The following inclusion criteria were used: 1) histologically proven PCa, 2) a non-metastatic disease in accordance with conventional imaging findings; 3) a PSA doubling time (PSAdt) <10 months, 4) a GS > 8 and 5) no pelvic node > 2 cm. The group of hsPCa and CRPCa patients, were compared by using a non-parametric statistical analysis. Moreover, a logistic regression analysis and ROC curves were used.

RESULTS

140 patients were included. Of these, 82 patients were affected by hsPCa, and 58 had a CRPCa. Overall, 18F-Choline PET/CT was positive in 99/140 (70.7%). It was positive in 55/82 (67.1%) hsPCa patients and in 44/58 (75.9%) CRPCa subjects, respectively. The site of recurrence at 18F-Choline PET/CT were: 16 (27.6%) and 20 (24.4%) in prostatic bed, 25 (43.1%) and 24 (29.3%) in loco-regional lymph nodes and in 27 (46.6%) and 28 (34.1%) in distant organs, respectively for CRPCa and hsPCa patients. The optimal cut-off values for PSA at the time of PET/CT for the prediction or recurrence were 0.5 vs. 2.5 ng/mL for all site of recurrence (AUC: 0.70 vs. 0.72), 0.48 vs. 3.4 ng/mL for prostatic bed (AUC: 0.60 vs. 0.59), 0.5 vs. 1.5 for loco-regional lymph nodes (AUC: 0.62 vs. 0.57) and 2.2 vs. 2.8 ng/mL for distant metastasis (AUC: 0.74 vs. 0.71), respectively in CRPCa and hsPCa (all p=NS). Sensitivities and specificities of 18F-Choline PET/CT for the identification of recurrence disease in all patient population, in hsPCa and CRPCa were 83.7% and 87.5%, 78.9% and 88.9%, 91.4% and 85.7%, respectively.

CONCLUSIONS

the rate of positive 18F-Choline PET/CT is similar in patients with a hsPCa and CRPCa, in case of low PSAdt and high GS. Therefore, non-metastatic PCa patients should be assessed by molecular imaging, in order to adapt the most appropriate therapeutic approach.

Impact of COVID-19 Pandemic on Cardiovascular Testing in Asia

Background

The coronavirus disease-2019 (COVID-19) pandemic significantly affected management of cardiovascular disease around the world. The effect of the pandemic on volume of cardiovascular diagnostic procedures is not known.

Objectives

This study sought to evaluate the effects of the early phase of the COVID-19 pandemic on cardiovascular diagnostic procedures and safety practices in Asia.

Methods

The International Atomic Energy Agency conducted a worldwide survey to assess changes in cardiovascular procedure volume and safety practices caused by COVID-19. Testing volumes were reported for March 2020 and April 2020 and were compared to those from March 2019. Data from 180 centers across 33 Asian countries were grouped into 4 subregions for comparison.

Results

Procedure volumes decreased by 47% from March 2019 to March 2020, showing recovery from March 2020 to April 2020 in Eastern Asia, particularly in China. The majority of centers cancelled outpatient activities and increased time per study. Practice changes included implementing physical distancing and restricting visitors. Although COVID testing was not commonly performed, it was conducted in one-third of facilities in Eastern Asia. The most severe reductions in procedure volumes were observed in lower-income countries, where volumes decreased 81% from March 2019 to April 2020.

Conclusions

The COVID-19 pandemic in Asia caused significant reductions in cardiovascular diagnostic procedures, particularly in low-income countries. Further studies on effects of COVID-19 on cardiovascular outcomes and changes in care delivery are warranted.

Prevalence of interstitial pneumonia suggestive of COVID-19 at 18F-FDG PET/CT in oncological asymptomatic patients in a high prevalence country during pandemic period: a national multi-centric retrospective study

PURPOSE

To assess the presence and pattern of incidental interstitial lung alterations suspicious of COVID-19 on fluorine-18-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) ([18F]FDG PET/CT) in asymptomatic oncological patients during the period of active COVID-19 in a country with high prevalence of the virus.

METHODS

This is a multi-center retrospective observational study involving 59 Italian centers. We retrospectively reviewed the prevalence of interstitial pneumonia detected during the COVID period (between March 16 and 27, 2020) and compared to a pre-COVID period (January-February 2020) and a control time (in 2019). The diagnosis of interstitial pneumonia was done considering lung alterations of CT of PET.

RESULTS

Overall, [18F]FDG PET/CT was performed on 4008 patients in the COVID period, 19,267 in the pre-COVID period, and 5513 in the control period. The rate of interstitial pneumonia suspicious for COVID-19 was significantly higher during the COVID period (7.1%) compared with that found in the pre-COVID (5.35%) and control periods (5.15%) (p < 0.001). Instead, no significant difference among pre-COVID and control periods was present. The prevalence of interstitial pneumonia detected at PET/CT was directly associated with geographic virus diffusion, with the higher rate in Northern Italy. Among 284 interstitial pneumonia detected during COVID period, 169 (59%) were FDG-avid (average SUVmax of 4.1).

CONCLUSIONS

A significant increase of interstitial pneumonia incidentally detected with [18F]FDG PET/CT has been demonstrated during the COVID-19 pandemic. A majority of interstitial pneumonia were FDG-avid. Our results underlined the importance of paying attention to incidental CT findings of pneumonia detected at PET/CT, and these reports might help to recognize early COVID-19 cases guiding the subsequent management.

Neuropsychological and Pet Study of Depersonalization and Derealization: A Single Case Report

The present work depicts the case of a young man suffering from a depersonalization and derealization (DD) disorder, which mainly affects his own body. When the symptoms concern something else, they almost exclusively affect living beings. Neuropsychological and neuropsychiatric studies, as well as functional neuroanatomy studies, have led to hypothesize possible relationships among cognitive-neurofunctional alterations and symptoms of depersonalization and derealization. The present study suggests that a malfunction of the left frontal and prefrontal cortex causes deficits of working memory, producing some of the symptoms of DD.

The Role of Fluorine-18-Deoxyglucose (Fdg) Positron Emission Tomography (Pet) Whole Body Scan (Wbs) in the Staging and Follow-Up of Cancer Patients: Our First Experience

We report the results of FDG PET whole body scan in 75 cancer patients in whom tumor extent was defined by surgical, histological or cytological findings and clinical follow-up. Twenty-five had malignant lymphomas, 24 lung carcinomas, and 26 other types of solid tumors. Twenty-three patients were evaluated at disease onset, before therapy, and 37 at the moment of tumor recurrence; the remaining 15 patients were in complete remission after treatment and were taken as controls. Visual and quantitative PET results were compared with conventional imaging (US, CT scan and/or MRI, and Tc99m MDP bone scan).

In the 60 patients with active disease, PET as well as conventional imaging were able to locate the primary tumor in all 23 patients studied at disease onset. However, with regard to lymph node and distant metastases, PET provided the same information as conventional imaging in 31 cases (51.6%), but revealed further neoplastic foci in 29 cases (48.4%), 21 in lymph nodes and 8 at distant sites. The sensitivity of PET, in comparison with conventional imaging, was 100% versus 100% for the detection of the primary tumor, 97.6% versus 55.8% for the localization of node metastases, and 100% versus 55.5% for the visualization of distant metastases. The specificity, calculated in the group of 15 disease-free patients, was 100% for PET and 86.6% for conventional imaging. The therapeutic approach was modified in 12 patients (20%) on the basis of the PET results. Furthermore, in 14 cases (23.3%) with advanced disease, PET provided complete information on tumor spread, otherwise obtainable only by taking together the results of all other diagnostic procedures. Our data indicate a higher accuracy of FDG PET whole body scan compared to conventional imaging techniques in the evaluation of metastatic spread both at initial diagnosis and during follow-up, with an important impact on therapeutic decision-making. Moreover, by providing complete information on tumor spread in some cases, PET can become a profitable tool in terms of cost reduction.

Treatment with combined dabrafenib and trametinib in BRAFV600E-mutated metastatic malignant melanoma: a case of long-term complete response after treatment cessation

Here, we report the case of a patient, diagnosed with BRAF^V600E-mutated metastatic malignant melanoma M1a, who achieved a complete metabolic response after 7 months of treatment with the combination of dabrafenib and trametinib. After 31 months, the treatment was interrupted for patient’s decision. To date October 2017, 18 months after the interruption of the treatment with the combination of dabrafenib and trametinib, follow-up Positron Emission Tomography (PET) scans are still documenting complete metabolic response.

Serial 18F-choline-PET imaging in patients receiving enzalutamide for metastatic castration-resistant prostate cancer: response assessment and imaging biomarkers

AIM

High rate of non-target lesions in metastatic castration-resistant prostate cancer usually limits applicability of Response Evaluation Criteria in Solid Tumors (RECIST) criteria, and this has led to a growing interest in using PET/computed tomography (CT). We prospectively investigated the role of (18)F-choline (FCH)-PET/CT in patients receiving enzalutamide after docetaxel.

PATIENTS & METHODS

30 patients were monitored by means of FCH-PET/CT before and during the treatment. A Cox proportional hazards regression model was used to assess the associations between metabolic parameters and clinical outcomes.

RESULTS

Univariate analysis showed no significant correlation between biochemical and FCH-PET responses. Multivariate analysis showed that only baseline maximum standardized uptake value (SUVmax) significantly correlated with biochemical progression-free survival, radiological progression-free survival and overall survival.

CONCLUSION

Our findings suggest that FCH-PET/CT may play a role in defining prognosis of patients receiving enzalutamide because baseline SUVmax proved to be an independent prognostic factor.

Prognostic value of PET/CT in patients with lymphoma treated with autologous stem cell transplantation for relapsed/refractory or high risk disease

BACKGROUND

Positron emission tomography/computed tomography (PET/CT scan) has increasingly been used for management of lymphoma, however few and conflicting data have been provided in the setting of high dose therapy with autologous stem cell transplantation (ASCT) so far.

METHODS

We retrospectively evaluated the outcome of 47 NHL patients who underwent ASCT for relapsed/refractory disease or high risk disease or partial response after first line treatment, with the aim of testing sensitivity, specificity, positive and negative prognostic value of PET/CT performed before and after ASCT.

RESULTS

In our experience pre ASCT-PET/CT predicts outcome of non-Hodgkin's lymphoma patients with chemosensitive relapse, whereas post ASCT-PET showed a better prognostic value for relapsed disease.

CONCLUSIONS

Results of our study, if confirmed by studies on a larger scale, could significantly contribute to design future trials and optimize the management of lymphoma patients.

Metabolic response by choline positron emission tomography (cPET) to enzalutamide (ENZ) in castration-resistant prostate cancer (CRPC) patients (pts): Preliminary results of a monoinstitutional prospective study

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Background: ENZ is a new generation hormone therapy, able to produce a survival improvement in CRPC pts pre-treated with docetaxel. In Italy, ENZ is not approved yet for the daily clinical practice but until few months ago it was available through a named patient programme (NPP). Since in our Hospital CRPC pts are regularly assessed by cPET to evaluate the treatment response, so pts treated with ENZ were monitored in the same way. Methods: Eligible pts received ENZ at the standard dose of 160 mg po daily until progression. The cPET was performed at baseline, at the 3rd treatment month and thereafter every 4 mos. For each cPET we recorded the median of the maximum standard uptake values (SUVmax) of the 5 most choline-avid region of interest (ROI) and the overall number of ROIs with SUVmax > 2.5. A progressive disease (PD) was defined as the increase ≥ 30% of median SUVmax or the appearance of at least two new ROIs; a partial response (PR) as the reduction ≤ 30% of median SUVmax compared to the baseline; otherwise we considered the disease as stable (SD). Results: Out of the 31 CRPC pts treated with ENZ in our hospital from 09/12 to 03/13, 28 had complete cPET data for evaluation. The baseline median SUVmax of all evaluable pts was 10.82. At 3 mos the median SUVmax decreased to 9.30 (7 PR, 12 SD, 9 PD). Among the 19 pts evauable at 7 mos, the median SUVmax was 7.15 (8 PR, 9 SD, 2 PD). The correlation between the best metabolic response and the prostate specific antigen (PSA) response is showed in the Table. Conclusions: Our preliminary data showed a good concordance between the cPET response and biochemical response in either responding or progressing pts, while most of the pts with stable metabolic parameters showed a good PSA reduction. This is to our knowledge the first report concerning the metabolic response to ENZ and its correlation to PSA response. Further studies are required to define the role and use of cPET in monitoring the treatment efficacy in pts receiving ENZ. [Table: see text]

Biochemical and objective response to abiraterone acetate withdrawal: incidence and clinical relevance of a new scenario for castration-resistant prostate cancer

OBJECTIVE

To describe the incidence and clinical relevance of biochemical and objective responses to abiraterone acetate (AA) withdrawal (AAWD) in patients with castration-resistant prostate cancer (CRPC).

MATERIALS AND METHODS

Twenty-six patients with progressive CRPC treated with first-line docetaxel-based chemotherapy were administered with AA at the standard dose of 1000 mg/day in combination with prednisone until progression. The patients were regularly followed up during treatment and after AAWD.

RESULTS

Nineteen of the 26 patients discontinued AA because of progression. Three of the patients undergoing AAWD experienced a biochemical response, which was accompanied by a metabolic and radiological response as revealed by choline positron emission tomography in 2 cases.

CONCLUSION

Regardless of the underlying molecular bases, AAWD response does not occur rarely. It is sometimes long-lasting and accompanied by a metabolic and radiographic improvement. AAWD response should be taken into account when further therapeutic strategies are planned in patients with CRPC with progressive disease during abiraterone therapy.

18F-FDG-PET/CT

[18F]FDG has been the first radiopharmaceutical used for human brain PET studies and still is the most used radiotracer worldwide for PET and PET/CT oncologic applications. In the assessment of brain tumors, in spite of its low sensitivity in some histological exams, chiefly low-grade lesions, its prognostic value remains of high clinical impact. Moreover, the reliability of [18F]FDG in examining not only the tumor itself, but also the functional state of the whole brain, makes this tracer a valuable tool for treatment decisions and patient management, even nowadays when new tracers (especially amino-acids) are available. In addition, [18F]FDG has a role in the differential diagnosis between relapse and necrosis when assessing aggressive tumors and to establish dedifferentiation in low-grade lesions. With the growing of available therapies, another emerging application of [18F]FDG is the monitoring of response to treatment, even though more evidence is needed to assess the best scanning time. Finally, the implementation of CT in PET devices most likely will improve the sensitivity and specificity of [18F]FDG, even though more data are needed to better understand which is the real advantage of PET/CT with respect to multimodality imaging. Currently, the possible added value of PET/CT is in the study of secondary brain lesions. It is believable that in the future we will keep on speaking about this "old" radiotracer, still alive.

Imaging with non-FDG PET tracers: outlook for current clinical applications

Apart from the historical and clinical relevance of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG), various other new tracers are gaining a remarkable place in functional imaging. Their contribution to clinical decision-making is irreplaceable in several disciplines. In this brief review we aimed to describe the main non-FDG PET tracers based on their clinical relevance and application for patient care.

Retrospective study on PET-SPECT imaging in a large cohort of myotonic dystrophy type 1 patients

The aim was to study brain involvement in myotonic dystrophy type 1 by single photon emission tomography (SPECT) and positron emission tomography (PET). 58 DM1 patients were subjected to SPECT; 17 to both SPECT and PET. SPECT patients were grouped as 'normally perfused' and 'abnormally perfused'; PET patients as 'normal performers' and 'abnormal performers'. To quantify hypoperfusion and/or hypometabolism, we used a semi-quantitative scale. To localize focal hypoperfusion/hypometabolism, nine cerebral areas of involvement were identified. The Chi-square, Wilcoxon, McNemar tests were used for statistics. SPECT showed abnormalities in 52/58 patients. PET showed an abnormal glucidic uptake in 15/17. Hypoperfusion was mild/moderate in 50/58 patients, mostly involving the left supratentorial areas. Abnormal glucidic uptake was mainly observed in the left frontal lobe. Abnormalities in blood perfusion and/or glucose metabolism are frequent in DM1. These abnormalities involve the left more often than the right hemisphere, the frontal lobe more than other lobes. Such abnormalities are more often cortical than subcortical.

Tumor relapse after pancreatic cancer resection is detected earlier by 18-FDG PET than by CT

INTRODUCTION

Pancreatic cancer recurrence is often difficult to detect by conventional imaging. Our aim was to evaluate the impact of fluorodeoxyglucose-positron emission tomography (FDG-PET) in the diagnosis of recurrent pancreatic cancer.

METHODS

One-hundred thirty-eight patients were followed after resection for pancreatic cancer. Sixty-six underwent only CT and were excluded. Seventy-two patients also had FDG-PET. Recurrent patients were divided in two groups: group-1, CT positive and group 2, CT non diagnostic, FDG-PET positive. Characteristics and survival curves of the two groups were compared. Significance was set at p < 0.05.

RESULTS

Overall, tumors recurred in 63 of 72 (87.5%) patients; two patients had a second cancer resected, thanks to FDG-PET. Tumor relapse was detected by CT in 35 patients and by FDG-PET in 61. Prognostic factors were similar in groups 1 and 2. Five out of 35 group 1 patients underwent surgery (two R0, two bypass, and one exploratory). Ten out of 28 group 2 patients underwent surgery (four R0, two R2, two bypass, and two exploratory). FDG-PET influenced treatment strategies in 32 of 72 patients (44.4%). Group 2 patients survived longer (P = 0.09), but the difference was not significant. Disease-free survival was similar in groups 1 and 2.

CONCLUSION

Tumor relapse is detected earlier by FDG-PET than by CT. FDG-PET can help select the best candidates for surgical exploration, although the real benefit is still to be defined. It influences treatment strategies in a significant percentage of patients. An earlier diagnosis did not influence survival due to the lack of effective therapies.

Radiotracer imaging studies in hepatic encephalopathy: ISHEN practice guidelines

There is lack of consensus on radiotracer usage in hepatic encephalopathy (HE). We have focused our attention on three main areas: (i) radiotracer imaging in animal models of HE, (ii) methodological issues of radiotracer imaging in HE and (iii) radiotracer imaging studies on the pathophysiology and (new) therapies in HE. We suggest the following: 1. Positron emission tomography (PET) and single photon emission computed tomography lend themselves to the study of animal models of HE, but the models that are suitable depend on the specific research question. Magnetic resonance imaging (MRI) may be a useful alternative technique. 2. Owing to the cost of the technique, there is a need for multicentre human PET studies to overcome the problem of underpowered small studies being undertaken in individual research centres. There should be a unified PET protocol with central, anonymised data analysis in one centre, using validated methodology, on behalf of all participating centres. Such studies would be useful for the assessment of early intervention in patients with subtle neuropsychiatric symptoms, or for clarification of the effect of liver transplantation on HE. 3. While radiotracer imaging modalities remain useful research tools for the study of pathogenesis and for the assessment of treatment effects, there is no consensus on the use of imaging in routine clinical practice for diagnosis and prognosis. The most promising objective tools appear to be magnetic resonance spectroscopy (MRS) and volumetric MRI, which can be performed in multiple centres without the difficulties that radiotracer imaging entail.

Exercise technetium 99m sestamibi single-photon emission computed tomography late after coronary artery bypass surgery: long-term follow-up

BACKGROUND AND HYPOTHESIS

The prognostic value of exercise technetium 99m sestamibi single-photon emission computed tomography (SPECT) imaging in patients with previous bypass surgery is unknown. The aim of our study was to assess the prognostic information obtained with exercise scintigraphy performed for routine follow-up or reappearance of symptoms.

METHODS

We studied 75 patients referred to our Center at a mean of 38 +/- 53 months from the revascularization procedure and prospectively followed them for 38 +/- 24 months.

RESULTS

Fifteen patients (20%) had events at follow-up: there were 4 cardiac deaths, 3 nonfatal acute myocardial infarctions, 8 late revascularization procedures (4 percutaneous transluminal angioplasty and 4 repeat bypass surgery). Univariate analysis identified a history of typical angina (p = 0.001), a clinically positive ergometric test (p = 0.009), peak exercise heart rate (p = 0.0003), percentage of maximal predicted heart rate (p = 0.0001), peak exercise double product (p = 0.048), therapy during exercise (p = 0.003), scintigraphic summed reversibility score (i.e., the summation of the segmental differences between stress and rest) (p = 0.014), as significant predictors of events. Three multivariate models were built, with clinical variables (Model 1, chi square 15.97), ergometric variables (Model 2, chi square 19.66), and with scintigraphic variables added to clinical/ergometric variables (Model 3, chi square 31.13). The scintigraphic variable selected in the model as significant predictor of events was the summed reversibility score (p = 0.008).

CONCLUSIONS

Exercise sestamibi SPECT scintigraphy provides optimal prognostic information after clinical and ergometric parameters in patients with previous bypass surgery.

Long-term prognostic value of 18F-FDG PET in patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy

OBJECTIVE

The purpose of this study was to assess the prognostic value of (18)F-FDG PET performed at restaging in patients with locally advanced rectal cancer who previously underwent neoadjuvant radiochemotherapy.

SUBJECTS AND METHODS

Eighty-eight patients with histologically proven rectal cancer classified at clinical TNM stages II and III were enrolled. Six weeks after radiochemotherapy completion, all patients were restaged by sonography, CT, MRI, endoscopy, and (18)F-FDG PET. Surgery was performed in all patients within 8-9 weeks from completion of radiochemotherapy. Median follow-up after surgery was 38 months (range, 6-66 months).

RESULTS

The 5-year overall survival and disease-free survival were 83% and 73%, respectively. Cox multivariate analysis showed that only two parameters at restaging were independent prognostic predictors of both overall survival and disease-free survival: pathologic stage and, especially, after radiochemotherapy (18)F-FDG PET findings. The 5-year overall survival was 91% in patients with a negative PET after radiochemotherapy versus 72% in those with a positive PET (p = 0.024) after radiochemotherapy, whereas disease-free survival was 81% and 62% (p = 0.003) for those with the negative and positive PET findings, respectively. Statistical data were further enhanced when combining the pathologic stage with the (18)F-FDG PET results: 95% 5-year overall survival in the PET-negative pathologic stages 0 and I patients versus 70% in PET-positive pathologic stages II-IV patients (p = 0.001), whereas disease-free survival was 93% and 65% (p = 0.0003) for the negative and positive PETs, respectively.

CONCLUSION

In patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy, the combined evaluation of pathologic stage and after-radiochemotherapy (18)F-FDG PET at restaging identified a subgroup of patients characterized by good response to radiochemotherapy and a more favorable prognosis. In these patients, a conservative surgical approach might be considered.

Implementation of 18F-FDG PET/CT in the management of colon cancer

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Background: we began using PET in 1994 and since the beginning of 2000 we started with a PET/CT system. Aim of our study was to evaluate if PET/CT is a decision making tool in patients with a history of colon tumors. Methods: we performed PET/CT in 26 patients, 14 males and 12 females (mean age 60.9, range 42–75 years) already treated for a colon cancer. Each patient was submitted to two PET/CT scans in a period of 5–11 months. PET/CT was performed using 18F-FDG as radiopharmaceutical. In all patients other examinations were perfomed, such as liver ecography, pelvis MRI and CT scan. Results: in the first PET/CT imaging, 11/26 patients presented with normal tumor markers but suspected relapse on the basis of CI, 7/26 had increased markers but negative CI, the other 8 patients had both CI and tumor markers meaningful for recurrence. 7/26 PET/CT were normal: 5 cases with negative tumor markers but positive CI and 2 patients with increased CEA levels. Among the 19/26 positive PET/CT scans, 7 patients had normal marker levels. All positive PET/CT patients were treated and, at the second examination, progressive disease was evident in 11 out of 19. For the 7 previous negative PET/CT, the second findings showed tumor recurrence in 2 patients, but PET/CT became negative in 5 previously positive cases, submitted to surgery and/or chemotherapy. This method detected relapse in 73% of the patients and, during the follow up, it was sensitive to identify progressive disease or to prove treatment’colon cancer, based on tumoral marker assays and CI, is poorly sensitive to detect relapse. Our PET/CT data show that 37% of cases with normal marker levels have a recurrent disease. The overall results of our preliminary data lead to further considerations: 1) PET/CT gives a precise localization of lung or nodal metastases and local relapse; 2) the repeated PET/CT scan is reliable also to evaluate the effect of therapies; 3) this imaging modality may be crucial to detect relapse, but more data are needed to assess the proper time to perform PET/CT in the follow up to have a real gain in life expectancy.

No significant financial relationships to disclose.

Diagnosis of recurrent breast cancer: 18F-FDG PET/TAC as first choice

10681

Background: we began using PET diagnosis in 1994 and since the beginning of 2000 we started with a PET/CT system. Aim of our study was to evaluate if this new imaging modality may be the first step in the detection of recurrence in patients with a history of breast tumors. Methods: we reviewed retrospectively 22 patients (mean age 60, range 46–76 years) already treated for a breast cancer. A total of 32 PET/CT scans were performed (repeated in 10 patients). All patients were submitted to other examinations, such as bone scintigraphy and liver ecography, but also mammography and CT scan. Results: 14/32 PET/CT were negative for recurrence in 10 patients (4 scans as a second one). In a mean follow up of 10 months, 1 case is not yet clear: in presence of relevant increase of Ca15.3 (up to 176 ng/ml) the first scan was negative and the second one evidentiated a pattern of lung inflammation. Among the other 13/14 negative scans, 3 patients presented ambiguous/positive bone scintigraphy for metastases, not assessed at the final diagnosis. 18/32 PET/CT scans were positive for local recurrence or distant metastases. Among these positive cases, a patient with normal bone scintigraphy presented a mild uptake of FDG in the right omerus. The second scan (5 months later) showed focal increased uptake of FDG in the same bone site, not evident in the CT images, and many small lung nodules, 1–2 mm size. In 3 patients PET localized muliple bone lesions, in 2 CT was completely normal. Finally, 1 out of the 18 positive results was false positive: a patients with a single lung nodule (1.5 cm) was submitted to surgery and the final diagnosis was benign lesion. PET/CT was crucial for the patient’s management in 19 out of 22 patients. Conclusions: recurrent breast cancer is generally characterized by multiple sites of metastases and few cases take advantage of surgical resection. In our group of 22 patients just 2 out of them received surgery (for local relapse and lung metastases). Therefore, in most cases a whole body examination, like PET/CT may be more useful respect to other modalities to assess how spread is the recurrence. Further data are needed but, in our preliminary experience, PET/CT seems to be the first choice to evaluate patients with previous breast cancer.

No significant financial relationships to disclose.

Clinical usefulness of 18-fluorodeoxyglucose positron emission tomography in the management of patients with nonpancreatic periampullary neoplasms

BACKGROUND

18-Fluorodeoxyglucose positron emission tomography (18-FDG PET) has been investigated for the diagnosis and staging of gastrointestinal malignancies including pancreatic adenocarcinoma. The aim of this study was to examine the clinical usefulness of 18-FDG PET in the diagnosis and follow-up evaluation of patients with periampullary neoplasms.

METHODS

Twenty-five patients underwent whole-body 18-FDG PET and abdominal computed tomography (CT). Pathologic confirmation was obtained in all patients by surgical resection or biopsy examination. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value (SUV). Positivity was assumed when a focal uptake occurred with an SUV of 2.5 or greater.

RESULTS

Between January 1998 and December 2003, 14 ampullary, 7 bile duct, and 4 duodenal tumors were included in the study. PET showed increased focal uptake in 22 patients (88%): 11 of 14 (79%) ampullary tumors, and 100% of bile duct and duodenal tumors. PET showed a focal uptake in 11 of 12 patients without detectable mass at CT scan, and lymph node metastases in 6 patients. An SUV value of 2.7 discriminated adenomas or noninvasive cancers (n = 6) from invasive malignancies (n = 14). Follow-up evaluation including CT scan and PET was performed in 12 patients: PET showed recurrent disease not seen by CT in 4 patients, confirmed CT findings in 6 patients, and showed an unsuspected primary lung cancer in 1 patient and colon cancer in another patient.

CONCLUSIONS

18-FDG PET is very sensitive for detecting periampullary neoplasms. It may be useful to differentiate benign or borderline lesions from invasive tumors when no mass has been identified by traditional imaging. Finally, it is very useful in the follow-up evaluation of resected patients to identify recurrent disease or other malignancies.

[Intraoperative transesophageal echocardiography in the endovascular treatment of thoracic aortic aneurysms]

AIM

Endovascular surgery is an efficacious alternative to conventional surgery in the treatment of descending thoracic aorta aneurysms. However, primary and delayed endoleaks are some endovascular technology's weak points. They are usually detected by angiography or angio CT, but many information may be obtained by transesophageal echocardiography (TEE) both as to endoleaks and to endograft's correct placement. Our purpose is to confirm, on the basis of our experience, the validity of this technique chosen both by us and by other groups with a wider casuistry.

METHODS

We positioned endografts for the treatment of degenerative or post-traumatic aneurysms of the descending thoracic aorta using TEE, together with angiography, during surgery in 8 out of 9 patients. TEE was carried out on the same 8 patients also before surgery, and for some patients even in the follow-up together with angio CT, after 6 and 12 months.

RESULTS

In the situations where TEE was used we found 5 cases of endoleaks and 1 of these was not detected by angiography because of its small dimensions. All of these endoleaks were immediately corrected with more angioplasty or graft extensions; in a case, where we could not utilize the TEE, the problem solved spontaneously after 30 days as it was confirmed both by angiography and angio TC. The statistical analysis with the Student t test is significant for P < 0.005.

CONCLUSIONS

We think that using TEE during the placement of an endograft on the descending thoracic aorta may help to obtain useful information in addition to those that we can obtain with angiography. Therefore, this may lead to improve the technique and to reduce possible both immediate or delayed complications.

A case of advanced Hodgkin lymphoma with breast involvement treated with a combination of gemcitabine and pegylated liposomal doxorubicin

Gemcitabine in combination with pegylated liposomal doxorubicin has been recognized as an effective treatment in patients with refractory solid tumors. To our knowledge, this is the first case of relapsed Hodgkin lymphoma with breast involvement successfully treated with this association.

[Positron emission tomography with fluorodeoxyglucose in gastro-entero-pancreatic tumors: diagnostic role and prognostic implications]

From November 1994 to November 2004, seventy-seven patients with neuroendocrine gastro-entero-pancreatic tumor (71% pancreatic) were investigated with 18-fluorine-deoxi-glucose positron emission tomography (FDG-PET). PET results were compared with CT-scan, MRI and octreoscan scintigraphy and clinico-pathologic features of patients and survival. Overall PET sensitivity was 57%; 78% of malignant tumors, 67% of borderline and 17% of benign tumors were detected by FDG-PET. No duodenal tumor was detected by PET scan. Only 16% of primary less than 2 cm in size was localized. In 16% of cases PET scan provided new information able to change therapeutic management. In PET positive patients the addictive information obtained by PET scan when compared with octreoscan, MRI and CT scan were respectively 50% more, 26% more and 30% more. In malignant neuroendocrine tumors PET positivity was related to short survival. No patient with malignant tumor died for disease progression in the follow-up when PET was negative, while 13/35 PET positive patients died (p <0.003). FDG-PET proved to be a second line technique in neuroendocrine digestive tumors. PET results improve clinical staging of disease and is related to survival in malignant cases; in 16% of cases may change the therapeutic option.

F-18-fluorodeoxyglucose positron emission tomography in differentiating malignant from benign pancreatic cysts: a prospective study

The differential diagnosis between benign and malignant pancreatic cystic lesions may be very difficult. We recently found that F-18-fluorodeoxyglucose positron emission tomography (18-FDG PET) was useful for the preoperative work-up of pancreatic cystic lesions. This study was undertaken to confirm these results. From February 2000 to July 2003, 50 patients with a pancreatic cystic lesion were prospectively investigated with 18-FDG PET in addition to helical computed tomography (CT) and, in some instances, magnetic resonance imaging (MRI). The validation of diagnosis was based on pathologic findings after surgery (n=31), percutaneous biopsy (n=4), and according to follow-up in 15 patients. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value (SUV). The accuracy of FDG PET and CT was determined for preoperative diagnosis of malignant cystic lesions. Seventeen patients had malignant cystic lesions. Sixteen (94%) showed increased 18-FDG uptake (SUV>2.5), including two patients with carcinoma in situ. Eleven patients (65%) were correctly identified as having malignancy by CT. Thirty-three patients had benign tumors: two patients showed increased 18-FDG uptake, and four patients showed CT findings of malignancy. Sensitivity, specificity, positive and negative predictive value, and accuracy of 18-FDG PET and CT in detecting malignant tumors were 94%, 94%, 89%, 97%, and 94% and 65%, 88%, 73%, 83%, and 80%, respectively. 18-FDG PET is accurate in identifying malignant pancreatic cystic lesions and should be used in combination with CT in the preoperative evaluation of patients with pancreatic cystic lesions. A negative result with 18-FDG PET may avoid unnecessary operation in asymptomatic or high-risk patients.

Thiethylperazine-induced parkinsonism: in vivo demonstration of dopamine D2 receptors blockade

Thiethylperazine (Torecan) is a piperazine phenothiazine employed to relieve vertigo. Its use may be associated with extrapyramidal side effects (dystonia, akathisia, tardive dyskinesia) (Sulkava, 1984), but parkinsonism has rarely been described. We describe a woman who, 1 month after the onset of thiethylperazine treatment, developed parkinsonism that disappeared 2 months after withdrawal of the drug. However, cerebral single-photon emission computed tomography (SPECT) with the dopamine (DA) D2 receptors ligand 123I-iodobenzamide (123I-IBZM) revealed a persistent reduced DA D2 receptors activity (by 45%) in the basal ganglia (BG), which may be clinically not effective.

Restaging after neoadjuvant chemoradiotherapy for rectal adenocarcinoma: role of F18-FDG PET

Multimodality treatment of loco-regional advanced rectal cancer has demonstrated to improve local control and overall survival. Proctoscopy, digital rectal examination (DRE), computer tomography (CT), endorectal ultrasound (ERUS), and magnetic resonance imaging (MRI) cannot correctly detect downstaging in rectal tumors after chemo radiation therapy (CRT). New imaging techniques, like 18F-FDG PET, may play some role in predicting the pathologic response to CRT before surgical resection. Aim of the present study was to further investigate the accuracy and predictive value of 18F-FDG PET in a large series of patients with rectal cancer treated with preoperative intensified CRT. Between January 2000 and December 2003, 81 patients with histologically proven adenocarcinoma in clinical stage II-III disease, according to criteria of TNM classification, were included in this study. All patients were submitted to diagnostic staging workup with DRE, proctoscopy with biopsy, ERUS, CT scan of the abdomen and pelvis or pelvic MRI plus liver ultrasonography, coloscopy or barium colonic enema. One month later the end of CRT all patients were submitted to diagnostic restaging work-up (DRW) and 18F-FDG PET. Surgery was performed 8-9 weeks after the end of CRT and pathologic stage was defined. Moreover a pathologic assessment of tumor regression was made with tumor regression grade score (TRG). PET correctly identified 22/28 (79% specificity) patients with complete pathologic response (pCR). However, sensitivity was 45% (24/53) while PPV, and NPV were equal to 77 and 43%, respectively. Total PET accuracy rate was 56%. PET sensitivity increased from 45 to 56% if the end-point was pCR, or TRG score, respectively. The best correlation was found between PET findings and pathologic stage (P <0.01) or TRG score (P <0.01). The accurate identification of rectal cancer patients with major pathological response after preoperative CRT further supports the necessity of designing prospective studies with new and more accurate was imaging technologies with the main object of offering conservative treatment in responder patients.

Does liver-disease aetiology have a role in cerebral blood-flow alterations in liver cirrhosis?

BACKGROUND

Studies using brain-imaging techniques have shown changes in regional blood flow (rCBF) in patients with liver cirrhosis. It remains unknown whether the aetiology of liver disease accounts for these changes.

AIMS

To evaluate whether the aetiology of liver cirrhosis is associated with different patterns of rCBF.

MATERIALS AND METHODS

A total of 50 patients with end-stage liver disease and no overt encephalopathy were studied. Thirteen age-matched subjects admitted to the neurology department for headache were used as controls. Exclusion criteria were focal brain lesions, severe brain atrophy and any abnormalities found on computed tomography scan suggesting other central nervous system diseases, alcohol intake or use of neuroactive drugs for at least 6 months. rCBF was assessed using single-positron-emission tomography (SPECT) with 99mTc-hexamethylpropylene amine oxime (99mTc-HM-PAO) as a tracer in all patients and controls. The Mann-Whitney U test was used for statistical analysis.

RESULTS

The liver-disease aetiology was as follows: alcoholic (A) in 19 patients; viral (V) (hepatitis B virus, hepatitis D virus, hepatitis C virus) in 14 patients; alcoholic with concomitant viral (A + V) in five patients; and cholestatic (C) (primary biliary cirrhosis, primary sclerosing cholangitis) in 12 patients. SPECT showed significantly lower rCBF in cirrhotic patients than in controls for most cortical and subcortical regions and in alcoholic and viral patients than in cholestatic liver disease patients for some cortical regions. When patients were grouped according to previous alcohol abuse (including cases with a concomitant viral aetiology), rCBF was significantly lower in the frontal superior, medial and temporal inferior regions in the alcoholic group.

CONCLUSIONS

Cerebral blood flow is significantly lower in patients with liver cirrhosis than in controls and, among cirrhotics, it is lower in alcoholic and viral cirrhosis than in cholestatic liver disease. In patients with previous alcohol abuse, cerebral blood flow was significantly more reduced in the frontal and temporal regions compared with patients without previous alcohol abuse.

18-Fluorodeoxyglucose positron emission tomography in predicting survival of patients with pancreatic carcinoma

The prediction of survival of patients with pancreatic cancer is usually based on tumor staging and grading and on the level of tumor markers. However, accurate tumor staging can be obtained only after resection, and still there is a great difference in survival rates among patients with the same clinicopathologic parameters. Recently the uptake of 18-fluorodeoxyglucose (FDG) by positron emission tomography (PET) has been found to be correlated with survival in patients with pancreatic cancer. This study evaluated the role of 18FDG PET as a prognostic factor for patients with pancreatic cancer. From June 1996 to July 2002, a total of 118 patients underwent PET for pancreatic cancer. The standardized uptake value (SUV) of 18FDG was calculated in 60 of them, and these patients were divided into high (>4) and low (< or =4) SUV groups. They were also evaluated according to the tumor node metastasis (TNM) classification system of the International Union Against Cancer, and by tumor grade, medical or surgical treatment, diabetes, age, sex, and CA 19-9 serum levels. Twenty-nine cancers showed high and 31 showed low SUVs. Survival was significantly influenced by tumor stage (P=0.0001), tumor grade (P=0.01), and SUV (P=0.005). Multivariate analysis showed that only stage (P=0.001) and SUV (P=0.0002) were independent predictors of survival. When patients who were analyzed for SUV were stratified according to the other variables, FDG uptake was related to survival also after stratification for the following: stage III to IVa (P=0.002), stage IVb (P=0.01), tumor resection (P=0.006), moderately differentiated tumors (P=0.01), age less than 65 years (P=0.006), CA 19-9 levels greater than 300 kU/L (P=0.002), and absence of diabetes (P=0.0001). The SUV calculated with 18FDG PET is an important prognostic factor for patients with pancreatic cancer and may be useful in selecting patients for therapeutic management.

Frontal cerebral blood flow is impaired in patients with heart transplantation

Patients with cardiovascular disease have cognitive function disturbances that are still evident after heart transplantation (HT). The aim of this study was to evaluate cerebral function in transplant patients and to assess whether cyclosporine therapy was responsible for cerebral abnormalities 1 year after transplantation. Six HT patients, eight liver transplant (LT) patients, and ten age-matched healthy controls underwent regional cerebral blood flow (rCBF) assessment by the (99m)Tc-hexamethyl-propylene-amineoxime ((99m)Tc-HM-PAO) single-photon emission computed tomography (SPECT) technique. The rCBF was correlated with cyclosporine blood levels. rCBF in HT and LT patients was similar to that of controls in all regions assayed, except for the frontal inferior region of HT patients, where it was significantly lower than in controls. No correlations between rCBF and cyclosporine blood levels were found in either HT or LT patients. In conclusion, the cerebral abnormalities seen in patients after HT but not after LT may be due to long-standing cerebral hypoperfusion resulting from severe heart disease, whereas cyclosporine does not account for such functional alterations.

Evidence of reverse mismatch with positron emission tomography imaging in a patient with reversible myocardial dysfunction

We describe the case of a patient who came to our attention because of a reversible depression of myocardial contractility, probably due to myocarditis. A positron emission tomography study showed, in correspondence to the malfunctioning segments, a decreased F18-2-fluoro-2-deoxyglucose (F18-FDG) uptake in the presence of a normal perfusion as assessed by means of N13-labeled ammonia uptake. This phenomenon, called "reverse mismatch", shows that viability is not always dependent on FDG uptake and that it could be associated with the recovery of myocardial contractility. Some interpretations of the association between a reversible dysfunction and a reduced myocardial glucose metabolism are presented. The central role of nitric oxide and of cyclic guanosine monophosphate is hypothesized to explain both the mechanical and metabolic abnormalities.

Advantages of positron emission tomography (PET) with respect to computed tomography in the follow-up of lymphoma patients with abdominal presentation

For abdominal lymphoma patients, fluorine-18 fluorodeoxyglucose positron emission tomography (PET) provides unique information on the presence of residual active disease. We provide an update on the largest reported cohort of patients whose management following induction therapy was based on routine PET and computed tomography (CT) restaging. Fifty-nine patients with Hodgkin's disease or aggressive non-Hodgkin's lymphoma presenting abdominal involvement (35% with bulky disease) were studied with both PET and CT following combined chemotherapy/radiation treatment. After treatment, 3/3 (100%) patients who were PET+/CT- relapsed, compared with 0/7 patients in the PET-/CT- subset. Among the 49 patients who were CT+, six of the 10 (60%) who were PET+ relapsed, as compared with only two of the 39 (5%) who were PET-. The actuarial relapse-free survival (RFS) rates were 0 and 100% in the PET+/CT- and PET-/CT- subsets, respectively. In the PET+/CT+ subset, RFS was 94% at 5 years. PET restaging is very valuable for the identification of patients who would need appropriate second-line therapy because of the presence of residual active abdominal disease and should be made widely available in combination with CT.

Treatment of Buerger's disease with electrical spinal cord stimulation--review of three cases

Buerger's disease or obliterating thromboangiitis is an inflammatory pathologic condition affecting the distal vascular segments; it strikes young adults, especially males and heavy smokers. Medical and surgical treatment often fail to heal these patients, especially considering the frequent relapse of this disease linked with tobacco abuse--definitive healing often involves limb amputation. Electrical spinal cord stimulation is evaluated in this study with an analgesic aim and for improvement in skin microcirculation, with the goal of long-term healing of diseased limbs.

Value of 18-fluorodeoxyglucose positron emission tomography in the management of patients with cystic tumors of the pancreas

OBJECTIVE

To assess the reliability of 18-fluorodeoxyglucose positron emission tomography (18-FDG PET) in distinguishing benign from malignant cystic lesions of the pancreas.

SUMMARY BACKGROUND DATA

The preoperative differential diagnosis of cystic lesions of the pancreas remains difficult: the most important point is to identify malignant or premalignant cysts that require resection. 18-FDG PET is a new imaging procedure based on the increased glucose metabolism by tumor cells and has been proposed for the diagnosis and staging of pancreatic cancer.

METHODS

During a 4-year period, 56 patients with a suspected cystic tumor of the pancreas underwent 18-FDG PET in addition to computed tomography scanning, serum CA 19-9 assay, and in some instances magnetic resonance imaging or endoscopic retrograde cholangiopancreatography. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value. The accuracy of 18-FDG PET and computed tomography was determined for preoperative diagnosis of a malignant cyst.

RESULTS

Seventeen patients had malignant tumors. Sixteen patients (94%) showed 18-FDG uptake with a standard uptake value of 2.6 to 12.0. Twelve patients (70%) were correctly identified as having malignancy by computed tomography, CA 19-9 assay, or both. Thirty-nine patients had benign tumors: only one mucinous cystadenoma showed increased 18-FDG uptake (standard uptake value 2.6). Five patients with benign cysts showed computed tomography findings of malignancy. Sensitivity, specificity, and positive and negative predictive values for 18-FDG PET and computed tomography scanning in detecting malignant tumors were 94%, 97%, 94%, and 97% and 65%, 87%, 69%, and 85%, respectively.

CONCLUSIONS

18-FDG PET is more accurate than computed tomography in identifying malignant pancreatic cystic lesions and should be used, in combination with computed tomography and tumor markers assay, in the preoperative evaluation of patients with pancreatic cystic lesions. A positive result on 18-FDG PET strongly suggests malignancy and, therefore, a need for resection; a negative result shows a benign tumor that may be treated with limited resection or, in selected high-risk patients, with biopsy, follow-up, or both.