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PURPOSE: To assess the value of CT-perfusion in determining the quantitative vascularization features of early hepatocellular carcinoma (HCC) in cirrhotic patients. MATERIALS AND METHODS: A total of 35 cirrhotic patients with single histologically proven HCC not exceeding 3cm in diameter underwent conventional triple-phase multidetector computed tomography (MDCT) examination. All patients were also examined with CT-perfusion (CTp) technique after i.v. injection of 50mL of iodinated contrast. Data were analyzed using a dedicated software which generated a quantitative map of liver parenchyma perfusion. The following parameters were assessed: hepatic perfusion (HP); blood volume (BV); arterial perfusion (AP); time to peak (TTP) and hepatic perfusion index (HPI). Univariate Wilcoxon signed rank test was used for statistical analysis. RESULTS: In the 35 HCCs evaluated, the following quantitative data were obtained: HP (mL/s/100g): median=47.0 (1(st)qt=35.5; 3(st)qt=61.2); BV (mL/100mg): median=22.5 (1(st)qt=18.4; 3(st)qt=27.7); AP (mL/min): median=42.9 (1(st)qt=35.8; 3(st)qt=55.6); HPI(%): median=75.3 (1(st)qt=63.1; 3(st)qt=100); TTP(s): median=18.7 (1(st)qt=16.8; 3(st)qt=24.5). Perfusion values calculated in cirrhotic liver parenchyma were HP: median=10.3 (1(st)qt=9.1; 3(st)qt=13.2); BV: median=11.7 (1(st)qt=9.6; 3(st)qt=15.5); AP: median=10.4 (1(st)qt=8.6; 3(st)qt=11.3); HPI: median=17.5 (1(st)qt=14.3; 3(st)qt=19.7); TTP: median=44.6 (1(st)qt=40.3; 3(st)qt=50.1). HP, BV, HPI and AP were found to be significantly higher in HCC lesion than in liver parenchyma (p

PURPOSE: Detection of recurrence in prostate cancer patients with biochemical failure after radical prostatectomy by [(11)C]choline PET/CT depends on the prostate-specific antigen (PSA) level. The role of other clinical and pathological variables has not been explored. METHODS: A total of 2,124 prostate cancer patients referred to our Institution for [(11)C]choline PET/CT from December 2004 to January 2007 for restaging of disease were retrospectively considered for this study. Inclusion criteria were: previous treatment by radical prostatectomy, and biochemical failure, defined as at least two consecutive PSA measurements of >0.2 ng/ml. These criteria were met for 358 patients. Binary logistic analysis was used to investigate the predictive factors of [(11)C]choline PET/CT. PET/CT findings were validated using criteria based on histological analysis, and follow-up clinical and imaging data. Receiver operating characteristic (ROC) analysis was used to assess the performance of [(11)C]choline PET/CT in relation to PSA levels. RESULTS: The mean PSA level was 3.77 +/- 6.94 ng/ml (range 0.23-45 ng/ml; median 1.27 ng/ml). PET/CT was positive for recurrence in 161 of 358 patients (45%). On an anatomical region basis, [(11)C]choline pathological uptake was observed in lymph nodes (107/161 patients, 66%), prostatectomy bed (55/161 patients, 34%), and in the skeleton (46/161 patients, 29%). PET/CT findings were validated using histological criteria (46/358, 13%), and follow-up clinical and imaging criteria (312/358, 87%). Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were, respectively, 85%, 93%, 91%, 87%, and 89%. In multivariate analysis, high PSA levels, advanced pathological stage, previous biochemical failure and older age were significantly (P < 0.05) associated with an increased risk of positive PET/CT findings. The percentage of positive scans was 19% in those with a PSA level between 0.2 and 1 ng/ml, 46% in those with a PSA level between 1 and 3 ng/ml, and 82% in those with a PSA level higher than 3 ng/ml. ROC analysis showed that PET/CT-positive and PET/CT-negative patients could be best distinguished using a PSA cut-off value of 1.4 ng/ml. CONCLUSIONS: In addition to PSA levels, pathological stage, previous biochemical failure and age should be considered by physicians when referring prostate cancer patients with biochemical failure after radical prostatectomy to [(11)C]choline PET/CT.

(60)Cu and (64)Cu are useful radioisotopes for positron emission tomography (PET) radiopharmaceuticals and may be used for the preparation of promising agents for diagnosis and radiotherapy. In this study, the production and purification of (60/64)Cu starting from (60/64)Ni using a new automated system, namely Alceo, is described. A dynamic process for electrodeposition and dissolution of (60/64)Ni/(60/64)Cu was developed. Preliminary production yields of (60)Cu and (64)Cu were 400 and 300mCi, respectively. (64)Cu was used to radiolabel the hypoxia detection tracer ATSM with a specific activity of 2.2+/-1.3Ci/micromol.

Purpose. To find correlation between dose-volume histograms (DVHs) of the intestinal cavity (IC) and moderate-severe acute bowel toxicity in men with prostate cancer treated with pelvic nodal irradiation. Methods and Materials. The study group consisted of 191 patients with localized prostate cancer who underwent whole-pelvis radiotherapy with radical or adjuvant/salvage intent during January 2004 to November 2007. Complete planning/clinical data were available in 175 of these men, 91 of whom were treated with a conventional four-field technique (50.4 Gy, 1.8 Gy/fraction) and 84 of whom were treated with IMRT using conventional Linac (n = 26, 50.4 Gy, 1.8 Gy/fraction) or Helical TomoTherapy (n = 58, 50–54 Gy, 1.8–2 Gy/fraction). The IC outside the planning target volume (PTV) was contoured and the DVH for the first 6 weeks of treatment was recovered in all patients. The correlation between a number of clinical and DVH (V10–V55) variables and toxicity was investigated in univariate and multivariate analyses. The correlation between DVHs for the IC outside the PTV and DVHs for the whole IC was also assessed. Results. Twenty-two patients experienced toxicity (3/22 in the IMRT/tomotherapy group). Univariate analyses showed a significant correlation between V20–V50 and toxicity (p = 0.0002–0.001), with a higher predictive value observed for V40–V50. Previous prostatectomy (p = 0.066) and abdominal/pelvic surgery (p = 0.12) also correlated with toxicity. Multivariate analysis that included V45, abdominal/pelvic surgery, and prostatectomy showed that the most predictive parameters were V45 (p = 0.002) and abdominal/pelvic surgery (p = 0.05, HR = 2.4) Conclusions. Our avoidance IMRT approach drastically reduces the incidence of acute bowel toxicity. V40–V50 of IC and, secondarily, previous abdominal/pelvic surgery were the main predictors of acute bowel toxicity.

AIMS AND BACKGROUND: Evaluation of the metabolic response to radiotherapy in nonsmall cell lung cancer patients is commonly performed about three months after the end of radiotherapy. The aim of the present study was to assess with positron emission tomography/computed tomography (PET/CT) and [18F]fluorodeoxyglucose changes in glucose metabolism during and after radiotherapy in non-small cell lung cancer patients. METHODS AND STUDY DESIGN: In 6 patients, PET/CT scans with [18F]fluorodeoxyglucose were performed before (PET0), during (PET1; at a median of 14 days before the end of radiotherapy) and after the end of radiotherapy (PET2 and PET3, at a median of 28 and 93 days, respectively). The metabolic response was scored according to visual and semiquantitative criteria. RESULTS: Standardize maximum uptake at PET1 (7.9 +/- 4.8), PET2 (5.1 +/- 4.1) and PET3 (2.7 +/- 3.1) were all significantly (P < 0.05; ANOVA repeated measures) lower than at PET0 (16.1 +/- 10.1). Standardized maximum uptake at PET1 was significantly higher than at both PET2 and PET3. There were no significant differences in SUV(max) between PET2 and PET3. PET3 identified 4 complete and 2 partial metabolic responses, whereas PET1 identified 6 partial metabolic responses. Radiotherapy-induced increased [l8F]fluorodeoxyglucose uptake could be visually distinguished from tumor uptake based on PET/CT integration and was less frequent at PET1 (n = 2) than at PET3 (n = 6). CONCLUSION: In non-small cell lung cancer, radiotherapy induces a progressive decrease in glucose metabolism that is greater 3 months after the end of treatment but can be detected during the treatment itself. Glucose avid, radiotherapy-induced inflammation is more evident after the end of radiotherapy than during radiotherapy and does not preclude the interpretation of [18F]fluorodeoxyglucose images, particularly when using PET/CT.

PURPOSE: Transgenic adenocarcinoma of the mouse prostate (TRAMP) mice spontaneously develop hormone-dependent and hormone-independent prostate cancer (PC) that potentially resembles the human pathological condition. The aim of the study was to validate PET imaging as a reliable tool for in vivo assessment of disease biology and progression in TRAMP mice using radioligands routinely applied in clinical practice: [(18)F]FDG and [(11)C]choline. METHODS: Six TRAMP mice were longitudinally evaluated starting at week 11 of age to visualize PC development and progression. The time frame and imaging pattern of PC lesions were subsequently confirmed on an additional group of five mice. RESULTS: PET and [(18)F]FDG allowed detection of PC lesions starting from 23 weeks of age. [(11)C]Choline was clearly taken up only by TRAMP mice carrying neuroendocrine lesions, as revealed by post-mortem histological evaluation. CONCLUSION: PET-based molecular imaging represents a state-of-the-art tool for the in vivo monitoring and metabolic characterization of PC development, progression and differentiation in the TRAMP model.

PURPOSE: To report planning and acute toxicity data of the first 60 patients treated within a Phase I-II study with moderate hypofractionation by image-guided helical tomotherapy. METHODS AND MATERIALS: Various clinical target volumes (CTVs) were defined: CTV1-pelvic nodes; CTV2-upper portion of seminal vesicles; CTV3-lower portion of SV; CTV4-prostate; overlap between planning target volume (PTV) 4 and rectum. Different doses to each PTV were simultaneously delivered in 28 fractions. For 31 low-risk patients: 56.0, 61.6, and 71.4 Gy for PTV2-4, respectively; for 20 intermediate-risk patients: 51.8, 61.6, 65.5, and 74.2 Gy for PTV1-4, respectively; for 9 high-risk patients: 51.8 and 65.5 Gy for PTV1-2 and 74.2 Gy for PTV3-4. For all patients, the dose to overlap was 65.5 Gy. RESULTS: The mean fraction of rectum receiving more than 65 Gy (V65) and rectal Dmax were 10% and 70.8 Gy respectively. In cases of pelvic node irradiation, the intestinal cavity (outside PTV) receiving > 45 and 50 Gy was 86 and 12 cc, respectively. A homogeneous dose distribution within each PTV was guaranteed. Acute genitourinary toxicity according to RTOG scoring system was as follows: 21/60 (35%) Grade 1, 12/60 (20%) Grade 2, 2/60 (3%) Grade 3. Acute rectal toxicities were: 18/60 (30%) Grade 1. Twelve (20%) patients showed Grade 1 upper intestinal toxicity (uGI). No patients experienced >/= Grade 2 acute rectal or uGI side effects. CONCLUSIONS: This study shows excellent results with regard to acute toxicity. Further research is necessary to assess definitive late toxicity and tumor control outcome.

AIM: Anti-androgenic hormonal therapy in prostate cancer patients with concomitant meningioma may result in tumor growth and development of neurological symptoms. Positron emission tomography/computed tomography (PET/CT) with [(11)C]choline is used for restaging prostate cancer patients with biochemical failure. In vitro and in vivo data support altered choline metabolism in meningiomas. METHODS: During a retrospective study in prostate cancer patients with biochemical failure referred to our institution between November 2004 and Ja-nuary 2007, encephalic focal uptake of [(11)C]choline was incidentally noted in 4 patients, 2 of which had been taking luteinizing hormone-releasing hormone analogs. RESULTS: Subsequent to the incidental finding, one patient underwent surgical removal of the meningioma; strict neuroradiological follow-up was planned for the 3 other patients. CONCLUSIONS: We suggest that in prostate cancer patients candidate for anti-androgenic therapy the whole body [(11)C]choline PET/CT scan should include the whole skull to check for the possible presence of meningiomas. This could help to identify patients at risk for the development of neurological symptoms during anti-androgenic therapy and help the referring urologist in the clinical management of these patients.

Positron emission tomography/computed tomography introduction in the clinical management of patients with suspected recurrence of ovarian cancer: a cost-effectiveness analysisAim of this study was to evaluate the economic impact of the introduction of positron emission tomography/computed tomography (PET/CT) in the early detection of recurrent ovarian cancer through a cost-effectiveness analysis of different diagnostic strategies. Thirty-two consecutive patients with suspected ovarian cancer recurrence, studied by both contrast enhanced abdominal CT and PET/CT, were retrospectively included in the study. Three different diagnostic strategies were evaluated and compared: (1) CT only or baseline strategy; (2) PET/CT for negative CT or strategy A; (3) PET/CT for All or strategy B. For each one, expected costs, avoided surgery and incremental cost-effectiveness ratio (ICER) were calculated to identify the most cost-effective strategy. The number of positive patients increased from baseline strategy (20/32) to strategy A and B (30/32 and 29/32 respectively). Positron emission tomography/computed tomography reoriented physician choice in 31% and 62% of patients (strategies A and B respectively). Strategy A is dominated by strategy B, which is more expensive (2909 Euro vs. 2958 Euro), but also more effective (3 cases of surgery avoided) and presents an ICER of 226.77 Euro per surgery avoided (range: 49.50-433.00 Euro). Positron emission tomography/computed tomography introduction in this population is cost-effective and allowed to redirect the clinical management of patients towards more appropriate therapeutic choices.

PURPOSE:: Positron emission tomography/computed tomography (PET/CT) with C-11 choline has been used for staging, restaging, and follow-up of various tumors, whereas its role for imaging meningiomas has only been preliminarily explored. The aim of this study was to compare C-11 choline and F-18 fluorodeoxyglucose (F-18 FDG) uptake in meningiomas and relate these findings to the histopathological analysis. METHODS:: Two sequential three-dimensional PET/CT scans with 370 MBq (10 mCi) of C-11 choline and 370 MBq (10 mCi) of F-18 FDG were performed 2 hours apart in 7 patients with histologically confirmed meningiomas. Five patients had WHO grade I and 2 had WHO grade II meningioma. For each scan, two-dimensional regions of interest were drawn on tumor boundaries and on the contralateral side on CT images and copied to the corresponding PET images. SUVmax and tumor-to-background ratio were calculated. RESULTS:: Relative to the contralateral side, C-11 choline uptake was increased in all meningiomas, whereas F-18 FDG uptake was decreased in 6 patients and increased in 1 of the 2 patients with grade II meningiomas. In the whole group, SUVmax of C-11 choline and F-18 FDG were 3.6 +/- 1.3 and 5.7 +/- 1.3, respectively. The tumor-to-background ratio for C-11 choline was much higher than that for F-18 FDG (5.3 +/- 0.8 vs. 0.9 +/- 0.2, respectively) (P < 0.001). The uptake of C-11 choline was higher in patients with grade II than in grade I meningiomas. CONCLUSIONS:: These preliminary results suggest that C-11 choline may better image meningiomas in comparison with F-18 FDG. Clinical applications of C-11 choline PET/CT for grading and follow-up of meningiomas need to be assessed in further studies.

PURPOSE: To assess setup and organ motion error by means of analysis of daily megavoltage computed tomography (MVCT) of patients treated with hypofractionated helical tomotherapy (71.4-74.2 Gy in 28 fractions). METHODS AND MATERIALS: Data from 21 patients were analyzed. Patients were instructed to empty the rectum carefully before planning CT and every morning before therapy by means of a self-applied rectal enema. The position of the prostate was assessed by means of automatic bone matching (BM) with the planning kilovoltage CT (BM, setup error) followed by a direct visualization (DV) match on the prostate. Deviations between planning and therapy positions referred to BM and BM + DV were registered for the three main axes. In case of a full rectum at MVCT with evident shift of the prostate, treatment was postponed until after additional rectal emptying procedures; in this case, additional MVCT was performed before delivering the treatment. Data for 522 fractions were available; the impact of post-MVCT procedure was investigated for 17 of 21 patients (410 fractions). RESULTS: Prostate motion relative to bony anatomy was limited. Concerning posterior-anterior shifts, only 4.9% and 2.7% of fractions showed deviation of 3 mm or greater of the prostate relative to BM without and with consideration of post-MVCT procedures, respectively. Interobserver variability for BM + DV match was within 0.8 mm (1 SD). CONCLUSIONS: Daily MVCT-based correction is feasible. The BM + DV matching was found to be consistent between operators. Rectal emptying using a daily enema is an efficient tool to minimize prostate motion, even for centers that have not yet implemented image-guided radiotherapy.

RATIONALE AND OBJECTIVES: Our goal was to prospectively determine the value of perfusion computed tomography (CT) in the quantitative assessment of tumor-related angiogenesis in cirrhotic patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Forty-seven patients met all the following inclusion criteria: 1) Child-Pugh class A or B liver cirrhosis; 2) presence of a single lesion suspected as HCC at screening ultrasound examination; and 3) lesion diameter between 1 and 3 cm. All patients underwent contrast-enhanced ultrasound, pre- and post-contrast triple-phase CT, and perfusion computed tomographic study using multidetector 16-slice CT. Six parameters related to the blood microcirculation and tissue perfusion were measured for the focal liver lesion and cirrhotic parenchyma: perfusion (P), tissue blood volume (BV), hepatic perfusion index (HPI), arterial perfusion (AP), portal perfusion (PP), and time to peak (TTP). Perfusion parameters were described with quartile values of their distribution; univariate paired and unpaired Wilcoxon signed rank tests were used for statistical analysis. RESULTS: HCC was diagnosed in 21 of the 47 patients; in the remaining 26, HCC was not found at contrast-enhanced ultrasound and multidetector 16-slice computed tomographic study. The values of perfusion parameters measured within tumor tissue were: P (ml/s/100 g): median = 47.0 (first quartile = 36.0, third quartile = 61.4); BV (ml/100 mg): median = 24.0 (first quartile = 18.7, third quartile = 29.3); HPI (%): median = 78.4 (first quartile = 62.9, third quartile = 100); AP (ml/min): median = 45.9 (first quartile = 39.0, third quartile = 60.1); PP (ml/min): median = 9.0 (first quartile = 0.0, third quartile = 24.5); and TTP (seconds): median = 18.7 (first quartile = 16.3, third quartile = 26.5). The corresponding values calculated in cirrhotic surrounding parenchyma were P (ml/s/100 g): median = 11.5 (first quartile = 9.4, third quartile = 13.9); BV (ml/100 mg): median = 10.7 (first quartile = 7.1, third quartile = 14.2); HPI (%): median = 10.6 (first quartile = 8.7, third quartile = 11.9); AP (ml/min): median = 13.2 (first quartile = 10.1, third quartile = 15.5); PP (ml/min) median = 55.2 (first quartile = 40.1, third quartile = 79.5); and TTP (seconds): median = 41.7 (first quartile = 38.9, third quartile = 44.6). P, BV, HPI, and AP values were higher (P < .001), whereas PP and TTP were lower (P < .001) in HCC relative to the surrounding liver. Values of perfusion parameters in the cirrhotic liver of patients with and without HCC were not significantly different (P > .001). CONCLUSION: In cirrhotic patients with HCC, perfusion computed tomographic technique can provide quantitative information about tumor-related angiogenesis.

Purpose. Huntington’s disease (HD) is a progressive neurodegenerative disorder, which is characterised by prominent neuronal cell loss in the basal ganglia with motor and cognitive disturbances. One of the most well-studied pharmacological models of HD is produced by local injection in the rat brain striatum of the excitotoxin quinolinic acid (QA), which produces many of the distinctive features of this human neurodegenerative disorder. Here, we report a detailed analysis, obtained both in vivo and in vitro of this pharmacological model of HD. Materials and methods. By combining emission tomography (PET) with autoradiographic and immunocytochemical confocal laser techniques, we quantified in the QA-injected striatum the temporal behavior (from 1 to 60 days from the excitotoxic insult) of neuronal cell density and receptor availability (adenosine A2A and dopamine D2 receptors) together with the degree of microglia activation. Results. Both approaches showed a loss of adenosine A2A and dopamine D2 receptors paralleled by an increase of microglial activation. Conclusion. This combined longitudinal analysis of the disease progression, which suggested an impairment of neurotransmission, neuronal integrity and a reversible activation of brain inflammatory processes, might represent a more quantitative approach to compare the differential effects of treatments in slowing down or reversing HD in rodent models with potential applications to human patients.

We used positron emission tomography (PET) and the dopamine transporter (DAT) ligand [(11)C]FECIT to measure loss of nigrostriatal dopaminergic neurons in early phase of early onset (EOPD) and late onset Parkinson's disease (LOPD). The analysis was carried out with both regions of interest and voxelwise method (SPM2), at group and single subject levels. Genetic analysis tested for the mutations occurring most frequently in Caucasian population. A significant, bilateral, asymmetric DAT reduction was observed in both EOPD and LOPD. Noteworthy, the side and severity of DAT binding reduction significantly correlated with the severity and asymmetry of motor clinical scores. The two EOPD patients carrying mutations in the PARK2 and PARK6 genes, respectively, displayed the lowest values, bilaterally. This work demonstrates that severity of nigrostriatal damage in early disease phase of sporadic PD is not dependent on age at onset. Genetically determined PD is associated with more severe and widespread dopaminergic impairment.

A case of a patient with bronchioloalveolar cell predominate lung adenocarcinoma (BAC) studied using integrated Positron Emission Tomography and Computed Tomography (PET/CT) with both 18F-fluorodeoxyglucose ([18F]FDG-PET) and [11C]Choline ([11C]Choline-PET) is described, with the aim of evaluating a new non invasive imaging method to detect and stage BAC, and providing information on tumour biology in vivo. The information derived from combining the two tracers could help in distinguishing lung adenocarcinoma with large BAC components ([18F]FDG negative and [11C]Choline positive) from inflammatory lesion ([18F]FDG and [11C]Choline positive). In addition, the simultaneous use of two PET tracers, evaluating two different metabolic pathways, together with histopathologic, immunohistochemical and gene expression analysis, could help to improve understanding of tumour in vivo behaviour.

Sarcoidosis is a chronic disease of unknown etiology characterized by the presence of T lymphocytes, mononuclear phagocytes, and noncaseating epithelioid granulomas in the tissues. Central nervous system involvement occurs in about 5% of the cases. The chronic form of neurosarcoidosis is particularly resistant to medical treatments. No universally accepted therapeutic protocols are currently available. Corticosteroids are the first line of therapy, but other immunosuppressive treatments are frequently added to the patient's regimen, although this strategy is not adequately supported by controlled clinical trials. For patients resistant to or not tolerating multiple alternate immunotherapeutic drugs, some authors suggest central nervous system radiotherapy. We present a case of a patient with neurosarcoidosis involving the hypothalamo-hypophyseal region and causing panhypopituitarism who had a poor response to and experienced severe side effects from conventional immunosuppressive treatments. The patient experienced a good clinical response to cranial irradiation. We review the literature on this subject.

PURPOSE: To report on planning and toxicity findings of hypofractionated adjuvant radiotherapy with helical Tomotherapy (HTT) after radical prostatectomy (RP) for prostate carcinoma (pCa). METHODS AND MATERIALS: Fifty consecutive patients submitted to RP for pT2R1/pT3a/pT3b-pN0 pCa were enrolled in a Phase I-II trial to receive 58Gy/20 fractions (5/week) on tumoral bed. Endpoint was to verify a risk of toxicity and biochemical failure not exceeding that observed in our Institutional 3DCRT, conventionally fractionated series (153 patients). Toxicities were graded according the RTOG scoring system. RESULTS: Excellent coverage of PTV and high homogeneity of dose distribution were always achieved. Median follow-up was 25 months. Acute G2-3 RTOG genitourinary (GU) and acute G2 intestinal toxicities were similar (12% vs 15.6% and 4% vs 7%, respectively), while acute G2 proctitis was 0% vs 9% in HTT and 3DCRT group, respectively. Similarly, late Grade 2 gastrointestinal sequelae were 0% vs 8.5%. The incidence of late urethral stricture, 8% and 9% in HTT and 3DCRT group, respectively, is comparable to that of RP-only series. CONCLUSIONS: Acute toxicity and early late toxicity outcomes of a moderately hypofractionated regimen with HTT post-RP are excellent. A longer follow-up is needed to fully assess the validity of this approach.

To prospectively assess perfusion computed tomography (CT) for evaluation of tumor vascularity of early hepatocellular carcinoma (HCC) in patients with cirrhosis. METHODS:: The study cohort included 30 patients who had Child-Pugh class A or B liver cirrhosis and a single histopathologically confirmed HCC not exceeding 3 cm in diameter. All patients underwent perfusion CT study using a multidetector 16-slice CT. Four perfusion parameters were measured for the HCCs and cirrhotic liver parenchyma: hepatic perfusion (HP), blood volume (BV), arterial perfusion (AP), and time to peak (TTP). Perfusion parameters were described with quartile (qt) values of their distribution; univariate paired Wilcoxon signed rank test was used for statistical analysis. RESULTS:: The values of perfusion parameters measured within tumor tissue were the following: HP (milliliters per 100 g per minute): median = 45.7 (first qt = 35.3; third qt = 61.3); BV (milliliters per 100 mg): median = 20.6 (first qt = 13.0; third qt = 27.6); AP (milliliters per minute): median = 44.2 (first qt = 36.7; third qt = 57.0); TTP (seconds): median = 18.7 (first q = 15.9; third qt = 24.0). Our data showed that HP, BV, and AP values were higher (P < 0.001), whereas TTP was lower (P < 0.001), in HCCs relative to the cirrhotic liver parenchyma. For all the CT perfusion parameters calculated, there was a significant difference between HCC and background cirrhotic liver. CONCLUSIONS:: Preliminary results suggest that in patients with cirrhosis and early HCC, perfusion CT is a feasible technique for noninvasive assessment of tumor vascularity.

New complex tissue microstructure estimators have been presented recently in order to elucidate white matter fibre orientations. Since these algorithms are based on the diffusionweighted signal profile, the estimations are affected by noise artefacts. The proven robustness of these methods cannot counteract distortions since the statistical Rician behavior has not been taken into account. In this study, two techniques to counteract the noise distortions are presented to improve the fibre orientation estimations. Simulations and in vivo experiments show an improvement in the angular resolution and convergence of the results. One of these strategies represents a good compromise between computational cost and result improvements.

Positron emission tomography/computed tomography (PET/CT) with C-11 choline is currently used for restaging prostate cancer in patients with biochemical failure. Skeletal Paget disease can be associated with prostate cancer, and bone scintigraphy can differentiate the 2 conditions. We report the case of a 74-year-old patient with prostate cancer who displayed multiple areas skeletal uptake of C-11 choline on a restaging PET/CT, which was attributed to both metastatic and pagetic bone diseases. The pattern of C-11 choline uptake was different between the 2 conditions, probably in relation to the different mechanisms of disease. The possibility of C-11 choline uptake in pagetic bone should be kept in mind when interpreting PET/CT findings in patients with prostate cancer.

Purpose The accuracy of positron emission tomography (PET)/CT with [11C]choline for the detection of prostate cancer is not well established. We assessed the dependence of [11C]choline maximum standardized uptake values (SUVmax) in the prostate gland on cell malignancy, prostate-specific antigen (PSA) levels, Gleason score, tumour stage and anti-androgenic hormonal therapy. Methods In this prospective study, PET/CT with [11C]choline was performed in 19 prostate cancer patients who subsequently underwent prostatectomy with histologic sextant analysis (group A) and in six prostate cancer patients before and after anti-androgenic hormonal therapy (bicalutamide 150 mg/day; median treatment of 4 months; group B). Results In group A, based on a sextant analysis with a [11C]choline SUVmax cutoff of 2.5 (as derived from a receiver-operating characteristic analysis), PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 72, 43, 64, 51 and 60%, respectively. In the patient-by-patient analysis, no significant correlation was detected between SUVmax and PSA levels, Gleason score or pathological stage. On the contrary, a significant (P

PURPOSE: The purpose of this study was to prospectively determine the diagnostic accuracy of PET/CT in the detection of recurrence in patients with treated uterine cancers. METHODS: Twenty-five women, ranging in age from 37 to 79 years (mean 58.9 years), who underwent primary surgical treatment for either a cervical or an endometrial cancer met the inclusion criterion of the study, which was suspicion of recurrence based on results of routine follow-up procedures. PET/CT was performed after administration of (18)F-fluorodeoxyglucose (FDG); two readers interpreted the images in consensus. Histopathological findings or correlation with results of subsequent clinical and imaging follow-up examinations served as the reference standard. Diagnostic accuracy of PET/CT was reported in terms of the proportion of correctly classified patients and lesion sites. RESULTS: Tumour recurrence was found at histopathological analysis or follow-up examinations after PET/CT in 14 (56%) of the 25 patients. Patient-based sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT for detection of tumour recurrence were 92.9%, 100.0%, 100.0%, 91.7% and 96.0%, respectively. Lesion site-based sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT were 94.7%, 99.5%, 94.7%, 99.5% and 99.0%, respectively. CONCLUSION: This preliminary study shows that PET/CT may be an accurate method for the evaluation of recurrence in patients who have been treated for uterine cancers and are undergoing follow-up.

AIM: The aim of this study was to evaluate the economic impact of the introduction of positron emission tomography (PET) in the clinical management of patients with known or suspected lung cancer through a cost-effectiveness analysis of different diagnostic strategies. METHODS: In Italy, 75 patients with known or suspected lung cancer were included in the study. Three different diagnostic strategies were compared: 1) baseline or traditional strategy, i.e. computed tomography (CT) alone; 2) strategy A, i.e. PET for indefinite CT; 3) strategy B, i.e. PET for all. For each strategy expected costs and life expectancy, as measured by life year saved (LYS), were evaluated. Incremental cost-effectiveness ratio (ICER) was calculated to identify the most effective strategy. RESULTS: Compared to the baseline strategy, the introduction of PET changed the clinical management in 40% of cases in strategy A and in 51% of cases in strategy B, with an optimization of the clinical management. Costs of strategy A (2 735.42 Euro) and strategy B (2 984.52 Euro) were, respectively, 8% and 18% higher than the baseline strategy (2 534.81 Euro). LYS was 2.04 and 2.64 for strategy A and B, which were, respectively, 4% and 35% higher than the baseline strategy (1.96 LYS). The ICERs were 2 507.63 Euro/LYS and 415.17 Euro/LYS for strategy A and B, respectively. Strategy A is dominated by strategy B, which is more expensive, but also more effective. CONCLUSION: In Italy, the introduction of PET in the clinical management of all patients with known or suspected lung cancer previously evaluated with CT is cost-effective and allows to gain 2.64 life years at an annual cost of about 415 Euro.

PURPOSE: To assess and quantify the possible benefit deriving from IMRT with Helical Tomotherapy (HTT) delivery to the pelvic nodal area in patients with prostate cancer in terms of reduction of acute and late toxicities. METHODS AND MATERIALS: Thirty-five patients candidate to radical or postoperative RT on whole pelvis (WPRT) were treated with HTT, while receiving a concomitant boost to the prostate or the prostatic bed (median 74.2 and 72Gy, respectively) within a moderately hypofractionated (28-33 fractions; median HTT duration 44 days) regimen. Median and mean doses to whole pelvis were 52 and 54Gy, respectively. One of the major goals of planning optimisation was to minimize the dose received by the intestinal cavity (IC) outside the nodal PTV. RESULTS: HTT resulted to be very efficient in sparing the IC even at dose levels below 30-35Gy and guaranteed a significant sparing of bladder and rectum even at intermediate-low doses (V20-V40). No acute Grade 3 RTOG toxicity was recorded. Eighteen G1 and two G2 GU acute toxicities, 13 G1 upper GI acute toxicities, 8 G1 and 1 G2 acute proctitis were observed; no patient experienced G2 upper GI toxicity. After a median FU of 11.5 months (>10 in 18 patients) one case of late G3 GU toxicity was reported in one post-prostatectomy treated patient; no G2 late rectal bleeding or other GI toxicity was recorded. CONCLUSIONS: WPRT with HTT resulted in a very low incidence of acute Grade 2 and in the disappearance of acute Grade 3 toxicities.

Changes in D2 receptors during antidepressant therapy have been reported in patients with major depressive disorder using PET/SPET. The aim of this study was to evaluate modifications in D2 receptors that might occur in patients affected by obsessive-compulsive disorder (OCD) during serotonin reuptake sites inhibitors (SSRIs). To this purpose, we measured the in vivo binding of [11C]raclopride ([11C]Rac)in the brain of a group of OCD naïve patients before and after the repeated administration of the inhibitor SSRI fluvoxamine. Eight patients with a Diagnostic and Statistical Manual of Mental Disorders IVth edition diagnosis of OCD completed the study undergoing a PET scan and a complete clinical evaluation before and during treatment with fluvoxamine. Patients have been compared also with a group of nine age-matched normal volunteers. Fluvoxamine treatment significantly improved clinical symptoms and increased [11C]Rac binding potential (BP) in the basal ganglia of OCD patients (7.55.2, 6.96.9, and 9.99.3% in dorsal caudate, dorsal putamen, and ventral basal ganglia, respectively; p

This article reviews the state of the art of PET/CT applications in radiotherapy, specifically its use in disease staging, patient selection, treatment planning and treatment evaluation. Diseases for which radiotherapy with radical intent is indicated will be considered, as well as those in which PET/CT may actually change the course of disease. The methodological and technological aspects of PET/CT in radiotherapy are discussed, focusing on the problem of target volume definition with CT and PET functional imaging and the problem of tumor motion with respect to imaging and dose delivery.