Annals of Nuclear Medicine (v.25, #3)

Present and future of FDG-PET/CT in ovarian cancer by Kazuhiro Kitajima; Koji Murakami; Setsu Sakamoto; Yasushi Kaji; Kazuro Sugimura (155-164).
Integrated FDG-PET/CT has been used successfully for the diagnosis, staging, restaging, therapy monitoring and prognostic prediction of ovarian cancer as well as various other malignant tumors. Compared with conventional PET/non-contrast CT images, combined PET/contrast-enhanced CT images with intravenous iodine contrast medium and sufficient radiation dose may contribute to a more accurate diagnosis with higher confidence. In the future, tracers other than FDG and integrated PET/MRI will be realized. We herein review the place and role of FDG-PET/CT in the management of ovarian cancer, discussing its usefulness and limitations in the imaging of these patients.
Keywords: FDG; PET/CT; Ovarian cancer; Staging; Restaging

Effect of dialysis on cerebral blood flow in depressive end-stage renal disease patients by Hyun-Yeol Nam; Sang Heon Song; Seong-Jang Kim; Ihm Soo Kwak; In Joo Kim; Soo Bong Lee; Dong Won Lee; Bum Soo Kim; Kyoungjune Pak; Yong-Ki Kim; Hyun Sil Yun (165-171).
The aim of this study was to investigate regional cerebral blood flow (rCBF) changes of end-stage renal disease (ESRD) patients with depressive symptoms during dialysis.Fourteen patients with ESRD underwent Tc-99m ethylcysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) and were evaluated the severity of depressive mood at pre-dialytic period and at least 6 months after dialysis initiation. rCBF was analyzed using statistical parametric mapping (SPM) in brain SPECT image. The responder was defined as a decrease of ≥25% in Hamilton Depression Rating Scale (HDRS) score from baseline HDRS score.Pre-dialysis brain SPECT did not show any rCBF differences between responders and non-responders. The follow-up brain SPECT revealed a significant higher perfusion in left middle temporal gyrus of responder group when compared with non-responder (hemisphere coordinate X, Y, Z; −58, −2, −16, peak Z = 3.36, p = 0.046). In responder, a significant increase in rCBF was found in right parahippocampal gyrus (hemisphere coordinate X, Y, Z; 30, −40, −14, peak Z = 3.51, p = 0.043). In non-responder, there were significant decreases in rCBF in left superior frontal gyrus (hemisphere coordinate X, Y, Z; −22, 30, 42, peak Z = 3.86, p = 0.032) and right orbitofrontal cortex (hemisphere coordinate X, Y, Z; 10, 58, −6, peak Z = 3.81, p = 0.046).The present findings showed the characteristic patterns of rCBF changes in depressive ESRD patients having maintenance dialysis. Further investigations in brain blood flow and glucose metabolism are needed to elucidate the effect of dialysis itself and the difference of according to dialysis modality in patients having depression and ESRD.
Keywords: End-stage renal disease; Depression; Dialysis; Statistical parametric mapping; Brain SPECT

Normal variants of bowel FDG uptake in dual-time-point PET/CT imaging by Akira Toriihara; Katsuya Yoshida; Isao Umehara; Hitoshi Shibuya (173-178).
To evaluate the normal variants of the physiological bowel 2-deoxy-2-[18F]fluoro-d-glucose (FDG) uptake in dual-time-point positron emission tomography/computed tomography (PET/CT).We performed a retrospective review of 206 consecutive asymptomatic subjects who underwent whole-body FDG PET/CT for medical checkup in our institution. The criteria for exclusion of the subjects from this study were as follows: history of abdominal surgeries or endoscopic mucosal resection, history of any malignant tumors, symptoms of diarrhea or constipation, a positive fecal occult blood test, elevated serum carcinoembryonic antigen (CEA) level, and hyperglycemia (more than 110 mg/dl). A total of 39 subjects (32 males, 7 females, mean age 58.1 years old) were enrolled in this retrospective study. Two radiologists evaluated the dual-time-point FDG PET/CT images of these 39 subjects, retrospectively. FDG uptakes in 5 areas (small bowel (SB), cecum and ascending colon (AC), transverse colon (TC), descending colon (DC), and rectosigmoid colon (RS)) were scored visually in comparison with the activity in the liver (0 = no uptake, 1 = activity less than that in the liver, and 2 = activity equal to or greater than that in the liver) in the early and delayed image. The scores decided by two radiologists were averaged and this average score was defined as the bowel uptake score (BUS). For 34 areas with the BUS of 2 in either the early or delayed images, the maximum standardized uptake values (SUVmax) were measured for semiquantitative analysis. Wilcoxon’s signed rank test and paired t test were adopted for the statistical analyses.The average BUS in the early/delayed images was 1.19/1.17 (SB), 0.81/1.23 (AC), 0.10/0.35 (TC), 0.35/0.59 (DC), and 1.17/1.54 (RS), respectively. The average SUVmax of the 34 areas with a score of 2 was 3.11 in the early images and 3.76 in the delayed images. The scores in the AC, TC, DC and RS, and the SUVmax were significantly higher in the delayed images (p < 0.05).Physiological FDG uptake in the colon increases significantly from the early to the delayed phase in dual-time-point PET/CT imaging, which should be carefully taken into consideration in the diagnosis of bowel diseases.
Keywords: FDG; PET/CT; Bowel; Physiological uptake; Dual-time-point

Small lesions detectability with the Biograph 16 Hi-Rez PET/CT scanner and fast imaging protocols: performance evaluation using an anthropomorphic thoracic phantom and ROC analyses by Roberta Matheoud; Lucia Leva; Chiara Secco; Gianmauro Sacchetti; Patrizia Della Monica; Marco Brambilla; Eugenio Inglese (179-188).
The purpose of this study was to evaluate the impact on lesion detectability of fast imaging protocols using 18F-FDG and a 3-dimensional LSO-based PET/CT scanner.An anthropomorphic thoracic phantom was used simulating the anatomical structures of radioactivity distribution for the upper torso of an underweight patient. Irregularly shaped targets of small dimensions, the zeolites, were located inside the phantom in an unpredictable position for the observers. Target-to background ratios and target dimensions were selected in order to sample the range of detectability. Repeated imaging was performed to acquire PET images with varying emission scan duration (ESD) of 1, 2, 3 and 4 min/bed and background activity concentrations of 10, 5 and 3 kBq/mL in the torso cavity. Three observers ranked the targets and a receiver operating characteristic analysis was performed for each acquisition protocol.Detection performances improved when passing from a short (ESD = 1 min) protocol to longer (ESD ≥ 2 min) protocols. This improvement was established with adequate statistical significance.Short image acquisition times of 1 min/bed using 18F-FDG and the specific scanner model considered in the study lead to reduced lesion detectability and should be avoided also in underweight patients.
Keywords: PET/CT; ROC; Lesion detection; Emission scan duration

Omission of [15O]CO scan for PET CMRO2 examination using 15O-labelled compounds by Yasuhiro Sasakawa; Nobuyuki Kudomi; Yuka Yamamoto; Toshihide Monden; Nobuyuki Kawai; Yoshihiro Nishiyama (189-196).
CBF, OEF and CMRO2 provide us important clinical indices and are used for assessing ischemic degree in cerebrovascular disorders. These quantitative images can be measured by PET using 15O-labelled tracers such as C15O, C15O2 and 15O2. To reduce the time of scan, one possibility is to omit the use of CBV data. The present study investigated the influence of fixing the CBV to OEF and CMRO2 values on subjects with and without cerebrovascular disorders.The study consisted of three groups, namely, GROUP-0 (n = 10), GROUP-1 (n = 9), and GROUP-2 (n = 10), corresponding to—without significant disorder, with elevated CBV, and with reduced CBF and elevated OEF, respectively. All subjects received PET examination and using the PET data OEF and CMRO2 images were computed by fixing CBV and with CBV data. The computed OEF and CMRO2 values were compared between the methods.The OEF and CMRO2 values obtained by fixing the CBV were around 10% underestimation against that with CBV data. The regression analysis showed that these values were comparable (r = 0.93–0.98, P < 0.001). The simulation showed that fixing of the CBV would not derive significant error in either OEF or CMRO2 values, when changed from 0 to 0.08 ml/g.This study shows the feasibility of fixing the CBV value for computing OEF and CMRO2 values in the PET examination, suggesting the CO scan could be eliminated.
Keywords: Positron emission tomography; CBF; CMRO2 ; CBV; 15O-labelled compounds

Impact of radioguided occult lesion localization on the correct excision of malignant breast lesions: effect of histology and tumor size by John Patrick Pilkington Woll; Montserrat Cortés Romera; Ana Maria García Vicente; Beatriz González García; Margarita Delgado Portela; Jose Manuel Cordero García; Ricardo Pardo García; Ceferino Molino Trinidad; Angel Maria Soriano Castrejón (197-203).
To evaluate the impact of radioguided occult lesion localization (ROLL) in the correct location and excision of malignant breast lesions, and analyze if these results are affected by the histology and tumor size.A total of 105 patients with occult breast lesions were studied. The mean age was 55 years. An intralesional dose of 18.5 MBq of 99mTc-labeled macroaggregated human albumin (AMA) was administered using stereotaxic mammography or ultrasound. Surgical resection was carried out with the help of a gammadetector probe. In the histological study, disease-free margin was defined by a distance between the tumor lesion and the surgical margin of more than 1 mm. The possible influence of tumor histology and lesion diameter with respect to free/affected margins was analyzed.Correct radiotracer placement was achieved in 100/105 of the cases (95.2%). In the remaining 5 cases (4.8%), radiotracer placement was incorrect, with 2 of them being malignant lesions that were found by macroscopic inspection, and the other 3 having benign pathology. Among the malignant lesions (44 cases), correct placement of the radiotracer was achieved in 42 cases (95.5%). Of these 42 malignant lesions, in which the ROLL was correctly performed, free surgical margins were obtained in 24 cases (57.1%), while the other 18 (42.9%) had infiltrated surgical margins. The most common histological type among the malignant lesions was invasive ductal carcinoma (71.4%). The histological types with an increased frequency of infiltration of surgical margins were invasive and microinvasive cancer (94.4%). All the affected margins were in lesions greater than 10 mm, and the highest incidence was in those between 20 and 30 mm (55.5%).In our experience, the advantages of the ROLL technique are a precise localization of malignant breast lesions (95.5%) and an increased probability of a complete excision with free margins in more than one half of them. Nevertheless, special consideration should be taken when dealing with invasive and microinvasive cancers and in those exceeding 10 mm because of their higher incidence of infiltrated margins.
Keywords: ROLL; Radioguided occult lesion localization; Non-palpable breast lesions; Free surgical margins; Malignant breast lesions

Erratum to: Impact of radioguided occult lesion localization on the correct excision of malignant breast lesions: effect of histology and tumor size by John Patrick Pilkington Woll; Montserrat Cortés Romera; Ana María García Vicente; Beatriz González García; Margarita Delgado Portela; Jose Manuel Cordero García; Ricardo Pardo García; Ceferino Molino Trinidad; Angel María Soriano Castrejón (205-205).

Overall and gender-based negative predictive value of a normal gated myocardial perfusion SPECT study: a single center experience by Maseeh Uz Zaman; Nosheen Fatima; Abdus Samad; M. Ishaq; Zahed Rasheed; Dad J. Balcoh; Kawsih Rehman; Javeria Bano; M. Asif Wali (207-211).
A normal gated myocardial perfusion imaging (GMPI) has been found to have high diagnostic and negative predictive value (NPV) in western population. The goal of the present study was to evaluate the overall and gender-based NPV of a normal GMPI in local population.This is a prospective study conducted at Nuclear Cardiology Department of Karachi Institute of Heart Diseases (KIHD), Karachi from December 2008 till May 2009. All patients (with intermediate risk) with a normal GMPI with adequate dynamic or dipyridamole stress were included and followed up for 18 months (mean 15 ± 3 months) for fatal or non-fatal infarctions.The mean ejection fraction (EF) of studied population was 69 ± 8% while mean end diastolic (EDV) and end systolic volume (ESV) were 71 ± 19 and 22 ± 11 ml, respectively. In studied female cohort, the mean EF (%), EDV (ml) and ESV (ml) were 71 ± 08, 64 ± 15 and 19 ± 09, respectively. In studied male cohort, the mean EF (%), EDV (ml) and ESV (ml) were 66 ± 06, 82 ± 18 and 27 ± 11, respectively. At 18 months follow-up, one fatal (male patient) and one non-fatal MI (male patient) were reported. The overall NPV was 99.4% over 18 months follow-up with an event rate of 0.6% (95% CI 0.03–1.16%) and annualized event rate of 0.3%. The NPV and annualized event in subgroup analyses, was similar for female and male (P = 0.213).We conclude that a normal GMPI with adequate stress in our population has high NPVs for major cardiac events as in western population. In addition, the prognostic utility of GMPI is similar for both men and women.
Keywords: Normal gated MPI; Tc-99m MIBI; Negative predictive value; Ejection fraction; Annualized event rate

Semiquantitative analysis of C-11 methionine PET may distinguish brain tumor recurrence from radiation necrosis even in small lesions by Shozo Okamoto; Tohru Shiga; Naoya Hattori; Naoki Kubo; Toshiki Takei; Norio Katoh; Yutaka Sawamura; Kenichi Nishijima; Yuji Kuge; Nagara Tamaki (213-220).
11C-Methionine positron emission tomography (MET-PET) has been used to distinguish brain tumor recurrence from radiation necrosis. Because the spatial resolution of conventional PET scanners is low, partial volume effect (PVE) may decrease the detectability of small tumor recurrence. The aim of this study is to investigate the diagnostic value of MET-PET upon semiquantitative analyses in particular PVE-affected small lesions.First, we performed a phantom experiment to investigate what size lesion is affected by PVE. This study included 29 patients (33 lesions) suspected of recurrent brain tumors by magnetic resonance imaging (MRI) after radiation therapy. All of them received MET-PET. Semiquantitative analysis was performed using maximum standardized uptake value (SUVmax) and lesion-versus-normal ratio (L/N ratio). ROC analysis was also assessed about the diagnostic value of MET-PET.From the result of the phantom experiment, lesions smaller than 20 mm in brain mode or smaller than 30 mm in whole-body mode were defined as PVE-affected lesions. Histological analysis or clinical follow-up confirmed the diagnosis of tumor recurrence in 22 lesions, and radiation necrosis in 11 lesions. L/N ratios of recurrence and necrosis for overall lesions were 1.98 ± 0.62 and 1.27 ± 0.28, respectively (p < 0.01). In the PVE-affected lesions, L/N ratio for recurrence (1.72 ± 0.44) was also significantly higher than that for necrosis (1.20 ± 0.11) (p < 0.01). On the ROC analysis for the PVE-affected lesions, the area under the curve for L/N ratio (0.897) was significantly higher than that for SUVmax (0.718) (p < 0.05). These areas under the curve were almost equal to that of overall lesions for L/N ratio (0.886) and for SUVmax (0.738).Semiquantitative analysis of MET provided high diagnostic value even for PVE-affected small lesions. MET-PET enables early diagnosis of recurrence of brain tumor in the follow-up after the radiation therapy.
Keywords: Methionine PET; Radiation necrosis; Partial volume effect

Predicting sentinel lymph node metastasis in breast cancer with lymphoscintigraphy by Atsushi Noguchi; Masahisa Onoguchi; Takeshi Ohnishi; Terumi Hashizume; Akiyoshi Kajita; Masahiro Funauchi; Toshizo Katsuda; Kazuyoshi Motomura (221-226).
Lymphoscintigraphy is an effective method for detecting sentinel lymph nodes (SLNs). However, the rate and degree of SLN detection is not uniform. We quantified SLNs detected with lymphoscintigraphy, and investigated correlations with factors that may influence detection. We then attempted to predict SLN metastasis from lymph node counts, comparing the predictions to subsequent biopsy results.We assessed lymph node counts in 100 breast cancer patients in whom a single SLN was detected with a fixed lymphoscintigraphy procedure. We examined correlations between the counts and factors known to influence lymphoscintigraphic SLN detection (age, body mass index, tumor size, and presence or absence of metastasis), and determined reference values (lymph node counts of 10.0, 19.4 and 53.0) which were used to predict SLN metastasis in 100 subsequent patients. The predictions were then compared with the SLN biopsy findings.SLN counts correlated strongly with the presence or absence of metastasis, with metastasis-positive lymph nodes showing significantly lower counts than negative nodes (p < 0.001). Prediction of SLN metastasis achieved a 100% positive predictive value at a reference value of 10.0, and a 100% negative predictive value at a reference value of 53.0. At a reference value of 19.4, the sensitivity, specificity, and diagnostic accuracy were 77.8, 73.2, and 74.0%, respectively.The SLN counts detected with lymphoscintigraphy were significantly lower in metastasis-positive lymph nodes than in metastasis-negative lymph nodes. This suggests that prediction of SLN metastasis in breast cancer is possible using lymphoscintigraphy.
Keywords: Lymphoscintigraphy; Sentinel lymph node; Breast cancer; Metastatic prediction

18F-FDG-PET/CT findings in primary pulmonary mixed squamous cell and glandular papilloma by Tomohiro Abiko; Satoko Koizumi; Iwao Takanami; Fumihiko Tanaka (227-229).
A 55-year-old female had an abnormal shadow on chest radiograph. Computed tomography (CT) revealed a 26-mm tumor mass in the left upper lobe. No malignant findings were obtained by bronchoscopic cytology or histopathological diagnostics, but on positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) examination the maximum SUV was 9.01 in accordance with the tumor mass shadow on CT. Video-assisted thoracoscopic surgery was performed as clinically suspected of lung cancer, and the diagnosis was pulmonary mixed squamous cell and glandular papilloma (PMSGP). Primary PMSGP is extremely rare, and this is the first to describe the PET findings of this disease.
Keywords: Pulmonary mixed squamous cell and glandular papilloma; FDG-PET; Lung cancer; Video-assisted thoracoscopic surgery (VATS)