Annals of Nuclear Medicine (v.22, #2)

Improved detection of breast cancer on FDG-PET cancer screening using breast positioning device by Hayato Kaida; Masatoshi Ishibashi; Teruhiko Fujii; Seiji Kurata; Etsuyo Ogo; Maki Tanaka; Naofumi Hayabuchi (95-101).
The aim of this study was to investigate the detection rate of breast cancer by positron emission tomography cancer screening using a breast positioning device.Between January 2004 and January 2006, 1,498 healthy asymptomatic individuals underwent cancer screening by fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) at our institution; 660 of 1498 asymptomatic healthy women underwent breast PET imaging in the prone position using the breast positioning device to examine the mammary glands in addition to whole-body PET imaging. All subjects that showed abnormal 18F-FDG uptake in the mammary glands were referred for further examination or surgery at our institution or a local hospital. Our data were compared with the histopathological findings or findings of other imaging modalities in our institution and replies from the doctors at another hospital.Of the 660 participants, 7 (1.06%) were found to have breast cancers at a curable stage. All the seven cancers were detected by breast PET imaging, but only five of these were detected by whole-body PET imaging; the other two were detected by breast PET imaging using the breast positioning device.In cancer screening, prone breast imaging using a positioning device may help to improve the detection rate of breast cancer. However, overall cancer including mammography and ultrasonography screening should be performed to investigate the false-negative cases and reduce false-positive cases. The effectiveness of prone breast PET imaging in cancer screening should be investigated using a much larger number of cases in the near future.
Keywords: Fluorine-18 fluorodeoxyglucose positron emission tomography; Breast cancer; Cancer screening; Prone position; Breast positioning device

Performance of FDG-PET/CT in the diagnosis of recurrent endometrial cancer by Kazuhiro Kitajima; Koji Murakami; Erena Yamasaki; Shingo Hagiwara; Ichio Fukasawa; Noriyuki Inaba; Yasushi Kaji; Kazuro Sugimura (103-109).
To evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) using 18-F-fluorodeoxyglucose (FDG), compared with PET alone, in the diagnosis of suspected endometrial cancer recurrence.Thirty women who had undergone primary surgery for histopathologically proven endometrial cancer with suspected recurrence because of clinical, cytological, biochemical, and/or radiological findings were enrolled in this study. PET and integrated PET/CT images were evaluated by two different experienced radiologists by consensus for each modality. A final diagnosis of recurrence was confirmed by histopathology, other imaging and clinical follow-up for longer than 1 year. The statistical significance of differences between PET and PET/CT was determined by the McNemar test.Patient-based analysis showed that the sensitivity, specificity, and accuracy of PET/CT were 93% (14/15), 93% (14/15), and 93% (28/30), respectively, whereas for PET, the corresponding data were 80% (12/15), 80% (12/15), and 80% (24/30), respectively (P = 0.479, 0.479, and 0.134, respectively). CT from PET/CT resolved the false-positive PET results because of hyper-metabolic activity of benign inflammatory lesions and physiological variants and moreover detected lung metastasis and para-aortic lymph node metastasis that PET missed. However, tiny para-aortic lymph node metastasis could not be detected even with PET/CT.Integrated FDG-PET/CT is a useful complementary modality for providing good anatomic and functional localization of sites of recurrence during follow-up of patients with endometrial cancer.
Keywords: Endometrial cancer; Recurrence; 18F-FDG; PET/CT

Pulmonary drug toxicity: FDG-PET findings in patients with lymphoma by Toshiki Kazama; Silvana C. Faria; Yoshitaka Uchida; Hisao Ito; Homer A. Macapinlac (111-114).
The objective of this study was to evaluate the prevalence and positron emission tomography (PET) imaging features of pulmonary drug toxicity in patients with lymphoma during or just following chemotherapy.A total of 677 PET scans on 460 patients with lymphoma (351 non-Hodgkin’s lymphoma, 92 Hodgkin’s disease, and 17 both Hodgkin’s and non-Hodgkin’s lymphoma) were performed for the evaluation of chemotherapy response. In 51 patients, abnormal accumulation on both sides of the chest was reported. A review of medical records, 18fluorodeoxyglucose (18FDG)-PET scans, and chest computed tomography (CT) was performed, and cases with probable drug toxicity were identified. Inclusion criteria of probable drug toxicity were abnormal but symmetrical FDG accumulation in both lungs seen during or just following the completion of chemotherapy, the abnormal accumulation or corresponding abnormal CT findings resolved on sub sequent studies, exclusion of clinical diagnosis of pneumonia, radiation pneumonitis, or lymphoma involvement.In 10 patients (six men and four women, average age 47.3), 2.2% of cases, probable drug toxicity was identified. In all 10 cases, diffuse and subpleural-dominant FDG accumulation was seen on FDG-PET scans, and scattered or diffuse ground-glass opacities were observed on chest CT. Four patients reported symptoms, and six patients did not report any symptoms.Diffuse and peripheral-dominant FDG accumulation in the lung, which may represent pulmonary drug toxicity, was not uncommon in patients with lymphoma who underwent chemotherapy. FDG-PET scan might be able to detect pulmonary drug toxicity in asymptomatic patients.
Keywords: FDG; PET; Lymphoma; Lung; Chemotherapy

Assessment of diastolic function using 16-frame 201Tl gated myocardial perfusion SPECT: a comparative study of QGS2 and pFAST2 by Shigeki Nagamachi; Hideyuki Wakamatsu; Seigo Fujita; Ryuichi Nishii; Kiyohisa Kamimura; Shogo Kiyohara; Shigemi Futami; Hisamitsu Onitsuka; Yasuko Nagoshi; Shozo Tamura; Keiichi Kawai; Hideo Arita (115-122).
The objective of the present study is to investigate the correlations across various types of interface software for 201Tl gated myocardial perfusion SPECT (MPS) in calculating two common diastolic function parameters (DFx), peak-filling rates (PFR), and time-to-peak filling (TTPF).A total of 109 patients (66 men and 43 women; age 35–78 years) were studied. All patients were classi-fied into three groups (i.e., ND, no-defect group; SD, small-defect group; LD, large-defect group) to clarify the influence of perfusion defects possibly affecting the analysis. Two kinds of available software, namely, quantitative gated SPECT (QGS2) and perfusion and functional analysis for gated SPECT (pFAST2) with cardioGRAF were used to obtain PFR and TTPF. Finally, we analyzed the correlation between DFx obtained with the two different kinds of software.The values of LVEF, PFR, and TTPF were assessed in all patients. In both the ND (correlation coefficients were 0.92, 0.79, and 0.99, respectively) and SD groups (correlation coefficients were 0.74, 0.88, and 0.98, respectively), a strong correlation was observed. In contrast, PFR did not show a significant correlation in the LD group.With the two different kinds of software, QGS2 and pFAST2, the calculated PFR was almost equal and showed good correlations in both ND and SD groups. In contrast, the numerical value varied between the two methods, and its correlation was poor in the LD group. However, TTPF showed a good correlation regardless of the presence of perfusion defects, and the values were equal. TTPF was confirmed to be a stable diastolic index across the two kinds of software, QGS2 and pFAST2, in 201Tl gated MPS.
Keywords: Left ventricular diastolic function; 201Tl gated myocardial perfusion SPECT; QGS2; pFAST2

Preoperative evaluation of hyperparathyroidism: the role of dual-phase parathyroid scintigraphy and ultrasound imaging by Aysun Sukan; Mehmet Reyhan; Mehmet Aydin; Ali F. Yapar; Yasar Sert; Tuba Canpolat; Ayse Aktas (123-131).
The aim of this study was to evaluate the efficacy of dual-phase 99mTc-methoxyisobutylnitrile (MIBI) parathyroid scintigraphy (PS) and ultrasound (US) in primary (pHPT) and secondary (sHPT) hyperparathyroidism.A total of 69 patients (mean age 47 ± 16; age range 14–79 years), including 19 patients with sHPT were enrolled in this study. Preoperative serum intact parathyroid hormone (iPTH) levels, calcium (Ca), phosphate (P), alkaline phosphatase, and 24-h urinary-free Ca measurements were obtained. Concomitant thyroid pathology was also recorded.Histopathology revealed 30 solitary adenomas and 71 hyperplastic glands in 55 patients. The remaining patients’ histopathology revealed normal parathyroid, thyroid, or lymph nodes. The sensitivities of MIBI and US in pHPT were 70% and 60%, respectively. It was 60% for both procedures in sHPT. The overall sensitivity of combined US + MIBI in pHPT and sHPT was 81% and 71%, respectively. The overall specificity of MIBI and US was 87% and 91%; positive predictive value (PPV) was 94% and 92%, respectively. MIBI and US identified the parathyroid pathology in 92% and 85% of patients in the non-concomitant thyroid disease group, and in 53% and 47% of patients in the concomitant thyroid disease group, respectively. The weight of the gland between primary and secondary hyperparathyroidism did not reveal a significant difference (P = 0.4). Significant differences were found with respect to age, PTH, Ca, and P levels between the pHPT and sHPT (P < 0.001). Intact PTH levels showed significant differences between MIBI positive and negative patients (P = 0.013), and also US positive and negative patients (P = 0.012). A significant negative correlation was found between iPTH and Ca at sHPT (P < 0.001).The concomitancy of thyroid disease greatly influences scintigraphic and ultrasonographic detection of parathyroid pathology in pHPT and sHPT. The combination of MIBI and US appears promising for localizing parathyroid pathology in patients with both primary and secondary hyperparathyroidism. The concordance rate is high together with a lower chance of missing concomitant thyroid pathology, which might alter the surgical approach.
Keywords: Hyperparathyroidism; 99mTc-MIBI; Ultrasound; Thyroid nodules

Nonfunctioning endocrine pancreatic tumor examined with 18F-FDG PET/CT by Nobuyuki Toshikuni; Kyohei Kai; Masayoshi Fujisawa (133-137).
A 71-year-old woman with type 2 diabetes mellitus complained of generalized fatigue. A 36-mm tumor in the pancreatic tail was detected with ultrasonography. The tumor was found to have marked hypervascularity with contrast-enhanced computed tomography (CT) and magnetic resonance. Combined 18F-fluorodeoxyglucose positron emission tomography and CT (18F-FDG PET/CT) showed 18F-FDG by the tumor with a maximal standardized uptake value of 2.98 at 50 min and 3.29 at 100 min following injection of 18F-FDG. 18F-FDG PET/CT suggested no extrapancreatic spread of the tumor. The patient had no pancreatic hormone-associated symptoms. Distal pancreatectomy was performed, and a well-differentiated endocrine tumor was diagnosed. The resected specimen showed neither infiltration of adjacent structures nor metastasis to regional lymph nodes. The present case suggests that 18F-FDG PET/CT is a reliable modality for staging endocrine pancreatic tumors.
Keywords: 18F-FDG PET/CT; Pancreas; Nonfunctioning endocrine tumor

Osteoradionecrosis (ORN) of the pelvic bone presenting as a progressive osteolytic lesion, following three-dimensional conformal radiotherapy (3DCRT) with concurrent chemotherapy, is a clinical diagnostic challenge that must be differentiated from an osseous metastasis. We report on a case with an unusual presentation of ORN mimicking bony metastasis that should be taken note of by physicians. A 46-year-old woman who had recurrent cervical cancer in the right pelvic sidewall underwent concurrent salvage chemoradiotherapy. She received 63 Gy 3DCRT. At 22 months, post-RT, an asymptomatic but enlarging osseous defect in the right ilium, located within the area covered by a 95% isodose line, was demonstrated on pelvic computed tomography (CT). ORN was confirmed by whole-body [18F] fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography (PET) CT scan and CT-guided bone biopsy. A localized, growing ORN of pelvic bone after high-dose 3DCRT is an uncommon late complication. Differential diagnosis between ORN and bony metastasis may be possible with low FDG uptake of ORN on PET-CT scans.
Keywords: Osteoradionecrosis; Conformal RT; FDG-PET CT

Shortened protocol in practical [11C]SA4503-PET studies for sigma1 receptor quantification by Muneyuki Sakata; Yuichi Kimura; Mika Naganawa; Masatomo Ishikawa; Keiichi Oda; Kenji Ishii; Kenji Hashimoto; Kunihiro Chihara; Kiichi Ishiwata (143-146).
In practical positron emission tomography (PET) diagnosis, a shortened protocol is preferred for patients with brain disorders. In this study, the applicability of a shortened protocol as an alternative to the 90-min PET scan with [11C]SA4503 for quantitative sigma1 receptor measurement was investigated. Tissue time-activity curves of 288 regions of interest in the brain from 32 [11C]SA4503-PET scans of 16 healthy subjects prior to and following administration of a selective serotonin reuptake inhibitor (fluvoxamine or paroxetine) were applied to two algorithms of quantitative analysis; binding potential (BP) was derived from compartmental analysis based on nonlinear estimation, and total distribution volume (tDV) was derived from Logan plot analysis. As a result, although both BP and tDV tended to be underestimated by the shortened method, the estimates from the shortened protocol had good linear relationships with those of the full-length protocol. In conclusion, if approximately 10% differences in the estimated results are acceptable for a specific purpose, then a 60-min measurement protocol is capable of providing reliable results.
Keywords: [11C]SA4503; Sigma1 receptor; PET; Kinetic