Annals of Nuclear Medicine (v.22, #8)

Clinical significance of 18F-FDG uptake by primary sites in patients with diffuse large B cell lymphoma in the head and neck: a pilot study by Byung Hyun Byun; Im Il Na; Gi Jeong Cheon; Hye Jin Kang; Kyeong Min Kim; Seung-Sook Lee; Baek-Yeol Ryoo; Chang Woon Choi; Sang Moo Lim; Sung Hyun Yang (645-651).
This pilot study was launched to explore the utility of positron emission tomography scans, at the time of diagnosis, for clinical outcomes in patients with primary extranodal non-Hodgkin’s lymphoma (PENHL) in the head and neck, retrospectively.Twenty-two patients with a diffuse large B cell lymphoma (DLBCL) among those with a PENHL were included. We retrospectively evaluated the clinical outcomes of patients according to the maximum standardized 18F-fluoro-2-deoxy-glucose (18F-FDG) uptake value of the primary lesion (SUVp). The SUVp was initially analyzed as a continuous variable. The cut-offvalue of SUVp was obtained from receiver-operating characteristic analysis to predict event-free survival. Using this value, patients were divided into those with a low and high SUV.Seventeen patients (59%) were men and the median age was 50 years. Most primary sites were in Waldeyer’s ring (73%). The SUVp ranged from 3.3 to 23.7. The international prognostic index (IPI < 2 vs. ≥ 2) was associated with the SUVp (P = 0.014). Patients with low SUVp showed favorable survival (P = 0.015). After IPI scores were stratified, the survival difference remained significant (P = 0.029).The results of this pilot investigation indicate that 18F-FDG uptake of the primary lesion may be related with survival outcomes in patients with extranodal DLBCL in the head and neck. Further studies are needed to confirm and extend these results.
Keywords: 18F-fluoro-2-deoxy-glucose; PET; PET/CT; Lymphoma; Prognosis

Internal radiotherapy using 32P colloid or microsphere for refractory solid tumors by Wen Gao; Lu Liu; Gao-Jun Teng; Guo-Sheng Feng; Guan-Sheng Tong; Nai-Rong Gao (653-660).
The aim of this work was to study the effectiveness of 32P colloids or microspheres, by arterial interventional administration or stromal injection in the treatment of refractory solid tumors.By arterial intervention, under the guidance of computerized tomography, X-ray, ultrasonogram, or under direct vision of the surgical field, 32P microspheres (259–685 MBq) or radioactive colloid (281–666 MBq) was administered to 60 cases with refractory solid tumors. Tumor inhibition rate, side effects, survival period, and so on were observed.The tumor growth was obviously inhibited after the intratumoral injection of 32P colloid. The average survival time in the 60 cases was 35 months with a high tumor inhibition rate (93.4%). Thirty-one cases were completely relieved (51.7%), and 25 cases achieved partial remission (PR, 41.7%). One case with right lobe hepatocellular carcinoma has survived 90 months. The drug was ineffective only in four cases, including one patient who died of gastrointestinal hemorrhage and three of hepatic failure. No other obvious side effects were observed. Intratumoral necrosis, intense fibrosis in the tumor mass, and an integrated capsule encompassing the tumor were revealed by histological examination.Arterial interventional administration or stromal injection with 32P microspheres or colloid revealed a very fair clinical effectiveness in the treatment of refractory solid tumors. The range of safe effective dosage for 32P glass microspheres and 32P chromic phosphate in one treatment course is 555–740 MBq and 185–370 MBq, respectively.
Keywords: Refractory solid tumor; Internal radiotherapy; Phosphorus radioisotope

The relationships among urinary tract infection (UTI), vesicoureteral reflux (VUR), and permanent renal damage in children are not fully understood. The aim of this study was to evaluate the incidence of renal scarring in children with a history of UTI and to determine the change in the probability of permanent renal damage owing to the presence of VUR documented on micturating cystourethrography (MCU).We analyzed 201 children (400 renal units, two children with solitary kidney). Seventy-four boys and 127 girls (aged 7 months to 7 years, median 2.5 years) with culture verified UTI were referred for technetium-labeled dimercaptosuccinic (DMSA) renal scintigraphy 4-6 months after acute UTI. MCU was also performed mostly 1 month prior to DMSA. Statistical analysis was performed using χ2 test or Fisher’s exact test. Likelihood ratio (LR) positive and negative, diagnostic odds ratio (DOR), and post-test probability of (no) disease were calculated for VUR on MCU versus scarring on DMSA.Vesicoureteral reflux was found in 158 (39.5%) kidneys, and evaluated as grades I, II, III, IV, and V in 3, 70, 43, 25, and 17 refluxing renal units (RRU), respectively. Permanent renal damage according to DMSA was seen in 15.2% (61/400) kidneys. Scarring was shown in 29.7% (47/158) of kidneys with VUR and in 5.8% (14/242) kidneys without VUR (P < 0.0001). LR positive was 2.353 (95% CI 1.889, 2.865), LR negative 0.341 (95% CI 0.209, 0.523), and DOR 6.895 (95% CI 3.533, 14.093). Rate of scarring significantly increased with VUR of grades III, IV, and V. There was no significant difference in the incidence of scarring in kidneys without VUR and RRU with low-grade (I and II) VUR (P = 0.306). The presence of VUR on MCU increased the chance of renal damage on DMSA by about 15%, whereas negative MCU increased the chance of no-renal involvement by 9%.Micturating cystourethrography should not be used as a first-line test to rule out the permanent renal damage owing to UTI. The priority of imaging strategy should be focused on early identification of renal lesions to prevent further deterioration.
Keywords: Urinary tract infection; Vesicoureteral reflux; Renal scintigraphy; MCU

Regional cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2) can be estimated from C15O, H2 15O, and 15O2 tracers and positron emission tomography (PET) using an autoradiographic (ARG) method. Our objective in this study was to optimize the scan time for 15O2 gas study for accurate estimation of OEF and CMRO2.We evaluated statistical noise in OEF by varying the scan time and error caused by the tissue heterogeneity in estimated OEF and CMRO2 using computer simulations. The characteristics of statistical noise were investigated by signal-to-noise (S/N) ratio from repeated tissue time activity curves with noise, which were generated using measured averaged arterial input function and assuming CBF = 20, 50, and 80 (ml/100 g per minute). Error caused by tissue heterogeneity was also investigated by estimated OEF and CMRO2 from tissue time activity curve with mixture of gray and white matter varying fraction of mixture. In the simulations, three conditions were assumed (i) CBF in gray and white matter (CBFg and CBFw) was 80 and 20, OEF in gray and white matter (E g and E w) was 0.4 and 0.3, (ii) CBFg and CBFw decreased by 50%, and E g and E w increased by 50% when compared with conditions (i) and (iii). CBFg and CBFw decreased by 80%, and E g and E w increased by 50% when compared with condition (i).The longer scan time produced the better S/N ratio of estimated OEF value from three CBF values (20, 50, and 80). Errors of estimated OEF for three conditions owing to tissue heterogeneity decreased, as scan time took longer. Meanwhile in the case of CMRO2, 3 min of scan time was desirable.The optimal scan time of 15O2 inhalation study with the ARG method was concluded to be 3 min from taking into account for maintaining the S/N ratio and the quantification of accurate OEF and CMRO2.
Keywords: O-15 oxygen gas; Positron emission tomography; Autoradiographic method

Clinical significance of diastolic function as an indicator of myocardial ischemia assessed by 16-frame gated myocardial perfusion SPECT by Ichiro Nakae; Shinro Matsuo; Tetsuya Matsumoto; Kenichi Mitsunami; Minoru Horie (677-683).
Studies have suggested that ischemia-induced diastolic dysfunction persists longer than systolic dysfunction. We examined whether global left ventricular (LV) diastolic function during stress testing assessed by 16-frame gated myocardial perfusion single-photon emission computed tomography (SPECT) is useful as an indicator of myocardial ischemia.Thirty-nine patients underwent 16-frame technetium-99m (Tc-99m) quantitative gated SPECT (QGS), including treadmill exercise testing for suspected ischemic heart disease. Diastolic parameters of the first-third filling fraction (1/3FF), and the peak filling rate (PFR) were calculated by a time-volume curve from the QGS data.The patients were divided into four groups, namely, IS, NL, DN, and DD, on the basis of tracer accumulation and the LV ejection fraction (LVEF) at rest. In the IS group (reversible tracer uptake reduction suggesting ischemia; n = 11), LVEF, 1/3FF, and PFR after stress were significantly lower than those at rest, whereas in the NL group (normal perfusion; n = 10) and DN group (fixed tracer uptake reduction with normal systolic function; EF ≥ 60% at rest; n = 10), LVEF, 1/3FF, and PFR after stress did not differ from those at rest. However, in the DD group (fixed tracer uptake reduction with cardiac dysfunction; EF < 60%, average 47.1%; n = 8), LVEF, 1/3FF, and PFR were significantly altered after stress.Altered global LV diastolic function during stress assessed by 16-frame gated myocardial perfusion SPECT is useful for the detection of myocardial ischemia. However, similar findings are observed in patients with cardiac dysfunction but without detectable ischemia. Our findings do suggest that tests should be performed with caution to determine whether ischemia exists on the basis of altered global LV function after stress in patients with cardiac dysfunction.
Keywords: Diastolic function; Myocardial ischemia; Exercise; Myocardial scintigraphy

The implication of hot spots on bone scans within the irradiated field of breast cancer patients treated with mastectomy followed by radiotherapy by Won Park; Seung Jae Huh; Jung Hyun Yang; Seok Jin Nam; Jeong Han Kim; Joon Young Choi; Sook Young Woo; Hae Young Kim; Jae Myoung Noh; Jung Il Ryu (685-691).
To analyze the implication of abnormal hot spots in the irradiated field of patients treated with mastectomy followed by radiotherapy for breast cancer.We reviewed 1842 consecutive bone scans performed on 292 patients treated with a modified radical mastectomy and followed by radiotherapy. If abnormal hot spots at the irradiated sites were detected in the bone scans, we evaluated further studies to determine whether bone metastases were present. Radiation was given using 4 or 6 MV X-rays at a dosage of 50.4 Gy during 5.5 weeks with a dosage per fraction of 1.8 Gy. The follow-up period was 25–136 months (median 57 months).Sixty patients (20.6%) developed bone metastasis. Solitary rib metastases were identified in four patients; all were detected outside of the irradiated field. Of 232 patients who did not develop bone metastases, hot spots in the irradiated field were detected in 30 patients (12.9%). A simple rib facture at the site of a hot spot was demonstrated in four patients. The cumulative incidence of hot spots at 5 years was 12.9%. The cumulative incidence of hot spots was more common in postmenopausal women, patients who were less than 60 kg, patients who received adjuvant hormonal therapy and patients who had radiation that included the supraclavicular area.We confirmed that the hot spots within the irradiated fields might be benign, especially in patients who were postmenopause, had a low body weight, received adjuvant hormonal therapy and who had radiation that included the supraclavicular area.
Keywords: Breast cancer; Irradiation; Mastectomy; Bone scan; Hot spot

Correlation between FDG-PET findings and GLUT1 expression in salivary gland pleomorphic adenomas by Choichi Horiuchi; Mamoru Tsukuda; Takahide Taguchi; Yukari Ishiguro; Koji Okudera; Tomio Inoue (693-698).
One reason for the difficulty in accurate preoperative pathological diagnosis of major salivary gland tumors with fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) is the tendency of pleomorphic adenomas to have a high, standardized uptake value (SUV). The expression of glucose transporter 1 (GLUT1) and the quantity of GLUT1 messenger RNA (mRNA) were analyzed in specimens of pleomorphic adenoma to identify whether GLUT1 is responsible for the increased glucose uptake in FDG-PET examinations of these tumors.Eighty salivary gland tumors resected at Yokohama City University Hospital were retrospectively investigated. FDG-PET was performed prior to surgery. PET images were evaluated by two experienced radiologists. GLUT1 was immunohistochemically stained, and GLUT1 mRNA density was quantified using real-time polymerase chain reaction in 10 of 40 pleomorphic adenomas.The pleomorphic adenomas stained positively for GLUT1, and there was significant correlation between the GLUT1 index and the SUV in FDG-PET.GLUT1 is expressed in salivary gland pleomorphic adenomas. Furthermore, the GLUT1 index shows significant correlation with the SUV of FDGPET. This result suggests that GLUT1 plays an important role in increasing FDG uptake in salivary gland pleomorphic adenomas.
Keywords: FDG-PET; GLUT1; Immunohistochemistry; Real-time PCR; Pleomorphic adenoma

18F-FDG-PET of musculoskeletal tumors: a correlation with the expression of glucose transporter 1 and hexokinase II by Kenichiro Hamada; Yasuhiko Tomita; Ying Qiu; Binglin Zhang; Takafumi Ueda; Akira Myoui; Ichiro Higuchi; Hideki Yoshikawa; Katsuyuki Aozasa; Jun Hatazawa (699-705).
It remains controversial whether positron emission tomography (PET) with 2-deoxy-2-[F-18]fluoro-d-glucose (F-18-FDG) can differentiate between benign and malignant musculoskeletal tumors. To uncover the mechanism of F-18-FDG accumulations, we analyzed the correlation between the F-18-FDG accumulation and the expression of glucose transporter 1 (Glut-1) and hexokinase II (HK-II) in benign and malignant musculoskeletal tumors.The maximum standardized uptake values (SUVmax) of F-18-FDG in 24 benign and 26 malignant musculoskeletal tumors were compared with the histologic malignancies, and the expression of Glut-1 and HK-II was analyzed by immunohistochemistry.The SUVmax for malignant tumors (6.33 ± 4.79) was significantly higher than those with benign tumors (3.47 ± 3.12, P < 0.01). The expression of Glut-1 was high in 12 patients (all malignant) and low in 38 patients (24 benign and 14 malignant), and the expression of HK-II was high in 36 patients (11 benign and 25 malignant) and low in 14 patients (13 benign and 1 malignant). Cases with high expression of Glut-1 and HK-II at immunohistochemistry showed a higher SUVmax than those with low expression (Glut-1 8.03 ± 5.10 and 3.98 ± 3.53, P < 0.01; HK-II 5.73 ± 4.49 and 2.99 ± 3.02, P < 0.01). No significant dividing threshold of the SUVmax of F-18 FDG was found for the differential diagnosis between benign and malignant tumors or for the expression of Glut-1 and HK-II.The limited capability of F-18 FDG-PET in the differential diagnosis of musculoskeletal tumors is owing partly to the various levels of Glut-1 and HK-II expression in individual tumors.
Keywords: Positron emission tomography; Maximum standardized uptake values; Glucose transporter 1; Hexokinase II; Musculoskeletal tumor

There are different protocols of reconstruction in myocardial gated imaging that produce different values of left ventricular ejection fraction (EF). We attempted to determine how the parameters of reconstruction affect the calculated EF. The results were statistically compared with the values obtained from angiography and echocardiography.In this retrospective study, the data from 23 patients were used. All the patients had the angiographic and the echocardiographic data within 2 weeks before the test. Imaging was performed using a single-head gamma camera using technetium-99 methoxyisobutylisonitrile. The image data were reconstructed using 50 different combinations of the ramp, Hanning, Butterworth, Wiener, and Metz filters. The ordered subset expectation maximization (OSEM) technique was also examined using 12 combinations of iteration and subset. The calculated EF values were analyzed and compared with the echocardiographic and angiographic results.The backprojection technique produced higher values of EF than those derived from echocardiography and angiography. The OSEM on the other hand produced lower values when compared with echocardiography and angiography. On using the backprojection technique, the maximum correlation between the values derived from gated single-photon emission tomography and echocardiography (r = 0.88, P < 0.01) and angiography (r = 0.81, P < 0.01) was observed when using the Metz filter (full width at half maximum = 5 mm and order = 9) and the Gaussian filter (α = 3), respectively. In the case of the OSEM technique, the maximum correlation with both angiography and echocardiography was observed when using the iteration = 2 and the subset = 12.On the average, the backprojection technique produces higher values, and iteration technique produces lower estimation of the EF when compared with angiography and echocardiography.
Keywords: ECG-gated SPET; Ejection fraction; Image reconstruction; Filtered backprojection; OSEM

Histiocytic sarcoma: PET-CT evaluation of a rare entity by Emel Yaman; Banu Ozturk; Ozlem Erdem; Nahide Gokcora; Ugur Coskun; Omer Uluoglu; Mustafa Benekli (715-717).
Histiocytic sarcoma is a rare malignancy of hematopoietic origin. Lymph nodes, skin, and extranodal sites, especially gastrointestinal tract, are commonly involved. Some cases reported in the past as non-Hodgkin’s lymphoma are now classifi ed as histiocytic sarcoma by detailed immunohistochemical studies. Patients with clinically localized disease have a good prognosis whereas those with lymphatic involvement have an aggressive course. In our case, histiocytic sarcoma was detected, originating from the skin over the left shoulder associated with disseminated lymphadenopathy. A positron emission tomography/computed tomography examination was done for evaluating the extent of the disease which showed pathologic increased 18F-fl uorodeoxyglucose uptake in the lymph nodes, indicating widespread disease. The pertinent literature is reviewed.
Keywords: Histiocytic sarcoma; PET-CT; Disseminated disease

Drug-induced pneumonitis detected earlier by 18F-FDG-PET than by high-resolution CT: a case report with non-Hodgkin’s lymphoma by Tomohiko Yamane; Osami Daimaru; Satoshi Ito; Takeshi Nagata; Kazuhiko Yoshiya; Nobuyuki Fukaya; Shinichi Ito; Teruhiko Imai; Hideo Uchida (719-722).
Drug-induced pneumonitis is a serious and an unpredictable side effect of chemotherapy in patients with malignant lymphoma. We present the case of a 51-year-old man who developed drug-induced pneumonitis during chemotherapy for non-Hodgkin’s lymphoma in which pneumonitis was detected earlier by 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) than by high-resolution computed tomography (HRCT). After five courses of chemotherapy, 18F-FDG-PET was performed for assessing residual lesions, and diffuse lung uptake was incidentally observed. No symptoms were present, and HRCT performed immediately following PET revealed no abnormalities. Mild dyspnea appeared 3 days after PET, and additional HRCT revealed patchy ground-glass opacities disseminated with the appearance of interlobular septum thickening. Drug-induced pneumonitis was finally diagnosed, and treatment was initiated. 18F-FDG-PET can be an imaging modality for detecting drug-induced pneumonitis at an extremely early stage in which HRCT is incapable of revealing any abnormal changes.
Keywords: 18F-FDG-PET; High-resolution CT; Drug-induced pneumonitis; Chemotherapy; Malignant lymphoma

Gated 99mTc-MIBI single-photon emission computed tomography for the evaluation of left ventricular ejection fraction: comparison with three-dimensional echocardiography by Piotr Lipiec; Paulina Wejner-Mik; Maria Krzemińska-Pakuła; Jacek Kuśmierek; Anna Płachcińska; Remigiusz Szumiński; Anna Kapusta; Jarosław D. Kasprzak (723-726).
Parameters of left ventricular systolic function directly influence the management of patients with suspected coronary artery disease (CAD). Quantitative gated single-photon emission computed tomography (QGS; Cedars-Sinai Medical Center, Los Angeles, CA, USA) allows the computation of left ventricular ejection fraction (LVEF) from myocardial perfusion imaging studies which are frequently performed on patients with suspected CAD. Three-dimensional (3D) echocardiography is considered to be the echocardiographic “gold standard” for the quantification of LVEF. We sought to compare QGS with 3D echocardiography in the evaluation of EF in patients with suspected CAD.Ninety-one consecutive patients with suspected CAD, scheduled for coronary angiography, underwent rest electrocardiographic-gated technetium-99m methoxyisobutylisonitrile SPECT (G-SPECT) with measurement of LVEF by QGS and transthoracic 3D echocardiography with off-line measurement of LVEF (Tomtec 4D LV Analysis 1.1). The diagnosis of CAD was based on coronary angiography, performed on every patient.Nine patients were excluded from the analysis owing to unsuitability for 3D echocardiography (8 patients) or G-SPECT (1 patient). In the remaining group of 82 patients, 71 (87%) had significant CAD, 34 (42%) had a history of myocardial infarction, and 50 (61%) had perfusion defects at rest G-SPECT images. The mean LVEF measured by QGS and 3D echocardiography was 53 ± 13% and 53 ± 10%, respectively. The mean difference in LVEF between 3D echocardiography and QGS was 0.1 ± 6.0% (P = 0.87), and the correlation between the values obtained by both methods was high (r = 0.88, P < 0.001). The largest discrepancies were observed in patients with small ventricular volumes.In patients undergoing diagnostic work-up for CAD, the measurement of LVEF by QGS algorithm provides high correlation and satisfactory agreement with the results of reference ultrasound method-3D echocardiography.
Keywords: Left ventricular ejection fraction; Gated single-photon emission computed tomography; Three-dimensional echocardiography; Coronary artery disease