Clinical Significance of 18F-fluorodeoxyglucose and Glucose Transporter 1 mRNA in Clear Cell Renal Cell Carcinoma.

BACKGROUND/AIM: 18F-fluorodeoxyglucose (FDG) uptake measurement on positron emission tomography/computed tomography (PET/CT) is difficult in renal tumors because of the nearby renal parenchyma and urinary tract, which excrete FDG. We carefully examined the maximum standardized uptake value (SUVmax) on FDG-PET/CT and investigated the relationship between major glucose transporters in the kidney and clear cell renal cell carcinoma (ccRCC) progression. PATIENTS AND METHODS: Forty-five patients with ccRCC underwent FDG-PET/CT for staging and nephrectomy. Glucose transporter mRNA expression was examined in the removed kidney. RESULTS: SUVmax was increased in high-stage and high-grade tumors. Glucose transporter 1 (GLUT1) mRNA expression was higher in tumor tissues, in contrast to other glucose transporters. SUVmax was not correlated with GLUT1 mRNA expression. Kaplan-Meier analysis showed reduced overall and recurrence-free survival in the high SUVmax group. CONCLUSION: Primary ccRCC lesions show a high SUVmax and GLUT1 mRNA over-expression. SUVmax increases with tumor upstaging and upgrading.

BNCT for primary synovial sarcoma.

Synovial sarcoma is a rare tumor requiring new treatment methods. A 46-year-old woman with primary monophasic synovial sarcoma in the left thigh involving the sciatic nerve, declining surgery because of potential dysfunction of the affected limbs, received two courses of BNCT. The tumor thus reduced was completely resected with no subsequent recurrence. The patient is now able to walk unassisted, and no local recurrence has been observed, demonstrating the applicability of BNCT as adjuvant therapy for synovial sarcoma. Further study and analysis with more experience accumulation are needed to confirm the real impact of BNCT efficacy for its application to synovial sarcoma.

Comparison of 18F-FDG PET/CT and 67Ga-SPECT for the diagnosis of fever of unknown origin: a multicenter prospective study in Japan.

OBJECTIVE: The aim of this multicenter prospective study was to compare the sensitivity of 18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) with that of 67Ga single photon emission computed tomography (SPECT) for the identification of the site of greatest importance for the final diagnosis of the cause of fever of unknown origin (FUO). METHODS: The study participants consisted of patients with an axillary temperature ≥ 38.0 °C on ≥ 2 occasions within 1 week, with repeated episodes for ≥ 2 weeks prior to providing consent, and whose final diagnosis after undergoing specific examinations, including a chest-to-abdomen CT scan, was uncertain. All the patients underwent FDG-PET/CT imaging first, followed by 67Ga-SPECT imaging within 3 days. The results of the FDG-PET/CT and 67Ga-SPECT examinations were reviewed by the central image interpretation committee (CIIC), which was blinded to all other clinical information. The sensitivities of FDG-PET/CT and 67Ga-SPECT were then evaluated with regard to identifying the site of greatest importance for a final diagnosis of the cause of the fever as decided by the patient's attending physician. The clinical impacts (four grades) of FDG-PET/CT and 67Ga-SPECT on the final diagnosis were evaluated. RESULTS: A total of 149 subjects were enrolled in this study between October 2014 and September 2017. No adverse events were identified among the enrolled subjects. Twenty-one subjects were excluded from the study because of deviations from the study protocol. Among the 128 remaining subjects, a final diagnosis of the disease leading to the appearance of FUO was made for 92 (71.9%) subjects. The final diagnoses in these 92 cases were classified into four groups: noninfectious inflammatory disease (52 cases); infectious disease (31 cases), malignancy (six cases); and other (three cases). These 92 subjects were eligible for inclusion in the study's analysis, but one case did not meet the PET/CT image acquisition criteria; thus, PET/CT results were analyzed for 91 cases. According to the patient-based assessments, the sensitivity of FDG-PET/CT (45%, 95% CI 33.1-58.2%) was significantly higher than that for 67Ga-SPECT (25%, 95% CI 15.5-37.5%) (P = 0.0029). The clinical impact of FDG-PET/CT (91%) was also significantly higher than that for 67Ga-SPECT (57%, P < 0.001). CONCLUSIONS: FDG-PET/CT showed a superior sensitivity to 67Ga-SPECT for the identification of the site of greatest importance for the final diagnosis of the cause of FUO.

Clinically significant association of elevated expression of nuclear factor E2-related factor 2 expression with higher glucose uptake and progression of upper urinary tract cancer.

BACKGROUND: There is growing evidence that the transcription factor nuclear factor E2-related factor 2 (Nrf2) is the major participant in regulating antioxidants and pathways for detoxifying reactive oxygen species (ROS), as well as having a vital role in tumor proliferation, invasion, and chemoresistance. It was also recently reported that Nrf2 supports cell proliferation by promoting metabolic activity. Thus, Nrf2 is involved in progression of cancer. Upper urinary tract urothelial carcinoma (UTUC) is a biologically aggressive tumor with high rates of recurrence and progression, resulting in a poor prognosis. However, the role of Nrf2 in UTUC is largely unknown. METHODS: In order to study the role of Nrf2 in UTUC from the metabolic perspective, we retrospectively assessed Nrf2 expression in the surgical specimen and the preoperative maximum standard glucose uptake (SUVmax) on [18F]fluorodeoxy-glucose positron emission tomography (18F-FDG-PET) of 107 patients with UTUC who underwent radical nephroureterectomy. RESULTS: Increased expression of Nrf2 in the primary lesion was correlated with less differentiated histology, local invasion, and lymph node metastasis, and was also an independent indicator of shorter overall survival according to multivariate analysis. Furthermore, increased expression of Nrf2 was associated with higher preoperative SUVmax by the primary tumor on 18F-FDG-PET, while Nrf2 expression and SUVmax were also significantly correlated in the metastatic lymph nodes. Among the 18 patients with lymph node metastasis at nephroureterectomy who underwent retroperitoneal lymph node dissection and received adjuvant chemotherapy, the patients with higher Nrf2 expression in the primary tumor had worse recurrence-free survival. CONCLUSIONS: These results suggest that constitutive activation of Nrf2 might be linked with tumor aerobic glycolysis and progression of UTUC, indicating that Nrf2 signaling in the tumor microenvironment promotes progression of UTUC.

Introduction of nuclear medicine research in Japan.

There were many interesting presentations of unique studies at the Annual Meeting of the Japanese Society of Nuclear Medicine, although there were fewer attendees from Europe than expected. These presentations included research on diseases that are more frequent in Japan and Asia than in Europe, synthesis of original radiopharmaceuticals, and development of imaging devices and methods with novel ideas especially by Japanese manufacturers. In this review, we introduce recent nuclear medicine research conducted in Japan in the five categories of Oncology, Neurology, Cardiology, Radiopharmaceuticals and Technology. It is our hope that this article will encourage the participation of researchers from all over the world, in particular from Europe, in scientific meetings on nuclear medicine held in Japan.

Radical nephrectomy and regional lymph node dissection for locally advanced type 2 papillary renal cell carcinoma in an at-risk individual from a family with hereditary leiomyomatosis and renal cell cancer: a case report.

BACKGROUND: Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal dominant tumor susceptibility syndrome, and the disease-related gene has been identified as fumarate hydratase (fumarase, FH). HLRCC-associated kidney cancer is an aggressive tumor characterized by early metastasis to regional lymph nodes and distant organs. Since early diagnosis and provision of definitive therapy is thought to be the best way to reduce the tumor burden, it is widely accepted that germline testing and active surveillance for an at-risk individual from a family with HLRCC is very important. However, it still remains controversial how we should treat HLRCC-associated kidney cancer. We successfully treated the patient with locally advanced HLRCC-associated kidney cancer, who has received active surveillance because of at-risk individual, by radical nephrectomy and extended retroperitoneal lymph node dissection, and examined surgically resected samples from a molecular point of view. CASE PRESENTATION: We recommended that 13 at-risk individuals from a family with HLRCC should receive active surveillance for early detection of renal cancer. A 48-year-old woman with a left renal tumor and involvement of multiple regional lymph nodes with high accumulation of fluorine-18-deoxyglucose on positron emission tomography was treated with axitinib as a neoadjuvant therapy. Preoperative axitinib induced the shrinkage of the tumor with decreased fluorine-18-deoxyglucose accumulation. Resected samples showed two thirds tumor tissue necrosis as well as high expression of serine/threonine kinase Akt and low expression of nuclear factor E2-related factor 2 (Nrf2) which activates anti-oxidant response and protects against oxidative stress in viable cancer cells. Targeted next-generation sequencing revealed that FH mutation and loss of the second allele were completely identical between blood and tumor samples, suggesting that FH mutation plays a direct role in FH-deficient RCC. She has remained well after radical operation for over 33 months. CONCLUSIONS: FH mutation plays a role in tumorigenic feature, a metabolic shift to aerobic glycolysis, and increased an anti-oxidant response phenotype in HLRCC-associated kidney cancer.

Abnormal 18F-FDG uptakes in the prostate due to two different conditions of urine reflux: a mimicker of prostate cancer.

A 69-year-old man with lung cancer underwent 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for staging. FDG PET/CT showed high uptakes in the prostate gland with calcification, and magnetic resonance imaging was recommended to check the prostatic malignancy. T2-weighted images revealed midline cystic lesion at the base to midgland level and cystic lesion in right apical peripheral zone. We suspected urine reflux conditions. Voiding cystourethrography demonstrated those cystic lesions were communicating with the urethra. Therefore these lesions were diagnosed as the prostatic utricle cyst and the dilated prostatic duct in peripheral zone. We conclude that the urine reflux condition should be recognized as a prostate benign lesion with FDG accumulation.

¹8F-Fluorodeoxyglucose Positron Emission Tomography for Evaluating the Response to Neoadjuvant Chemotherapy in Advanced Esophageal Cancer.

BACKGROUND/AIM: The purpose of the present study was to improve the diagnostic precision of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) after neoadjuvant chemotherapy (NAC) in patients with advanced esophageal cancer. PATIENTS AND METHODS: Thirty patients underwent FDG-PET/CT before and after NAC. The maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) were measured. Patients were divided into two pathological response groups: "responders" (grades 1b-3) or "non-responders" (grades 0-1a). RESULTS: Overall, 11 patients were responders. Significant differences were present for the post-NAC SUVmax (p=0.070), %decrease in SUVmax (p=0.017), post-NAC MTV (p=0.014), and %decrease in MTV (p=0.003). CONCLUSION: Receiver operating characteristic curve analysis showed that the %decrease in MTV of the primary tumor was the best indicator of response to NAC. We are currently striving to improve the accuracy of this assessment method.

Usefulness of 18F-Fluorodeoxyglucose Positron Emission Tomography for Follow-Up of 13-cis-Retinoic Acid Treatment for Residual Neuroblastoma After Myeloablative Chemotherapy.

13-cis-retinoic acid (13-cis-RA) treatment is used as a second-line treatment for residual or recurrent neuroblastoma. However, determining the duration of 13-cis-RA treatment for residual and recurrent neuroblastoma can be a problem because it is difficult to evaluate the effectiveness of the treatment.We performed 13-cis-RA treatment to remove residual active neuroblastoma cells in an 8-year-old boy with stage 4 neuroblastoma that developed from a left sympathetic ganglion and had been treated with chemotherapy, surgery, autologous peripheral blood stem-cell transplantation, and radiotherapy. F-fluorodeoxyglucose positron emission tomography (F-FDG-PET) and iodine-123 metaiodobenzylguanidine (I-MIBG) scintigraphy obtained immediately before 13-cis-RA treatment both showed positive findings in the area of the primary lesion. At 18 months after 13-cis-RA treatment, there was accumulation on I-MIBG scintigraphy but no uptake on F-FDG-PET, and 13-cis-RA treatment was suspended. The patient has been in complete remission for 3 years. In comparing the effectiveness of the 2 imaging modalities for monitoring the response to 13-cis-RA treatment, we considered that F-FDG-PET was superior to I-MIBG scintigraphy because F-FDG-PET images were not affected by the cell differentiation induced by 13-cis-RA treatment in our case. Thus, F-FDG-PET was useful for determining the treatment response and outcomes.We have reported a case of residual neuroblastoma treated with differentiation-inducing 13-cis-RA therapy. Different results were produced with F-FDG-PET and I-MIBG scintigraphy. The cessation of 13-cis-RA treatment was based on F-FDG-PET findings and there has been no relapse for 3 years.

Feasibility of detecting small intestinal disease by FDG-PET/CT.

Positron emission tomography (PET)/computed tomography with (18)F-fluorodeoxyglucose (FDG) is widely used for the diagnosis of malignant tumors. However, we occasionally encounter cases in which pathological accumulation is indistinguishable from physiological accumulation. We conducted a retrospective study of the maximum standardized uptake value (SUVmax) and the distribution pattern of FDG accumulation in 80 evaluable patients with records of accumulation in the small intestine identified from data acquired at Dokkyo Medical University PET Center from March 2005 to December 2010. Our aim was to distinguish pathological accumulation from physiological accumulation. Nineteen of the 80 patients had lesions that required some form of treatment. These lesions were categorized as pathological accumulation, while other 65 lesions in 61 patients were categorized as physiological accumulation. Cases with diffuse accumulation in the intestinal tract were assigned to Group L (linear), all others to Group F (focal), in our analysis. Lesions were focal in 22 patients and linear in 62. The pathological accumulation group had a mean SUVmax of 12.2, which was higher than that of 5.0 in the physiological accumulation group, and included more lesions that were categorized into Group F (16 of 19 lesions). The sensitivity and specificity for detecting focal accumulation regarded as being pathological accumulation were 84% and 91%, respectively, and accuracy was 89%. The sensitivity and specificity with a cut-off SUVmax of 5.87 obtained in the ROC analysis were 84% and 78%, respectively, and accuracy was 80%. Evaluation of SUVmax in the small intestine and the distribution pattern of FDG accumulation may be useful for diagnosing lesions in the small intestine.

Clinically significant association between the maximum standardized uptake value on 18F-FDG PET and expression of phosphorylated Akt and S6 kinase for prediction of the biological characteristics of renal cell cancer.

BACKGROUND: The relationship between the clinicopathological features and molecular changes associated with standardized uptake value (SUV) determined by Positron emission tomography (PET) with [18F] fluorodeoxyglucose (18F-FDG PET) in human renal cell carcinoma (RCC) has not been elucidated. On the other hand, overactivation of the phosphatidylinositol 3'kinase (PI3K), serine/threonine kinase Akt, and mammalian target of rapamycin (mTOR) pathway has been detected in a variety of human cancers, including RCC. So far, little is known about the relationship between the SUV and these proteins in human RCC. Thus, it is important to study the relevance of SUV with clinicopathological features in human RCCs from a molecular point of view. METHODS: Seventy-seven consecutive patients with RCC who underwent nephrectomy and pretreatment determination of the maximum SUV (SUVmax) by 18F-FDG PET were analyzed. We investigated the relationship between the SUVmax, phosphorylated-Akt (Ser-473) (pAkt(Ser-473)), phosphorylated-Akt (Thr-308) (pAkt(Thr-308), and phosphorylated-S6 ribosomal protein (Ser-235/236) (pS6) protein levels in the primary tumor and various clinicopathological features. RESULTS: The average SUVmax of the primary tumor was 6.9 (1.5 to 40.3). A higher SUVmax was correlated with higher expression of pAkt(Ser-473), pAkt (Thr-308), and pS6 protein in the primary tumor. A higher SUVmax and increased expression of pAkt (Ser-473), pAkt (Thr-308), and pS6 of the primary tumor was associated with less tumor differentiation, a higher pT stage, regional lymph node involvement, microscopic vascular invasion, and distant metastasis, as well as with early relapse following radical nephrectomy in patients who had localized or locally advanced RCC without distant metastasis (cTanyNanyM0) and with shorter overall survival in all patients. CONCLUSIONS: A higher SUVmax on 18F-FDG PET is associated with elevated tumor levels of pAkt and pS6 protein and with aggressive behavior and metastatic potential of RCC, as well as with early relapse following radical nephrectomy and shorter overall survival. These findings suggest that SUVmax may be useful for predicting the biological characteristics of RCC.

Nuclear medicine practice in Japan: a report of the seventh nationwide survey in 2012.

OBJECTIVE: The Subcommittee on the Survey of Nuclear Medical Practice in Japan has performed a nationwide survey of nuclear medicine practice every 5 years since 1982 to survey contemporary nuclear medicine practice and its changes over the years. METHODS: The subcommittee sent questionnaires, including the number and category of examinations as well as the kind and dose of the radiopharmaceuticals during the 30 days of June 2012, to all the nuclear medicine institutes. The total numbers for the year 2012 were then estimated. RESULTS: A total of 1,167 institutes responded to the survey, including the 14 in vitro assay institutes and 266 PET centers. The recovery rate was 92 %. The number of gamma cameras installed was 1,425 in total, with 9 % decrease in 5 years. Dual-head cameras and hybrid SPECT/CT scanners accounted for 84 and 10.5 %, respectively. The number of single-photon tracer studies in 2012 was 1.15 million which means decrease in 19 % in 5 years and 29 % in 10 years. All but cerebral perfusion study and sentinel lymphoscintigraphy have decreased. Bone scintigraphy was a leading examination (38.7 %), followed by cardiac studies (29.4 %) and cerebral perfusion study (18.5 %) in order. SPECT studies showed an increase from 42.3 to 47.2 %. PET centers have also increased from 212 to 295, as compared to the last survey. The 135 PET centers have installed one or two in-house cyclotrons. PET studies showed 25.5 % increase in 5 years, with oncology accounting for 96.3 %. (18)F-FDG accounted for 98.2 % (505,990 examinations). PET examinations using (11)C-methionine have been increasing, with 3,352 examinations in 2012. The number of new PET studies using (11)C-PIB PET was 695. (131)I-radioiodine targeted therapies showed an increase, including 3,644 patients (53.6 %) for thyroid cancer and 4,889 patients (17.9 %) for hyperthyroidism. Out-patient thyroid bed ablation therapy with 30 mCi of (131)I accounted for 21.0 % of cancer patients. The number of admission rooms decreased from 158 to 135 in 5 years. In vitro radioassays have been declining continuously since 1992, with the number of studies of 9.0 million in 2012. CONCLUSIONS: Single-photon examinations showed a continuous tendency toward a decline in the survey. In contrast, the number of hybrid SPECT/CT scanner examinations has increased. PET/CT study in the oncology field and radionuclide targeted therapy have steadily increased.

Utility of FDG-PET/CT in the evaluation of the response of locally advanced breast cancer to neoadjuvant chemotherapy.

Neoadjuvant chemotherapy (NAC) is effective in down-staging a primary tumor before surgery, and quick differentiation between responders to NAC and nonresponders is needed. We investigated the utility of [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT) in evaluating the therapeutic effectiveness of NAC. We investigated 25 patients who underwent NAC for stage II and III noninflammatory breast cancer. FDG-PET/CT was undertaken before and after NAC to determine the maximum standardized uptake value (SUVmax) reduction rate. Findings were compared with postoperative histopathologic evaluation of therapeutic response. It was not possible to accurately assess tumor response to NAC using CT. However, using the SUVmax reduction rate, we noted a significant difference (P=0.0420) between patients who were responsive and nonresponsive to NAC. The sensitivity and specificity were as high as 83.3% and 78.9%, respectively. This study demonstrated that FDG-PET/CT can differentiate responders from nonresponders. This improves patient management by avoiding unnecessary chemotherapy.

¹8F-fluorodeoxyglucose positron emission tomography for evaluation of thymic epithelial tumors: utility for World Health Organization classification and predicting recurrence-free survival.

OBJECTIVES: (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) plays an important role in many oncological settings. In this study, we assessed the utility of (18)F-FDG-PET for predicting the histological classification, stage and survival of thymic epithelial tumors. METHODS: We retrospectively analyzed 37 patients with thymic epithelial tumors who underwent PET before surgical resection and investigated the relationship between the maximum of standardized uptake value (SUVmax) of each tumor and the WHO classification, recurrence-free survival, and tumor-related gene expressions. RESULTS: The study included 15 males and 22 females, ranging in age from 22 to 81 years (mean 64 years). The tumor histology of 31 tumors was thymoma and that of the remaining tumors was thymic carcinoma. The Masaoka tumor stage was as follows: stage I in 18, II in 9, III in 5 and IV in 5 patients. The patients were divided into three groups according to a simplified histologic classification: low-risk thymoma (types A, AB and B1, n = 21), high-risk thymoma (types B2 and B3, n = 10) and thymic carcinoma (n = 6). The SUVmax of low-risk group (SUVmax ≤4.27) was significantly lower than that of high-risk group (p = 0.0114) and that of thymic carcinomas (SUVmax >4.27) was also significantly higher than that of thymomas (p < 0.0001). The group of high SUVmax (SUVmax >4.27) had significantly inferior recurrence-free survival to that of less value (SUVmax ≤4.27) (p = 0.0009). The SUVmax were not correlated with tumor-related gene expressions. CONCLUSION: The SUVmax of (18)F-FDG-PET reflects WHO classification of thymic epithelial tumors. High SUVmax predicts lower recurrence-free survival of the tumors.

Preoperative nodal staging of uterine cancer: is contrast-enhanced PET/CT more accurate than non-enhanced PET/CT or enhanced CT alone?

OBJECTIVE: To determine whether contrast-enhanced PET/CT is more accurate than either non-enhanced PET/CT or enhanced CT alone for nodal staging of uterine cancer. METHODS: Forty patients with endometrial cancer and cervical cancer underwent conventional PET/CT scan with low-dose CT (ldCT), followed by full-dose CT with IV contrast (ceCT) before radical hysterectomy with pelvic and, when applicable, para-aortic lymphadenectomy. Three data sets of PET/ldCT, PET/ceCT, and enhanced CT images were interpreted separately by two readers. For region-specific comparisons, para-aortic and pelvic lymph nodes were divided into the bilateral para-aortic, common iliac, external iliac, internal iliac, and obturator areas. Based on histopathological findings as the gold standard, we compared the diagnostic accuracy between the three methods using McNemar test with Bonferroni's adjustment. RESULTS: Of the 40 patients, 21 underwent pelvic lymphadenectomy only. Region-based analysis showed that the sensitivity, specificity, and accuracy of PET/ceCT were 61.4% (27/44), 98.1% (308/314), and 93.6% (335/358), respectively, whereas those of PET/ldCT were 52.3% (23/44), 96.8% (304/314), and 91.3% (327/358), respectively, and those of enhanced CT were 40.9% (18/44), 97.8% (307/314), and 90.8% (325/358), respectively. Although PET/ceCT had the best sensitivity among the three imaging modalities, a significant difference was observed only between PET/ceCT and enhanced CT (p = 0.0027). Although PET/ceCT had better sensitivity and accuracy than PET/ldCT, the differences between the two imaging methods did not reach statistical significance (p = 0.046 and p = 0.047, respectively). CONCLUSION: PET/ceCT is slightly but not significantly superior to PET/ldCT for nodal staging of uterine cancer. Nodal metastasis cannot be excluded even if PET/ceCT gives negative findings.

FDG-PET/CT imaging of elastofibroma dorsi.

OBJECTIVE: The purpose of this study was to assess retrospectively the characteristics of FDG uptake in elastofibroma dorsi using integrated PET/CT. METHODS: From 10,261 oncology FDG-PET/CT scans performed over a 2-year period, findings suggestive of elastofiboma dorsi were observed in 46 FDG-PET/CT scans of 34 patients. As 20 patients had bilateral lesions and 14 had unilateral lesions, a total of 75 elastofibroma dorsi lesions on images were identified in this study. For visual analysis of intensity of FDG uptake , a four-point grading system was used: grade 0 for no uptake, grade 1 for less uptake than the liver, grade 2 for uptake comparable to the liver, and grade 3 for intense uptake greater than the liver. For quantitative analysis, the standardized uptake value (SUV) was calculated. The relationships between SUV and age, blood glucose level, lesion size, and related symptoms were also assessed. RESULTS: Among the 75 lesions, 4 had an uptake grade of 0, 41 had grade 1, 25 had grade 2, and 5 had grade 3. The mean SUV (±SD) of the 75 lesions was 2.0 ± 0.63 (range 0-5.1). The Pearson correlation coefficient test indicated a weak positive correlation between SUV and lesion size and no correlation between SUV and either age or blood glucose level. The SUVs of patients with symptoms due to the disease and patients without symptoms were almost the same. CONCLUSION: Mild and moderate uptake of FDG is frequently observed in elastofibroma dorsi, which should not be misinterpreted as abnormal accumulation observed in malignant lesions.

Present and future of FDG-PET/CT in ovarian cancer.

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.

Seguimiento posterior a la cirugía curativa para el cáncer colorrectal: impacto de la tomografía por emisión de positrones - tomografía computarizada (PET/TC) / Follow-up after curative surgery for colorectal cancer: impact of positron emission tomography - computed tomography (PET/CT)

El seguimiento postoperatorio tiene un rol importante para la sobrevida del paciente después de la resección curativa del cáncer colorrectal. OBJETIVOS: Describir las características del seguimiento con tomografía por emisión de positrones (PET) integrado a tomografía axial computarizada (CT) (PET/CT) y su impacto en los sobrevivientes de cáncer colorrectal (CCR) posterior a la resección con intención curativa en un hospital universitario en la prefectura de Tochigi, Japón. MATERIAL Y MÉTODOS: Revisión consecutiva de las historias clínicas de 209 pacientes sometidos a estadificación prequirúrgica con PET/CT para la resección curativa de cáncer colorrectal entre abril de 2005 y marzo de 2008. La información de la evaluación postoperatoria se revisó hasta setiembre de 2008. RESULTADOS: De 209 pacientes que fueron estadificados preoperatoriamente por CCR, 207 (varones/mujeres = 125/82; edad promedio = 65,2 ± 11,4 años) fueron operados con intención curativa e incluidos en el presente estudio. La tasa de cumplimiento con los lineamientos de seguimiento de la Sociedad Japonesa para el Cáncer de Colon y Recto (JSCCR) fue del 53%. La sobrevida acumulada total al final del intervalo de estudio fue de 96.4%. La prueba más utilizada en el seguimiento postoperatorio del CCR fue el antígeno carcinoembrionario (CEA). La PET/CT fue la prueba que detectó más pacientes con lesiones recurrentes (n = 11; valor predictivo positivo = 23.4), entre ellos un paciente con lesión asintomática curable (metástasis a nódulo linfático inguinal), siendo la prueba con mayor efectividad (2.1%). No obstante, su elevado costo convierte a la PET/ CT en el procedimiento menos costo-efectivo. CONCLUSIONES: La utilización de PET/CT en el seguimiento posoperatorio tras resección curativa en CCR ha demostrado ser una alternativa individualizada y efectiva en el hallazgo de enfermedad asintomática curable. El estudio sistemático con CEA y CT como primera línea de despistaje y PET...

Postoperative surveillance has an important role in patient survival after curative resection of colorectal cancer. OBJECTIVES: To describe the characteristics of the follow-up with positron emission tomography(PET) / computed tomography (CT)(PET/CT) and its impact in colorectal cancer (CRC) survivors after curative resection in a university hospital in Tochigi Prefecture, Japan. MATERIALS AND METHODS: Consecutive review of patients hospital charts who underwent presurgical staging with PET/CT for curative resection of colorectal cancer between April 2005 and March 2008. The follow-up data of these patients was reviewed until September 2008. RESULTS: Of 209 patients presurgically staged for CRC, 207 (male/female = 125/82; mean age = 65.3 ± 11.3 years) underwent curative resection and were included in the present study. The compliance rate with the Japanese Society for Cancer of the Colon and Rectum (JSCCR) follow-up guidelines was 53%. The cumulative survival at the end of study interval was 96.4%. The test most commonly used in postoperative follow-up of CRC was the carcinoembryonic antigen (CEA). PET/CT was the test that detected more patients with recurrent lesions (n = 11, positive predictive value = 23.4), including one patient with an asymptomatic curable recurrence (inguinal lymph node metastasis), also being the most effective test (2.1%). However, its high cost makes it the less cost-effective. CONCLUSIONS: The use of PET/CT in the postoperative follow-up after curative resection in CRC has proven to be an individualized and effective alternative in the finding of asymptomatic disease curable. Systematic CEA tests with contrast-enhanced CT as a first line of screening and PET/CT as a second line may be an alternative follow up approach after curative resection for CRC.