Junichi Omagari

A clinical evaluation of FDG-PET to assess the response in radiation therapy for bronchogenic carcinoma

The clinical usefulness of FDG-PET in the prediction and assessment of response to radiation therapy in patients with bronchogenic carcinoma was evaluated. Thirty patients with untreated bronchogenic carcinoma were included in the study. All patients received FDG-PET before the initiation of radiation therapy, while 20 also received it after completing the therapy. The tumor to muscle ratio (TMR) was used as an index of the FDG uptake. The tumor response to therapy was classified as either a partial response (PR, n = 21) or no change (NC, n = 9) according to changes in the tumor size. Prognosis was made 6 months after the initiation of therapy, and was classified as either relapse (n = 19) or non-relapse (n = 9). The FDG uptakes both before and after therapy were compared with tumor response and prognosis. A high FDG uptake was noted in all 30 lesions before therapy. No significant differences in the uptake before therapy was observed according to the histological types nor T factors (UICC). The lesions with a higher uptake (TMR more than 7) responded better to therapy than those with a lower uptake (p < 0.05). The decrease in the uptake after therapy tended to be more prominent in the PR group than in the NC group. The rate of relapse was higher in lesions with a higher uptake before therapy (TMR more than 10) than in those with a lower uptake. The relapse group also showed a higher uptake after therapy than the non-relapse group. In addition, all 6 lesions showing a higher uptake (TMR more than 5) after therapy eventually relapsed (p < 0.05). Two lesions demonstrating a lower uptake both before and after therapy did not relapse, although no tumor regression due to the therapy was observed. These results indicate that FDG-PET plays a complementary role in both predicting and assessing the therapeutic response and prognosis in patients with bronchogenic carcinoma.

Comparison of diffusion-weighted MRI and 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for detecting primary colorectal cancer and regional lymph node metastases.

To examine the usefulness of diffusion‐weighted MRI (DW‐MRI) for the detection of both primary colorectal cancer and regional lymph node metastases, and compare its performance with 2‐[fluorine‐18]‐fluoro‐2‐deoxy‐D‐glucose positron emission tomography (FDG‐PET) in the same patients.

A case of diffuse-type primary hepatic lymphoma mimicking diffuse hepatocellular carcinoma

Primary hepatic lymphoma (PHL) is a very rare disease, especially in the diffuse type. We report a case of a middle-aged man with hepatitis C virus infection who developed diffuse-type PHL mimicking diffuse hepatocellular carcinoma (HCC). Contrast-enhanced computed tomography (CT) and magnetic resonance imaging showed diffusely infiltrated hypovascular lesions throughout the liver, but no intrahepatic portal venous thrombus was observed. Diffusion-weighted imaging and 18F-FDG positron emission tomography/CT, respectively, showed a very low apparent diffusion coefficient value and high FDG uptake. These findings were more suggestive of diffuse-type PHL than diffuse HCC. Liver biopsy examination confirmed a diagnosis of diffuse large B-cell lymphoma. Systemic staging revealed no evidence of nodal or bone marrow involvement, so PHL was diagnosed. The patient was treated with chemotherapy and achieved complete remission. We suggest that a combination of image modalities may enable differentiation of diffuse-type PHL from diffuse HCC.

The detection rates and tumor clinical/pathological stages of whole-body FDG-PET cancer screening

Objective: FDG-PET has been used for cancer screening, mainly in East-Asia, and cancers are found not infrequently. However, their stages have not been clarified. We examined the detection rates of various cancers using whole-body PET for the screening of cancers in asymptomatic individuals, focusing on their clinical and pathological stages.Methods: Whole-body PET was obtained as a part of our cancer screening program among 3,426 healthy subjects. All subjects participated in a course of PET examination in conjunction with conventional examinations including a medical questionnaire, tumor markers, immunological fecal occult blood test, neck and abdominal ultrasonography and whole body computed tomography. A diagnosis and staging was obtained by an analysis of the pathological findings or by an analysis of the clinical follow-up data.Results: Malignant tumors were discovered in 65 lesions found in 3,426 participants (1.90%). The PET findings were true-positive in 46 of the 65 cancer cases. The cancers were found in the following organs: the colon 14; thyroid gland 10; stomach 7; lung 5; liver 3; breast 2; and one each in the kidney, gallbladder, esophagus, pancreas and retroperitoneum. The stages were as follows: stage 0 5, stage I 17, stage II 10, stage III 7, and stage IV 6. One was an unknown primary. There were 19 false-negative findings (0.6%) on PET. Six cancers (0.18%) were missed in our screening program.Conclusions: PET imaging has the potential to detect a wide variety of cancers at potentially curative stages. Most PET-negative cancers are early stage cancers, and thus can be detected using other conventional examinations such as endoscopy.

Assessment of FDG retention differences between the FDG-avid benign pulmonary lesion and primary lung cancer using dual-time-point FDG-PET imaging.

Purpose The aim of this study was to clarify FDG retention differences between FDG-avid benign pulmonary lesions (BPLs) and primary lung cancers (PLCs), and between tuberculous and non-tuberculous BPLs using dual-time-point FDG-PET imaging.

Primary non-Hodgkin's lymphoma of the maxillary sinus.

Primary non-Hodgkins lymphoma of the maxillary sinus is a rare lesion. We studied nine patients with malignant lymphoma involving the maxillary sinus, treated between 1980 and 1994 in the Kyushu University Hospital. All lymphomas had a diffuse pattern; five were the large-cell type, two the mixed type, and one the small lymphatic and small cleaved type. Immunohistologically, all tumors were B-cell type. Using the Ann Arbor staging system, six patients were classified as stage I, two stage II, and one stage IV. Two patients received only radiotherapy because of advanced age; the remaining seven received a combination of radiotherapy and chemotherapy (CHOP or VEPA). The tumor doses ranged from 30 to 51 Gy (mean, 46.7). The mean follow-up was 51 months. Only one patient (stage IV) died of disease, and eight stage I-II patients were rendered disease-free. The 5-year survival rate was 80%, suggesting that primary lymphoma of the maxillary sinus has a relatively good prognosis.

Non-Hodgkin lymphoma and coexisting primary cancers: a retrospective clinical analysis of 10 patients.

The simultaneous occurrence of non-Hodgkin lymphoma (NHL) and primary cancers is rare, and the treatment strategy for both malignancies is unclear. The authors analyzed the clinical records of 10 patients with NHL and coexisting primary cancers. All patients initially had symptoms of NHL, and all carcinomas were found at the initial workup of NHL by chance. The most common primary sites of coexisting cancers were the stomach (six patients) and the colon (two). Histologically, the majority of NHLs were intermediate grade, and all lesions were B-cell type. All primary cancers were adenocarcinoma. Initially, NHL was treated with radiotherapy or chemotherapy. Six primary cancers were resected surgically or endoscopically after the remission of NHL. The remaining four patients received no treatment for primary cancers because of advanced stages or early relapse of NHL. Three patients died of NHL, one died of cancer, and six were still alive, five without evidence of disease and one with disease. The authors conclude that early detection of a coexisting cancer and appropriate treatment after the remission of NHL may increase the possibility of a cure.

Determinants of Extraaortic Arterial 18F-FDG Accumulation in Asymptomatic Cohorts: Sex Differences in the Association with Cardiovascular Risk Factors and Coronary Artery Stenosis

The objective of this study was to evaluate extraaortic arterial 18F-FDG accumulation in asymptomatic cohorts by sex and to clarify the association between extraaortic arterial 18F-FDG accumulation and cardiovascular risk factors (CRFs) and coronary artery stenosis (CAS). Methods: Five hundred twenty-one asymptomatic individuals (351 men and 170 women) who underwent cancer and CAS screening were enrolled. We evaluated extraaortic arterial 18F-FDG accumulation in the carotid artery (CA) and iliofemoral artery (IFA) and classified the accumulation patterns into 3 types. Type 1 patients had no extraaortic arterial 18F-FDG accumulation, type 2 had accumulation in either the CA or the IFA, and type 3 had accumulation in both the CA and IFA. CRFs (age, low-density lipoprotein [LDL] and high-density lipoprotein [HDL] cholesterol, triglyceride concentration, visceral abdominal fat, hypertension, diabetes, and smoking) and significant CAS were examined in relation to each accumulation type. Results: The men showed more extensive extraaortic arterial 18F-FDG accumulation than the women. Type 3 accumulation (60.4% vs. 37.1%, P < 0.0001) was more frequently observed in men, whereas type 2 (34.2% vs. 44.7%, P = 0.02) and type 1 (5.4% vs. 18.2%, P < 0.0001) accumulation were more frequent in women. The CRFs other than smoking tended to be worse with extensive extraaortic arterial 18F-FDG accumulation. A multivariate logistic regression analysis showed that hypertension, age, LDL cholesterol, triglyceride, and visceral abdominal fat were significantly associated with type 3 accumulation in men, and LDL cholesterol and HDL cholesterol (inversely) were significantly associated with type 3 accumulation in women. CAS was found in 4.2% (9/212) of male patients and in 1.6% (1/63) of female patients with type 3 accumulation, whereas no CAS was found in the other 2 types. Conclusion: The men showed more extensive extraaortic arterial 18F-FDG accumulation than the women. LDL cholesterol was associated with extensive extraaortic arterial 18F-FDG accumulation in both sexes, but the other CRFs associated with extensive extraaortic 18F-FDG arterial accumulation differed between the sexes. The type 3 accumulation was considered to pose a risk of CAS, especially in male patients, whereas non–type 3 accumulation presented little risk.

Chest wall and axillary lymph node FDG uptake associated with cancer vaccine therapy for lung cancer.

Cancer vaccines are now undergoing clinical investigations, and clinical trials of therapeutic cancer vaccines have been conducted mainly for advanced cancer patients. We experienced 2 cases of multifocal F-18 fluoro-2-deoxy-D-glucose uptake in the chest wall and axillary lymph nodes associated with personalized peptide vaccine therapy for recurrent lung cancer. In this article, we report fluoro-2-deoxy-D-glucose -positron emission tomography and positron emission tomography/computed tomography findings.

FDG-PET/CT findings of peritoneal lymphomatosis.

Peritoneal lymphomatosis (PL) is an extensive lymphomatous infiltration of the intraperitoneal portion of the subperitoneal space, which is a rare presentation of lymphoma. Using CT or MRI findings alone, it is difficult to differentiate between lymphomatosis, carcinomatosis, and other pathological entities.We experienced two PL cases and herein report the FDG-PET/CT findings. High FDG uptakes were found in omental and peritoneal infiltration, gastric wall involvement, and lymph node involvement in the epiphrenic region, although retroperitoneal lymph node involvement was absent. Systemic abnormal FDG uptakes suggested PL rather than carcinomatosis, and FDG-PET/CT findings were useful for the diagnoses.