Unusual Diffuse and Heterogeneous FDG Uptake in Appendicular Bone Marrow Space in a Patient with Acute Lymphoblastic Leukemia.

We describe a case of F-18-2-fluoro-2-deoxyglucose (FDG) uptake in the appendicular bones on a positron emission tomography/computed tomography (PET/CT) scan in a 20-year-old woman with a diagnosis of acute lymphoblastic leukemia. An FDG PET/CT was performed on this patient because of fever of unknown origin, revealing diffuse and heterogeneous FDG uptake in the bone marrow space of both humeri, femurs, and tibiae. The patient underwent magnetic resonance imaging, which demonstrated bone infarction with heterogeneous high, intermediate, and dark signal intensities on T1- and T2-weighted images in the same areas.

Splenosis Mimicking Peritoneal Seeding of Advanced Colon Cancer Can Be Identified by Spleen SPECT/CT and FDG PET/CT.

This case report demonstrates that Tc-99m labeled heat-damaged red blood cell single-photon emission computed tomography/computed tomography (spleen SPECT/CT) and F-18 fluorodeoxyglucose positron emission tomography/CT (FDG PET/CT) could noninvasively confirm splenosis mimicking peritoneal seeding of advanced sigmoid colon cancer with hepatic metastases, and played a crucial role in determining the treatment plan.

Physiological Uptake of Radioactive Iodine Around an Artificial Eyeball Observed with Single-Photon Emission Computed Tomography/Computed Tomography After Radioactive Iodine Treatment.

Radioactive iodine treatment is useful for ablating remnant thyroid tissue and metastasis of well-differentiated thyroid cancer with long-lasting effects. A scintigraphy after radioactive iodine treatment is a major imaging modality for detecting metastasis and assessing the management of metastasis. However, caution is required when reading the scan due to potential false-positive findings. In this study, scintigraphy and single-photon emission computed tomography/computed tomography images after radioactive iodine treatment revealed a physiological uptake of radioactive iodine due to lacrimal secretion around an artificial eyeball; such findings have not been reported previously.

Iodine Uptake in Retroperitoneal Cysts after Radioactive Iodine Treatment.

Radioactive iodine ablation has long-lasting effects on remnant thyroid tissue and metastasis from well-differentiated thyroid cancer. After radioactive iodine treatment, scintigraphy is a major imaging modality for detecting metastasis and assessing its management. False-positive iodine uptake can be found in many aberrant locations, including cysts. This report describes iodine uptake in retroperitoneal cysts in a 62-year-old woman diagnosed with papillary thyroid carcinoma. Radioiodine scintigraphy was performed after iodine therapy. Abnormally increased iodine activity was noted in the left upper abdomen. Additional radiologic examinations helped in preventing invasive biopsy.

Detecting Synchronous Thyroid Adenoma and False-Positive Findings on Technetium-99m MIBI Single Photon-Emission Computed Tomography/Computed Tomography.

Technetium (Tc)-99m-methoxyisobutylisonitrile (MIBI) single photon-emission computed tomography/computed tomography (SPECT/CT) is now being used increasingly for preoperative localization of parathyroid adenomas. Tc-99m-MIBI scintigraphy in a 52-year-old man with a diagnosis of primary hyperparathyroidism revealed two focal areas with retention of radioactivity in the left lobe of the thyroid gland on the delayed phase of MIBI SPECT/CT but no significant focal radioactive uptake on MIBI planar images. The patient subsequently underwent left partial parathyroidectomy. Histological analysis identified one lesion to be thyroid hyperplasia and the other to be parathyroid adenoma. This case demonstrates the value of MIBI SPECT/CT for localization of a parathyroid lesion when compared with planar images and that false-positive findings can lead to misdiagnosis in a patient with coexisting thyroid disease. An appropriate diagnostic work-up that includes Tc-99m MIBI SPECT/CT in addition to ultrasonography is helpful for an accurate diagnosis in patients with concomitant thyroid disease.

Dual-Time-Point FDG Uptake Correlates with Prognostic Factors of Invasive Breast Cancer: Clinical Usefulness of Early Delayed Scanning.

This study investigated correlations between fluorodeoxyglucose (FDG) uptake in tumors as assessed by modified dual-time-point (mDTP) FDG positron emission tomography/computed tomography (PET/CT) in invasive breast cancer (iBC) and several prognostic parameters. Thirty-two women who underwent mastectomies for iBC were retrospectively evaluated. mDTP scanning was performed using standard FDG PET/CT (PET1), followed by early delayed acquisition (PET2) without repositioning and additional CT scanning. Using maximal standardized uptake values on PET1 (SUV1) and PET2 (SUV2) in the primary breast tumor, the percentage changes between SUV1 and SUV2 (retention index, (RI)) were calculated. Prognostic parameters (e.g., tumor size and stage; number of metastatic lymph nodes; histologic grade; expression of estrogen receptor (ER), progesterone, epidermal growth factor receptor (HER-2), and p53; and the Ki-67 labeling index (LI)) were evaluated from the surgical specimens. PET2 scans were conducted 17.7 ± 1.5 min after PET1. RI values gradually increased as the histologic grade increased (p = 0.016), and were significantly higher when ER expression was absent (p = 0.023) and Ki-67 LI was high (p < 0.001). RI values also showed a moderately positive correlation with Ki-67 LI (r = 0.629; p < 0.001). RI correlated with well-known biologic prognostic factors of iBC and mDTP scanning, which could be used as a substitute for conventional DTP PET.

Multimodal Imaging in Klippel-Trénaunay-Weber Syndrome: Clinical Photography, Computed Tomoangiography, Infrared Thermography, and 99mTc-Phytate Lymphoscintigraphy.

We report the case of a 19-year-old man who presented with a 12-year history of progressive fatigue, feeling hot, excessive sweating, and numbness in the left arm. He had undergone multimodal imaging and was diagnosed as having Klippel-Trénaunay-Weber syndrome (KTWS). This is a rare congenital disease, defined by combinations of nevus flammeus, venous and lymphatic malformation, and hypertrophy of the affected limbs. Lower extremities are affected mostly. Conventional modalities for evaluating KTWS are ultrasonography, CT, MRI, lymphoscintigraphy, and angiography. There are few reports on multimodal imaging of upper extremities of KTWS patients, and this is the first report of an infrared thermography in KTWS.

Radiation recall dermatitis triggered by sorafenib after radiation therapy for hepatocellular carcinoma.

Sorafenib is widely used for unresectable and metastatic hepatocellular carcinomas. Radiation recall dermatitis (RRD) is an acute inflammatory reaction confined to previously irradiated skin that occurs after the administration of certain drugs. RRD after sorafenib treatment is rare; five cases have been reported thus far. We describe a 44-year-old man irradiated for chest wall bone metastasis from hepatocellular carcinoma. Eight days after radiotherapy completion, systemic therapy for metastatic hepatocellular carcinoma was initiated with sorafenib treatment. Eleven days after starting sorafenib, the patient complained of erythematous rash with pruritus in the chest wall, in a location consistent with the previous radiation field. Sorafenib was continued at the same dose, despite the RRD. The skin reaction subsided over the next 2 weeks without any medical intervention.

The role of adjuvant external beam radiation therapy for papillary thyroid carcinoma invading the trachea.

PURPOSE: To evaluate the effect of adjuvant external beam radiation therapy (EBRT) on local failure-free survival rate (LFFS) for papillary thyroid cancer (PTC) invading the trachea. MATERIALS AND METHODS: Fifty-six patients with locally advanced PTC invading the trachea were treated with surgical resection. After surgery, 21 patients received adjuvant EBRT and radioactive iodine therapy (EBRT group) and 35 patients were treated with radioactive iodine therapy (control group). RESULTS: The age range was 26-87 years (median, 56 years). The median follow-up period was 43 months (range, 4 to 145 months). EBRT doses ranged from 50.4 to 66 Gy (median, 60 Gy). Esophagus invasion and gross residual disease was more frequent in the EBRT group. In the control group, local recurrence developed in 9 (9/35, 26%) and new distant metastasis in 2 (2/35, 6%) patients, occurring 4 to 68 months (median, 37 months) and 53 to 68 months (median, 60 months) after surgery, respectively. Two patients had simultaneous local recurrence and new distant metastasis. There was one local failure in the EBRT group at 18 months after surgery (1/21, 5%). The 5-year LFFS was 95% in the EBRT group and 63% in the control group (p = 0.103). In the EBRT group, one late grade 2 xerostomia was developed. CONCLUSION: Although, EBRT group had a higher incidence of esophagus invasion and gross residual disease, EBRT group showed a better 5-year LFFS. Adjuvant EBRT may have contributed to the better LFFS in these patients.

Inferior Vena Cava Filter Thrombus: a Possible Cause of an Unanticipated Finding of (99m)Tc-labeled Red Blood Cell Scintigraphy.

(99m)Tc-labeled red blood cell scintigraphy, a sensitive and specific diagnostic test, is useful for patients suspected of suffering from active gastrointestinal bleeding. This study follows a case of a patient who was suspected of gastrointestinal bleeding after an inferior vena cava filter was inserted due to a deep vein thrombosis of the femoral vein. To evaluate an exact focus of bleeding, (99m)Tc-labeled red blood cell scintigraphy was executed. Herein, an unanticipated finding of (99m)Tc-labeled red blood cell scintigraphy probably due to a thrombus on the inferior vena cava filter is reported.

Arteriovenous fistula stent infection diagnosed with radiolabelled leucocyte scintigraphy.

Infectious complications of haemodialysis in patients with arteriovenous fistula stent are rare. In addition, patients with low-grade infection are more difficult to diagnose. Here, we report the first case of low-grade infection of an arteriovenous fistula stent diagnosed using (99m)Tc-hexamethylpropylene amine oxime (HMPAO)-labelled leucocyte scintigraphy. A 62-year-old man with end-stage renal disease was referred for prolonged fever. We performed (99m)Tc-HMPAO-labelled leucocyte scintigraphy following a work-up according to fever of unknown origin. A focal uptake on the left forearm compatible with the arteriovenous fistula stent insertion site was shown, and the stent was removed. (99m)Tc-HMPAO-labelled leucocyte scintigraphy could be a suitable method for assessing vascular stent infection in low-grade fever.

Epiphora after radioactive iodine therapy in a low-risk patient.

It has been demonstrated that radioactive iodine therapy (RIT) is very useful for ablating remnant thyroid tissue or metastatic lesions after total thyroidectomy in well-differentiated thyroid cancer. Epiphora as a result of lacrimal drainage system obstruction is a rare complication of RIT. Previous studies have shown that most patients with epiphora after RIT are old ages, females, and with high cumulative radioactive iodine dose. Here, we report on a case of epiphora with low-risk factors including young ages, male, and 5.5-GBq (150-mCi) dose in the first RIT.

Incidental focal uptake in oropharynx due to lingual thyroid on diagnostic 131I whole-body scan after total thyroidectomy.

After total thyroidectomy for papillary thyroid carcinoma, a 37-year-old woman underwent a 2-mCi (131)I whole-body scan which demonstrated focal uptake in the anterior neck and in the oropharynx. Preoperative contrast-enhanced neck computed tomography demonstrated a small enhancing nodule typical for ectopic thyroid at the tongue base. She was then treated with 150 mCi (131)I. Small asymptomatic lingual thyroid remnants typically do not affect high-dose (131)I therapy.

Ultrashort-acting insulin may improve on 18F-FDG PET/CT image quality in patients with uncontrolled diabetic mellitus.

OBJECTIVE: It is known that the poor image quality of (18)F-fluorodeoxyglucose ((18)F-FDG) PET scans leads to interpretation difficulty in patients with uncontrolled diabetes mellitus (DM). We usually delay (18)F-FDG PET examination when patients show high glucose levels. This study was performed to evaluate the usefulness and effects of ultrashort-acting insulin on (18)F-FDG PET/computed tomography (CT) imaging in DM patients. MATERIALS AND METHODS: A total of 105 DM patients (68 men and 37 women) were included. Ultrashort-acting insulin was intravenously injected when patients showed high glucose levels (>190 mg/dl). (18)F-FDG was injected 60 min after ultrashort-acting insulin injection, and PET/CT images were acquired. Image quality was graded by consensus using the following scale: 1, good; 2, moderate; and 3, poor. The mean standardized uptake value (SUV(mean)) of the liver, gluteal muscle, and brain was assessed to evaluate the effects of ultrashort-acting insulin. RESULTS: The group administered ultrashort-acting insulin (n=52, blood glucose level: 243.7 ± 46.2 mg/dl) showed a significantly higher glucose level compared with the group not administered ultrashort-acting insulin (n=53, 177.1 ± 5.2 mg/dl). Nevertheless, the image quality of the group with ultrashort-acting insulin was not significantly different from that of the group without ultrashort-acting insulin (χ(2) -test, P=0.47). No significant differences were seen in SUV(mean) in the liver (P=0.13), gluteal muscle (P=0.71), and brain (P=0.16) between groups. CONCLUSION: Ultrashort-acting insulin can be used to improve the image quality of F-FDG PET/CT in uncontrolled DM patients without significant differences in SUV.

Symptomatic late-onset sialadenitis after radioiodine therapy in thyroid cancer.

OBJECTIVE: The aim of this study was to document the subjective and objective findings of symptomatic late-onset sialadenitis after radioiodine therapy in patients with differentiated thyroid cancer. METHODS: Subjective symptoms related to sialadenitis and Tc-99m pertechnetate salivary gland scintigram findings were assessed in 118 patients (26 males, 92 females) both before and during the late phase (mean 338 days) after the administration of radioiodine. RESULTS: Twelve of the 118 patients (10.2 %) complained of symptomatic sialadenitis in the late phase without symptoms during the early phase (within 7 days of radioiodine administration). Significant associations were found between subjective symptoms and visual scintigram findings during the late phase (p = 0.023). Furthermore, uptake and excretion by both parotid glands were significantly affected by radioiodine therapy. CONCLUSIONS: Symptomatic late-onset sialadenitis occurred at an incidence of 10.2 %, and salivary gland function was affected in both parotids in most patients.

Usefulness of (18)F-fluoride PET/CT in Breast Cancer Patients with Osteosclerotic Bone Metastases.

PURPOSE: Bone metastasis is an important factor for the treatment and prognosis of breast cancer patients. Whole-body bone scintigraphy (WBBS) can evaluate skeletal metastases, and (18)F-FDG PET/CT seems to exhibit high specificity and accuracy in detecting bone metastases. However, there is a limitation of (18)F-FDG PET in assessing sclerotic bone metastases because some lesions may be undetectable. Recent studies showed that (18)F-fluoride PET/CT is more sensitive than WBBS in detecting bone metastases. This study aims to evaluate the usefulness of (18)F-fluoride PET/CT by comparing it with WBBS and (18)F-FDG PET/CT in breast cancer patients with osteosclerotic skeletal metastases. MATERIALS AND METHODS: Nine breast cancer patients with suspected bone metastases (9 females; mean age ± SD, 55.6 ± 10.0 years) underwent (99m)Tc-MDP WBBS, (18)F-FDG PET/CT and (18)F-fluoride PET/CT. Lesion-based analysis of five regions of the skeletons (skull, vertebral column, thoracic cage, pelvic bones and long bones of extremities) and patient-based analysis were performed. RESULTS: (18)F-fluoride PET/CT, (18)F-FDG PET/CT and WBBS detected 49, 20 and 25 true metastases, respectively. Sensitivity, specificity, positive predictive value and negative predictive value of (18)F-fluoride PET/CT were 94.2 %, 46.3 %, 57.7 % and 91.2 %, respectively. Most true metastatic lesions on (18)F-fluoride PET/CT had osteosclerotic change (45/49, 91.8 %), and only four lesions showed osteolytic change. Most lesions on (18)F-FDG PET/CT also demonstrated osteosclerotic change (17/20, 85.0 %) with three osteolytic lesions. All true metastatic lesions detected on WBBS and (18)F-FDG PET/CT were identified on (18)F-fluoride PET/CT. CONCLUSION: (18)F-fluoride PET/CT is superior to WBBS or (18)F-FDG PET/CT in detecting osteosclerotic metastatic lesions. (18)F-fluoride PET/CT might be useful in evaluating osteosclerotic metastases in breast cancer patients.

Primary Malignant Fibrous Histiocytoma in Mediastinum: Imaging with (18)F-FDG PET/CT.

Malignant fibrous histiocytoma (MFH) is the most common soft tissue tumor which often occurs in the extremities and the retroperitoneum. Primary mediastinal MFH is rare; thus, findings on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) of mediastinal MFH have not been reported yet. We report herein the case of a 64-year-old man who was presented with a superior mediastinal mass. The mass showed intense (18)F-FDG uptake with central metabolic defect on PET/CT. The maximum standardized uptake value was 17.4. After tumor removal via median sternotomy, an MFH of the storiform-pleomorphic type was diagnosed on histopathologic examination. We present the first report of (18)F-FDG PET/CT imaging of MFH in the superior mediastinum.

Relation between fluorodeoxyglucose uptake and glucose transporter-1 expression in gastric signet ring cell carcinoma.

PURPOSE: Gastric signet ring cell carcinoma (GSRC) is known to have low fluorodeoxyglucose (FDG) uptake. The aim of the study was to investigate the relation between FDG uptake and glucose transporter (GLUT)-1 expression and clinicopathologic parameters in cases of GSRC. MATERIALS AND METHODS: Forty patients (28 men, mean age 54 ± 12 years) with histologically confirmed GSRC who underwent pre-operative [(18)F]FDG PET/CT were enrolled. Maximum standardized uptake values (SUVmax) were compared with clinicopathologic parameters and GLUT-1 expression. Cases were divided based on GLUT-1 expression in tumor tissues into a membranous group (n = 17) and a cytoplasmic group (n = 23). RESULTS: Mean SUVmax was significantly higher in the membranous group than in the cytoplasmic group (6.06 ± 2.79 vs. 3.67 ± 1.54, P = 0.03). Gastric wall invasion, depth of invasion, extent of LN metastasis, overall stage, and tumor size were found to be related to SUVmax. On the other hand, age, sex, and the presence of distant metastasis were not related to SUVmax. Multivariate analysis revealed that membranous GLUT-1 expression and the extent of LN metastasis independently predicted high FDG uptake. CONCLUSIONS: This study demonstrates that high FDG uptake is mediated by membranous GLUT-1 expression in GSRC.

Clinical Significance of Diffuse (18)F-FDG Uptake in Residual Thyroid Gland after Unilateral Thyroid Lobectomy.

PURPOSE: We investigated the clinical significance of diffuse uptake in remaining thyroid after unilateral lobectomy for thyroid cancer. METHODS: A total of 144 thyroid cancer patients who underwent (18)F-FDG PET/CT after lobectomy were enrolled in the present study. The PET/CT images were evaluated for the presence of diffuse (18)F-FDG uptake with maximum SUV (SUVmax) >2.0 in the residual thyroid and placed into one of two groups: with diffuse uptake and without diffuse uptake group. Clinical, laboratory, and PET/CT parameters in both groups were compared. Correlations between SUVmax of thyroid and available parameters were analyzed. RESULTS: Forty-two of 144 patients (29.2%) had diffuse thyroid uptake (mean SUVmax: 3.2 ± 1.1). All patients with diffuse uptake and 96 (94.1%) without diffuse uptake were receiving thyroxine therapy (P = 0.09). Thyroid function tests showed that most patients were euthyroid status (78.6 vs. 85.3%, P = 0.36). TgAb levels were significantly higher in patients with diffuse uptake (338.0 ± 664.6 vs. 57.3 ± 46.4, P < 0.0001). Mean attenuation values in the diffuse uptake group were significantly lower (72.2 ± 15. vs. 97.0 ± 16.0, P < 0.0001). An inverse correlation was found between SUVmax and mean attenuation values of residual thyroid in all patients (r = -0.57, P < 0.0001) and subgroup with diffuse uptake (r = -0.31, P < 0.05). CONCLUSION: In this study, diffuse (18)F-FDG uptake in the residual thyroid after unilateral lobectomy was a relatively frequent finding and may be associated with chronic thyroiditis. This uptake is not influenced by thyroid status or thyroxine therapy. The (18)F-FDG uptake is inversely correlated with mean attenuation value of thyroid.