Seyda Turkolmez

False-positive iodine-131 whole body scan due to a benign dermal lesion; intradermal nevus ( 131 I uptake in a benign nevus)

Whole body radioiodine scanning (WBS), along with plasma thyroglobulin level, remains a reference method for detecting residual or metastatic differentiated thyroid cancer, however, false-positive WBS is not uncommon. External contaminations by body secretions or excretions, inflammation, and cystic structures mimicking metastases in WBS have been reported. Various benign and malignant tumors having different histopathological natures accumulate radioiodine, but intradermal melanocytic nevus was not previously described in the literature, as far as we know. This report describes an unusual cause of false-positive WBS after radioablation therapy due to an intradermal nevus, and the possible mechanisms are discussed.

Dual phase 18F-fluorodeoxyglucose positron emission tomography/computed tomography with forced diuresis in diagnostic imaging evaluation of bladder cancer

INTRODUCTION (18)F-FDG PET has been regarded as a limited value in urooncology due to urinary excretion of the tracer. The purpose of this retrospective study was to investigate the clinical value of dual-phase FDG PET/CT with forced diuresis protocol (iv furosemide-voiding and oral hydration) in invasive or high grade bladder cancer. METHODS Fifty-one patients were included in this study. All patients underwent standard staging procedures and dual-phase FDG PET/CT before planned therapy. PET/CT findings before and after furosemide were compared with each other for pelvic region. Dual phase PET/CT findings were also compared with the results of prior imaging studies and all findings were correlated with final diagnosis (histopathology or clinical follow-up for at least 12 months). RESULTS Intravesical FDG activity significantly decreased in 90% of the patients with forced diuresis protocol. Eighty eight percent of the bladder findings and 20% of the local lymph node metastases, and other pelvic findings (local invasion and second primary malignancy of prostate) were detected only by the additional pelvic PET/CT images. As a result, dual phase PET/CT changed the staging and/or the therapy strategy in 16 patients (31%). CONCLUSION Dual phase FDG PET/CT contributes staging and decision of therapy strategy by detecting local disease and pelvic metastases with high accuracy when combined with forced diuresis protocol. Thus, we recommend dual phase imaging method with forced diuresis protocol in FDG PET/CT for bladder cancer and all other urogenital system malignities.

The role of postoperative Tc-99m pertechnetate scintigraphy in estimation of remnant mass and prediction of successful ablation in patients with differentiated thyroid cancer.

ObjectiveSurgery and radioactive iodine (RAI) ablation constitute the mainstay of the treatment of differentiated thyroid carcinoma (DTC). In this study, we aimed to evaluate the diagnostic value of postoperative early Tc-99m pertechnetate scanning to detect remnant thyroid tissue and predict ablation success. MethodsDTC patients evaluated with postoperative Tc-99m pertechnetate scintigraphy and treated with RAI between January 2007 and December 2014 were recruited. The results of Tc-99m pertechnetate scanning were compared with therapeutic I-131 whole-body scanning (TxWBS) and diagnostic I-131 whole-body scanning (DxWBS) performed 6–9 months after RAI. ResultsThere were 154 (21.5%) male and 563 (78.5%) female patients, with a mean age of 49.11±12.35 years. Postoperative Tc-99m pertechnetate scanning was positive in 499 patients (69.6%) and negative in 218 (30.4%) patients. There were 673 (93.9%) patients with a positive TxWBS scan and 44 (6.1%) patients with negative TxWBS scan. Considering TxWBS as the standard test, sensitivity, specificity, positive predictive value, and negative predictive value of Tc-99m pertechnetate scanning were 72.2, 70.5, 97.4, and 14.2%, respectively. DxWBS was positive in 57 (9.0%) and negative in 564 (91%) patients. Ablation dose was higher and preablation thyroglobulin was lower in patients with negative DxWBS (P=0.001 and 0.04, respectively). Overall, 171 (92.9%) of 184 patients with negative Tc-99m pertechnetate had negative DxWBS. ConclusionPostoperative Tc-99m pertechnetate scintigraphy has a high positive predictive value to detect remnant tissue in patients with DTC. Although negative Tc-99m pertechnetate scanning does not indicate removal of all thyroid tissue, it is related to successful ablation in more than 90% of patients.

Hot-Clot Artifacts in the Lung Parenchyma on F-18 Fluorodeoxyglucose Positron Emission Tomography/CT due to Faulty Injection Techniques: Two Case Reports

F-18-fluorodeoxyglucose (FDG) positron emission tomography/CT is an important whole-body imaging tool in the oncology and widely utilized to stage and restage various malignancies. The findings of significant focal accumulation of FDG in the lung parenchyma in the absence of corresponding CT abnormalities are related to the lung microembolism and known as hot-clot artifacts. Herein we present two cases with focal FDG uptake in the lung parenchyma with no structural lesions on the CT scan and discuss the possible mechanisms.

Determination of structural femoral head allograft viability and integrity with a novel diagnostic tool: SPECT/CT. A preliminary study

Objective To evaluate the viability and integrity of fresh frozen bulk femoral head allografts obtained from the institutional bone bank that were used to reconstruct severe acetabular defects and to validate the SPECT/CT method which gives both anatomical and functional data for this purpose. Methods We retrospectively reviewed 9 patients (6 female, 3 male; mean age 63.6 years). Preoperative and postoperative leg lengths, existence of the Trendelenburg sign, range of motion of the hip, visual analogue score (VAS), Harris Hip Score (HHS) and any complication were assesed at each follow-up. Radiographically, position of the cup, signs of loosening or migration, and union of the graft were all determined. At the latest follow-up, patients were evaluated with hybrid SPECT/CT. Results The average duration of follow-up was 38.1 months (24-50 months). The overall mean HHS and VAS scores were significantly improved (p<0.05). When hybrid SPECT/CT results were evaluated, the vascular phase of scintigraphy showed hyperaemia of the graft and the bone phase of scintigraphy showed normal or increased radiotracer uptake in the graft site in 7 patients. SPECT/CT images were used to determine the exact localisation of osteoblastic activity. 1 patient with minor resorption of the graft without clinical symptoms revealed mild osteoblastic activity. The patient who had no activity in the graft site was rerevised because of infection. Conclusions Institutional bank allografts are still excellent options for treating large acetabular defects in revision total hip arthroplasty where trabecular metals are not available or in common use. The Hybrid SPECT/CT method is a reliable, noninvasive method for evaluating both the integrity and viability of a bulk graft in 3-D.

A new approach for standardization and increased accuracy of lymph node washout thyroglobulin in patients with differentiated thyroid carcinoma.

High values of fine needle aspiration washout thyroglobulin (FNAB‐Tg) are diagnostic for metastatic lesions of thyroid cancer. However, there is not a consensus on cutoff for high FNAB‐Tg level. In this study, we aimed to determine a more accurate and standardized parameter for FNAB‐Tg.

Incidental FDG uptake in bilateral salpingitis due to Morgagni cyst hydatids on PET/CT scan in a patient with solitary pulmonary nodule

Interesting image Incidental FDG uptake in bilateral salpingitis due to Morgagni cyst hydatids on PET/CT scan in a patient with solitary pulmonary nodule Captación incidental de FDG en salpingitis bilateral debida a quiste hidatídico de Morgagni en PET/TC en una paciente con nódulo pulmonar solitario A 38-year-old woman, gravida 3, para 3, was referred to our clinic because of a regular shaped 18 mm × 10 mm solitary pulmonary nodule (SPN) in the left superior lobe on her thorax CT (Fig. 1A). 18 F-FDG PET/CT (Biograph 64; Siemens, Germany) scan Fig. 1. Transaxial slices of CT and PET images of thorax (A and B) show a mildly increased 18 F-FDG uptake in pulmonary nodule. Maximum intensity projection PET image (C) reveals intense hypermetabolic foci in the pelvic region and they remain in postvoiding delayed pelvic image (D).

Prognostic significance of standardized uptake value on 18fluorine-fluorodeoxyglucose positron emission tomography/computed tomography in patients with nasopharyngeal carcinoma

The aim of this study was to investigate the prognostic significance of standardized uptake value (SUV) on 18 fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma (NPC). Thirty-four patients who have histologically proven NPC and underwent 18F-FDG PET/CT were included in this study. After 18F-FDG PET/CT, all the patients received radiation therapy and 32 of them received concomitant weekly chemotherapy. The maximum SUV (SUVmax) at the primary tumor and the SUVmaxof the highest neck nodes were determined. The SUVmax-T ranged from 5.00 to 30.80 (mean: 15.37 ± 6.10) and there was no difference between SUVmax-T values for early and late stages (P = 0.99). The SUVmax-N ranged from 3.10 to 23.80 (mean: 13.23 ± 5.76). There was no correlation between SUVmax-T and SUVmax-N (r = 0.111, P = 0.532). There was no difference between the SUVmax-T and the positivity of neck lymph nodes (P = 0.169). The ability of SUVmaks-N to predict stage was obtained by a receiver operating characteristic (ROC) analysis. The area under the curve is 0.856 and the best cut-off value is 7.88. There was a good correlation between SUVmax-N and stage. While the mean SUVmax-T for the alive patients was slightly lower than that for the dead (14.65 ± 5.58 vs. 20.30 ± 7.92, P = 0.061), the difference between the groups was not statistically significant. Furthermore, there was no statistically significant difference for SUVmax-N between these two groups (P: 0.494). Cox-regression analysis showed that an increase in SUVmax-T and SUVmax-N was associated with death risk (relative risk [RR]: 1.13, P = 0.078 and RR: 1.052, P = 0.456, respectively). SUVmax-T and SUVmax-N were independent prognostic factors for survival in NPC patients. This will help the clinicians in choosing suitable candidates for more aggressive treatment modalities.

A case of sarcoidosis diagnosed by positron emission tomography/computed tomography

Sarcoidosis is a multisystem granulomatous disorder of unknown cause which may affect any organ or system but primarily involve the lungs and the lymphatic system. Extrapulmonary sarcoidosis represents approximately 30-50% of patients. We report the case of a 51-year-old female who presented with increasing complaints of a cough, weakness, weight loss, and chest pain and who was found to have a suspicious lesion on thorax computed tomography(CT). Fluorodeoxyglucose (FDG) positron emission tomography/CT performed for diagnostic purposes demonstrated increased FDG accumulation at the bilateral enlarged parotid and lacrimal gland and in the reticulonodular infiltration area located in the left lung as well as multiple lymphadenopathies with increased FDG accumulation. There were also hepatosplenomegaly and splenic uptake. Skin biopsy showed noncaseating granulomas, and the patient was diagnosed as stage 2 sarcoidosis.

PET/CT findings in a case with FDG-avid disseminated lacrimal gland MALToma with sequential development of large B-cell lymphoma and gastric MALToma.

Primary orbital lymphomas are rare; the major histopathologic type is extranodal marginal-zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) or MALToma. We present a case of a 79-year-old female patient with FDG-avid lacrimal gland MALToma with nodal and pulmonary involvement (stage IVE). Nasopharynx and gastric involvement were detected on restaging F-FDG PET/CT after rituximab therapy, and it was found to have a site of transformation to diffuse large B-cell lymphoma (DLBCL) in the nasopharynx. Gastric MALT lymphoma was also confirmed histopathologically, and she then underwent combination chemotherapy regimen, resulting in regression after 3 courses.