Hussein Farghaly

F-18 FDG PET/CT characterization of talc pleurodesis-induced pleural changes over time: a retrospective study.

Purpose: The current study characterized pleural changes induced by talc pleurodesis (TP), based on serial positron emission tomography/computer-tomography (PET/CT) with F-18 fluorodeoxyglucose (FDG). Materials and Methods: A total of 8 cancer patients who had both TP and PET/CT and no evidence of active pleural involvement after TP were retrospectively evaluated. Maximum standard uptake values, maximum Hounsfield units (HU), and thickness were followed over time. Results: The 8 patients had 25 PET/CT scans performed in an average of 22 months after TP. An increased FDG uptake was associated with an increase in pleural thickness within 5 months after TP, and both parameters showed statistical significance as compared with findings before TP. After 5 months of TP, the standard uptake value appeared to persist or increase further, and the pleural thickening stabilized. The formation of calcification was a slow process and might lag behind the changes in FDG metabolism and pleural thickness. The HU did not change significantly once pleural calcification had been formed. Conclusions: Knowledge of aforementioned pleural changes may help differentiate TP induced pleural inflammation from pleural malignancy and to avoid false-positive interpretation of FDG PET/CT exams.

Whole-Body 18F-FDG PET/CT: The Need for a Standardized Field of View—A Referring-Physician Aid

PET/CT fusion of anatomic and functional imaging modalities is in evolution, with rapid clinical dissemination. The imaged field of view (FOV) selected for whole-body PET/CT protocols is not standardized and varies by institution. Misuse of the term whole body, as well as the pressure to increase the number of daily studies by reducing scanning time, contributes to the lack of standardization. The purpose of this study was to evaluate variations in the FOV and arm positioning selected for whole-body PET/CT protocols at private, as well as academic, PET centers. Methods: Two hundred consecutive whole-body 18F-FDG PET/CT studies were retrospectively reviewed for FOV: 50 studies from a private stationary site, 50 studies from 2 separate private mobile sites (25 consecutive studies from each), and 100 studies from a stationary university site: 50 before and 50 after implementation of a true whole-body protocol covering the top of the head through the bottom of the feet. Data were categorized into 5 different anatomic scan lengths: base of skull to upper thigh, base of skull to mid thigh, top of head to upper thigh, top of head to mid thigh, and true whole-body. Studies were further categorized into 2 patient arm positions: up and down. Results: The private stationary and mobile sites had only 2 categories of anatomic scan lengths identified: base of skull to mid thigh, and top of head to upper thigh. At the university site, before implementation of a true whole-body protocol, the 5 different anatomic scan lengths were identified; after implementation, only the true whole-body scan length was identified. Patients’ arms in the private stationary sites were down 100% of the time. At the private mobile sites, patients’ arms were up 72% of the time and down 28% of the time. At the university site, patients’ arms were up 54% of the time and down 46% of the time. The same site, after implementation of a true whole-body protocol, had patients’ arms up 58% of the time and down 42% of the time. Overall, patients’ arms were up 46% of the time and down 54% of the time. Conclusion: The continued use of the term whole body is misleading because frequently it may not include the brain, skull, or significant portions of the upper and lower extremities. PET/CT anatomic scan length varied not only from one site to the next but also within individual sites. The Centers for Medicare and Medicaid Services have different current procedural terminology codes distinguishing between base of skull to upper thigh and true whole-body covering the top of the skull to the bottom of the feet, thus underscoring the need to standardize the terminology used in describing PET/CT scan length.

Are there radiographic, metabolic, and prognostic differences between cavitary and noncavitary nonsmall cell lung carcinoma? A retrospective fluorodeoxyglucose positron emission tomography/computed tomography study

Aims: The prognosis of nonsmall cell lung cancer with cavitation (NSCLC-c) is not well-known. We compared the positron emission tomography/computed tomography (PET/CT) findings and survival data of patients with NSCLC-c patients with those without cavitation (NSCLC-nc). Methods: Between 7/2004 and 6/2007, cavitary lung lesions were identified in 46/248 patients undergoing fluorodeoxyglucose (FDG) PET/CT for lung nodule characterization or lung cancer staging. Within the same period, 40 of 202 patients with NSCLC-nc were randomly selected for comparison. The primary was assessed by location, size, cell type, and standardized uptake value (SUV). Disease stage was determined according to American Joint Committee on Cancer guidelines for lung cancer. Kaplan–Meier method was used for survival analysis and Cox regression to assess the effect of clinical and imaging variables on survival. Results: NSCLC-c was found in 87% of patients that had a cavitary lung lesion at PET/CT. Squamous cell carcinoma, primary size and primary-to-liver SUV ratio differed significantly between NSCLC-c and NSCLC-nc, whereas age, gender, primary location, primary SUV, type of treatment, and disease stage did not. Median survival and overall 5-year survival were 19 months and 24% for NSCLC-c, and 31 months and 31% for NSCLC-nc, P = 0.23. Disease stage was the only predictor of survival. Conclusion: Cavitary lung lesions in patients undergoing FDG PET/CT harbor a significant risk for cancer. NSCLC-c is associated with squamous cell carcinoma, larger size, and greater FDG metabolism compared with NSCLC-nc, although these variables may not be predictive of survival. Nonetheless, PET/CT contributes to accurate staging and has an indirect impact on prognosis.

Technetium‑99m dimercaptosuccinic acid scan in evaluation of renal cortical scarring: Is it mandatory to do single photon emission computerized tomography?

Objectives: Renal cortical scintigraphy with technetium-99m (Tc-99m) dimercaptosuccinic acid (DMSA) is the method of choice to detect acute pyelonephritis and cortical scarring. Different acquisition methods have been used: Planar parallel-hole or pinhole collimation and single photon emission tomography (SPECT). This study compared planar parallel-hole cortical scintigraphy and dual-head SPECT for detection of cortical defects. Patients and Methods: We retrospectively reviewed 190 consecutive patients with 380 kidneys and 200 DMSA scans referred to rule out renal cortical scarring. The diagnoses were 52 vesicoureteric reflux, 61 recurrent urinary tract infection, 39 hydronephrosis, 20 renal impairment, and 18 hypertension. All patients were imaged 3 h after injection of Tc-99m DMSA with SPECT and planar imaging (posterior, anterior, left, and right posterior oblique views). For each patient, planar and SPECT images were evaluated at different sittings, in random order. Each kidney was divided into three cortical segments (upper, middle and lower) and was scored as normal or reduced uptake. The linear correlation coefficient for the number of abnormal segments detected between planner and SPECT techniques was calculated. Results: From 200 DMSA scans, 100 scans were positive for scar in SPECT images, from which only 95 scans were positive for scar in planner imaging. Out of the five mismatched scans, three scans were for patients with renal impairment and high background activity and two scans were for very small scars. No significant difference was seen in the average number of abnormal segments detected by planar versus SPECT imaging (P = 0.31). The average correlation coefficient between was high (r = 0.91 - 0.92). Conclusions: Tc-99m DMSA renal cortical scanning using SPECT offers no statistically significant diagnostic advantage over multiple views planar imaging for detection of cortical defect.Objectives: Renal cortical scintigraphy with technetium-99m (Tc-99m) dimercaptosuccinic acid (DMSA) is the method of choice to detect acute pyelonephritis and cortical scarring. Different acquisition methods have been used: Planar parallel-hole or pinhole collimation and single photon emission tomography (SPECT). This study compared planar parallel-hole cortical scintigraphy and dual-head SPECT for detection of cortical defects. Patients and Methods: We retrospectively reviewed 190 consecutive patients with 380 kidneys and 200 DMSA scans referred to rule out renal cortical scarring. The diagnoses were 52 vesicoureteric reflux, 61 recurrent urinary tract infection, 39 hydronephrosis, 20 renal impairment, and 18 hypertension. All patients were imaged 3 h after injection of Tc-99m DMSA with SPECT and planar imaging (posterior, anterior, left, and right posterior oblique views). For each patient, planar and SPECT images were evaluated at different sittings, in random order. Each kidney was divided into three cortical segments (upper, middle and lower) and was scored as normal or reduced uptake. The linear correlation coefficient for the number of abnormal segments detected between planner and SPECT techniques was calculated. Results: From 200 DMSA scans, 100 scans were positive for scar in SPECT images, from which only 95 scans were positive for scar in planner imaging. Out of the five mismatched scans, three scans were for patients with renal impairment and high background activity and two scans were for very small scars. No significant difference was seen in the average number of abnormal segments detected by planar versus SPECT imaging (P = 0.31). The average correlation coefficient between was high (r = 0.91 – 0.92). Conclusions: Tc-99m DMSA renal cortical scanning using SPECT offers no statistically significant diagnostic advantage over multiple views planar imaging for detection of cortical defect.

F-18 fluorodeoxyglucose positron emission tomography and/or computed tomography findings of an unusual breast lymphoma case and concurrent cervical cancer: a case report

IntroductionBreast lymphoma accounts for less than 1% of all non-Hodgkins lymphomas and approximately 0.1% of all breast neoplasms. Most breast lymphomas are classified as diffuse large B-cell lymphomas or as mucosa associated lymphoid tissue lymphomas. Concurrent cases of breast lymphoma and cervical cancer are extremely rare.Case presentationWe report a case of a 46-year-old woman of unknown ethnic origin diagnosed with concurrent diffuse large B-cell lymphoma of the breast and squamous cell cancer of the cervix that was detected and followed with F-18 fluorodeoxyglucose (FDG) positron emission tomography and/or computed tomography (PET/CT). The metastatic pattern of this case of breast lymphoma is similar to that of a typical metastatic breast carcinoma. These findings have never been described in the literature. PET/CT also demonstrated an incidentally intense FDG focus in the uterine cervix ultimately leading to the pathologic diagnosis of squamous cell carcinoma of the uterine cervix. An appropriate staging of breast lymphoma and cervical cancer with FDG PET/CT is important because of therapeutic consequence. This case report and review of the literature highlights the role of FDG PET/CT in staging and restaging of both breast lymphoma and cervical cancer.ConclusionsWe report a case of a breast lymphoma with a metastatic pattern similar to that of typical metastatic breast carcinoma. The FDG PET/CT scan also diagnosed a rare case of concurrent breast lymphoma and cervical cancer. This concurrence has not been reported previously in the medical literature.

Rate of thyroglossal duct remnant visualization after total thyroidectomy for differentiated thyroid carcinoma and its impact on clinical outcome of radioactive iodine (I-131) ablation.

Objectives: The rate and impact of thyroglossal duct remnant (TGDR) visualization in patients with hypothyroidism after total thyroidectomy for differentiated thyroid carcinoma (DTC) have not yet been fully determined. The aim of this study was to assess the rate of TGDR visualization in post total thyroidectomy whole body scan (WBS) for DTC and to evaluate its impact on the outcome of I-131 ablation. Methods: A total of 60 consecutive DTC patients (51 papillary thyroid Ca., and 9 Follicular thyroid Ca.), underwent total thyroidectomy, followed by WBS (using I-131 in 28 patients and I-123 in 32 patients), neck ultrasound (US), thyroglobulin (Tg) and Tg anti-bodies (TgAb) assay after 40 days and subsequent I-131 ablation. At 6 months later follow-up I-131 WBS, neck U/S, Tg and TgAb were performed following suspension of L-thyroxine for 1-month (thyroid stimulating hormone [TSH] >30 μIU/ml) in 53 patients and following recombinant human TSH stimulation in seven patients. Results: Of the studied 60 patients, 19/60 (31.7%) had a linear or focal radioactivity at the superior midline of the neck, suggesting TGDR (Group 1), and 41/60 (68.3%) had no uptake to suggest TGDR (Group 2). No significant difference regarding age, gender and histopathology between both groups. Neck US showed no evidence of thyroid tissue in the superior midline of the neck in both groups, and only a small or no residual thyroid tissue in patients of Group 1. There was a significant successful I-131 ablation rate among patients of group 1 compared to group 2 (79% in Group 1 vs. 41.5% in Group 2) (P = 0.007). Conclusions: Thyroglossal duct remnant visualization on WBS of hypothyroid subjects after total thyroidectomy suggests presence of only a small or no residual functioning thyroid tissue at the thyroid bed and can predict a good response to I-131 ablation.