Is True Whole-Body 18F-FDG PET/CT Required in Pediatric Lymphoma? An IAEA Multicenter Prospective Study

Guidelines recommend true whole-body ¹⁸F-FDG PET/CT scans from vertex to toes in pediatric lymphoma patients, although this suggestion has not been validated in large clinical trials. The objective of the study was to evaluate the incidence and clinical impact of lesions outside the "eyes to thighs" regular field of view (R-FOV) in ¹⁸F-FDG PET/CT staging (sPET) and interim (iPET) scans in pediatric lymphoma patients. Methods: True whole-body sPET and iPET scans were prospectively obtained in pediatric lymphoma patients (11 worldwide centers). Expert panel central review of sPET and iPET scans were evaluated for lymphoma lesions outside the R-FOV and clinical relevance of these findings. Results: A total of 610 scans were obtained in 305 patients. The sPET scans did not show lesions outside the R-FOV in 91.8% of the patients, whereas in 8.2% patients the sPET scans demonstrated lesions also outside the R-FOV (soft tissue, bone, bone marrow, and skin); however, the presence of these lesions did not change the clinical stage of any patient and did not affect treatment decision. Among the 305 iPET scans, there were no new positive ¹⁸F-FDG-avid lesions outside the R-FOV, when compared with their paired sPET scans. A single lesion outside the R-FOV on iPET occurred in 1 patient (0.3%), with the primary lesion diagnosed in the femur on sPET that persisted on iPET. Conclusion: The identification of additional lesions outside the R-FOV (eyes to thighs) using ¹⁸F-FDG PET/CT has no impact in the definition of the clinical stage of disease and minimal impact in the treatment definition of patients with pediatric lymphoma. As so, R-FOV for both sPET and iPET scans could be performed.

The Role of SPECT/CT Lymphoscintigraphy and Radioguided Sentinel Lymph Node Biopsy in Managing Papillary Thyroid Cancer

IMPORTANCE

Single-photon emission computed tomography/computed tomography (SPECT/CT) and radioguided sentinel lymph node biopsy (rSLNB) are techniques that could potentially benefit surgeons and pathologists in the identification of sentinel lymph node (SLN) metastases in patients with papillary thyroid carcinoma (PTC). Evidence suggests that these novel techniques lead to substantial changes in PTC management by reducing understaging and of occult lymph node (LN) metastases and optimizing neck surgery by increasing the necessity of lateral lymphadenectomy and decreasing central lymphadenectomy.

OBJECTIVES

To correlate the presence of LN metastases in PTC with clinical and pathological features using SPECT/CT and rSLNB.

DESIGN, SETTING, AND PARTICIPANTS

For this prospective cohort study from June 2010 to November 2013, 42 patients with thyroid nodules suspicious for papillary carcinoma or classified as malignant on cytology examination without suspicion of lymph node metastases by clinical and ultrasound examinations were recruited from a single public medical institution.

INTERVENTIONS

All 42 patients underwent preoperative lymphoscintigraphy after an ultrasound-guided peritumoral injection of Technetium Tc 99m nanocolloid. Cervical images were acquired with a SPECT/CT scanner 15 minutes after radiotracer injection. Approximately 2 hours after lymphoscintigraphy, the patients were submitted to intraoperative rSLNB using a handheld gamma probe. All SLNs identified were removed alongside with non-SLNs from the same compartment. Papillary thyroid carcinoma, SLNs and non-SLNs were submitted for histopathology and immunohistochemical analyses.

RESULTS

Of the 42 patients initially enrolled, 37 were included in analysis, including 6 men and 31 women with a mean (range) age of 47 (22-83) years. Overall, T stage was as follows: T1, 23 patients (62.2%); T2, 8 patients (21.6%); and T3, 6 patients (16.2%). Sentinel lymph nodes were identified in 92% of the patients, and among these metastases were present in 17 patients (46%). The SLNs were false-negative in 3 patients. Metastases in the lateral compartment ocurred in 7 patients (18%). There was a significant association between LN metastases and tumor size (odds ratio, 1.06; 95% CI, 1.00-1.13; P = .02), with a Cohen d effect of 0.683 (medium to large effect). Overall, 17 patients (46%) with LN metastases had management changed because they were submitted to higher radioiodine ablation doses and closer clinical surveillance.

CONCLUSIONS AND RELEVANCE

Radioguided SLNB is able to detect occult cervical lymph node metastases in patients with papillary thyroid carcinoma, and in 7 patients (18%) rSLNB detected lymph node metastases in the lateral compartments. The rSLNB technique lead to management change in 14 patients (37.8%).

Assessing the role of ¹⁸F-FDG PET and ¹⁸F-FDG PET/CT in the diagnosis of soft tissue musculoskeletal malignancies: a systematic review and meta-analysis

PURPOSE

Twelve years ago a meta-analysis evaluated the diagnostic performance of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in assessing musculoskeletal soft tissue lesions (MsSTL). Currently, PET/CT has substituted PET imaging; however, there has not been any published meta-analysis on the use of PET/CT or a comparison of PET/CT with PET in the diagnosis of MsSTL. Therefore, we conducted a meta-analysis to identify the current diagnostic performance of (18)F-FDG PET/CT and determine if there is added value when compared to PET.

METHODS

A systematic review of English articles was conducted, and MEDLINE PubMed, the Cochrane Library, and Embase were searched from 1996 to March 2015. Studies exploring the diagnostic accuracy of (18)F-FDG PET/CT (or dedicated PET) compared to histopathology in patients with MsSTL undergoing investigation for malignancy were included.

RESULTS

Our meta-analysis included 14 articles composed of 755 patients with 757 soft tissue lesions. There were 451 (60 %) malignant tumors and 306 benign lesions. The (18)F-FDG PET/CT (and dedicated PET) mean sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for diagnosing MsSTL were 0.96 (0.90, 1.00), 0.77 (0.67, 0.86), 0.88 (0.85, 0.91), 0.86 (0.78, 0.94), and 0.91 (0.83, 0.99), respectively. The posterior mean (95 % highest posterior density interval) for the AUC was 0.92 (0.88, 0.96). PET/CT had higher specificity, accuracy, and positive predictive value when compared to a dedicated PET (0.85, 0.89, and 0.91 vs 0.71, 0.85, and 0.82, respectively).

CONCLUSION

(18)F-FDG PET/CT and dedicated PET are both highly accurate in the diagnosis of MsSTL. PET/CT is more accurate and specific and has a higher positive predictive value than PET.

Factors affecting (223)Ra therapy: clinical experience after 532 cycles from a single institution

PURPOSE

The aim of this study was to identify baseline features that predict outcome in (223)Ra therapy.

METHODS

We retrospectively reviewed 110 patients with metastatic castration-resistant prostate cancer treated with (223)Ra. End points were overall survival (OS), progression-free survival (PFS), bone event-free survival (BeFS), and bone marrow failure (BMF). The following parameters were evaluated prior to the first (223)Ra cycle: serum levels of hemoglobin (Hb), prostate-specific antigen (PSA), alkaline phosphatase (ALP), Eastern Cooperative Oncology Group (ECOG) status, pain score, use of chemotherapy, and external beam radiation therapy (EBRT). During/after (223)Ra we evaluated: the total number of radium cycles (RaTot), the PSA doubling time (PSADT), and the use of chemotherapy, EBRT, abiraterone, and enzalutamide.

RESULTS

A significant reduction of ALP (p < 0.001) and pain score (p = 0.041) occurred throughout the (223) Ra cycles. The risk of progression was associated with declining ECOG status [hazard ratio (HR) = 3.79; p < 0.001] and decrease in PSADT (HR = 8.22; p < 0.001). RaTot, ALP, initial ECOG status, initial pain score, and use of abiraterone were associated with OS (p ≤ 0.008), PFS (p ≤ 0.003), and BeFS (p ≤ 0.020). RaTot, ALP, initial ECOG status, and initial pain score were significantly associated with BMF (p ≤ 0.001) as well as Hb (p < 0.001) and EBRT (p = 0.009). On multivariable analysis, only RaTot and abiraterone remained significantly associated with OS (p < 0.001; p = 0.033, respectively), PFS (p < 0.001; p = 0.041, respectively), and BeFS (p < 0.001; p = 0.019, respectively). Additionally, RaTot (p = 0.027) and EBRT (p = 0.013) remained significantly associated with BMF.

CONCLUSION

Concomitant use of abiraterone and (223)Ra seems to have a beneficial effect, while the EBRT may increase the risk of BMF.

Determination of Skeletal Tumor Burden on 18F-Fluoride PET/CT

The purpose of this study was to define a method to assess skeletal tumor burden with 18F-labeled sodium fluoride PET/CT (18F-fluoride PET/CT) and evaluate the reproducibility of these measurements.

METHODS

Ninety-eight consecutive patients (90 men; mean age±SD, 65.7±14.2 y) underwent 158 18F-fluoride PET/CT scans for evaluation of skeletal metastatic disease. In order to determine the mean normal bone SUV, initially a 1-cm spheric volume of interest (VOI) was placed over 5 bone sites: T12, L5, sacrum, right iliac bone, and right femur. For each patient, the mean SUVmax for all sites was generated. Afterward, a threshold value of normal bone uptake was established. Subsequently, skeletal tumor burden was determined by generating volumetric data using a whole-body segmentation method. Any SUVmax below the normal threshold was excluded from analysis, as were VOIs not related to metastatic disease. Statistics for the remaining VOIs were then generated and defined as the skeletal metastatic tumor burden by 2 parameters: total lesion fluoride uptake above an SUVmax of 10 (TLF10) and fluoride tumor volume above an SUVmax of 10 (FTV10). TLF10 and FTV10 reproducibility was determined using 2 independent and experienced PET/CT interpreters analyzing a subset of 13 18F-fluoride PET/CT scans.

RESULTS

Mean (±SD) normal bone SUVmax was 6.62±1.55 for T12, 6.11±1.73 for L5, 4.59±1.74 for sacrum, 5.39±1.72 for right iliac bone, and 3.90±1.57 for right femur. The mean normal SUVmax for all 543 sites was 5.32±0.99. On the basis of these values, an SUVmax threshold of 10 was chosen to exclude normal bone from the volumetric calculations. Semiautomated measurements of TLF10 and FTV10 exhibited high interobserver reproducibility, within ±0.77% and ±3.62% of the interinterpreter average for TLF10 and FTV10, respectively.

CONCLUSION

Determination of skeletal tumor burden with 18F-fluoride PET/CT is feasible and highly reproducible. Using an SUVmax threshold of 10 excludes nearly all normal bone activity from volumetric calculations.

[Effects of cisapride and chest physical therapy on the gastroesophageal reflux of wheezing babies based on scintigraphy]

OBJECTIVE: To evaluate the effect of cisapride and chest physical therapy on the gastroesophageal reflux of wheezing babies. METHODS: We prospectively assessed the presence of technetium ((99)Tc) in the upper, middle, and lower esophagus of 25 wheezing babies (13 with GERD and 12 without GERD) using scintigraphy. Both groups underwent clinical investigation, including laboratory, X-ray and scintigraphy tests, for the etiology of the wheezing baby syndrome (WBS) and GERD. Expiratory Flow Acceleration (EFA) was performed before and after treatment with cisapride. The total time of GER episodes was accounted for each portion of the esophagus during scintigraphy and during EFA. RESULTS: Cisapride significantly reduced the total reflux time in the upper esophagus (P<0.05), but showed no influence during EFA. After cisapride therapy, EFA increased the total reflux time in the upper and medium esophagus; however, no statistical significance was found. Infants with GERD presented a shorter total reflux time in the distal esophagus (P<0.05) during EFA. After cisapride treatment, no statistical significance was found. Infants without GERD also presented reduced total reflux time in the distal esophagus during EFA (P<0.05). Those with GERD had increased total reflux time in the distal esophagus (P<0.05) before and after cisapride treatment during EFA and scintigraphy. CONCLUSIONS: Cisapride was effective in reducing the total reflux time, mainly in the upper esophagus. EFA apparently increased the number of episodes of GER, without achieving statistical significance. Further studies are necessary to investigate the effects of chest physical therapy according to body positions.

Brain single-photon emission computed tomography and magnetic resonance imaging in Machado-Joseph disease

BACKGROUND

Machado-Joseph disease (MJD) is one of the most frequently encountered spinocerebellar ataxias. However, few reports on brain single-photon emission computed tomographic (SPECT) imaging (BSI) with hexylmethylpropylene amineoxine labled with technetium Tc 99m and magnetic resonance imaging (MRI) have been performed for the evaluation of patients with MJD.

OBJECTIVES

To investigate possible abnormalities with BSI and MRI in patients with MJD and to correlate these findings with the duration of symptoms; cerebellar, extrapyramidal, and pyramidal syndromes; and the molecular characteristics of the MJD mutation.

PATIENTS AND METHODS

Twelve patients (8 males and 4 females [mean age, 39 years]) with genetically proven MJD were studied. The patients underwent BSI and MRI on the same day. Brain SPECT imaging was performed after an intravenous injection of 99mTc-hexylmethylpropylene amineoxine. The transaxial, coronal, and sagittal BSIs obtained were submitted to visual and semiquantitative analyses. Magnetic resonance imaging was obtained in a 2-T system with coronal, sagittal, transaxial, and 3-dimensional (volumetric) acquisitions. The volumes of the cerebellar hemispheres and vermis were calculated. Control groups for BSI (22 female and 20 male subjects [mean age, 33 years]) and MRI (13 female and 4 male subjects [mean age, 32.2 years]) were included for comparison.

RESULTS

Correlation was observed between the perfusion abnormalities identified by visual analysis in the BSI with the structural abnormalities observed on MRI in the parietal lobes and vermis. Brain SPECT imaging identified (by visual analysis) more perfusion abnormalities in the inferior portion of the frontal lobes, mesial and lateral portions of the temporal lobes, basal ganglia, and cerebellar hemispheres. Magnetic resonance imaging identified more abnormalities in the pons and superior portions of the frontal lobes. Olivary atrophy was identified by MRI. Semiquantitative analysis showed a statistically significant difference of perfusion in the inferior and superior portions of the frontal lobes, lateral portion of the temporal lobes, parietal lobes, left basal ganglia, cerebellar hemispheres, and vermis when compared with the control group. A significant difference was noted between the vermis and cerebellar volumes on MRI when compared with the control group. A significant relationship was observed between the perfusion of the left parietal lobe (P =.05) and extrapyramidal syndrome. There was a tendency toward an inverse relationship between the duration of symptoms and the perfusion of the cerebellar hemispheres (rho = -0.37; P =.24) and volume of the vermis (rho = -0.30; P =.34); between the length of the expanded (CAG)n repeat and the perfusion of the left parietal lobe (rho = -0.32; P =.36), vermis (rho = -0.28; P =.43), and pons (rho = -0.28; P =.42). A direct association was observed between the length of the expanded (CAG)n repeat and the perfusion of the lateral portion of the right temporal lobe (rho = 0.67; P =.03).

CONCLUSIONS

Brain SPECT imaging and MRI were capable of identifying subclinical abnormalities in individuals with MJD. These findings may be helpful for a better understanding of the pathophysiology of this disease.

Activation of the growth plates on three-phase bone scintigraphy: the explanation for the overgrowth of fractured femurs

Children with an uncomplicated femoral fracture, treated with superimposition of fragments and intentional shortening, usually develop overgrowth of the fractured femur and the ipsilateral tibia which may compensate for the initial shortening and enable the limb in question to reach a length similar to that on the normal side. The overgrowth is evaluated clinically and by scanography. The increased metabolic activity of the growth plates that support this overgrowth has not been documented by any laboratory method. In order to evaluate the metabolic activity of the growth plates, 18 patients (11 males, seven females; mean age 6.1 years) with fractures of the femur were studied at three different time intervals (2-5 months, 6-12 months and 18-24 months). Three-phase bone scintigraphy was performed in all patients. Ten children (five males, five females; mean age 7.5 years) who had had bone imaging for other reasons were used as the control group. Visual analysis of the flow and equilibrium phases was performed for the distal femoral and proximal tibial growth plates. Visual and semi-quantitative analyses of the delayed images were performed for the distal femoral and proximal and distal tibial growth plates. Semi-quantitative analyses yielded the following activity ratios: (a) the distal femoral growth plate of the fractured femur to the contralateral one (FR); (b) the proximal growth plate of the tibia on the side of the fractured femur to the contralateral one (TpR); (c) the distal growth plate of the tibia on the side of the fractured femur to the contralateral one (TdR); and (d) in the control group, the distal growth plates of both femora (FCG) and the proximal (TCGp) and distal (TCGd) growth plates of the tibiae. Visual analysis of the blood flow, equilibrium and delayed images showed increased activity in the distal femoral growth plates during the first and second time intervals, but not during the third. No significant activity changes were found in the proximal and distal tibial growth plates during any of the phases analysed. The mean and standard deviation for FR in the three time intervals were: FRI=1.22+/-0.27, FRII=1.17+/-0.16 and FRIII=1.09+/-0.20. FR values were significantly higher than in the control group (FCG=0.99+/-0.03) (P=0.033). The mean and standard deviation for TpR in the three time intervals were: TpRI=1.08+/-0.18, TpRII=0.94+/-0.09 and TpRIII=0.96+/-0.20. TpR values were not significantly different from those in the control group (TCGp=1.00+/-0.05). However, TpRI was significantly higher than TpRII (P=0.043). The mean and standard deviation for TdR in the three time intervals were: TdRI=1.10+/-0.41, TdRII=1.05+/-0.15 and TdRIII=1.13+/-0.36. TdR values were not significantly higher than in the control group (TCGd=1.00+/-0.04) (P=0.777). These results support the concept that three-phase bone imaging is able to quantify and determine that activation occurs in the distal femoral and proximal tibial growth plates of fractured femora. This phenomenon may explain the overgrowth observed in this injured bone structure.

Gallium-67 imaging in a patient with paracoccidioidomycosis: a case report

A 26 year-old female was admitted with abdominal pain, fever and weight loss. The clinical and laboratory investigations led to the diagnosis of paracoccidioidomycosis. Gallium-67 whole body images correlated well with the clinical course of the disease and with the patient's prognosis.

Detection of synchronous carcinomas of the colon with F-18 fluorodeoxyglucose: a case report

Colon and rectal carcinomas are common in North America and Northwestern Europe. In South America, the risk of this disease is not as great. Adenocarcinomas are the most common types of tumors, and they occur mainly in the descending colon, sigmoid, and rectum. A patient with a possible right colon carcinoma was examined using F-18 FDG.

Thyroid suppression test with L-thyroxine and [99mTc] pertechnetate

OBJECTIVE

The thyroid suppression test is still used in some centres as an adjunt in the diagnosis of autonomous functioning thyroid nodules. With the purpose of minimizing the disadvantages of the original T3 suppression test, we have evaluated the efficacy of a method using L-thyroxine as TSH suppression agent and [99 mTc] pertechnetate as radiopharmaceutical.

DESIGN

Open nonrandomized prospective study

MATERIALS AND METHODS

A control group of 15 normal volunteers (11 males, 4 females; 21-35 years, mean 26.4 years) and a patient group of 20 patients (18 females, 2 males; 27-83 years, mean 53.6 years) divided into 4 subgroups, were studied: 7 patients with autonomous functioning nontoxic nodules, 3 with autonomous functioning toxic nodules, 7 with Graves disease and 3 with nonautoimmune diffuse toxic goitre. Baseline thyroid uptake and imaging were begun 20 minutes after an intravenous injection of 370 MBq (10 mCi) of [99 mTc] pertechnetate. This was followed by a single daily intake of 2 microg/kg of L-thyroxine, for 10 days. Thyroid imaging and uptake were then repeated.

RESULTS

In the control group [99 mTc] pertechnetate uptake after L-thyroxine suppression had a mean reduction of 75.8 +/- 7.69% (58-87%) in comparison to the baseline level. All subjects were euthyroid by clinical and laboratory criteria and none complained of side-effects, despite significant suppression of TSH levels. In the patient group, thyroid uptake after suppression decreased in 10 patients (maximum reduction 39%), was unchanged in 2 patients and increased in the remaining 8 patients.

CONCLUSION

The method described was efficient for demonstration of autonomous thyroid tissue, since none of the patients showed significant reduction of thyroid uptake after L-thyroxine suppression compared with the control group. This test was as effective as the original T3 suppression test, but more convenient to the patient: no side-effects, ease of hormonal intake, low dosimetry and short stay in the nuclear medicine laboratory.

Cerebrovascular disease in newborn infants. Report of three cases with clinical follow-up and brain SPECT imaging

The clinical and neurological findings of three neonates with the diagnosis of cerebrovascular disease are reported. The neuropsychological evaluation disclosed impairment of fine motor function, coordination, language, perception and behavioral disturbances. Brain SPECT imaging revealed perfusional deficits in the three cases.

Brain SPECT imaging in Huntington's disease before and after therapy with olanzapine. Case report

Olanzapine, an atypical antipsychotic drug, was administered to a patient with Huntington's disease (HD) with marked choreiform movements. Brain SPECT with 99mTc-HMPAO was performed before and after treatment. Brain SPECT imaging has been performed in patients with HD in order to determine the status of basal ganglia perfusion. The use of brain SPECT with 99mTc-HMPAO before and after treatment in patients with HD has not been yet reported. The marked hypoperfusion of the basal ganglia on brain SPECT performed before therapy with olanzapine improved significantly after treatment.

Orthopedic pathology of the lower extremities: scintigraphic evaluation in the thigh, knee, and leg

Radionuclide imaging (RI) of the osseous and nonosseous structures of the thigh, knee, and leg provide important diagnostic and prognostic information upon which the orthopedic surgeon can base treatment planning and management decisions. 99mTc-MDP scintigraphy is essential in overuse injuries such as stress fractures and shin splints. RI is important in assessing complications of trauma. It is the only imaging modality able to assess the magnitude of physeal stimulus caused by femoral fractures and to predict a favorable or unfavorable outcome of leg length by semiquantitative analysis; SPECT imaging can detect and locate decreased metabolism associated with posttraumatic closure of the physeal plate to predict growth arrest and deformities. Three-phase bone imaging (TPBI) is essential to differentiate hypervascular from avascular nonunions and follow delayed union. In osteonecrosis of the knee, bone scintigraphy precedes radiography changes even in stage l of the disease. 99mTc-MDP and 99mTc-HIG imaging are powerful tools in determining the outcomes of osteoarthritis and rheumatoid arthritis, respectively. Bone scintigraphy can also detect chronic ligament and acute and chronic meniscal lesions. The combined use of TPBI, gallium-67 citrate imaging, and indium-111 or 99mTc-HMPAO labeled leukocytes is important to diagnose and differentiate acute from chronic osteomyelitis, and to detect infected knee prostheses. Thallium-201 chloride imaging and 99mTc-sestamibi imaging have an important role in the assessment of tumor response to chemotherapy and in the quantification of tumor viability.