Diffusely increased F-18 FDG uptake in bone marrow in a patient with acute anemia and recent erythropoietin therapy

Correlations between glucose metabolism of bone marrow on 18 F-fluoro-D-glucose PET/computed tomography and hematopoietic cell populations in autoimmune diseases

PURPOSE

This study aims to investigate which hematopoieticcell populations, clinical factors, and laboratory values are associated with FDG uptake in bone marrow (BM) on FDG PET/CT in patients with autoimmune diseases.

METHODS

Forty-six patients with autoimmune disease who underwent FDG PET/CT and BM aspiration (BMA) between 2017 and 2022 were enrolled. The max and mean standard uptake values (SUVmax and SUVmean, SUVs) of FDG in BM, liver, and spleen were measured, and the bone marrow-to-liver SUVs ratios (BLRmax and BLRmean, BLRs) and spleen-to-liver SUVs ratios (SLRmax and SLRmean, SLRs) were calculated. BMA and clinical and laboratory parameters were collected and evaluated for association with BLRs and SLRs.

RESULTS

The patients were divided into the Grade II group (20; 43.5%) and Grade III groups (26; 56.5%) according to hemopoietic activity. The BLRmax ( P = 0.021), proportion of granulocytes ( P = 0.011), metamyelocytes ( P = 0.009), myelocytes ( P = 0.024), and monocytes ( P = 0.037) in BM were significantly higher in the Grade II group. Multivariate (stepwise) linear regression analyses showed that the proportion of granulocytes in BM was the strongest and only independent factor ( P < 0.0001) associated with BLRmax with an adjusted R2 of 0.431 in model 1. In model 2, ferritin ( P = 0.018), CRP ( P = 0.025), and the proportion of metamyelocytes ( P = 0.043) in BM were correlated with BLRmax with an adjusted R2 of 0.414.

CONCLUSION

The FDG uptake in BM is associated with hemopoietic activity and is regulated by hyperplastic granulocytes, particularly immature metamyelocytes, in patients with autoimmune diseases. Glucose metabolism in the BM correlates with the severity of systemic inflammation.

The value of the SUV ratio between lymph node and bone marrow in predicting pelvic lymphatic metastasis of patients with locally advanced cervical cancer: an integrated PET/CT study

PURPOSE

This study aimed to evaluate the value of the standardized uptake value (SUV) ratio between lymph nodes and bone marrow (BM) measured by Fluorine-18-fluorodeoxyglucose PET and computed tomography ( 18 F-FDG PET/CT) for predicting pelvic lymph node (PLN) metastasis in patients with locally advanced cervical cancer (LACC).

MATERIALS AND METHODS

A total of 62 patients with pathological stage Ib-IVa cervical cancer who underwent 18 F-FDG PET/CT before treatment were reviewed retrospectively. We measured the metabolic and morphological parameters of lymph nodes and primary tumors, bone marrow SUV (SUVBM) and calculated the ratio of lymph nodes maximum SUV (SUVmax) to bone marrow SUV (SUVLN/BM) and the ratio of short-axis diameter to long-axis diameter (Ds/l) of lymph nodes. A receiver operating characteristic (ROC) curve was performed to evaluate the diagnostic efficacy of each parameter.

RESULTS

There were 180 lymph nodes with pathological evidence included in the study. Our results indicated that Ds/l, SUVmax of lymph nodes (SUVLN) and SUVLN/BM were independent risk factors for PLN metastasis in LACC ( P  < 0.05), and SUVLN/BM showed the best diagnostic performance by ROC curve analysis. The SUVBM in the anemia group was significantly higher than that in the nonanemia group (3.05 vs. 2.40, P  < 0.05); furthermore, false-positive cases decreased when the SUVLN/BM was used as the diagnostic criterion instead of SUVLN, especially in the anemia group. ROC curve analysis showed that the area under the curve value of the combination of SUVLN/BM and Ds/l was 0.884 ( P  < 0.05), which was higher than Ds/l or SUVLN/BM alone.

CONCLUSIONS

SUVLN/BM could improve the ability to predicting PLN metastasis in patients with LACC, and the diagnostic efficacy of the combination of SUVLN/BM and Ds/l might be better than that of a single parameter.

Prognostic Value of Bone Marrow FDG Uptake Pattern of PET/CT in Newly Diagnosed Diffuse Large B-cell Lymphoma

Purpose: The value of ¹⁸F-fluorodeoxyglucose positron emission tomography /computed tomography (¹⁸F-FDG PET/CT) in assessing bone marrow involvement (BMI) of lymphoma remains controversial. The present study aims to evaluate the prognostic meaning of bone marrow FDG uptake pattern in PET/CT of newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients.

Materials and Methods: 193 newly diagnosed DLBCL patients were retrospectively analyzed. All patients received 6-8 cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP). The type of BM FDG uptake pattern was recorded by two blinded reviewers independently. The relationship between clinicopathologic features and BM patterns was analyzed. The prognostic value of different BM patterns was evaluated by Log-rank test and Cox-regression analysis.

Results: Out of 193 patients, 28 (15%) patients had focal BM FDG uptake higher than liver (fPET+), 18 (9%) patients showed diffuse BM uptake higher than liver (dPET+) and 147 (76%) patients had normal BM uptake (lower than liver) (nPET). BMB positive was found in 35.7% (10/28) of fPET+ patients, in 16.7% (3/18) of dPET+ patients and in 0.7% (1/147) of nPET patients. Diffuse BM pattern was associated with lower hemoglobin level and a trend of higher erythrocyte sedimentation rate (ESR). dPET+ patients had similar 3y-progression-free survival (3y-PFS) and 3y-overall survival (3y-OS) compared with nPET patients (80.5% vs 81.5%, p=0.701; 94.1% vs 90.6%, p=0.809, respectively), while fPET+ patients had worse 3y-PFS and 3y-OS compared with fPET- patients (32.7% vs 81.4%, p<0.001; 69.4% vs 90.9%, p=0.003, respectively). Multivariate analysis showed fPET+ (HR=2.270, p=0.025) and stage III/IV (HR=4.909, p=0.026) were independent predictors for PFS, but no factors were independently predictive for OS.

Conclusion: PET/CT-directed BM patterns are meaningful in predicting prognosis of newly diagnosed DLBCL patients. Focal BM pattern is an independent predictor for PFS.

Is There Any Potential of FDG PET/CT in Monitoring Disease Activity in Familial Hemophagocytic Lymphohistiocytosis?

FDG PET/CT was performed in a 30-year-old woman to detect the source of fever of unknown origin. The images showed widespread abnormal activity, consistent with lymphoma. However, lymph node biopsy revealed only inflammation, and a diagnosis of familial hemophagocytic lymphohistiocytosis was eventually made after familial hemophagocytic lymphohistiocytosis-specific gene was detected. After proper therapy, a follow-up FDG PET/CT examination 2 months later showed resolution of most of the previously seen lesions.

18F-FDG PET/CT findings in a patient with Sweet syndrome associated with myelodysplastic syndrome

A 73-year-old man was admitted to our hospital because of a 2-year history of repeated painful edematous erythemas on the skin and pancytopenia for the last 8 months. FDG PET/CT demonstrated multiple cutaneous foci with increased tracer accumulation throughout the body, multiple FDG-avid lymph nodes in the mediastinum, bilateral pulmonary hili and abdomen, and diffusively increased FDG uptake of bone marrow. A skin biopsy revealed infiltration by neutrophilic granulocytes consistent with Sweet syndrome. Myelodysplastic syndrome was established on bone marrow aspiration and biopsy.

Effect of erythropoietin on bone marrow uptake of 18F-fluorocholine in prostate cancer: comparison with 18F-fluoride uptake

The effect of erythropoietin stimulation on bone marrow uptake of FDG has been well documented. Similar metabolic activation of bone marrow with (18)F-fluorocholine (FCH) has not been previously reported. FCH PET/CT was performed in a patient with biochemical recurrent prostate cancer who was receiving erythropoietin for hemochromatosis. Diffuse skeletal uptake of FCH was seen. (18)F-Fluoride PET/CT performed the following day demonstrates multiple abnormal focal bone metastases. Generalized skeletal uptake of FCH results in poor contrast between the metastases compared to noninvolved bone. The metabolic activation of bone marrow by erythropoietin could result in false-negative FCH results for detecting bone metastases.

Altered biodistribution on FDG-PET with emphasis on brown fat and insulin effect

(18)F-fluorodeoxyglucose (FDG) is the radiotracer used in the vast majority of positron emission tomography (PET) cancer studies. FDG is a powerful radiotracer that provides valuable data in many cancer types. Normal FDG biodistribution is easily identified. In the PET-only era, physiological uptake provided important anatomical landmarks. However, the normal biodistribution of FDG is often variable and can be altered by intrinsic or iatrogenic factors. Recognizing these patterns of altered biodistribution is important for optimal FDG-PET interpretation. Altered FDG uptake in muscles, brown adipose tissue, bone marrow, the urinary tract, and the bowel is demonstrated in a significant proportion of patients, which can hide underlying malignant foci or mimic malignant lesions. The introduction of PET/computed tomography revolutionized PET imaging, bringing much-needed anatomical information. This modality allowed better characterization of some types of uptake, particularly brown adipose tissue FDG uptake. Different approaches to minimize interference from altered FDG biodistribution should be considered when performing PET scans. Otherwise, careful review and correlation of metabolic (FDG-PET) and anatomical (computed tomography) data should be performed to accurately characterize the foci of increased FDG uptake.

A bone marrow F-18 FDG uptake exceeding the liver uptake may indicate bone marrow hyperactivity

OBJECTIVE

In clinical positron emission tomography (PET) studies for oncology, it is occasionally required to differentiate a diffuse increase in bone marrow (BM) F-18 fluoro-2-deoxyglucose (FDG) uptake due to the involvement of malignancy or hematopoietic disease and that due to the administration of hematopoietic cytokines, an inflammation reaction, or stimulation by some types of malignancy. The objectives of this study were to clarify the relationships between BM F-18 FDG uptake and blood parameters as well as age, and also to determine the degree of F-18 FDG accumulation that constitutes an abnormal level referring to blood parameters.

METHODS

Records of 65 patients, 32 with benign diseases and 33 with malignancies without metastasis in bone and liver until a half year after the PET examination, were analyzed retrospectively. Regions of interest were placed on the liver and the lower thoracic and lumbar vertebrae to measure the standardized uptake value (SUV), and vertebral SUVs were averaged as the BM SUV(mean). The BM SUV(mean) was divided by the liver SUV to calculate the BM/liver ratio. The relationships among the BM SUV(mean), or BM/liver ratio, and blood parameters and age were tested using multiple regression analysis.

RESULTS

In both patients with and without malignancy, a multiple regression model using the BM/liver ratio showed a higher coefficient of determination value than that using the BM SUV(mean), indicating that the correction by the liver SUV reduced the interindividual variation in the BM SUV(mean). The BM/liver ratio was negatively correlated with age (beta = -0.41 and -0.43, respectively) and positively correlated with serum C-reactive protein (CRP) level (beta = 0.39 and 0.46, respectively) in both groups of patients. Every patient with benign disease who had a ratio greater than or equal to 1 had an increased CRP level.

CONCLUSIONS

The BM F-18 FDG uptake depends on the patient's age and serum CRP level, both with and without malignancy. A BM F-18 FDG uptake greater than or equal to that of the liver may indicate BM activation.

[Potential sources of diagnostic pitfall and variants in FDG-PET/CT]

Oncological FDG PET show variants and findings that may lead to a diagnostic error and that may be clarified by the morfofunctional imaging from PET/CT. In this article we show the experience acquired since a Siemens PET/CT Biograph LSO Pico3D was applied in our centre. We describe some representative examples of FDG distribution patterns which may lead to erroneous interpretations of the clinical studies when they refer to specific clinical situations. The examples included are classified into two main groups according to the cause: Technical and biological, and the latter into physiological and non-physiological (pathophysiological). Patterns are described within the biological group showing changes of the FDG biodistribution that may reduce the uptake in tumoural lesions, the physiological variants that may be interpreted as pathology, the effects of previous treatment and uptakes related to benign diseases.

CONCLUSION

We consider that knowledge of these variants and findings to be crucial in order to obtain optimal performance of PET/CT and to overcome the PET limitations.

Intercostal Muscle Contraction or Rib Bone Marrow Activity?

Diffuse and uniform FDG uptake in the ribs and the intercostal muscles might appear similar on FDG-PET images and a reliable differentiation between the two is important for accurately identifying the underlying process. The former usually suggests excessive contraction of intercostal muscles mostly due to chronic obstructive pulmonary disease, whereas the latter signifies either bone marrow stimulation or involvement by a pathologic process. At times, images may appear confusing and may be misinterpreted. However, in both clinical settings, there are additional ancillary signs, which are helpful in making a correct diagnosis. We herein present 2 case vignettes from each category in which other ancillary signs helped to distinguish FDG rib uptake from intercostal muscle uptake.

Correlations between 18F-FDG uptake by bone marrow and hematological parameters: measurements by PET/CT

The aim of this study was to investigate the correlations between (18)F-FDG uptake by bone marrow and various hematological parameters. Forty-eight patients who underwent FDG-PET/CT studies and also received hematological examinations within 5 days before or after the PET study were included in this study. All patients had not received chemotherapy. FDG uptake by bone marrow was measured as a standardized uptake value (SUV) on three-dimensional PET/CT fusion images, and the uptake ratio (UR) of the SUV of bone marrow to the SUV of longitudinal dorsal muscle was calculated. The correlations between the SUV and the UR of bone marrow and various hematological parameters were evaluated. Bone marrow FDG uptake was strongly correlated with the white blood cell counts but was not significantly correlated with the red blood cell and platelet counts. The neutrophil count was significantly correlated with bone marrow FDG uptake but the lymphocyte count was not. FDG uptake by bone marrow was specifically correlated with the neutrophil count, suggesting that the FDG uptake by bone marrow reflects marrow metabolism that is mainly regulated by granulocyte progenitors and stimulated by endogenous hematopoietic growth factors. They may also be helpful in interpreting PET images, especially for diagnosing bone marrow involvement by malignancy.

Diffuse Bone Marrow Uptake on F-18 FDG PET in Patients With Myelodysplastic Syndromes

It is well known that hematopoietic cytokine stimulation can cause diffuse increase of FDG accumulation in bone marrow on PET imaging, which simulates that seen in patients with bone marrow metastases. However, diffuse bone marrow FDG uptake can be caused by other etiologies. We report 2 patients who did not have a history of hematopoietic cytokine stimulation. The FDG PET images showed diffuse bone marrow FDG uptake, and the patients were diagnosed as having myelodysplastic syndromes. These cases demonstrate that diffuse FDG uptake by bone marrow can suggest neoplastic disease of the hematopoietic tissues.

Effect of colony-stimulating factor and conventional- or high-dose chemotherapy on FDG uptake in bone marrow

PURPOSE

Granulocyte or granulocyte-macrophage colony stimulating factor (CSF), usually used in conjunction with chemotherapy, may interfere with the( 18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) reading. The purpose of this study is to evaluate the effects of CSF, conventional-or high-dose chemotherapy on bone marrow FDG uptake.

METHODS

Two hundred and forty-one FDG PET scans obtained in 163 patients with lymphoma and no pathologically and radiologically proven bone marrow involvement were analyzed. The standardized uptake value (SUV) of each patient's spine was measured.

RESULTS

Among patients with no recent history of CSF use, the average SUV in 36 patients with no history of chemotherapy was 1.60+/-0.34, that in 49 patients with a history of conventional-dose chemotherapy was 1.37+/-0.32, and that in 12 patients with a history of high-dose chemotherapy was 1.26+/-0.25 (P=0.008 and 0.002, respectively by Mann-Whitney U test). In 80 patients treated with conventional-dose chemotherapy and CSF, the average SUV after discontinuation of CSF was as follows: 0-7 days, 2.37+/-1.19; 8-14 days: 2.04+/-0.67; 15-21 days: 1.87+/-0.52; 22-30 days: 1.59+/-0.18; 31-90 days: 1.54+/-0.36. In 45 patients treated with high-dose chemotherapy and CSF, no significant increase in bone marrow uptake was seen in most of them.

CONCLUSION

Bone marrow FDG uptake may be increased by CSF treatment and may be decreased by chemotherapy. In patients treated with conventional-dose chemotherapy and CSF, increased marrow uptake will return to the pretreatment value approximately 1 month after discontinuation of CSF.

[Correlation of hematologic parameters with bone marrow and spleen uptake in FDG PET]

OBJECTIVE

To assess the relationship between various hematologic parameters and bone marrow (BM) and splenic uptake of FDG in PET imaging.

MATERIAL AND METHODS

29 patients with Hodgkin's disease (HD) referred for baseline FDG PET imaging before treatment and without evidence of bone marrow (BM) involvement were included in the study. Splenic uptake also was analyzed in 18 patients without splenic involvement. BM and splenic activity were visually graded on a 3 point scale. Activity pattern was classified as homogeneous or heterogeneous. Semi-quantitative analysis was also performed by drawing regions of interest (ROI) over the spine and spleen. ROIs also were drawn over right lung and liver. FDG uptake ratios for the spine and spleen in comparison with the lung and liver were generated. Visual scoring of marrow and splenic uptake, and the various ratios were correlated with hemoglobin (Hb), white blood cell (WBC), and platelet counts, and correlation coefficients were calculated.

RESULTS

In 27/29 patients (93 %) BM and in 18/18 patients (100 %) spleen uptake was diffuse. There was a direct correlation between BM and spleen uptake of FDG with increasing WBC, which was stronger than the inverse correlation seen with Hb (the lower the Hb the greater the uptake). Correlation with platelet counts was weaker.

CONCLUSION

There is a correlation between hematologic parameters such as Hb, WBC and platelet counts and the uptake of FDG in BM and spleen in PET imaging. Knowledge of this correlation should help to better interpret and understand PET imaging.