18F-FDG super bone marrow uptake: A highly potent indicator for the malignant infiltration

Applications of 18F-Fluorodesoxyglucose PET Imaging in Leukemia

The main finding that 18F-FDG PET imaging can reveal in patients with leukemias is the presence of bone marrow (BM) infiltration in both acute or chronic forms. This ability can influence and guide the use of BM biopsy but also assess to therapy response. Additionally 18F-FDG PET imaging has been reported as particularly useful for the diagnosis of leukemias in patients with non specific symptoms. In the case of acute leukemias it revealed also a role for the evaluation of extramedullary forms while in the case of chronic forms a role for the assessment of Richter transformation has been reported.

Case report: 18F-FDG PET/CT skeletal superscan-like in an adult patient with acute lymphoblastic leukemia

We herein describe a rare case of adult acute lymphoblastic leukemia with an 18florine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) skeletal superscan-like appearance. The degree of bone marrow uptake was so intense that it far exceeded the level of physiological cerebral uptake and radiourinary activity. The distribution was remarkably similar to a superscan seen on skeletal scintigraphy. Skeletal superscans of 18F-FDG PET/CT have been reported in hematological diseases, solid tumors with extensive bone metastasis, and metabolic diseases. Thus, we reviewed the PET/CT images of cases reported, indicating that more homogeneous distribution, without primary tumor and specific mandibular and skull activity, may be suggestive of hematological diseases.

PET/CT in leukemia: utility and future directions

2-Deoxy-2-[ 18 F]fluoro- d -glucose PET/computed tomography ([ 18 F]FDG PET/CT) has proven to be a sensitive method for the detection and evaluation of hematologic malignancies, especially lymphoma. The increasing incidence and mortality rates of leukemia have raised significant concerns. Through the utilization of whole-body imaging, [ 18 F]FDG PET/CT provides a thorough assessment of the entire bone marrow, complementing the limited insights provided by biopsy samples. In this regard, [ 18 F]FDG PET/CT has the ability to assess diverse types of leukemia The utilization of [ 18 F]FDG PET/CT has been found to be effective in evaluating leukemia spread beyond the bone marrow, tracking disease relapse, identifying Richter's transformation, and assessing the inflammatory activity associated with acute graft versus host disease. However, its role in various clinical scenarios in leukemia remains unacknowledged. Despite their less common use, some novel PET/CT radiotracers are being researched for potential use in specific scenarios in leukemia patients. Therefore, the objectives of this review are to provide a thorough assessment of the current applications of [ 18 F]FDG PET/CT in the staging and monitoring of leukemia patients, as well as the potential for an expanding role of PET/CT in leukemia patients.

Recurrent Marginal Zone Lymphoma with Bone Marrow Involvement Detected by ¹⁸F-FDG PET/CT and Biopsy: A Diagnostic Challenge

BACKGROUND Marginal zone lymphoma is a low-grade, B-cell, non-Hodgkin lymphoma. Bone marrow involvement (BMI) of leukemia or lymphoma can usually be displayed in fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) with high standardized uptake values (SUV), while diffuse homogeneous ¹⁸F-FDG bone marrow uptake (BMU) in PET/CT primarily reflects hyperplastic bone marrow status. This report is of a 74-year-old man presenting with anemia and a diagnosis of recurrent marginal zone lymphoma with bone marrow involvement identified with 18F-FDG PET/CT imaging and biopsy. CASE REPORT A 64-year-old man with severe anemia and body weight loss of 7 kg in 1 month was diagnosed with marginal zone lymphoma, stage III, in July 2011. He went into complete remission in April 2012 after 6 cycles of chemotherapy, with Hb restored. Anemia and diffuse homogeneous ¹⁸F-FDG BMU in PET/CT were then noted during a routine check-up in October 2021, and recurrent disease was established through positive biopsy of subcutaneous nodules and bone marrow. Subsequent complete remission after 6 cycles of combination therapy was validated with pathologically negative BMI, the resolution of the slightly enhanced ¹⁸F-FDG BMU in PET/CT, and restored hemoglobin. CONCLUSIONS This report has highlighted the importance of follow-up for patients with lymphoma and supports the diagnostic role of ¹⁸F-FDG PET/CT imaging and the pathological verification in identifying malignant involvement in bone marrow.

The value of 18F-FDG PET/CT in the prediction of clinical outcomes of patients with acute leukemia treated with allogeneic hematopoietic stem cell transplantation

The present study aimed to determine whether ¹⁸F-FDG PET/CT performed before and/or after allogeneic hematopoietic stem cell transplantation (allo-HSCT) can predict clinical outcomes in acute leukemia (AL). A total of 79 examinations comprising 72 patients with AL who underwent ¹⁸F-FDG PET/CT before and/or after allo-HSCT were retrospectively enrolled between January 2011 and January 2019. Outcomes were assessed using overall survival (OS) and disease-free survival (DFS). A total of 63 examinations were PET-positive, while 16 examinations were PET-negative. Increased BM and splenic ¹⁸F-FDG uptake were observed in 24 (19/79) and 14% (11/79) of examinations, respectively. ¹⁸F-FDG-avid lymph nodes were observed in 38% (30/79) of examinations. E_NE_ME_S involvement was detected in 44% (35/79) of examinations. The presence of E_NE_ME_S involvement [OS hazard ratio (HR), 6.399; 95% confidence interval (CI), 1.843–22.224; P=0.003; post-HSCT OS: HR, 7.203; 95% CI, 1.510–34.369; P=0.013; DFS HR, 3.671; 95% CI, 1.145–11.768; P=0.029], post-transplantation minimal residual disease (DFS HR, 4.381; 95% CI, 1.594–12.040; P=0.004; pre-HSCT OS HR, 11.455; 95% CI, 1.336–98.179; P=0.026) and disease status (OS HR, 0.330; 95% CI, 0.128–0.848; P=0.021; post-HSCT OS HR, 0.195; 95% CI, 0.050–0.762; P=0.019; DFS: HR, 0.278; 95% CI, 0.091–0.851; P=0.025) could serve as an adverse prognostic factor in patients with AL treated with allo-HSCT. ¹⁸F-FDG PET/CT before and/or after allo-HSCT was a predictor for OS and DFS in patients with AL. E_NE_ME_S involvement detected using ¹⁸F-FDG PET/CT may help identify patients with AL who are likely to have unfavorable clinical outcomes.

Applications of PET in Diagnosis and Prognosis of Leukemia

As a malignant hematopoietic stem cell disease, leukemia remains life-threatening due to its increasing incidence rate and mortality rate. Therefore, its early diagnosis and treatment play a very important role. In the present work, we systematically reviewed the current applications and future directions of positron emission tomography (PET) in patients with leukemia, especially ¹⁸F-FDG PET/CT. As a useful imaging approach, PET significantly contributes to the diagnosis and treatment of different types of leukemia, especially in the evaluation of extramedullary infiltration, monitoring of leukemia relapse, detection of Richter’s transformation (RT), and assessment of the inflammatory activity associated with acute graft versus host disease. Future investigations should be focused on the potential of PET/CT in the prediction of clinical outcomes in patients with leukemia and the utility of novel radiotracers.

Utility of 18-fluorodeoxyglucose positron emission tomography in children with relapsed/refractory leukemia

OBJECTIVE

Few data are available on the clinical significance of 18-fluorodeoxyglucose positron emission tomography (FDG-PET/CT) results in patients with leukemia. We investigated the utility of FDG-PET/CT at the time of relapsed/refractory disease in pediatric patients with leukemia.

METHODS

Medical records of 28 children with suspected leukemia progression or recurrence during/after chemotherapy or allogeneic stem cell transplantation (allo-SCT) were retrospectively reviewed to determine the utility of FDG-PET/CT.

RESULTS

Twenty-two of the 28 patients have documented abnormal imaging findings during clinical follow-up, while six had were interpreted as not demonstrating signal consistent with active leukemia. Of the 22 patients with abnormal FDG-PET/CT studies 14 were found to have FDG-PET/CT reported as consistent with active leukemia and increased leukemia blasts on bone marrow biopsy. Regarding the eight patients without positive FDG-PET/CT and proven leukemia relapse, four had discordant findings on FDG-PET/CT and biopsy, and four had FDG-PET/CT reported as infection. Mean maximum standardized uptake values (SUVmax) were significantly higher among patients whose FDG-PET/CT findings were positive for leukemia as opposed to infectious disease (p < .05). Mean SUVmax was also significantly higher among patients with multifocal lesions on FDG-PET/CT than among those with diffuse lesions (p < .05).

CONCLUSIONS

The findings suggest that FDG-PET/CT may be a complementary imaging modality that could be combined with bone marrow examination to improve detection of subtle leukemic infiltration in children with suspected leukemia progression or recurrence after chemotherapy or allo-SCT.

A predicting model of bone marrow malignant infiltration in 18F-FDG PET/CT images with increased diffuse bone marrow FDG uptake

Purpose: To demonstrate the relationship between the etiologies of increased diffuse bone marrow (BM) ¹⁸F-FDG uptake and PET/CT imaging/clinical features, as well as to explore a predicting model of BM malignant infiltration (MI) based on decision tree. Methods: 84 patients with increased diffuse BM uptake were retrospectively enrolled. Their complete case record and PET/CT images were reviewed, with the maximal standardized uptake values of bone marrow (SUVmaxBM) and other imaging/clinical features were noted. At the same time, the differences in imaging/clinical features between bone marrow MI and non-MI groups were compared. The decision tree for predicting MI was established by C5.0 component of SPSS Clementine. Results: In patients with homogenously increased BM uptake, 21 patients had MI resulted from leukemia, lymphoma and small cell lung cancer (SCLC). MI group had higher SUVmaxBM than non-MI group (6.7±3.1 vs 4.2±0.9, p=0.001). However, a considerable proportion of MI patients had similar SUVmaxBM to non-MI patients, which were mainly seen in lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM), chronic myeloid leukemia (CML) and multiple myeloma (MM). There were significant differences in other factors between the two groups. MI patients were highly associated with SUVmaxAP/AX≥1 (the ratio of SUVmaxBM of appendicular skeleton to that of axial skeleton), hepatosplenomegaly, older age and lower rate of fever. The decision tree combining SUVmaxBM, SUVmaxAP/AX, fever and hepatosplenomegaly achieved a sensitivity of 81.0%, a specificity of 98.4% and an accuracy of 94.0% for predicting MI. Conclusion: Increased diffuse BM ¹⁸F-FDG uptake can be attributed to both bone marrow MI and benign etiologies. A decision tree based on C5.0 algorithm, combining PET/CT imaging and clinical features, is of potential use in discriminating BM malignant infiltration from patients with increased diffuse BM uptake.

Renal osteodystrophy presenting as a metabolic superscan on F-18 FDG PET/CT: A case report

RATIONALE

F-18 Fluoro Deoxyglucose positron emission tomography and computed tomography (F-18 FDG PET/CT) is a useful modality in the evaluation of patients with malignancies. Increased incidence of lympho-proliferative disorders has been reported in individuals with long-standing end-stage renal disorders treated with renal replacement therapy.

PATIENT CONCERNS

A 30-year-old male on peritoneal dialysis on account of end-stage renal disease. He had acute rejection of an earlier transplanted renal allograft. He was referred for an F-18 FDG PET/CT based on a clinical suspicion of lymphoma on account of bilateral inguinal lymphadenopathy associated with bilateral pedal swelling.

DIAGNOSIS

Renal osteodystrophy was diagnosed based on diffusely intense F-18 FDG uptake in the axial skeleton, focal uptake in the costochondrial junctions and linear cortical uptake in the appendicular skeleton. No findings suggestive of lymphoma was seen.

INTERVENTIONS

A diagnosis of renal osteodystrophy with no evidence of a lymphoma prevented futile biopsy of inguinal lymphadenopathy. Patient continued with peritoneal dialysis with no further intervention OUTCOMES:: Regular follow-up of patient to monitor calcium, phosphate and parathyroid hormone levels. Treatment will be indicated when laboratory results as well as clinical signs and symptoms are suggestive.

LESSON

Metabolic bone disorder such as is seen in renal osteodystrophy should be considered in the differential diagnoses in patients with diffusely increased bone uptake on F-18 FDG PET/CT scan.