MR imaging of osteonecrosis of the knee in children with acute lymphocytic leukemia

[18F]FDG PET-MR in the Evaluation and Follow-Up of Incidental Bone Ischemic Lesions in a Mono-Center Cohort of Pediatric Patients Affected by Hodgkin's Lymphoma

Hodgkin's lymphoma (HL) is one of the neoplasms with the best prognosis in children, adolescents and young adults, but sufferers are burdened by the possibility of developing adverse effects such as Bone Ischemic Lesions (BILs) which are lesions of the bone caused by the loss of/reduction in blood flow. The main goal of this retrospective study was to evaluate the role of [¹⁸F]FDG-PET-MR in the early detection of BILs in a single-center cohort of uniformly treated pediatric HL patients. BILs were assessed through PET-MR images as the appearance of medullary lesion surrounded by a serpiginous, tortuous border. From 2017 to 2022, 10/53 (18.9%) HL patients developed BILs which were mostly (8/10 patients) multifocal. Overall, 30 lesions were identified in the 10 asymptomatic patients, all with the above-mentioned features at MR and with very low [¹⁸F]FDG uptake. BILs were incidentally detected during HL therapy (n = 6) and follow-up (n = 4), especially in the long bones (66.7%). No factors correlated with the occurrence of BIL were identified. No patients developed complications. PET-MR is a sensitive combined-imaging technique for detecting BILs that are asymptomatic and self-limiting micro-ischemic lesions. BILs can be monitored by clinical follow-up alone both during and after therapy.

Treatment options for secondary osteonecrosis of the knee

Knee osteonecrosis is a debilitating progressive degenerative disease characterized by subchondral bone ischemia. It can lead to localized necrosis, tissue death, and progressive joint destruction. For this reason, it is essential to diagnose and treat this disease early to avoid subchondral collapse, chondral damage, and end-stage osteoarthritis, where the only solution is total knee arthroplasty. Three types of knee osteonecrosis have been documented in the literature: spontaneous or primitive, secondary, and post arthroscopy. Spontaneous osteonecrosis is the most common type studied in the literature. Secondary osteonecrosis of the knee is a rare disease and, unlike the spontaneous one, involves patients younger than 50 years. It presents a particular set of pathological, clinical, imaging, and progression features. The management of secondary osteonecrosis is determined by the stage of the disorder, the clinical manifestation, the size and location of the lesions, whether the involvement is unilateral or bilateral, the patient's age, level of activity, general health, and life expectancy. This review aims to present the recent evidence on treatment options for secondary osteonecrosis of the knee, including conservative treatment, joint preserving surgery, and knee replacement.

The radiological and clinical follow-up of osteonecrosis in cancer patients

BACKGROUND

In patients with cancer, osteonecrosis (ON) lesions can affect multiple sites throughout the skeleton, including the long and short bones and the joints. The aims of this study were to explore the natural course of ON in patients treated for cancer by using radiological classification suitable for multisite ON lesions and to assess correlations between the ON grade and surgical procedures.

MATERIAL AND METHODS

Data were retrieved from hospital databases on 233 ON lesions in 54 patients (aged 2-73 years at cancer diagnosis; mean age: 25 years). ONs were graded according to the Niinimäki classification, based on magnetic resonance images. Medical records were reviewed to identify surgical procedures.

RESULTS

A total of 14 different ON sites were detected; the hip was the most common site (n = 51), followed by the femur (n = 45), tibia (n = 41) and knee (n = 37). Among the 233 ON lesions, 78.1% did not require surgical procedures. The remaining lesions required total joint arthroplasty (TJA; 40/233, 17.2%), core decompression (3.4%) and arthroscopy (1.3%). Most TJAs (33/40, 82.5%) were performed on the hip. ONs of the knee required TJAs only once; grade 3 knee ONs frequently healed (58%, 11/19). None of the diaphyseal or metaphyseal (grade 1-2) ONs of the long bones required surgery, and no fractures of those bones were identified.

CONCLUSIONS

In conclusion, the natural history of ONs varied by the grade and site. Based on our findings, we would not recommend routine radiological follow-ups for grades 1-2 ON lesions that do not affect the joints, because the clinical consequences of those lesions appear to be minimal, although pain relief would be warranted. In contrast, joint deformations (grade 5) require surgery; therefore, intervention studies should focus on grades 3-4 ON lesions.

Magnetic resonance imaging is the preferred method to assess treatment-related skeletal changes in children with brain tumors

PURPOSE

To evaluate the growing skeleton for potential altered skeletalgenesis associated with antiangiogenesis therapy.

PATIENTS AND METHODS

Knee radiographs and magnetic resonance imaging (MRI) were prospectively obtained on patients enrolled on two consecutive clinical trials using vandetanib, a potent oral (VEGF receptor 2) VEGFR-2 inhibitor alone or combined with dasatinib, a multiple tyrosine kinase inhibitor, in children with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

RESULTS

Fifty-nine patients (32 females) underwent 119 MRIs; 51 patients underwent 89 radiographs of the knees. The median age at enrollment was 6.2 years (range, 2.4-17.6 years). The dose of vandetanib ranged from 50 to 145 mg/m(2) /day. The median treatment duration was 205 days. Only two patients have not experienced disease progression after 18 and 60 months from diagnosis. MRI identified clinically significant premature physeal fusion in both knees of one patient, focal physeal thickening in one, osteonecrosis in eight patients (present at enrollment in one), and bony spicules crossing the physis in two patients (bilateral in one). MRI follow-up period averaged 5.3 months (range, 0-25.5 months; median, 3.5 months). Radiographs delineated normally fused physes in two patients but no cases of premature physeal fusion, osteonecrosis or bony spicules.

CONCLUSIONS

As MRI provided greater information than radiographs, and thus would be a more sensitive test to assess skeletalgenesis in pediatric patients.

Effectiveness of pamidronate as treatment of symptomatic osteonecrosis occurring in children treated for acute lymphoblastic leukemia

BACKGROUND

Osteonecrosis (ON) is a severe complication of acute lymphoblastic leukemia (ALL) treatments. Recent studies suggest that bisphosphonates might reduce pain and loss of motor function in patients with ON. We assessed the effects of pamidronate compared to standard care in patients with symptomatic ON (sON) and studied whether steroids might be continued after diagnosis of ON in some patients.

METHODS

We evaluated 17 patients with sON as complication of primary ALL treatment between 2000 and 2008. Fourteen patients were treated with pamidronate. Mobility and pain control were monitored in all patients. Affected joints were classified by magnetic resonance imaging (MRI) at ON diagnosis and after 6-72 months.

RESULTS

Out of 220 patients with ALL, 17 (7.7%) patients developed sON. The median age at ALL diagnosis was 11 years (range: 2.7-16.6 years) and sON occurred a median of 13.4 months (range: 2.5-34 months) after ALL diagnosis. Affected joints were hip, knee and ankle. MRI scans showed 7 severe, 4 moderate, and 6 mild ON lesions. Fourteen patients showed improvement in pain (77% of patients) and motor function (59% of patients), even though corticoids were reintroduced in 4 patients. MRI demonstrated improvement, stability or worsening in 6, 3, and 5 cases, respectively.

CONCLUSIONS

Pamidronate seems to be effective in the management of pain and motor function recovery in sON. Further studies are needed to provide evidence as to whether bisphosphonates can be recommended for the treatment or the prevention of ON in childhood ALL patients.

Knee pain in patients with cancer after chemotherapy, radiotherapy, and bone marrow transplantation

The causes of knee pain in patients with cancer with are different from those without cancer, and the purpose of this study was to evaluate these differences. Thirty-six patients with cancer who had knee pain who had undergone 1 or more modalities of treatment, including chemotherapy, radiotherapy, and bone marrow transplant, for a primary diagnosis of cancer were compared with a cohort of 40 patients without cancer who had knee pain. All patients were evaluated clinically and underwent radiographic examination, and some underwent computed tomography or magnetic resonance imaging examination. Among patients with a primary diagnosis of cancer, the most common diagnosis was lymphoma (n=10), and the most common causes of knee pain were avascular necrosis of bone, osteoarthritis, insufficiency fractures, and septic arthritis. In 5 patients, the classical signs of a septic knee were not present. Other causes of knee pain included meniscus tear and anterior cruciate ligament rupture with instability. The most common diagnosis in patients without cancer was osteoarthritis of the knee. No patient without cancer was diagnosed with avascular necrosis, metastatic lesion, or insufficiency fracture. Two patients without cancer were diagnosed with septic arthritis of the knee. This study showed that the causes of knee pain in patients with cancer are different from those without cancer. Septic arthritis may present without the classical clinical signs in patients with cancer, and a high index of suspicion should be maintained for it.

Osteonecrosis in children after therapy for malignancy

OBJECTIVE

Osteonecrosis in the growing population of childhood cancer survivors results from disease and treatment. Imagers must be knowledgeable about patient groups at risk for its development, patterns of involvement and potential implications. This review will focus on implications of this potentially life-altering toxicity.

CONCLUSION

Childhood cancer survivors are at increased risk for developing osteonecrosis. Because osteonecrosis is often asymptomatic until late in the process, imaging is critical for its detection and characterization when interventions may be most effective to ameliorate its progression.

How does osteonecrosis about the knee progress in young patients with leukemia?: a 2- to 7-year study

BACKGROUND

Osteonecrosis is a major treatment complication of pediatric leukemias owing to its potential to cause joint deterioration. Because of potential long-term effects of osteonecrosis on joints, information regarding its progression and collapse in different patients can be used to identify high-risk groups, advise the patients and parents of this complication, and potentially consider the risk for development of osteonecrosis in planning primary treatment.

QUESTIONS/PURPOSES

We therefore determined: (1) the incidence of joint collapse and/or pain in young patients with hematologic malignancies diagnosed with ON of the knee; (2) risk factors associated with collapse; and (3) the relationship between size and location of osteonecrotic knee lesions and the likelihood of joint collapse.

PATIENTS AND METHODS

We retrospectively reviewed 109 patients with hematologic malignancies and MRI-confirmed knee osteonecrosis. The median age was 11.5 years (range, 2.3-18.8 years) at primary diagnosis of hematologic malignancy and a median age of 13.4 years (range, 2.7-23.3 years) at diagnosis of osteonecrosis of the knee. For analyses, we used the first and last MR images. Minimum clinical followup was 2.3 years after diagnosis of knee osteonecrosis (median, 6 years; range, 2.3-7.17 years).

RESULTS

Joint collapse occurred in 22% (24 of 109). Older age, pain at osteonecrosis presentation, and lesions extending to the articular surface of distal femoral epiphyses were associated with joint collapse.

CONCLUSIONS

Younger patients and those without extensive femoral epiphyseal involvement have a better prognosis for osteonecrosis of the knee.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.