RPS 1416b - Multiple myeloma and lymphoma: advanced imaging and radiomics

Purpose:

To develop an MRI-DWI visual scale for tumour response evaluation in lymphomas and to compare its effectiveness with the PET/CT Deauville scale.

Methods and materials:

The study included 97 patients with lymphoma. Post-treatment whole-body MRI-DWI was interpreted using a 5-level scale: 1=all lymph nodes (LNs) ≤1 cm in short-axis size with no extra lymphatic lesions, 2=LNs >1 cm and extra lymphatic organ lesions with signal intensity (SI )>muscles on ADC maps with no bone marrow (BM) lesions, 3=LNs >1 cm and organ lesions with SI equal to muscles on ADC maps with no BM lesions, 4=LNs >1 cm and/or organ lesions with SI<muscles on ADC maps and/or BM lesions, and 5=increase of lesions size and/or appearance of new lesions. Post-treatment PET/CTs were interpreted using a 5-level Deauville scale. Treatment response was classified as complete (CR, scores 1-3) or non-complete (NCR, scores 4-5). Progression-free survival (PFS) and overall survival (OS) were compared in patients with CR and NCR.

Results:

The number of chemotherapy courses was 3-8. According to MRI-DWI, 85 patients achieved CR and 12 NCR, PET/CT 75 and 22, respectively. The tumour response category coincided in 83 (86%) patients. 2-year PFS in patients with MRI-DWI CR and NCR was 87% and 22% (p=0.0), 3-year OS 93% and 64% (p=0.003), respectively. 2-year PFS in patients with PET/CT CR and NCR was 89% and 46% (p=0,0), 3-year OS 92% and 75% (p=0.013), respectively.

Conclusion:

A simple MRI-DWI visual scale for tumour response evaluation in lymphomas was proposed. A high concordance with the PET/CT Deauville scale was demonstrated. The proposed MRI-DWI scale may be used as a non-irradiative alternative to the Deauville scale.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

Multiple myeloma (MM) is a haematological malignancy characterised by the clonal proliferation of plasma cells that determines bone lesions with different patterns of involvement. Due to prolonged corticosteroid therapy, MM patients have an increased risk of pathological fractures and osteonecrosis of the proximal femur. According to the Durie & Salmon PLUS criteria and new MY-RADS score, MRI is of prognostic relevance to evaluate the disease extent (medullary and extra-medullary lesions).

Methods and materials:

We reviewed MRI data from January 2018-August 2019 of n=52 patients (29 men and 23 women; mean age 65±13years) with MM at the level of the hip (including the proximal femur). Hip lesions have been classified according to the MY-RADS score and lesion characteristics in a diffuse pattern, focal pattern, mixed pattern, osteonecrosis, and pathological fractures. Descriptive statistical analysis was performed to summarise the dataset.

Results:

Among the 52 selected MM patients, a total of n=40 (40/52; 77%) reported at least one hip lesion, n=10 patients at least two hip lesions (10/52; 20%), and n=2 (2/52; 3%) subjects had no lesions. According to hip lesions classification, n=6 osteonecrosis of the femoral head, n=26 diffuse pattern, n=10 focal pattern, n=15 mixed pattern, and n=5 pathological fractures were observed. Intra and interobserver agreement of MY-RADS score were 0.78 and 0.65, respectively.

Conclusion:

MRI detects bone lesions in the hip and proximal femur in 97% of patients. In n=11/52, 21% of patients, a surgical consult was necessary. MRI allows the differentiation of bone pattern involvement in MM, which is useful for risk stratification using the MY-RADS score.

Limitations:

The retrospective nature of the study and relatively small number of patients.

Ethics committee approval

The retrospective study protocol was approved by our institutional review board.

Funding:

No funding was received for this work.

Purpose:

To compare CT and WBMRI in staging and follow-up during and post-therapy in young MM patients.

Methods and materials:

From September 1, 2018-July 31, 2019, 219 WBMRI were performed with a Magnetom Aera 1.5T (Siemens Healthcare, Erlangen, Germany) using established protocols.

We reviewed 121 exams (89 patients, median age: 58.3). All had a histological report by bone marrow biopsy and a low-dose CT was performed.

Results:

In 28/89 patients, we found a diffuse infiltration pattern at WB-DWI defined as hyperintensity in STIR sequences, hypointensity T1, and signal restriction in DWI of the spongy vertebral body. In 26 cases, the diagnosis was confirmed by a histological bone marrow report, with 2 false-positives and high concordance between the two methods. The plasma cell infiltration rate did not correlate with the grade of signal restriction on DWI. Instead, the DWI/ADC values correlated with the response to therapy.

In 43/89 patients (48.3%), the WBMRI protocol showed extraskeletal findings (benign and malignant) that previous CT-staging did not report; some of them (3 breast cancer, 4 prostatic cancer, 1 renal cell carcinoma, 1 HCC, 1 colon cancer, and 1 jugular thrombosis) changed the clinical treatment.

Conclusion:

WBMRI is a functional imaging technique comprising anatomical and functional sequences with an emerging role in the management of MM patients. It allows highly sensitive detection of diffuse bone marrow infiltration patterns and focal lesions according to the International Myeloma Working Group Consensus Reccomandation (June 2019).

In our study, we found that, when available, WBMRI should be the first choice in young patients with MM to avoid radiation exposure.

Limitations:

A retrospective study.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

Lymph nodes (LN) are examined in every CT scan. Until now, an evaluation is only possible with morphological criteria. With dual-energy CT (DE-CT) systems, iodine concentration (IC) can be measured which could conduct an improved evaluation. The purpose of the study was to define standard values for IC of cervical, axillary, and inguinal LN in DE-CT, as these do not yet exist despite their clinical relevance.

Methods and materials:

Imaging data of 297 patients who received a DE-CT in a portal-venous phase and showed healthy LN was retrospectively collected from the institutional PACS system. No present history of malignancy, inflammation, or trauma in the examined region was present. For each patient, the IC of the 3 largest LN of the examined area was measured. Normalisation to different structures was performed.

Results:

The normalisation of the IC of LN to artery, vein, muscle, or a combination of those, did not lead to a decreased value-range. The smallest range and confidence interval of IC was found when using absolute values of IC for each region. Hereby, the mean values (95% confidence interval) for IC of LN were found: 2.09 mg/ml (2.00-2.18 mg/ml) for the neck, 1.24 mg/ml (1.16-1.33 mg/ml) for the axilla, and 1.11 mg/ml (1.04-1.17 mg/ml) for the groin.

Conclusion:

The current study suggests standard values for IC of LN in DE-CT which could be used to differentiate between healthy and pathological lymph nodes.

Limitations:

IC could be affected by the used CT-protocol.

Ethics committee approval

The retrospective study was approved and conducted in accordance with the guidelines of the institutional review board. Informed consent was waived by the institutional review board due to the retrospective design of the study.

Funding:

No funding was received for this work.