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Updated: Jan 1, 2026
A Melanoma Patient-Derived Xenograft Model
Published on: May 20, 2019
DCE-MRI perfusion predicts pseudoprogression in metastatic melanoma treated with immunotherapy
Yoshie Umemura1, Diane Wang2, Kyung K Peck2,3
1Department of Neurology, University of Michigan, 1914 Taubman Center, 1500 E. Medical Center Dr., SPC 5316, Ann Arbor, MI, 48109 5316, USA. yoshie@med.umich.edu.
Purpose:
It can be challenging to differentiate pseudoprogression from progression. We assessed the ability of dynamic contrast enhanced T1 MRI (DCE-MRI) perfusion to identify pseudoprogression in melanoma brain metastases.
Methods:
Patients with melanoma brain metastases who underwent immunotherapy and DCE-MRI were identified. Enhancing lesions ≥ 5mm in diameter on DCE-MRI and that were new or increased in size between a week from beginning the treatment, and a month after completing the treatment were included in the analysis. The 90th percentiles of rVp and rKtrans and the presence or absence of hemorrhage were recorded. Histopathology served as the reference standard for pseudoprogression. If not available, pseudoprogression was defined as neurological and radiographic stability or improvement without any new treatment for ≥ 2 months.
Results:
Forty-four patients were identified; 64% received ipilimumab monotherapy for a median duration of 9 weeks (range, 1-138). Sixty-four lesions in 44 patients were included in the study. Of these, nine lesions in eight patients were determined to be pseudoprogression and seven lesions were previously irradiated. Forty-four progression lesions and eight pseudoprogression lesions were hemorrhagic. Median lesion volume for pseudoprogression and progression were not significantly different, at 2.3 cm3 and 3.2 cm3, respectively (p = 0.82). The rVp90 was smaller in pseudoprogression versus progression, at 2.2 and 5.3, respectively (p = 0.02), and remained significant after false discovery rate adjustment (p = 0.04).
Conclusions:
Pseudoprogression exhibited significantly lower rVp90 on DCE-MRI compared with progression. This knowledge can be useful for managing growing lesions in patients with melanoma brain metastases who are receiving immunotherapy.
Insights
Dynamic contrast-enhanced MRI (DCE-MRI) perfusion can help differentiate pseudoprogression from true progression in melanoma brain metastases. Lower rVp90 values on DCE-MRI indicate pseudoprogression, aiding treatment management.
Area of Science:
- Neuro-oncology
- Radiology
- Immunotherapy
Background:
- Differentiating pseudoprogression from progression is crucial for effective treatment of melanoma brain metastases.
- Immunotherapy has improved outcomes but can cause treatment-related changes that mimic progression.
Purpose of the Study:
- To evaluate the utility of dynamic contrast-enhanced T1 MRI (DCE-MRI) perfusion parameters in distinguishing pseudoprogression from true progression in melanoma brain metastases.
- To assess if DCE-MRI can aid in the management of growing lesions in patients receiving immunotherapy.
Main Methods:
- Retrospective analysis of melanoma brain metastases patients treated with immunotherapy and DCE-MRI.
- Inclusion criteria: enhancing lesions ≥ 5mm, new or increased in size between 1 week and 1 month post-treatment.
- Analysis of 90th percentiles of relative volume transfer constant (rKtrans) and relative plasma volume (rVp), and hemorrhage presence. Histopathology or clinical stability defined pseudoprogression.
Main Results:
- Sixty-four lesions in 44 patients were analyzed; 8 lesions (in 8 patients) were classified as pseudoprogression.
- Median lesion volumes were not significantly different between pseudoprogression (2.3 cm³ ) and progression (3.2 cm³ ).
- The 90th percentile of relative plasma volume (rVp⁹⁰) was significantly lower in pseudoprogression (2.2) compared to progression (5.3) (p=0.02), remaining significant after adjustment (p=0.04).
Conclusions:
- Pseudoprogression in melanoma brain metastases demonstrates significantly lower rVp⁹⁰ on DCE-MRI compared to true progression.
- DCE-MRI perfusion parameters, specifically rVp⁹⁰, can be a valuable tool for managing growing lesions in patients undergoing immunotherapy.
- This finding aids in accurate diagnosis and appropriate treatment adjustments for melanoma brain metastases.
