In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 38, No. 15_suppl ( 2020-05-20), p. 2532-2532
Abstract:
2532 Background: The evaluation of response in the context of treatment with stereotactic radiotherapy (SRT) or immune checkpoint inhibitors (ICI) or both, which represent major therapeutic options for patients with melanoma brain metastases, remains challenging due to potential tumor hemorrhage, pseudoprogression, and radionecrosis. Methods: We reviewed clinical and neuroimaging data of 62 melanoma patients, including 26 patients with BRAF-mutant tumors, with newly diagnosed brain metastases treated with immune checkpoint inhibitors (ICI) alone (n = 10, group 1), SRT alone or in combination with other systemic therapies (n = 20, group 2) or ICI plus SRT (n = 32, group 3). Response was assessed retrospectively using RECIST 1.1, RANO or iRANO criteria. Results: The MRI scans of 52 patients were available for central review. Patients received steroids at BM diagnosis in 10% in group 1, 60% in group 2 and 50% in group 3. Pseudoprogression was documented in 7 patients: 3 patients in group 2 (19%) and 4 patients (12%) in group 3. Radionecrosis was documented in 7 patients: 2 patients in group 2 (12%) and 5 patients (16%) in group 3. Patients treated with ICI alone had the worst outcome. Using RANO criteria by central review instead of local investigator assessment increased the rate of progressive disease (PD) as best response for the evaluation of SRT targets but not for the evaluation of the overall brain. Using complete RANO (including clinical assessment and steroid use) instead of RECIST criteria increased the rate of PD as best response, due to clinical deterioration noted in patients with MRI findings that did not qualify for PD. This pattern was seen in patients from all three groups. In contrast, the complete response (CR) rate was unaffected by the criteria used. More PD were also observed when comparing MRI only iRANO criteria versus complete iRANO criteria including clinical status and steroid use. Conclusions: Pseudoprogression is uncommon with ICI alone, suggesting that growing lesions in such patients should trigger an intervention. Pseudoprogression rates were similar after SRT alone or in combination with ICI. Response assessment criteria should be considered carefully when designing clinical studies for patients with brain metastases who receive SRT.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2020.38.15_suppl.2532
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2020
detail.hit.zdb_id:
2005181-5
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