Tuesday, December 6, 2016

Radiological evaluation of response to melanoma treatments

Another reason liquid assays (as discussed here last month:  Blood tests to diagnose, check response to therapy, and use as follow-up in melanoma! ) would be so helpful:

Patterns of response to anti-PD-1 treatment: an exploratory comparison of four radiological response criteria and associations with overall survival in metastatic melanoma patients.  Khoja, Kibiro, Metser, et al. Br J Cancer. 2016 Oct 4.  

Radiological assessment of response to checkpoint inhibitors remains imperfect. We evaluated individual lesion and inter-patient response by response evaluation (RECIST) 1.1, immune-related response criteria (irRC), CHOI and modified CHOI (mCHOI) and correlated response with overall survival (OS). Thirty-seven patients with 567 measurable lesions treated with pembrolizumab in the Keynote 001 trial were studied. Association of response with OS was determined.  Response varied according to site; lung lesions had the highest rate of complete response (69 out of 163 (42%) vs other sites 71 out of 404 (18%). Delayed response post first scan was seen in 2 out of 37 (5%) deemed progressive (PD) by RECIST and 2 out of 14 (14%) deemed PD by irRC. Modified CHOI criteria showed response of 38% (14 out of 37). Change in tumour size and density on first follow-up assessment was associated with OS with each 1000 mm2 increase in tumour size from baseline increasing the hazard of dying by 25.9%.  Response defined by any criteria had superior OS. Response by any criterion was prognostic. Novel patterns of response and changes on treatment in tumour density suggest complex anti-tumour responses to immunotherapy.  

Then there is this report on using ultrasound to determine progression vs pseudo progression ~
Ultrasonographic findings can identify 'pseudoprogression' under nivolumab therapy.   Imafuku, Hata, Kitamura, et al.  Br J Dermatol. 2016 Nov 22. 

'Pseudoprogression' is often seen in patients with melanomas who are treated with immune-checkpoint inhibitors such as nivolumab or ipilimumab. We sometimes evaluate metastatic lesions by imaging tests such as CT or PET-CT. 'Pseudoprogression' usually occurs upon the initial administration, which may make it difficult for the physician to determine the disease condition. In our two cases of metastatic melanoma treated with nivolumab (anti-PD-1 antibody), we examined the ultrasonography (US) of target lesions that could be accessed from the body surface, such as those of the regional lymph node or subcutaneous metastasis. In both cases, the US revealed a lesion approximately 10% greater in size after 40-50 days of nivolumab administration, even though the blood flow inside the tumour was reduced by about 20% within 50 days. From about 100 days after blood flow reduction was detected by US, the tumours began to decrease in size. However, contrast CT was unable to detect the association between tumour size and tumour blood flow. The present cases suggest that US could be a powerful tool for differentiating between 'pseudoprogression' and real progressive disease in patients treated with cancer immunotherapies such as those involving immune-checkpoint inhibitors. The misdiagnosis of progressive disease can lead to unnecessary alternations in the current treatment. Therefore, the US findings in our study could be clinically useful and educational for physicians.  

Good data to know when depending on radiology studies as evaluation of status and progression.  But wouldn't it be nice to just do a blood draw????  At least some of the time???? - c

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