Thank You so much for sharing - such Good News!!
It sounds as your DH's tumors do Not like Folfirinox at all
You must be very pleased with these News!
Regarding your 'SUV question' - I have not read up on SUV before today, because my hubby has never had a test that has made me look for info. I see that member jhocno197 has replied, but I always need to see references to statements (due to bad experiences from other Forums) so I tried to find some. I found these two below. Maybe these references can help you investigate more to understand. (The last reference talk a lot about how to calculate)
From (2016) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4880772/
"An experienced nuclear medicine physician interpreted the whole-body PET images, and was blinded for patient’s history, clinical findings, and conventional imaging.
It was considered the difference the two 18FDG-PET-CT for the early response assessment (delta ∆ SUV). In patients with multiple metastases, it was chosen randomly three to five lesions with 18FDG-PET-CT uptake. Patients with less than five lesions: all the lesions were evaluated. European Organization for Research and Treatment in Cancer (EORTC) criteria for PET-CT were used: partial response is when delta SUV drop more than 25%, disease progression is when delta SUV increases more than 25% or appearance of new metastatic lesions and stable disease when the SUV decrease be less than 25% or the increase be less than 25% (34).
A responder patient was defined as someone that had partial or complete response. "
From (2017) http://jnm.snmjournals.org/content/58/4/523.full
"When acquired with careful attention to protocol, tumor SUV has a within-subject coefficient of variation of approximately 10%. In a response assessment setting, SUV reductions of more than 25% and increases of more than 33% are unlikely to be due to measurement variability. Broader margins may be required for sites with less rigorous protocol compliance, but in general, SUV is a highly repeatable imaging biomarker that is ideally suited to monitoring tumor response to treatment in individual patients."
"One issue that arises in test–retest studies of this kind is whether to analyze the data in the units of the original measurement (d expressed in SUV units) or in relative units (D expressed as a percentage). ... Characterizing repeatability in relative units is well suited to the way SUV is used in response assessment studies, which commonly quote percentage change in SUV relative to a baseline measurement. In addition to being easily interpreted, relative units are helpful when one is comparing literature reports that use different SUV formulations. SUV data derived using lean body mass as opposed to total body mass normalization have different ranges and are not directly comparable. However, the use of the relative difference D to characterize repeatability allows comparison of data from different reports irrespective of the SUV normalization schemes."