Hodgkin lymphoma, stage IIb, bulky. 130mm, after 8 cycle of ABVD, PET +, hypermetabolic mass and increase its size to 141mm! Why? Is Stanford V helpful?

Jury not out. There is ongoing trial to answer your question but previous studies suggest ABVD superior. That said, factors such as radiotx and personal immune response to Hodgkin D need to be considered. Fail cases to conventional chemoradiotx appear to respond to immune therapy, ie. PD-1 Blockade with Nivolumab in Relapsed or Refractory Hodgkin's Lymphoma N Engl J Med 2015; 372:311-319. Confirm ur dx 1st step.