又来请教反应问题。

The primary end point of the randomized arms was to determine the CR rate by positron emission tomography/computed tomography (PET-CT) imaging at the end of treatment (EOT; 6-8 weeks after cycle 6 day 1, or last dose of study treatment) as determined centrally by an IRC using the modified Lugano criteria (supplemental Material).

请问括号内的内容怎么翻译：（EOT; 6-8 weeks after cycle 6 day 1, or last dose of study treatmen）

为什么day后面又跟个“1”，实在是不好理解。