The phrase "a question of stages" is correct and usable in written English.
It can be used when discussing a process or situation that involves different phases or steps that need to be considered.
Example: "The project is complex, and it's really a question of stages; we need to tackle each phase one at a time."
Alternatives: "a matter of phases" or "an issue of steps".
The best therapy, therefore, is not a question of tumor stage, but is dependent on the individual mutational status and how rapidly the tumor progresses.
As India released the first technical details of its tests, the Foreign Minister of Pakistan, Gohar Ayub Khan, was quoted today as having said that it was not a question of whether Pakistan would stage a nuclear test, but when.
That left open a question of whether American bombers would have staging areas in any of Afghanistan's immediate neighbors.
I think it's a question of inevitably yes, but the issue staging.
At this stage, it seems a question of how quickly Novak Djokovic can get this done.
In essence, at this stage, it is a question of mindset.
Although Barney spends a lot of time with performers, making the question of staging spontaneity more explicit than usual, her best pictures seem to catch her subjects slightly off guard.
Sediments also affect the roughness and the frictional resistance of natural waterways, thus raising the question of stage-discharge-sediment transport relationships.
This same strategy, when applied to a drama, however, doesn't allow students to account for dramatic action, situational irony, subtext, questions of staging, and moments of ambiguity that, as any director will tell you, are the meat and potatoes of dramatic interpretation.
In fact, when we examine noncancer toxicity of agents, including examination of the changes in subjects without the fully developed endpoint in question, we see a progression of stages of increasing impact, and it is not only the final frank effect that shows dependence on exposure level or duration.
