The phrase "a key topic of" is correct and usable in written English.
It can be used when discussing an important subject or theme within a particular context, such as an article, presentation, or discussion.
Example: "Climate change is a key topic of our upcoming conference, and we will have several experts speaking on the issue."
Alternatives: "an important subject of" or "a central theme of".
For instance, stop and frisk, which on Monday was ruled unconstitutional, will likely be a key topic of Tuesday's debate.
A key topic of the school in quiry will be where integrated schools have succeeded and why, Senator Mondale said.
Fertilizer is a key topic of discussion everywhere — most obviously because sustainable intensification means curbing overuse in the industrial world.
Morrison will attend the G20 finance ministers meeting in China on Friday, where he expects Brexit will be a key topic of discussion.
Since the pioneering studies developed by Alan G. Davenport, the equivalent static actions on structures are a key topic of the wind engineering research.
Besides improving the energy efficiency by reducing energy consumption and improving the match between energy supply and demand, energy quality issues have become a key topic of interest.
The ability to tune supramolecular chirality both on nano and meso scale is a key topic on the design of mimetic antenna systems.
Understanding how to create a superior CX is a key topic on the minds of most marketing leaders.
Knowledge of electronic and molecular structure of excited states of photosensitizers and intermediates of catalysts is a key topic for rational design of systems for artificial photosynthesis.
Moreover the smart and transparent memory management is a key topic for the development of the CUDA programming model, as demonstrated by the Unified Memory (http://devblogs.nvidia.com/parallelforall/unified-memory-in-cuda-6/) feature introduced CUDA 6.0.
In doing so, our work addresses 21st century skill assessment in two ways, namely of inquiry (designing and conducting experiments), and in the context of complex systems, a key topic area of 21st century skills.
