Could these two words be replaced in any context or the meaning is not exactly the same? In particular if I'm listening a podcast or a radio show do hosts of this show discuss one theme after another or one topic after another? Or both words could be used in this context?
When referring to something like a podcast or a regular column, theme refers to the overall subject of the work. "It's a weekly podcast about economics" is the same as "The theme of the podcast is economics". Topic, on the other hand, refers to the subject of an individual episode. "Today we have three topics: long-term interest rates, the Tokyo stock market, and last week's unemployment report".
In other kinds of short works, for example a stand-alone essay for school, "theme" and "topic" are generally interchangeable.
EDIT: as prompted by @Andrew below: For larger works, especially fiction or persuasive writing, the "topic" is the actual, literal subject being discussed, while the "theme" is the broader subject, the point or message that the author is trying to convey.
As John says, "theme" is more diffuse and general than "topic". "Topic" is focused.
Examples might be "Disneyworld has a fantasy theme", and "the topic of the discussion was world peace". But "the theme of the conference was world peace" because a conference is likely to have many discussions. "The topic of the conference was world peace" would sound slightly odd, but only slightly. "Theme" isn't quite as flexible as «тема» is.
In your radio example, "one topic after another", but "the theme of today's programming is the climate disaster, and climate experts all around the planet will discuss the topics of reducing CO2, human overpopulation, and the prospect of pan-extinction."