Brief Answer:
Radiation is localized, with less general side effects.

Detailed Answer:
Hello and thanks for using HCM.

I have read your question and understand your concerns.

It depends on what tumor or disease and the exact location, in order to have a better understanding of your concerns.

For example, a lesion near basal ganglia in brain could pose more risk of worsening Parkonson's if treated by radiation instead of chemotherapy.

It is known also that chemotherapy worsens all previous diseases including Parkonson's.

In general, radiation therapy is localized, not systemic, and with less general side effects.

But, the nature and sensibility of the lesion that should be treated towards radiation and chemo is needed also to be known.

Hope you found the answer helpful.

Let me know if I can assist you further.

Take care.

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