Final answer:
Stereotactic radiosurgery performed after the resection of a malignant meningioma is an example of adjuvant therapy, which is a secondary treatment used to improve therapeutic outcomes by focusing radiation in a way that enhances the therapeutic ratio. Therefore, the correct option is a.
Step-by-step explanation:
The question is asking about a specific type of therapy used after the surgical removal of a malignant meningioma, which is a type of brain tumor. Stereotactic radiosurgery performed after the resection of a malignant meningioma is an example of adjuvant therapy. Adjuvant therapy is additional treatment given after the primary treatment to lower the risk of the cancer coming back. This can include various treatment modalities such as chemotherapy, radiation therapy, hormone therapy, targeted therapy, or immunotherapy, depending on the type of cancer and other factors.
In the context of the question, the use of stereotactic radiosurgery represents a form of radiotherapy that contributes to an improved therapeutic ratio. By focusing radiation beams from multiple angles to converge on the site of the tumor, this technique aims to maximize the radiation dose to the cancer cells while minimizing exposure to the surrounding healthy tissue. This approach enhances the ratio of cancer cells destroyed to normal cells affected, thereby improving patient outcomes.