**Core Concept**
Gamma Knife is a type of stereotactic radiosurgery (SRS) device used to treat various types of intracranial lesions, including arteriovenous malformations (AVMs), brain tumors, and trigeminal neuralgia. It delivers precise, high-dose radiation to small, well-defined targets within the brain.

**Why the Correct Answer is Right**
Gamma Knife works by using a large number of cobalt-60 sources arranged in a helmet-like configuration to deliver a focused beam of radiation to the target. The radiation is precisely directed at the target using a stereotactic frame, which allows for accurate localization and targeting of the lesion. This technique is particularly useful for treating lesions that are difficult to access surgically or for patients who are poor candidates for open surgery.

**Why Each Wrong Option is Incorrect**
**Option A:** Gamma Knife is not typically used for treating conditions outside the brain, such as spinal cord tumors or peripheral nerve disorders.
**Option B:** While Gamma Knife is a type of radiosurgery, it is not the same as conventional radiation therapy, which is used to treat a broader range of conditions.
**Option C:** Gamma Knife does not involve the use of a traditional surgical incision or the removal of tissue.

**Clinical Pearl / High-Yield Fact**
Gamma Knife is a non-invasive treatment option that allows for precise targeting of small lesions within the brain, reducing the risk of complications and improving patient outcomes.

**Correct Answer:** D.