**Core Concept**
Intraoperative sentinel lymph node detection is a technique used to identify the first lymph node to which cancer cells are likely to spread from a primary tumor, in this case, from the breast or melanoma in the axilla. This method helps in accurate staging and planning of further treatment.

**Why the Correct Answer is Right**
The correct answer involves the use of a radioactive tracer that is injected near the tumor site. This tracer accumulates in the sentinel lymph node due to its high blood flow and unique lymphatic drainage pattern. The surgeon can then use a gamma probe to detect the radioactive signal and remove the sentinel lymph node for histopathological examination. This technique is particularly useful in breast cancer and melanoma, allowing for more accurate staging and reducing the need for axillary lymph node dissection.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not mention a specific technique or method used for sentinel lymph node detection. While it may be related to the topic, it is too vague to be correct.
* **Option B:** This option is incorrect as it does not specify the use of a radioactive tracer or a gamma probe, which are essential components of the sentinel lymph node detection technique.
* **Option C:** This option is incorrect as it mentions a different procedure altogether, which is not related to sentinel lymph node detection.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the sentinel lymph node is not always the first lymph node to receive cancer cells, but it is the first node to receive cells from the primary tumor, making it a crucial marker for staging and planning treatment.

**Correct Answer: D. Radioisotope with a gamma probe.**