**Core Concept**
Sentinel lymph node biopsy is a procedure used in the management of cancer, particularly breast cancer, melanoma, and other malignancies. It involves identifying and removing the sentinel lymph node, which is the first lymph node to which cancer cells are likely to spread from the primary tumor. This procedure helps in determining the stage of cancer and guiding further treatment.

**Why the Correct Answer is Right**
The sentinel lymph node is identified using a radioactive tracer or a blue dye, which is injected near the tumor. The tracer or dye accumulates in the sentinel lymph node, making it identifiable. The sentinel lymph node biopsy is performed by removing this node and examining it for cancer cells. If the sentinel lymph node is negative, it is likely that the cancer has not spread to other lymph nodes, and further treatment may not be necessary. The sentinel lymph node biopsy is a crucial diagnostic tool in cancer management, helping to avoid unnecessary lymph node dissections.

**Why Each Wrong Option is Incorrect**
**Option A:** - This option is incorrect because sentinel lymph node biopsy is not used for diagnosing cancer recurrence. While it can be used to assess the presence of residual disease after treatment, its primary purpose is to determine the stage of cancer at the time of diagnosis.

**Option B:** - This option is incorrect because sentinel lymph node biopsy is not a treatment modality. It is a diagnostic procedure used to identify cancer spread, and treatment decisions are made based on the results.

**Option C:** - This option is incorrect because sentinel lymph node biopsy is not used for all types of cancer. While it is commonly used in breast cancer and melanoma, it may not be as useful in other types of cancer, such as colorectal cancer.

**Clinical Pearl / High-Yield Fact**
The sentinel lymph node biopsy is a minimally invasive procedure that can help avoid unnecessary lymph node dissections, reducing the risk of complications such as lymphedema and infection. It is essential to identify the sentinel lymph node accurately to ensure the correct staging of cancer.

**Correct Answer:** C.