Most radiosensitive tumor among following is –
**Core Concept**
Radiosensitivity refers to the susceptibility of cells or tissues to damage caused by ionizing radiation. Tumors with a high growth fraction, rapid cell division, and minimal DNA repair mechanisms are more responsive to radiation therapy.
**Why the Correct Answer is Right**
The most radiosensitive tumor among the options is the Burkitt lymphoma. This is because Burkitt lymphoma is a high-grade lymphoma with a high proliferative rate, resulting in a high growth fraction. The tumor cells have minimal DNA repair mechanisms, making them more susceptible to radiation-induced damage. Additionally, the tumor's rapid cell division rate leads to a higher likelihood of radiation-induced DNA breaks and cell death.
**Why Each Wrong Option is Incorrect**
**Option A:** Lymphoblastic lymphoma is a highly aggressive lymphoma, but it is not as radiosensitive as Burkitt lymphoma due to its lower growth fraction and more complex DNA repair mechanisms.
**Option B:** Medulloblastoma is a highly malignant brain tumor, but its radiosensitivity is comparable to, but not greater than, that of Burkitt lymphoma.
**Option C:** Ewing's sarcoma is a highly aggressive bone tumor, but its radiosensitivity is not as high as that of Burkitt lymphoma due to its lower growth fraction and more complex DNA repair mechanisms.
**Clinical Pearl / High-Yield Fact**
Burkitt lymphoma is a classic example of a tumor that is highly responsive to chemotherapy and radiation therapy, making it a prime candidate for curative treatment with these modalities.
**Correct Answer: C. Burkitt lymphoma**