**Core Concept:** Radiation therapy for bone pain relief in patients with bone metastases typically involves fractionation, which is the process of delivering radiation in smaller doses over a longer period. The goal is to achieve a balance between pain relief and minimizing the risk of radiation-induced complications.

**Why the Correct Answer is Right:** For bone pain relief, the recommended dose of radiation therapy is **D.** 50 Gy (Gray) in 20 fractions over 5 weeks is often used. This dose is chosen because it provides sufficient pain relief while minimizing the risk of complications such as radiation-induced bone marrow suppression and secondary malignancies. Lower doses may not be effective in controlling pain, while higher doses can increase the risk of complications.

**Why Each Wrong Option is Incorrect:**

A. 30 Gy in 10 fractions over 2 weeks (3 Gy per fraction): Lower dose, which may not be effective for pain relief.
B. 60 Gy in 10 fractions over 2 weeks (6 Gy per fraction): Higher dose may increase the risk of complications, such as radiation-induced bone marrow suppression and secondary malignancies.
C. 2 Gy per fraction for 50 fractions: This dose schedule is generally used for palliative radiotherapy (e.g., in case of brain tumors), not bone pain relief in bone metastases.

**Clinical Pearl:** When treating bone pain from bone metastases, it is essential to consider the balance between pain relief and the risk of complications. A dose of 50 Gy in 20 fractions over 5 weeks offers a reasonable compromise.

**Correct Answer:** D. 50 Gy in 20 fractions over 5 weeks.