**Core Concept**
Renal cell carcinoma (RCC) is a type of kidney cancer that can invade nearby structures, including the inferior vena cava (IVC) and renal vein. The involvement of these structures is crucial in determining the operability of the tumor.

**Why the Correct Answer is Right**
IVC involvement does not necessarily indicate inoperability. In fact, surgical resection of the tumor with IVC involvement is possible in selected patients. The decision to operate is based on various factors, including the patient's overall health, the extent of the tumor, and the presence of metastasis. The involvement of the IVC requires specialized surgical techniques, such as IVC reconstruction or replacement, but it does not preclude surgery altogether.

**Why Each Wrong Option is Incorrect**
**Option A:** Pre-op biopsy is not necessary. This is incorrect because a biopsy is essential for confirming the diagnosis of RCC and determining the tumor's histological subtype, which guides treatment decisions.
**Option C:** Pre-op radiotherapy is not essential. This is incorrect because preoperative radiotherapy may be considered in selected patients to shrink the tumor and make it more resectable.
**Option D:** Chest X-ray should be done to rule out pulmonary metastasis. This is incorrect because a chest X-ray is not sufficient to rule out pulmonary metastasis. A more comprehensive imaging study, such as a CT scan of the chest, is required to accurately assess for metastasis.

**Clinical Pearl / High-Yield Fact**
In patients with RCC invading the IVC, the primary concern is the risk of tumor thrombus embolization during surgery, which can lead to pulmonary embolism. Therefore, patients with IVC involvement require close monitoring and careful surgical planning to minimize this risk.

**✓ Correct Answer: B. IVC involvement indicates inoperability**