Prior to starting multimodal chemotherapy for osteosarcoma, which diagnostic test is NOT routinely indicated to establish baseline organ function?

• A. Glomerular filtration rate (GFR)
• B. Audiogram
• C. Pulmonary function test (PFT)
• D. Echocardiogram

Answer: (C)

Assessing baseline organ function before multimodal chemotherapy focuses on the toxicities linked to the drugs used. Evaluating kidney function with GFR is essential because cisplatin and methotrexate can injure the kidneys and drug clearance hinges on renal function. An audiogram is important due to the well-known risk of cisplatin-induced ototoxicity, which can be irreversible, so a baseline helps detect any changes during therapy. An echocardiogram is done because doxorubicin has a dose-dependent risk of cardiomyopathy; knowing the starting cardiac function guides safe dosing and monitoring for early cardiac effects. Pulmonary function testing isn’t routinely performed in this setting since the standard regimen for osteosarcoma (methotrexate, doxorubicin, cisplatin) doesn’t have a primary, predictable pulmonary toxicity like bleomycin does, and PFT would be reserved for patients with preexisting lung disease or planned exposure to agents with known pulmonary toxicity.