51yo otherwise healthy male who presented with weight loss, dyspnea, chest discomfort. CT with left apical pleural-based mass ~6cm, partially necrotic left AP window mediastinal lymph node mass ~3.5cm, left 3rd and 4th rib cortical destruction. PET with hypermetabolism of LUL mass, mediastinal LN, left 3rd-5th rib involvement, L3, and T3-T4 epidural space involvement, hypermetabolic R gluteus lesion. Core needle biopsy of LUL mass, pathology positive for spindle cell neoplasm, favor carcinoma. "Poorly differentiated neoplastic cells with a largely spindle cell morphology. Individual cells have largely moderate nuclear pleomorphism with nuclear hyperchromatism and a modest amount of cytoplasm. Scattered distinct nucleoli are present. The neoplastic cells are diffusely and strongly positive for CK7 and some patchy positivity for CK5/6. There is weak staining for GATA3 and SATB2. There is patchy weak positivity for NKX3.1. They are negative for CK20, CDX2, PAX8, mucicarmine, TTF-1, p40, and Napsin A. There is patchy positivity for both D2-40 as well as calretinin. In addition, there is MOC-31 and Ber-EP4 positivity as well as patchy positivity for BG8 controls stain appropriately." Would you recommend treating this as oligometastatic disease with RT to ribs, spine and gluteus lesions and concurrent chemoRT to the thoracic disease? Or treat as metastatic disease with systemic therapy? Also, given the spindle cell morphology, what regimen would you recommend using?