Table 1.

Categories and treatment options for OS.

Subtype of OS	Incidence	Common anatomical distribution	Chemosensitivity	Radiosensitivity
Conventional OS (3 subtypes: osteoblastic, chondroblastic, fibroblastic)	75.0%	Metaphysis of long bone around knee and shoulder joint, axial skeleton	Sensitive	Radiotherapy can be useful
Parosteal OS	3.5–4%	Posterior cortex of distal femur	Hyposensitivity	Hyposensitivity
Telangiectatic OS	3–4%	Similar to conventional OS	Sensitive	Hyposensitivity
Periosteal OS	1.5–2%	Tibia or femur	Hyposensitivity	Hyposensitivity
Small cell OS	1.5%	—	Sensitive	Sensitive
Low grade central OS	1–2%	Intramedullary distal femur, proximal tibia, pelvis	—	—
High-grade surface OS	<1%	Long bone, distal femur	Sensitive	Radiotherapy can be useful