NCCN ALL Response Criteria for Lymphomatous Extramedullary Disease Partial Remission

**Semantic type:** Intellectual Product

**Definition:** Greater than 50 percent disease in the sum of product of greatest perpendicular diameters (SPD) of the mediastinal enlargement for patients with a previous positive PET scan, post-treatment PET must be positive in at least one previously involved site. (Adapted from NCCN Guidelines, Version 1.2020, February 20, 2020)