Is contrast enhancement required to visualize a known breast tumor in a pre-operative CT scan?  Liesbeth J. Boersma, Bianca Hanbeukers, Carla Boetes, Jacques Borger, Piet van den Ende, Els van Haaren, Ruud Houben, Jos Jager, Lars Murrer, Suprapto Sastrowijoto, Angela van Baardwijk  Radiotherapy and Oncology  Volume 100, Issue 2, Pages 271-275 (August 2011) DOI: 10.1016/j.radonc.2011.06.027 Copyright © 2011 Elsevier Ireland Ltd Terms and Conditions

Fig. 1 Example of a clearly visible (A), doubtfully visible (B) or invisible tumor (C) on the native CT (A1–C1), with the corresponding CE-CT (A2–C2). Radiotherapy and Oncology 2011 100, 271-275DOI: (10.1016/j.radonc.2011.06.027) Copyright © 2011 Elsevier Ireland Ltd Terms and Conditions

Fig. 2 Example of a clearly visible (A), doubtfully visible (B) or invisible (C) tumor on the mammography. Radiotherapy and Oncology 2011 100, 271-275DOI: (10.1016/j.radonc.2011.06.027) Copyright © 2011 Elsevier Ireland Ltd Terms and Conditions

Fig. 3 Tumor volume on the CE-CT versus the native CT, r2=0.87 (Figure 3A), and maximum tumor diameter on the native CT, versus the maximum diameter on ultrasound (open squares) and pathology (closed squares) (r2=0.53 and 0.18, respectively), Figure 3B). Radiotherapy and Oncology 2011 100, 271-275DOI: (10.1016/j.radonc.2011.06.027) Copyright © 2011 Elsevier Ireland Ltd Terms and Conditions