Temporal CT changes after hepatic and renal interstitial radiotherapy in a canine model.
OBJECTIVE
The purpose of this work was to define the temporal CT characteristics of hepatic and renal ablation following point-source radioablation utilizing a low energy, photon X-ray source emitted from a miniature probe.


METHODS
Twelve mongrel dogs underwent each of three hepatic and two renal point-source radiation ablations. Animals underwent serial, dual phase, spiral CT scans and were killed at 1, 3, and 6 months after treatment.


RESULTS
Ablative lesions were clearly visible at 1 month following therapy and consistently diminished in size over the 6 months of follow-up. Lesion size tended to be proportional to dose delivered. Both hepatic and renal lesions were low in attenuation with frequent rim enhancement that diminished over time. Hepatic lesions frequently showed transient hepatic attenuation differences (THADs). Lesion size appeared independent of proximity to vessels.


CONCLUSIONS
Following hepatic or renal interstitial radiotherapy, lesions are generated that are similar in CT appearance to those produced by other ablative techniques. The presence of rim or THAD enhancement can be seen early on as part of the normal tissue-healing response.
Solomon
S B
SB
Department of Radiology, Johns Hopkins Hospital, Baltimore, MD 21287, USA. ssolomo@jhmi.edu
Koniaris
L G
LG
Chan
D Y
DY
Magee
C A
CA
DeWeese
T L
TL
Kavoussi
L R
LR
Choti
M A
MA
D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D014567:Urography