Fate of necrotic volume after microwave ablation of multiple liver metastases.
OBJECTIVE
The aim of this study was to find the rate of shrinkage of necrosis and time of peak ablation volume after multiple microwave ablations in the treatment of multiple liver metastases of colorectal cancer. These factors are not known and are important in evaluation of treatment and identification of local recurrence, as microwave treatment is becoming more used thanks to improved technology in diagnostics and interventional therapy.


METHODS
A retrospective analysis of non-cirrhotic patients with multiple liver only metastases of colorectal cancer, not suited for resection for this reason. Patients were selected for palliative microwave treatment at a liver multidisciplinary team conference. 68 ablations were made in six patients. Ablation volume was analysed with repeated imaging and computer analyses.


RESULTS
The ablation volume peeks after 5-7 days where after reduction of the necrosis in the liver occurs logarithmically with a 60% reduction of ablation volume after 100 days and 80% after a year.


CONCLUSIONS
Liver regeneration after microwave ablations occurs at a constant logarithmic rate after an initial expansion of the ablation volume during the first five days. Evaluation of ablation volume in comparison to tumour volume must take this into account so that follow-up imaging is properly timed.
J
J
Engstrand
H
H
Nilsson
A
A
Jansson
E
E
Jonas
J
J
Freedman
D055011:Ablation Techniques / Q000009:adverse effects / Q000401:mortality; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D008115:Liver Regeneration; D008279:Magnetic Resonance Imaging; D008297:Male; D008872:Microwaves / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D009336:Necrosis; D010166:Palliative Care; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden