JVIR 䡲 Scientific Session
Wednesday 䡲 S111
cell death after hyperthermia. Here, we have assessed the combination of Dbait and RFA in the treatment of human colorectal cancer model xenografted in nude mice. Materials and Methods: 98 mice were flank-grafted with HT29 (human colon adenocarcinoma). When tumor reached 500 mm3, mice were sham treated (n⫽19), treated by Dbait via local injections (n⫽20), treated by RFA using an incomplete ablation scheme (n⫽20) or treated by combination of Dbait and RFA (n⫽39 separated in two Dbait regimens). After RFA, 39 mice were sacrificed for blinded pathological study, and 59 others were followed for survival analysis. Results: Mice treated by RFA-Dbait had significantly longer survival as compared to RFA alone (median survival: 56 vs 39 days, p⬍0.05) while RFA improved survival as compared to controls (median survival: 39 vs 28 days, p⬍0.05). Pathological studies of tumor slice have demonstrated significant decrease of tumor area and cancer cell viability in the RFA-Dbait group. Conclusion: While the implication of DNA repair activity in heat sensitivity remains unclear, our results show that the addition of Dbait to RFA enhances the antitumor response in this model and provide an experimental basis for the use of Dbait as an additional therapy to RFA. Survival Study
Pathological Study
Number Median Treatment Sham treated
Partial
(days) Response* Response* Samples 28
Tumoral
Complete of Tumor
Viable Mitosis**
Cells (%)
0/12
0/12
7
19.4 ⫾ 1.5
74 ⫾ 3
Area (mm2) 23.7 ⫾ 8.2
Dbait (24 mg)
35
0/12
0/12
8
16 ⫾ 1.3
54 ⫾ 6.1
14.25 ⫾ 1.5
RFA
39
1/12
1/12
8
14 ⫾ 15
41 ⫾ 6.4
13.5 ⫾ 2.6
RFA ⫹ Dbait
44
5/12
1/12
8
4.4 ⫾ 1.7
21 ⫾ 6.6
5.75 ⫾ 1.6
56
3/11
6/11
8
(12 mg) RFA ⫹ Dbait
In progress In progress In progress
(24 mg) * RECIST criteria **Mean value of 5 representative fields at magnification ⫻40 for each tumor sample.
2:02 PM
Abstract No. 272
H.J. Bang1, P.J. Littrup, M.D.2, L. Klein3, B.P. Currier2, D.J. Goodrich4, J. Kuo1, H.D. Aoun2, B. Adam2; 1 Radiology, Wayne State University, Detroit, MI; 2 Radiology, Karmanos Cancer Institute, Detroit, MI; 3 University of Michigan, Ann Arbor, MI; 4University of California-Los Angeles, Los Angeles, CA Purpose: Percutaneous cryoablation (PCA) of metastatic breast cancer was conducted to assess complications, local tumor recurrences, and overall survival (OS). Materials and Methods: 9 CT and/or US-guided, percutaneous cryoablation procedures were performed on 9 tumors in 8 patients with oligometastatic disease from breast cancer. Tumor location was grouped according to metastatic sites: liver, lung and kidney. Complications were assessed according to Common Toxicity Criteria for Adverse Events Version 3.0 (CTCAE). Median survival was given from the time of stage IV diagnosis until PCA, in addition to survival time afterward in order to assess the adjunctive role of PCA. Treatment was centered on patients presenting with metastatic lesions who had already undergone resection of the primary cancer (e.g., mastectomy).
2:10 PM
Abstract No. 273
Assessing the effect of weight-based protocol modifications to lower dose from CT-guided liver and renal tumor ablations S. Gupta, R. Arellano, D.A. Gervais, D. Sahani; Radiology, Massachusetts General Hospital, Boston, MA Purpose: CT-guided interventions are increasingly replacing more invasive techniques for a variety of tumors in the abdomen.Despite benefits, procedure related radiation dose to patients are of concern. Our purpose was to measure existing radiation dose following image-guided percutaneous thermal ablations of hepatic and renal tumors and the effect on image-quality of weight based CT protocol modification for lowering the overall dose in these procedures. Materials and Methods: Between January 2009 and December 2009, CT-guided renal and hepatic ablations were reviewed to determine radiation doses as CT Dose index and Dose Length Product for the pre-, intra- and post-procedure scanning phases. A weight-based protocol modification (changes in kVp⫽100-120, mA⫽80-220) was then prospectively applied to renal and hepatic ablation performed subsequently. Patients were assigned to three weight categories as follows: Group 1⫽ ⬍180 pounds (lbs), Group 2 ⫽180-250 lbs and Group 3 ⬎250 lbs. Image quality, needle localization, lesion detection, ability to detect complications and overall operator satisfaction was noted for each case (score 1-5). The dose reduction following modification was then calculated. Results: Retrospective analysis found the average CTDi and DLP for CT guided ablations to be 16.5 and 268.5.The distribution of doses, pre, intra and post procedure was 29.88%, 35.11% and 35.0% and average CTDI was 14.8, 17.4 and 17.3 respectively. After protocol modifications, the mean CTDI for pre, intra and post procedure were 7.4, 6.2, 6.3, with a mean 59.64% reduction The operator showed high overall satisfaction with the modified images and rated the quality as diagnostic (3-5) and found adequate needle localization (4-5), lesion visibility (3-5) and ability to detect complications in all the cases. Conclusion: CT guided liver and renal ablation contributes substantial dose to the patients with significantly higher dose with liver ablation. Simple weight-based protocol modification of various phases of CT guidance can facilitate optimal procedure success with ⬎ 50% dose reduction.There was a significantly higher dose reduction for patients ⬎200lbs as compared to patients with weight ⬍180lbs.
WEDNESDAY: Scientific Sessions
Percutaneous cryoablation of metastatic breast cancer: initial survival, local control, and cost observations
Results: Tumor and procedure numbers, respectively, for each site were 4 liver, 3 lung and 2 kidney. A mean of 1.1 PCAs per patient was performed. There were no major complications (CTCAE) and zero local recurrences occurring in this study. Median OS for our patients from time of stage IV diagnosis was 3.8 years (46 months) with an observed 5-year survival rate of 25%. Average time from stage IV diagnosis until PCA was 16 months and average survival after treatment was 30 months. 75% (6/8) of patients had undergone at least a single mastectomy prior to PCA treatment. Conclusion: PCA of metastatic breast cancer lesions is a welltolerated adjunctive treatment with low recurrence and complications rates. PCA may be coupled with other treatments in order to better control metastatic disease, particularly those seeking local control of additional lesions following metastasectomy.