Parviz Farshid

Liver metastases of pancreatic cancer: role of repetitive transarterial chemoembolization (TACE) on tumor response and survival.

Objective: To evaluate the effect of chemoembolization on pancreatic cancer liver metastases. Method: Thirty-two patients with pancreatic cancer liver metastases retrospectively underwent chemoembolization (4- to 8-week intervals). Size-based evaluation (response evaluation criteria in solid tumors [RECIST]) and survival indexes were assessed overall and for sex and number of lesions. Results: Of the patients, 71.87% showed stable disease, 9.37% partial response (PR) and 18.75% progressive disease (PD). Survival rate for 1, 3, and 5 years from first TACE was 60%, 25%, and 11%, respectively. Median survival time was 16 months and for stable disease group was 20 months. Progression-free survival for 6 months and 1, 3, and 5 years was 84%, 57.3%, 20%, and 10%, respectively. There was significant difference between men and women in response. Survival rates for 1 and 5 years for the men were 80% and 14% and for the women were 47% and 0%. There was no significant difference between oligonodular liver lesion (n < 5) and multinodular (n > 5) groups. Survival rates for 1 and 5 years for oligonodular were 84% and 14%, and for multinodular was 50% and 0%. Conclusion: Repetitive TACE resulted in a relevant response for the control of liver metastases of pancreatic cancer with respectable median survival time. Interestingly, the number of lesions, statistically, was not an effective factor.

A liver-mimicking MRI phantom for thermal ablation experiments

PURPOSE To develop a liver-mimicking MRI gel phantom for use in the development of temperature mapping and coagulation progress visualization tools needed for the thermal tumor ablation methods, including laser-induced interstitial thermotherapy (LITT) and radiofrequency ablation (RFA). METHODS A base solution with an acrylamide concentration of 30 vol. % was prepared. Different components were added to the solution; among them are bovine hemoglobin and MR signal-enhancing contrast agents (Magnevist as T1 and Lumirem as T2 contrast agent) for adjustment of the optical absorption and MR relaxation times, respectively. The absorption was measured in samples with various hemoglobin concentrations (0%-7.5%) at different temperatures (25-80 degrees C) using the near-infrared spectroscopy, measuring the transmitted radiation through the sample. The relaxation times were measured in samples with various concentrations of T1 (0.025%-0.325%) and T2 (0.4%-1.6%) contrast agents at different temperatures (25-75 degrees C), through the MRI technique, acquiring images with specific sequences. The concentrations of the hemoglobin and contrast agents of the gel were adjusted so that its absorption coefficient and relaxation times are equivalent to those of liver. To this end, the absorption and relaxation times of the gel samples were compared to reference values, measured in an ex vivo porcine liver at different temperatures through the same methods used for the gel. For validation of the constructed phantom, the absorption and relaxation times were measured in samples containing the determined amounts of the hemoglobin and contrast agents and compared with the corresponding liver values. To qualitatively test the heat resistance of the phantom, it was heated with the LITT method up to approximately 120 degrees C and then was cut to find out if it has been melted. RESULTS In contrast to liver, where the absorption change with temperature showed a sigmoidal form with a jump at T approximately equal 45 degrees C, the absorption of the gel varied slightly over the whole temperature range. However, the gel absorption presented a linear increase from approximately 1.8 to approximately 2.2 mm(-1) with the rising hemoglobin concentration. The gel relaxation times showed a linear decrease with the rising concentrations of the respective contrast agents. Conversely, with the rising temperature, both T1 and T2 increased linearly and showed almost the same trends as in liver. The concentrations of hemoglobin and T1 and T2 contrast agents were determined as 3.92 +/- 0.42 vol. %, 0.098 +/- 0.023 vol. %, and 2.980 +/- 0.067 vol. %, respectively. The measured ex vivo liver T1 value increased from approximately 300 to approximately 530 ms and T2 value from approximately 45 to approximately 52 ms over the temperature range. The phantom validation experiments resulted in absorption coefficients of 2.0-2.1 mm(-1) with variations of 1.5%-2.95% compared to liver below 50 degrees C, T1 of 246.6-597.2 ms and T2 of 40.8-67.1 ms over the temperature range of 25-75 degrees C. Using the Bland-Altman analysis, a difference mean of -6.1/1.9 ms was obtained for T1/T2 between the relaxation times of the phantom and liver. After heating the phantom with LITT, no evidence of melting was observed. CONCLUSIONS The constructed phantom is heat-resistant and MR-compatible and can be used as an alternative to liver tissue in the MR-guided thermal ablation experiments with laser to develop clinical tools for real-time monitoring and controlling the thermal ablation progress in liver.

Retrospective Study on the Use of Different Protocols for Repeated Transarterial Chemoembolization in the Treatment of Patients with Hepatocellular Carcinoma

PURPOSE To evaluate local tumor control and survival rate after repeated transarterial chemoembolization using two different protocols in hepatocellular carcinoma (HCC) patients. MATERIALS AND METHODS A total of 190 patients (mean, 68 years) with HCC were repeatedly treated with transarterial chemoembolization in 4-week intervals. The chemotherapy protocol consisted of mitomycin C alone (n = 111) and mitomycin C with gemcitabine (n = 79). Embolization was performed with lipiodol and microspheres. Tumor response was evaluated by magnetic resonance imaging using Response Evaluation Criteria In Solid Tumors (RECIST) criteria. Survival rates were calculated using Kaplan-Meier method. RESULTS In the mitomycin C-only group, we observed partial response in 38.8% (43/111), stable disease in 27% (30/111), and progressive disease in 34.2% (38/111). In the mitomycin C/gemcitabine group (n = 79), partial response was observed in 43% (34/79), stable disease in 16.5% (13/79) and progressive disease in 40.5% (32/79). The overall 1- and 2-year survival rates were 56% and 28%, respectively. The overall median survival time from the start of transarterial chemoembolization treatment was 15 months. The median survival of patients treated with mitomycin C was 16.5 months and it was 12 months for patients treated with a combination of mitomycin C and gemcitabine. No statistically significant difference between the two groups was observed (P = .7). CONCLUSION Chemoembolization is an effective minimally invasive therapy option for palliative treatment of HCC patients. Mitomycin C only proves to be effective, the addition of gemcitabine was not advantageous.

Repetitive chemoembolization of hypovascular liver metastases from the most common primary sites

AIM To evaluate tumor response in patients with hypovascular liver metastases from the most common primary sites treated with chemoembolization. MATERIALS & METHODS Chemoembolization was performed in 190 patients (five groups) who had hypovascular liver metastases from the colon (n = 66), breast (n = 40), uveal malignant melanoma (n = 20), pancreas (n = 48) and stomach (n = 16). Surgical resection of primary sites had been performed for all included patients. Tumor response, survival statistics from the first chemoembolization using Kaplan-Meier method and progression rate of embolized lesions were evaluated by analysis of variance with Tukeys post hoc test. RESULTS Multiple comparison between the groups showed no statistical significant difference in local tumor response (H: 9.23; p > 0.05). Survival indices of the patients, including survival rate, progression-free survival rate, median survival time and time to progression, demonstrated significant difference between the groups during the follow-up period (H: 9.7; p = 0.045). The progression rate of treated liver metastases from colon, breast, uvea, pancreas and stomach were 16.6, 17.5, 30.0, 25.0 and 32.0%, respectively (p = 0.002). CONCLUSION Hypovascular liver metastases treated with chemoembolization may demonstrate equal local response, but are significantly different in rate of progression and survival.

Effect of chronic liver disease using a multivariate analysis of associated risk factors in patients with hepatocellular carcinoma treated with transarterial chemoembolization

Purpose: To evaluate the effect of chronic liver disease (CLD) in a multivariate analysis of associated risk factors in patients with hepatocellular carcinoma (HCC) using transarterial chemoembolization (TACE). Materials and methods: A total of 145 patients with HCC (99 men, 46 women; mean age: 63 years ±8.1; age range: 46-84 years) underwent 598 TACE procedures. The presence of CLD, number and location of lesions, tumor size, Child-Pugh score, vascularity, portal involvement and alpha fetoprotein value were analyzed using the multivariate regression model. Cox regression was used for survival analysis. Results: The median survival time was 26.7 months, and 78.6% of all treated lesions showed tumor responses. The presence of CLD (OR 2.12, P=0.004), Child-Pugh score B (OR 2.24, P=0.002), alpha fetoprotein >100ng/dl (OR 1.18, P 5cm (OR 4.12, P=0.002) and hypervascularity (OR 7.94, P=0.003) were significant effective factors for a local response when analyzed using a multivariate logistic model. Multivariate survival analysis using Coxs regression model during the median follow-up period of 25 months (range: 1-42 months) demonstrated a significant difference in survival rates (P values 5cm and hypervascularity statistically led to a significant effect in tumor response in HCC patients treated with TACE. Patient gender, location of lesion and involvement of portal vein showed no significant difference in response.