Radioembolization for primary and metastatic liver cancer

Performance evaluations of demons and free form deformation algorithms for the liver region

We investigated the influence of breathing motion on radiation therapy according to four- dimensional computed tomography (4D-CT) technology and indicated the registration of 4D-CT images was significant. The demons algorithm in two interpolation modes was compared to the FFD model algorithm to register the different phase images of 4D-CT in tumor tracking, using iodipin as verification. Linear interpolation was used in both mode 1 and mode 2. Mode 1 set outside pixels to nearest pixel, while mode 2 set outside pixels to zero. We used normalized mutual information (NMI), sum of squared differences, modified Hausdorff-distance, and registration speed to evaluate the performance of each algorithm. The average NMI after demons registration method in mode 1 improved 1.76% and 4.75% when compared to mode 2 and FFD model algorithm, respectively. Further, the modified Hausdorff-distance was no different between demons modes 1 and 2, but mode 1 was 15.2% lower than FFD. Finally, demons algorithm has the absolute advantage in registration speed. The demons algorithm in mode 1 was therefore found to be much more suitable for the registration of 4D-CT images. The subtractions of floating images and reference image before and after registration by demons further verified that influence of breathing motion cannot be ignored and the demons registration method is feasible.

Dosimetric aspects of 166Ho brachytherapy biodegradable glass seed

The purpose of this study is to perform absorbed dose calculations based on Monte Carlo simulations for a novel beta emitter bioglass Ho-166 seed which is proposed for treating small hepatocellular carcinomas (HCCs). The bioactive glass seed has been developed by use of the sol-gel method. Monte Carlo simulations were carried out for the seed using the version 5 of the (MCNP) Monte Carlo radiation transport code to investigate the dosimetric parameters recommended by the AAPM Task Group 60 (TG-60). Dose distributions due to the beta and photon radiation were obtained at different radial distances surrounding the source. The dose rate in water at the reference point was calculated to be 6.71 ± 0.4 cGy h(-1) μCi(-1). The anisotropy function values ranging from 0.745 to 1.928 were obtained for radial distances of 0.3-8 mm and polar angles of 0°-90°. The (166)Ho seed source can deliver high radiation doses to the tumor, while the short range of the beta particles limits damage to the adjacent normal tissue.

Treatment of recurrent intrahepatic cholangiocarcinoma

Background

The aims of this study were to evaluate risk factors for recurrence following hepatectomy with curative intent for intrahepatic cholangiocarcinoma (ICC), and predictors of survival after intrahepatic recurrence.

Methods

All patients with ICC who underwent liver resection between January 1997 and August 2011 in a single centre were analysed retrospectively. Clinicopathological factors likely to influence recurrence and postrecurrence survival were assessed by univariable and multivariable analysis.

Results

A total of 87 patients were analysed. R0 resection was achieved in 65 patients (75 per cent). Eighty-three patients survived more than 1 month after resection. Median survival was 33 months, with 1-, 3- and 5-year actuarial survival rates of 79, 47 and 31 per cent respectively. Recurrence occurred in 45 (54 per cent) of the 83 patients, most frequently in the liver (25 patients). Satellite nodules (odds ratio (OR) 8·17, 95 per cent confidence interval 1·38 to 48·53; P = 0·021), hilar lymph node metastases (OR 5·24, 1·07 to 25·75; P = 0·041) and perineural invasion (OR 9·68, 1·07 to 87·54; P = 0·043) were identified as independent risk factors for recurrence. Repeat hepatectomy (P = 0·003) and intra-arterial yttrium-90 radiotherapy (P = 0·048) were associated with longer survival after intrahepatic recurrence.

Conclusion

Satellite nodules, hilar lymph node metastases and perineural invasion are risk factors for recurrence following resection with curative intent for ICC. Repeat hepatectomy and labelled yttrium-90 radiotherapy may improve survival after intrahepatic recurrence.

Yttrium-90 microsphere radioembolization for treatment of lung cancer hepatic metastases

Because stage 4 lung cancer is associated with dismal 5-year survival rates, new treatment approaches targeting extrapulmonary disease are necessary. Yttrium-90 microsphere radioembolization is an emerging treatment for metastatic hepatic malignancies that results in high tumor response rates and extended patient survival. To date, application of this therapy toward management of lung cancer hepatic metastases has not been extensively described. Herein, we present 2 cases of effective yttrium-90 radioembolization for treatment of lung cancer hepatic metastases, and emphasize the potential coadjuvant value of this procedure in patients with advanced-stage lung cancer and liver-dominant metastatic disease.