Simultaneous detection of hepatocellular carcinoma and vessel thrombus by using SPIO-enhanced B-TFE with the T2 preparation pulse technique.

The purpose of this study was to compare between superparamagnetic iron oxide (SPIO)-enhanced three-dimensional balanced turbo field-echo (B-TFE) sequence with T2 preparation pulse (T2 prep) and T2*-weighted imaging (T2*WI) for the simultaneous detection of hepatocellular carcinoma (HCC) and vessel thrombus. For 1.5-T magnetic resonance imaging, SPIO was administered to 23 patients with a portal or venous tumor thrombus, and B-TFE with T2 prep and T2*WI were acquired. Regions of interest in the B-TFE and T2*WI were selected for the tumor, liver, tumor thrombus, and vessels. The contrasts of the HCC in the liver and the tumor thrombus in the vessels were determined from clinical image. Contrast was calculated using the mean value of the signal intensity on the HCC to the liver and tumor thrombus to vessels. The mean contrasts between HCC and the liver with the use of B-TFE and T2*WI were 0.61 ± 0.05 and 0.70 ± 0.04, respectively. The contrast of HCC to the liver was significantly higher in T2*WI than in B-TFE (p < 0.05). The mean contrasts between the tumor thrombus and vessels with the use of B-TFE and T2*WI were 0.28 ± 0.02 and 0.10 ± 0.02, respectively. The contrast of tumor thrombus in the vessels was higher in B-TFE than in T2*WI (p < 0.01). Kupffer imaging can be used to assess liver function and acquire morphological images using three-dimensional B-TFE with T2 prep. This technique would be helpful for simultaneous detection of HCC and tumor thrombus.

The Usefulness of Using Fiducial Marker in Proton Therapy for Locally Advanced Pancreatic Cancer.

BACKGROUND: Though the dosimetric criteria for the gastrointestinal tract were met, late gastrointestinal toxicity was seen in several cases. Therefore, we thought that it was caused by the positional variation of gastrointestine surrounding pancreatic cancer because of peristalsis. METHOD: They were confirmed by CT image regularly. And we evaluated that how much the difference of matching methods for correcting the positional variation influenced dose distribution. RESULT: The fiducial markers could follow the position of pancreatic cancer and the duodenum. But it could reproduce the dose distribution to pancreatic cancer and the duodenum. DISCUSSION: In proton therapy, the reproducible improvement of the duodenum position did not make the dose of the duodenum same as planning dose because the matching of fiducial markers made the positional relations between beam compensator and the duodenum change. CONCLUSION: The fiducial markers are useful for correcting the position of pancreatic cancer and the duodenum. But in proton therapy, it could not reproduce the dose distribution to pancreatic cancer and the duodenum.