High-intensity Focused Ultrasound Treatment (HIFU) for the Advanced Pancreatic Cancer

PURPOSE: We wanted to evaluate the levels of effect and safety of high-intensity focused ultrasound ablation (HIFU) for treating patients with advanced pancreatic cancer. MATERIALS AND METHODS: Nineteen sessions of HIFU, with the patients under general anesthesia, were performed in 18 patients with advanced pancreatic cancer. The change of the gray-scale of the target lesion was analyzed during HIFU, and MRI was performed before and after HIFU. We assessed the extent of coagulative necrosis, the change of pain and the complications after HIFU. The change of tumor size and the survival of patients were also evaluated. RESULTS: The average size of tumor was 4 cm in diameter. Eighty nine percent of the target tumors showed increased echogenicity. On MRI, necrosis of the entire target tumor occurred in 79% of the patients. After treatment, effective pain relief was noted in 89% of the patients. There were no major complications. No size increase of the treated tumor was noted during 24 weeks of follow-up for 10 patients. Six patients among 12 patients who were available for follow-up are still alive and they are receiving chemotherapy. Six patients expired due to other disease or progression of metastasis. CONCLUSION: HIFU is a safe method without any major complications, and it is effective for inducing tumor necrosis and achieving pain control for patients with advanced pancreatic cancer.

Evaluation of Therapeutic Effect of Acoustic Schwannoma After Gamma-Knife Radiosurgery using Follow-up MRI

PURPOSE: To evaluate, using short-term follow-up MR imagings, the usefulness of gamma-knife radiosurgery in patients with acoustic schwannoma. MATERIALS AND METHODS: In 34 patients (M:F=11:23, aged 11 -69 years) with acoustic schwannoma, eleven of whom had undergone microsurgical resection prior to gamma-knife radiosurgery, we retrospectively reviewed the serial MR imaging findings obtained before and after this procedure. Analysis focused on post-surgical changes in tumor volume and intratumoral enhancement, and the follow-up period ranged from 3 to 44 months. RESULTS: Follow-up imaging revealed that after radiosurgery, tumor size had decreased in 17 cases (50%), was unchanged in 14 (41.2%), and had increased in three (8.8%). Local tumor control was achieved in 31 of 34 cases (91.2%). Objectively defined tumor shrinkage was seen within 3 to 24 (median, 12) months of treatment, the rate of shrinkage increasing with longer follow-up. Three to 16 (median, 6) months after treatment, loss of central tumor enhancement was evident in 28 cases(82.4%). In 25 of 28 patients with intratumoral necrosis (89.3%), tumors were either smaller of their size was unchanged. Three to six (mean, 3.6) months after treatment, five cases demonstrated a transient size increase. CONCLUSION: Gamma-knife radiosurgery effectively controlled the growth of acoustic schwannoma, and intra-tumoral necrosis appears to be a predictable sign for decreased tumor size.

Evaluation of Therapeutic Effect of Acoustic Schwannoma After Gamma-Knife Radiosurgery using Follow-up MRI

PURPOSE: To evaluate, using short-term follow-up MR imagings, the usefulness of gamma-knife radiosurgery in patients with acoustic schwannoma. MATERIALS AND METHODS: In 34 patients (M:F=11:23, aged 11 -69 years) with acoustic schwannoma, eleven of whom had undergone microsurgical resection prior to gamma-knife radiosurgery, we retrospectively reviewed the serial MR imaging findings obtained before and after this procedure. Analysis focused on post-surgical changes in tumor volume and intratumoral enhancement, and the follow-up period ranged from 3 to 44 months. RESULTS: Follow-up imaging revealed that after radiosurgery, tumor size had decreased in 17 cases (50%), was unchanged in 14 (41.2%), and had increased in three (8.8%). Local tumor control was achieved in 31 of 34 cases (91.2%). Objectively defined tumor shrinkage was seen within 3 to 24 (median, 12) months of treatment, the rate of shrinkage increasing with longer follow-up. Three to 16 (median, 6) months after treatment, loss of central tumor enhancement was evident in 28 cases(82.4%). In 25 of 28 patients with intratumoral necrosis (89.3%), tumors were either smaller of their size was unchanged. Three to six (mean, 3.6) months after treatment, five cases demonstrated a transient size increase. CONCLUSION: Gamma-knife radiosurgery effectively controlled the growth of acoustic schwannoma, and intra-tumoral necrosis appears to be a predictable sign for decreased tumor size.