Asian Oceanian Radiology Forum 2018: International Education of Radiology in Asian Oceanian Countries

Role of Transarterial Embolization in the Management of Urologic Diseases

Transarterial embolization has been widely utilized in the management of urologic diseases. Acute hemorrhage can be caused by tumor, trauma, and percutaneous procedures and is the most common indication for embolization. In the past, surgical intervention was the standard treatment for urological bleeding. However, it entailed high morbidity and mortality. The demand for less-invasive treatments led to the use of transarterial embolization as an alternative to surgery. Embolization is a safe and effective treatment option for hemorrhage in various urological organs. Additionally, embolization has been employed to prevent or treat hemorrhage associated with angiomyolipoma or to treat high-flow priapism. Embolization of the target vessel in a superselective manner and use of appropriate embolic materials are key to a safe and effective procedure.

Percutaneous Metallic Stent Placement for Palliative Management of Malignant Biliary Hilar Obstruction

OBJECTIVE: To investigate the outcomes of percutaneous metallic stent placements in patients with malignant biliary hilar obstruction (MBHO). MATERIALS AND METHODS: From January 2007 to December 2014, 415 patients (mean age, 65 years; 261 men [62.8%]) with MBHO were retrospectively studied. All the patients underwent unilateral or bilateral stenting in a T, Y, or crisscross configuration utilizing covered or uncovered stents. The clinical outcomes evaluated were technical and clinical success, complications, overall survival rates, and stent occlusion-free survival. RESULTS: A total of 784 stents were successfully placed in 415 patients. Fifty-five patients had complications. These complications included hemobilia (n = 19), cholangitis (n = 13), cholecystitis (n = 11), bilomas (n = 10), peritonitis (n = 1), and hepatic vein-biliary fistula (n = 1). Clinical success was achieved in 370 patients (89.1%). Ninety-seven patients were lost to follow-up. Stent dysfunction due to tumor ingrowth (n = 107), sludge incrustation (n = 44), and other causes (n = 3) occurred in 154 of 318 patients. The median overall survival and the stent occlusion-free survival were 212 days (95% confidence interval [CI], 186−237 days) and 141 days (95% CI, 126−156 days), respectively. The stent type and its configuration did not affect technical success, complications, successful internal drainage, overall survival, or stent occlusion-free survival. CONCLUSION: Percutaneous stent placement may be safe and effective for internal drainage in patients with MBHO. Furthermore, stent type and configuration may not significantly affect clinical outcomes.

C-Arm Computed Tomography-Assisted Adrenal Venous Sampling Improved Right Adrenal Vein Cannulation and Sampling Quality in Primary Aldosteronism

BACKGROUND: Adrenal venous sampling (AVS) is a gold standard for subtype classification of primary aldosteronism (PA). However, this procedure has a high failure rate because of the anatomical difficulties in accessing the right adrenal vein. We investigated whether C-arm computed tomography-assisted AVS (C-AVS) could improve the success rate of adrenal sampling. METHODS: A total of 156 patients, diagnosed with PA who underwent AVS from May 2004 through April 2017, were included. Based on the medical records, we retrospectively compared the overall, left, and right catheterization success rates of adrenal veins during the periods without C-AVS (2004 to 2010, n=32) and with C-AVS (2011 to 2016, n=124). The primary outcome was adequate bilateral sampling defined as a selectivity index (SI) >5. RESULTS: With C-AVS, the rates of adequate bilateral AVS increased from 40.6% to 88.7% (P<0.001), with substantial decreases in failure rates (43.7% to 0.8%, P<0.001). There were significant increases in adequate sampling rates from right (43.7% to 91.9%, P<0.001) and left adrenal veins (53.1% to 95.9%, P<0.001) as well as decreases in catheterization failure from right adrenal vein (9.3% to 0.0%, P<0.001). Net improvement of SI on right side remained significant after adjustment for left side (adjusted SI, 1.1 to 9.0; P=0.038). C-AVS was an independent predictor of adequate bilateral sampling in the multivariate model (odds ratio, 9.01; P<0.001). CONCLUSION: C-AVS improved the overall success rate of AVS, possibly as a result of better catheterization of right adrenal vein.

Ultrasound-Guided Intraoperative Radiofrequency Ablation and Surgical Resection for Liver Metastasis from Malignant Gastrointestinal Stromal Tumors

OBJECTIVE: To evaluate the effectiveness, safety, and feasibility of intraoperative radiofrequency ablation (IORFA) under ultrasound guidance for the treatment of liver metastases from gastrointestinal stromal tumors (GISTs). MATERIALS AND METHODS: From August 2009 to February 2017, 24 patients with liver metastases of GISTs underwent IORFA, 14 underwent concurrent IORFA and primary GIST resection, and 10 underwent IORFA to treat hepatic recurrence after previous primary GIST resection. Seventy-six hepatic metastases were treated, of which 47 were surgically resected and 29 underwent IORFA. All included patients received imatinib therapy as standard treatment before and after IORFA or surgical resection. A retrospective medical record review was conducted, and follow-up data were collected. Technical success and effectiveness, overall and GIST-specific survival, and complications were assessed. RESULTS: The mean follow-up duration was 50.7 ± 34.7 months. The technical success rate of IORFA was 100%. New metastases developed in three of the 24 patients (12.5%) following a complete response 16, 51, and 95 months after IORFA, respectively. The cumulative one-, three-, and five-year overall survival rates were 100, 94.4, and 87.7%, respectively. The one-, three-, and five-year GIST-related survival rates were 100, 94.4, and 94.4%, respectively. Two major complications (biliary stricture and hepatic abscess) were observed. CONCLUSION: IORFA appears to be a feasible and safe treatment option for liver metastasis in patients with primary GISTs. In addition, IORFA and surgical resection may be complementary, helping to obtain complete response in cases of otherwise inoperable liver metastases secondary to GISTs.

Efficacy of Prophylactic Uterine Artery Embolization before Obstetrical Procedures with High Risk for Massive Bleeding

OBJECTIVE: To evaluate the safety and efficacy of prophylactic uterine artery embolization (UAE) before obstetrical procedures with high risk for massive bleeding. MATERIALS AND METHODS: A retrospective review of 29 female patients who underwent prophylactic UAE from June 2009 to February 2014 was performed. Indications for prophylactic UAE were as follows: dilatation and curettage (D&C) associated with ectopic pregnancy (cesarean scar pregnancy, n = 9; cervical pregnancy, n = 6), termination of pregnancy with abnormal placentation (placenta previa, n = 8), D&C for retained placenta with vascularity (n = 5), and D&C for suspected gestational trophoblastic disease (n = 1). Their medical records were reviewed to evaluate the safety and efficacy of UAE. RESULTS: All women received successful bilateral prophylactic UAE followed by D&C with preservation of the uterus. In all patients, UAE followed by obstetrical procedure prevented significant vaginal bleeding on gynecologic examination. There was no major complication related to UAE. Vaginal spotting continued for 3 months in three cases. Although oligomenorrhea continued for six months in one patient, normal menstruation resumed in all patients afterwards. During follow-up, four had subsequent successful natural pregnancies. Spontaneous abortion occurred in one of them during the first trimester. CONCLUSION: Prophylactic UAE before an obstetrical procedure in patients with high risk of bleeding or symptomatic bleeding may be a safe and effective way to manage or prevent serious bleeding, especially for women who wish to preserve their fertility.

Survey of Thoracic CT Protocols and Technical Parameters in Korean Hospitals: Changes before and after Establishment of Thoracic CT Guideline by Korean Society of Thoracic Radiology in 2008

We retrospectively reviewed the thoracic CT scan protocols and technical parameters obtained from hospitals in Korea, one group during May 2007 (n = 100) and the other group during January 2012 (n = 173), before and after the establishment of the thoracic CT Guideline in 2008. Each group was also divided into two subgroups according to the health care delivery level, i.e. the "A" subgroup from primary and the "B" subgroup from secondary and tertiary care hospitals. When comparing the data from 2007 and 2012, the tube current decreased from 179.1 mAs to 137.2 mAs. The scan interval decreased from 6.4 mm to 4.8 mm. Also, the insufficient scan range decreased from 19.0% to 8.7%, and the suboptimal quality scans decreased from 33.0% to 5.2%. Between groups A and B, group B had lower tube voltages, smaller scan thicknesses, and smaller scan intervals. However, group B had more phase numbers. In terms of the suboptimal quality scans, a decrease was seen in both groups. In conclusion, during the five-year time period between 2007 and 2012, a reduction in the tube current values was seen. And the overall image quality improved over the same time period. We assume that these changes are attributed to the implementation of the thoracic CT guideline in 2008.

Transcatheter Arterial Chemoembolization for Infiltrative Hepatocellular Carcinoma: Clinical Safety and Efficacy and Factors Influencing Patient Survival

OBJECTIVE: To evaluate the safety and efficacy of transcatheter arterial chemoembolization (TACE) in patients with infiltrative hepatocellular carcinoma (HCC) and to identify the prognostic factors associated with patient survival. MATERIALS AND METHODS: Fifty two patients who underwent TACE for infiltrative HCC were evaluated between 2007 and 2010. The maximum diameter of the tumors ranged from 7 cm to 22 cm (median 15 cm). Of 46 infiltrative HCC patients with portal vein tumor thrombosis, 32 patients received adjuvant radiation therapy for portal vein tumor thrombosis after TACE. RESULTS: The tumor response by European Association for the Study of the Liver criteria was partial in 18%, stable in 47%, and progressive in 35% of the patients. The median survival time was 5.7 months (Kaplan-Meier analysis). The survival rates were 48% at six months, 25% at one year, and 12% at two years. In the multivariable Cox regression analysis, Child-Pugh class (p = 0.02), adjuvant radiotherapy (p = 0.003) and tumor response after TACE (p = 0.004) were significant factors associated with patient survival. Major complications occurred in nine patients. The major complication rate was significantly higher in patients with Child-Pugh B than in patients with Child-Pugh A (p = 0.049, chi2 test). CONCLUSION: Transcatheter arterial chemoembolization can be a safe treatment option in infiltrative HCC patients with Child Pugh class A. Child Pugh class A, radiotherapy for portal vein tumor thrombosis after TACE and tumor response are good prognostic factors for an increased survival after TACE in patients with infiltrative HCCs.