THE EFFECTS OF CONE-BEAM COMPUTED TOMOGRAPHY IMAGING GUIDANCE ON PATIENT RADIATION EXPOSURES IN TRANS-ARTERIAL CHEMOEMBOLISATION FOR HEPATOCELLULAR CARCINOMA

This study investigated the effects of cone-beam computed tomography (CBCT) guidance in trans-arterial chemoembolisation (TACE) procedures on the number of digital subtraction angiography (DSA) runs acquired and total patient radiation exposure in patients with hepatocellular carcinoma (HCC). A retrospective, analytical cross-sectional, single institution, study was conducted. Dose data were compared across the control (DSA guidance alone) and study (DSA and CBCT guidance) groups. A total of 122 procedures were included within the study. There was a significant reduction in the number of DSA runs (3 vs 5, p < 0.001) and DSA air kerma-area product (PKA) (3077.3 vs 4276.6 μGym2, p = 0.042) for the study group when compared to the control group. Total procedural PKA and total procedural reference air kerma (Ka,r) were shown to be 50 and 73% higher, respectively, for the study group when compared to the control group. CBCT imaging guidance does reduce the number of DSA runs and DSA PKA required to complete the TACE procedure for patients diagnosed with HCC; however, a substantial increase in total procedural PKA is to be expected and it is thus important that this increased dose is carefully considered and justified.

Tremelimumab (day 1 only) and durvalumab in combination with transarterial chemoemobilization (TACE) in patients with hepatocellular carcinoma (HCC)

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Background: TACE induces a peripheral anti-tumor immune response, which may be amplified by immune checkpoint inhibitors (ICI). Combining TACE with dual ICI therapy has been shown to be safe and feasible. Recent data has suggested that Day-1 only anti-CTLA4 dosing, at a higher level of 300mg, could lead to a stronger immune response, and drive a greater expansion than lower dose regimens, whilst maintaining a tolerable safety profile. This novel schedule has not previously been combined with TACE. Methods: Patients with HCC (Childs Pugh A/B7, Barcelona clinic liver cancer stage B/C; ECOG 0/1; sorafenib-naive or experienced) were enrolled in a pilot study of tremelimumab at 2 dose levels (DL1: 75mg IV q4-weekly x 4 and DL2: 300mg IV D1 only) in combination with durvalumab (1500mg IV q-28d) and TACE (D36 +/- 96 hours) until progression of disease (per irRECIST) or off-study criteria. Peripheral immune monitoring was performed and tumor biopsies were obtained at time of TACE. Results: 13 patients enrolled on study; N = 3 at DL1 and N = 10 at DL2. M:F 10:3. Median age 70 (65-74). BCLC B/C 4/9. Extrahepatic disease 6/7. Aetiology: NASH (N = 3), alcohol-related disease (N = 1), HCV (N = 2), hemochromatosis (N = 1), unknown (N = 6). 1 pt discontinued due to G3 colitis. All patients evaluable for response with 2/10 pts on DL2 experiencing PR (at 8 weeks) and overall 7/13 SD and 1/13 PD as best response. Updated PFS and OS data to be presented. Conclusions: Tremelimumab (Day 1 only) and Durvalumab in combination with TACE is safe and feasible in patients with HCC. Follow-up is ongoing and full safety and efficacy data will be presented. Clinical trial information: 2019-002767-98.

Patient radiation dose during angiography and embolization for abdominal hemorrhage: the influence of CT angiography, fluoroscopy system, patient and procedural variables

Background

Angiography and embolization (AE) is a lifesaving, high radiation dose procedure for treatment of abdominal arterial hemorrhage (AAH). Interventional radiologists have utilized pre-procedure CT angiography (CTA) and newer fluoroscopic systems in an attempt to reduce radiation dose and procedure time.

Purpose

To study the factors contributing to the radiation dose of AE for AAH and to compare to the reference standard.

Materials and methods

This retrospective single-centre observational cohort study identified 154 consecutive AE procedures in 138 patients (median age 65 years; interquartile range 54–77; 103 men) performed with a C-arm fluoroscopic system (Axiom Artis DTA or Axiom Artis Q (Siemens Healthineers)), between January 2010 and December 2017. Parameters analysed included: demographics, fluoroscopy system, bleeding location, body mass index (BMI), preprocedural CT, air kerma-area product (PKA), reference air kerma (K_a,r), fluoroscopy time (FT) and the number of digital subtraction angiography (DSA) runs. Factors affecting dose were assessed using Mann–Whitney U, Kruskal–Wallis one-way ANOVA and linear regression.

Results

Patients treated with the new angiographic system (NS) had a median PKA, median K_a,r, Q3 PKA and Q3 K_a,r that were 74% (p < 0.0005), 66%(p < 0.0005), 55% and 52% lower respectively than those treated with the old system (OS). This dose reduction was consistent for each bleeding location (upper GI, Lower GI and extraluminal). There was no difference in PKA (p = 0.452), K_a,r (p = 0.974) or FT (p = 0.179), between those who did (n = 137) or did not (n = 17) undergo pre-procedure CTA. Other factors significantly influencing radiation dose were: patient BMI and number of DSA runs. A multivariate model containing these variables accounts for 15.2% of the variance in K_a,r (p < 0.005) and 45.9% of the variance of PKA (p < 0.005).

Conclusion

Radiation dose for AE in AAH is significantly reduced by new fluoroscopic technology. Higher patient body mass index is an independent key parameter affecting patient dose. Radiation dose was not influenced by haemorrhage site or performance of pre-procedure CTA.

Tremelimumab (day 1 only) and durvalumab in combination with transarterial chemoemobilization (TACE) in patients with hepatocellular carcinoma (HCC)

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Background: TACE induces a peripheral anti-tumor immune response, which may be amplified by immune checkpoint inhibitors (ICI). Combining TACE with dual ICI therapy has been shown to be safe and feasible. Recent data has suggested that Day 1-only anti-CTLA4 dosing could potentially lead to a stronger immune response with a tolerable safety profile though this novel schedule has not previously been combined with TACE. Methods: Patients with HCC (Childs Pugh A/B7, Barcelona clinic liver cancer stage B/C; ECOG 0/1; sorafenib-naive or experienced) were enrolled in a pilot study of tremelimumab at 2 dose levels (DL1: 75mg IV q4-weekly x 4 and DL2: 300mg IV D1 only) in combination with durvalumab (1500mg IV q-28d) and TACE (D36 +/- 96 hours) until progression of disease (per irRECIST) or off-study criteria. Peripheral immune monitoring was performed and tumor biopsies were obtained at time of TACE. Results: 13 patients enrolled on study; N = 3 at DL1 and N = 10 at DL2. M:F 10:3. Median age 70 (65-74). BCLC B/C 4/9. Extrahepatic disease 6/7. Aetiology: NASH (N = 3), alcohol-related disease (N = 1), HCV (N = 2), hemochromatosis (N = 1), unknown (N = 6). 1 patient discontinued due to G3 colitis. All patients evaluable for response with 2/10 patients on DL2 experiencing PR (at 8 weeks) and overall 8/13 SD and 3/13 PD as best response. Updated PFS and OS data to be presented. Conclusions: Tremelimumab (Day 1 only) and Durvalumab in combination with TACE is safe and feasible in patients with HCC. Follow-up is ongoing and full safety and efficacy data will be presented. Clinical trial information: 2019-002767-98.

Evaluation of a prospective adverse event reporting system in interventional radiology

AIM

To assess the performance of a prospective adverse event (AE) reporting system.

MATERIALS AND METHODS

Four hundred and seventy-one consecutive arterial procedures were performed in 465 patients (median age, 65 years; interquartile range, 54-77; 276 men) over 2 years by four interventional radiologists at a single centre where clinical follow-up was not performed routinely by interventional radiology (IR). AEs were reported prospectively using a radiology information system or in interventional radiologists' electronic records and combined in a departmental listing of adverse events (DLAE). A retrospective medical record review was performed to identify a reference standard list of AEs for this observational cohort study. AEs were graded according to the Society of Interventional Radiology AE classification system. Descriptive statistics were calculated for the performance of the DLAE. A model comparing the rate of reporting of AEs with and without integration of clinical follow-up was tested for significance.

RESULTS

Thirty-eight of the 471 (8%) IR procedures had an AE according to the reference standard. The DLAE identified 20/38 (53%) of AEs (K=0.67 [good agreement], 95% confidence interval [CI] agreement=0.53-0.81; p=0.0001; sensitivity 52.6% [95% CI, 36-69%], specificity 100% [95% CI, 99-100%], positive predictive value [PPV] 100%, negative predictive value [NPV] 96 [95% CI, 94.5-97%], accuracy 96% [95% CI, 94-97%]). The performance of the AE reporting system will improve with integration of clinical follow-up (p=0.0015).

CONCLUSION

A prospective AE reporting system without clinical integration will not detect all procedure complications.

Conventional angiography findings in hemodynamically unstable patients with acute abdominal hemorrhage and a negative CT bleeding study

Background

CT bleeding study (CTA) is regularly requested in acute abdominal haemorrhage (AAH) with haemodynamic instability by clinical teams and interventional radiologists because CTA can; detect arterial bleeding at low rates of hemorrhage, accurately localize the bleeding point and characterize the etiology.

How best to manage an unstable patient who has an AAH with a haematoma and no acute vascular findings on CTA represents a difficult clinical scenario for treating physicians and Interventional Radiologists.

Purpose

To review the conventional angiography (CA) findings and clinical outcome of hemodynamically unstable patients with AAH who had a preceding negative CTA.

Materials and methods

All patients who were hemodynamically unstable and underwent CTA and CA for acute arterial abdominal hemorrhage at our institution between 01/01/2010 and 31/12/2017 were identified. Patients with obstetric, penetrating trauma, abdominal aortic or venous sources of hemorrhage were excluded. Patients who had a negative CTA before CA were included. Patient medical records were reviewed for clinical outcome.

Results

In the study period 160 hemodynamically unstable patients underwent 178 CA procedures. 155 CA procedures were preceded by CTA. 141 CTAs demonstrated active bleeding or an abnormal artery. 14 CTAs in 13 patients demonstrated hematoma but no acute bleeding (mean age = 56-years; M:F, 12:1). Eight of the 14 CA studies demonstrated: active bleeding (n = 4), pseudoaneurysm (n = 1) or a truncated artery (n = 3). Cases of renal hemorrhage demonstrated a significantly higher proportion of false negative CTA studies (36%). Selective (n = 8) or empiric (n = 4) embolization was performed in twelve cases. All patients stopped bleeding and there were no mortalities.

Conclusion

In a cohort of hemodynamically unstable patients, 57% (8/14) of cases with no acute vascular findings on CTA demonstrated a source of hemorrhage on CA. The false negative rate of CTA was significantly higher for renal tract hemorrhage compared to other sites of bleeding.

Radiological findings in ischaemic cholangiopathy

Ischaemic cholangiopathy occurs as a consequence of deficient arterial blood flow to the bile duct wall. Bile duct ischaemia can lead to full-thickness necrosis, bile leakage, biloma formation, and sepsis. It is an important cause of graft failure post-orthotopic liver transplantation. In the native liver, the causes of biliary ischaemia are diverse and include vasculitis or a complication of endovascular procedures. The present review describes the pathology and radiological findings of ischaemic cholangiopathy and outlines the role of interventional radiology in its management.

The Role of Interventional Radiology in the Management of Obstetric and Gynaecological Haemorrhage

Aim We will review our experience of emergent arterial embolization used to treat haemodynamically unstable patients with obstetric and gynaecological haemorrhage. Methods This is a retrospective study of patients with haemodynamically unstable obstetric and gynaecological haemorrhage treated with emergent arterial embolization from 2010 to 2015. Results 22 patients (average age 41 (SD +/-9) years) had emergent arterial embolization. 63% had post-partum haemorrhage (PPH). 82% of cases were performed with conscious sedation and local anaesthesia. Embolization was technically successful in all cases. Embolization was clinically successful in 95% (21/22). In one case of PPH the patient represented six days later with recurrent bleeding and was treated with surgical suturing of the cervix. There were no complications or deaths. Conclusion Arterial embolization is a highly successful treatment of obstetric and gynaecological haemorrhage in unstable patients.

Scintigraphic assessment of arterial embolism at mixed thrombin and technetium 99m injection therapy for femoral pseudoaneurysms

BACKGROUND

Clinically evident arterial thrombosis is rare following thrombin injection therapy for femoral pseudoaneurysm. However, it is unclear to what extent injected thrombin may pass to the ipsilateral lower limb arteries.

AIMS

To assess if technetium 99m injected at the time of thrombin injection for femoral artery pseudoaneurysm therapy passes into the adjacent lower limb arteries.

METHODS

This was a prospective trial with institutional review board approval. Four consecutive patients with common femoral pseudoaneurysms and failed manual compression were enrolled. Under real-time colour flow doppler ultrasound, a mixture of 1000 IU thrombin and approximately 200 MBq technetium 99m was injected in 0.1-mL doses into the pseudoaneurysm until thrombosis occurred. Gamma camera imaging of the syringe before injection, the injected groin after thrombosis and the syringe after injection were performed. Analysis of the gamma camera information was performed to determine the amount of technetium 99m deposited in the arterial tree.

RESULTS

All the procedures were technically successful. A mean of 33% (range 3-50%; SD 21) of the administered technetium 99m dose was deposited in the arterial circulation during pseudoaneurysm therapy. No clinically evident arterial thrombosis was identified.

CONCLUSION

Technetium 99m is routinely deposited in the arterial circulation following injection of a mixture of thrombin and technetium for therapy of common femoral artery pseudoaneurysms. This suggests that arterial passage of thrombin is more common than clinically evident.

Does neoadjuvant doxorubicin drug-eluting bead transarterial chemoembolization improve survival in patients undergoing liver transplant for hepatocellular carcinoma?

PURPOSE

We aimed to compare the overall (OS) and disease-free survival (DFS) of patients undergoing orthotopic liver transplant (OLT) for hepatocellular carcinoma who did and did not have neoadjuvant doxorubicin drug-eluting bead transarterial chemoembolization (DEB-TACE).

METHODS

This is a retrospective study of 94 patients with HCC transplanted between 2000 and 2014 in a single tertiary center. Pre- and postoperative features, DFS and OS were compared between patients who received pre-OLT DEB-TACE (n=34, DEB-TACE group) and those who did not (n=60, non-TACE group). Radiologic and histologic response to neoadjuvant treatment as well as its complications were also studied.

RESULTS

There were no significant differences in post-transplantation DFS and OS rates between groups (5-year DFS: 70% in DEB-TACE group vs. 63% in non-TACE group, P = 0.454; 5-year OS: 70% in DEB-TACE group vs. 65% in non-TACE group, P = 0.532). The DEB-TACE group had longer OLT waiting time compared with the non-TACE group (110 vs. 72 days; P = 0.01). On univariate and multivariate analyses, alpha-fetoprotein (AFP) levels >500 ng/mL prior to OLT were associated with decreased OS and DFS regardless of neoadjuvant approach (hazard ratio of 6, P = 0.001 and 5.5, P = 0.002, respectively).

CONCLUSION

Patients who underwent neoadjuvant DEB-TACE and OLT for hepatocellular carcinoma had no statistically different OS or DFS at 3 and 5 years from patients undergoing OLT alone.

Midterm Analysis of Survival and Cause of Death Following Endovascular Abdominal Aortic Aneurysm Repair

Purpose:

To assess rates of complications, secondary interventions, survival, and cause of death following endovascular abdominal aortic aneurysm (AAA) repair over a 10-year period.

Materials and Methods:

Single-institution retrospective cohort study of all patients undergoing primary endovascular aortic aneurysm repair (EVAR) between July 2006 and June 2015. The population constituted 175 patients with 163 fusiform and 12 saccular AAAs. Of these, 149 (85%) were male, with mean age 75.4 (±7.1) years. Patients were followed up until June 30, 2016. Cause of death was determined from the national death register.

Results:

Mean follow-up was 34.4 (±24.4) months. The secondary intervention rate was 9.7%, and there were 4 aneurysm ruptures (0.8% annual incidence). Thirty-day mortality was 0.6%. Survival at 1, 3, and 5 years was 93.1%, 84%, and 64.9%, respectively. Forty-eight patients died during follow-up, 3 secondary to rupture, leading to overall and aneurysm-related death rates of 9.7 and 0.6 per 100 person-years. All other deaths were due to nonaneurysm causes, most commonly cardiovascular (n = 15), pulmonary (n = 13), and malignancy (n = 9). Baseline renal impairment ( P < .001), ischemic heart disease ( P < .05), age greater than 75 years ( P < .05), and urgent/emergency EVAR were associated with inferior long-term survival. Type II endoleak negatively influenced fusiform aneurysm sac regression ( P = .02), but there was no association between survival and occurrence of any complication or secondary intervention.

Conclusion:

The majority of deaths during medium-term follow-up post-EVAR are due to nonaneurysm-related causes. Survival is determined by the following baseline factors: renal impairment, ischemic heart disease, advanced age, and the presence of a symptomatic/ruptured aneurysm.

Fabrication and assessment of 3D printed anatomical models of the lower limb for anatomical teaching and femoral vessel access training in medicine

For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial cadavers are manufactured through three-dimensional (3D) printing of patient specific radiological data sets. In this article, a simple powder based printer is made more versatile to manufacture hard bones, silicone muscles and perfusable blood vessels. The approach involves blending modern approaches (3D printing) with more ancient ones (casting and lost-wax techniques). These anatomically accurate models can augment the approach to anatomy teaching from dissection to synthesis of 3D-printed parts held together with embedded rare earth magnets. Vascular simulation is possible through application of pumps and artificial blood. The resulting arteries and veins can be cannulated and imaged with Doppler ultrasound. In some respects, 3D-printed anatomy is superior to older teaching methods because the parts are cheap, scalable, they can cover the entire age span, they can be both dissected and reassembled and the data files can be printed anywhere in the world and mass produced. Anatomical diversity can be collated as a digital repository and reprinted rather than waiting for the rare variant to appear in the dissection room. It is predicted that 3D printing will revolutionize anatomy when poly-material printing is perfected in the early 21st century.

Fabrication and assessment of 3D printed anatomical models of the lower limb for anatomical teaching and femoral vessel access training in medicine

For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial cadavers are manufactured through three-dimensional (3D) printing of patient specific radiological data sets. In this article, a simple powder based printer is made more versatile to manufacture hard bones, silicone muscles and perfusable blood vessels. The approach involves blending modern approaches (3D printing) with more ancient ones (casting and lost-wax techniques). These anatomically accurate models can augment the approach to anatomy teaching from dissection to synthesis of 3D-printed parts held together with embedded rare earth magnets. Vascular simulation is possible through application of pumps and artificial blood. The resulting arteries and veins can be cannulated and imaged with Doppler ultrasound. In some respects, 3D-printed anatomy is superior to older teaching methods because the parts are cheap, scalable, they can cover the entire age span, they can be both dissected and reassembled and the data files can be printed anywhere in the world and mass produced. Anatomical diversity can be collated as a digital repository and reprinted rather than waiting for the rare variant to appear in the dissection room. It is predicted that 3D printing will revolutionize anatomy when poly-material printing is perfected in the early 21st century.

Transrectal Ultrasound Guided Biopsy of the Prostate: Is the Information Accessible, Usable, Reliable and Readable?

BACKGROUND/AIMS

To evaluate the accessibility, usability, reliability and readability of Internet information regarding transrectal ultrasound (TRUS) guided biopsy of the prostate.

MATERIALS AND METHODS

The terms "prostate biopsy", "TRUS biopsy" and "transrectal ultrasound guided biopsy of the prostate" were separately entered into the each of the top 5 most accessed Internet search engines. Websites were evaluated for accessibility, usability and reliability using the LIDA tool - a validated tool for the assessment of health related websites. Website readability was assessed using the Flesch Reading Ease Score and the Flesch Kincaid Grade Level.

RESULTS

Following the application of exclusion criteria, 82 unique websites were analyzed. There was a significant difference in scores depending on authorship categories (p ≤ 0.001), with health related charity websites scoring highest (mean 122.29 ± 13.98) and non-academic affiliated institution websites scoring lowest (mean 87 ± 19.76). The presence of advertisements on a website was associated with a lower mean overall LIDA tool score (p = 0.024). Only a single website adhered to the National Institutes for Health recommendations on readability.

CONCLUSIONS

This study demonstrates variability in the quality of information available to Internet users regarding TRUS biopsies. Collaboration of website design and clinical acumen are necessary to develop appropriate websites for patient benefit.

Radiofrequency ablation for neuroendocrine liver metastases: a systematic review

To determine the efficacy of radiofrequency (RF) ablation in neuroendocrine tumor (NET) liver metastases. A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight studies were included (N = 301). Twenty-six percent of RF ablation procedures were percutaneous (n = 156), with the remainder conducted at surgery. Forty-eight percent of patients had a concomitant liver resection. Fifty-four percent of patients presented with symptoms, with 92% reporting symptom improvement following RF ablation (alone or in combination with surgery). The median duration of symptom improvement was 14-27 months. However, recurrence was common (63%-87%). RF ablation can provide symptomatic relief in NET liver metastases alone or in combination with surgery.

Pancreatic metastasectomy: experience of the Irish National Surgical Centre for Pancreatic Cancer

BACKGROUND

Metastatic tumours of the pancreas are rare and the optimal management of these tumours remains unclear, given the paucity of data existing in the literature. We report our experience of pancreatic metastasectomy.

METHODS

Data were reviewed on all patients who underwent pancreatic resection for pathologically confirmed metastatic lesions over a consecutive 7-year period.

RESULTS

Seven patients (two men and five women) underwent a pancreatectomy for a metastatic pancreatic tumour. The primary tumours were renal cell carcinoma (n = 3), colorectal carcinoma (n = 2) and leiomyosarcoma (n = 2). There was no operative mortality. Postoperative morbidities occurred in two patients. The median follow-up was 49 months (range 17-76). Overall 1- and 2-year survivals were 100 and 86 %, respectively, with a 2-year disease-free survival of 72 %.

CONCLUSIONS

Our series further supports that pancreatic metastasectomy can be performed safely and achieves acceptable survival outcomes.

Evaluation of the particulate concentration in a gelatin-based phantom for sonographically guided lesion biopsy

OBJECTIVES

The purpose of this study was to determine the particulate concentration in a gelatin-based ultrasound phantom for lesion biopsy at 6 cm in depth to reduce visualization of the biopsy needle in the near field, simulating subcutaneous fat and tissue echogenicity, and maintain target lesion visualization.

METHODS

Four gelatin-based phantoms with cornstarch at concentrations of 4, 8, 12, and 16 g/L and an anechoic gelatin target at 7 cm in depth were rated on a 5-point scale by readers for visibility of the target lesion, similarity of near-field to abdominal subcutaneous fat echogenicity, and visibility of a 22-gauge spinal needle in the phantom. A timed sonographically guided localization task was performed on the anechoic target by 4 radiology residents using the 22-gauge spinal needle. Results were analyzed by comparative statistical analysis.

RESULTS

An increasing particulate concentration did not alter the similarity of near-field to abdominal subcutaneous fat echogenicity (P = .6) but did significantly reduce visibility of the anechoic target at a cornstarch concentration of 16 g/L (P = .04) and the 22-gauge needle at 12 g/L (P = .03). Decreased visualization of the needle or target lesion did not affect the time for needle localization of the anechoic target (P = .96).

CONCLUSIONS

The optimal ultrasound phantom cornstarch concentration was 12 g/L to reduce visualization of the spinal needle, simulating subcutaneous fat echogenicity while maintaining target lesion visualization.

Thirty years' experience with balloon dilation of benign postoperative biliary strictures: long-term outcomes

PURPOSE

To determine the effectiveness of percutaneous balloon dilation of benign postoperative biliary strictures.

MATERIALS AND METHODS

We received approval from our institutional review board to undertake this retrospective HIPAA-compliant study, and informed consent was waived. From April 1, 1977, to April 1, 2007, percutaneous biliary balloon dilation (PBBD) was performed in 85 patients with benign biliary strictures. In the 75 patients with follow-up (31 male, 44 female; mean age, 56 years; mean follow-up, 8 years), 205 PBBD procedures were performed during 112 treatments of 84 biliary strictures. PBBD of the stricture was performed with a noncompliant balloon (8-12-mm diameter). PBBD procedures were repeated at 2- to 14-day intervals until cholangiography demonstrated free drainage of contrast material to the bowel and no residual stenosis. An internal-external biliary drain was left in situ for a mean of 14-22 days and removed after a clinical trial of catheter clamping and a normal cholangiogram.

RESULTS

All procedures were technically successful, and 52, 11, 10, and two patients underwent a total of one, two, three, and four PBBD treatments, respectively. Four of 205 procedures (2%) led to major complications: two subphrenic abscesses, one hepatic arterial pseudoaneurysm, and one case of hematobilia treated with transfusion. Six patients died from unrelated causes and three from hepatitis C-related liver failure. The probability of a patient not developing clinically significant restenosis at 5, 10, 15, 20, and 25 years was 0.52, 0.49, 0.49, 0.41, and 0.41, respectively, after the first PBBD treatment and 0.43, 0.30, 0.20, 0.20, and 0.20, respectively, after the second PBBD treatment. No significant difference was found in the rate of clinically significant restenosis after the first PBBD between strictures at anastomotic and nonanastomotic sites (P = .75). During the follow-up period, 56 of 75 patients (75%) had successful management with PBBD.

CONCLUSION

PBBD of benign strictures demonstrates long-term effectiveness. No significant difference was found in the rate of clinically significant restenosis after PBBD of biliary strictures at anastomotic and nonanastomotic sites.

Absolute alcohol embolization of sporadic angiomyolipoma

Angiomyolipoma is a benign hamartoma. Seventy percent of angiomyolipomas occur sporadically in the general population and the remainder are associated with a syndrome. Of patients with tuberous sclerosis, 60 to 80% have an angiomyolipoma. Sporadic angiomyolipomas tend to be single and occur in an older age group. In tuberous sclerosis, the lesions are usually bilateral and multiple. Therapy is indicated when there are symptoms or when the lesion is greater than 4 cm. Criteria for further embolization include growth of the lesion by 2 cm at annual follow-up computed tomography and presentation with acute hemorrhage. We describe a case of a sporadic asymptomatic angiomyolipoma treated with absolute alcohol embolization.

Protecting the ureter during radiofrequency ablation of renal cell cancer: a pilot study of retrograde pyeloperfusion with cooled dextrose 5% in water

PURPOSE

To describe early experience with cooled dextrose 5% in water (D5W) solution retrograde pyeloperfusion during radiofrequency (RF) ablation of renal cell carcinoma (RCC) within 1.5 cm of the ureter with respect to feasibility, safety, and incidence of residual/recurrent tumor in proximity to the cooled collecting system.

MATERIALS AND METHODS

Between November 2004 and April 2007, 17 patients underwent 19 RF ablation sessions of RCCs within 1.5 cm of the ureter during cooled D5W pyeloperfusion (nine men, eight women; mean tumor size, 3.5 cm; mean age, 73 y; mean distance to ureter, 7 mm). RF ablation was performed with pulsed impedance control current. The records and imaging studies of patients treated with this technique were reviewed for demographics, indication, technique, complications, and tumor recurrence.

RESULTS

All 19 RF ablation and ureteral catheter placement procedures were technically successful. No patient developed a ureteral stricture or hydronephrosis during a mean of 14 months of follow-up (range, 4-32 months). Three patients had residual tumor on the first follow-up imaging study, but all three tumors were completely ablated after a second RF ablation session. No complications or deaths occurred. No recurrent tumor was seen anywhere in the treated tumors, and there was complete ablation of the tumor margin in proximity to the collecting system.

CONCLUSIONS

RF ablation of RCC within 1.5 cm of the ureter is feasible with cooled D5W retrograde pyeloperfusion and is not associated with reduced efficacy, ureteral injury, or early recurrence.

Radiofrequency Ablation of Bone with Cooled Probes and Impedance Control Energy Delivery in a Pig Model: MR Imaging Features

PURPOSE

To determine the coronal marrow ablation length and detect cortical thinning after radiofrequency ablation (RFA) of bone in a pig model.

MATERIALS AND METHODS

Twelve pigs underwent RFA with a 1- or 2-cm single internally cooled electrode placed at the mid-diaphyseal point of their long bones at 1, 7, or 28 days before euthanasia. Twelve minutes of impedance control radiofrequency energy was delivered at maximum output from a 200-W generator. Pigs were imaged with axial and coronal turbo spin-echo (SE) T1- and T2-weighted frequency-selective fat suppression sequences by using spectral presaturation with inversion recovery (SPIR). A radiologist blinded to the timing of the treatment and the results of other imaging sequences measured the coronal ablation zone length and cortical thickness. The pigs were euthanized, and the ablated bone underwent histologic examination.

RESULTS

At SPIR imaging, the zone of marrow ablation was defined as an area of low signal intensity surrounded by a high-signal-intensity band. At T1-weighted imaging, the zone of marrow ablation was defined as a heterogeneously isointense area surrounded by a low-signal-intensity band. The mean (+/-standard deviation) coronal marrow ablation zone measurement with SPIR imaging at 28 days was 47 mm +/- 9 (range, 34-73 mm) for the 1-cm electrode and 51 mm +/- 7 (range, 33-67 mm) for the 2-cm electrode. Two humeral fractures occurred at 21 and 28 days after therapy. Thinning of the cortex adjacent to the electrode insertion site was identified in the humeral group only.

CONCLUSION

The change in the marrow signal intensity with impedance-controlled RFA is larger than that reported for temperature-controlled protocols. RFA leads to bone weakening.

Radiofrequency ablation of osteoid osteoma with cooled probes and impedance-control energy delivery

OBJECTIVE

Our objective was to evaluate the efficacy of percutaneous radiofrequency ablation of osteoid osteoma with cooled radiofrequency probes and impedance control energy delivery from a 200-W generator. We also compared the outcome to published data for therapy with a 5-mm noncooled probe and temperature-controlled short-duration therapy protocols.

SUBJECTS AND METHODS

Radiofrequency ablation was performed on 11 patients with a clinical and radiologic diagnosis of osteoid osteoma. A cooled radiofrequency probe was introduced into the lesion under CT guidance. Twelve minutes of radiofrequency energy was delivered from a 200-W generator under impedance control. Postprocedural pain, function, and satisfaction were evaluated by means of an interview and questionnaire.

RESULTS

All procedures were technically successful. No serious complication occurred. Postoperative pain was scored at a mean of 6.9 +/- 3.06 (95% confidence interval) on a numeric rating scale. Postoperative pain was rated as similar to night pain. By 1 week after therapy, all patients had resolution of pain and returned to normal activity. There was no recurrence during the follow-up period (range, 6-27 months; mean, 14.4 months). Patients rated their satisfaction as high.

CONCLUSION

Radiofrequency ablation of osteoid osteoma with a high-energy delivery technique is safe and has a high success rate. When compared with patients in a published series using 5-mm probes and manual energy control from lower-output generators, our cohort showed increased postoperative pain scores and an increased interval to symptom resolution.

Abdominal aortic invasion by leiomyosarcoma

We describe a case of retroperitoneal leiomyosarcoma with extra- and intravascular involvement. The patient presented with abdominal aortic rupture secondary to tumor invasion and extensive tumor thrombus in the inferior vena cava. The presence of a rupture of the abdominal aorta is an important radiologic diagnosis to make because early endovascular or surgical repair can prevent a catastrophic free rupture. Inferior vena cava involvement by leiomyosarcoma may be locally resected in some cases but has a poor long-term survival rate.

MRI Features After Radiofrequency Ablation of Osteoid Osteoma with Cooled Probes and Impedance-Control Energy Delivery

OBJECTIVE

The purposes of our study were to determine the temporal changes in MR signal in bone after radiofrequency ablation of osteoid osteoma and the size of the zone of marrow signal change produced by the radiofrequency technique and to compare the size of the zone with published data for radiofrequency ablation with manual-control protocols.

MATERIALS AND METHODS

Radiofrequency ablation was performed in 10 patients with a clinical and radiologic diagnosis of osteoid osteoma. A cooled radiofrequency probe was inserted in the nidus. Twelve minutes of radiofrequency energy was applied from a 200-W radiofrequency generator in an impedance-control setting. MRI with multiplanar turbo spin-echo T1-weighted and STIR sequences was performed at 1, 7, and 28 days after the procedure in seven patients. The three remaining patients had follow-up imaging at 28 days only. The images were reviewed by two radiologists who categorized the imaging features and measured the marrow zone of signal alteration when visible. The size of the zone of marrow signal change produced by the radiofrequency technique was compared with published data for radiofrequency ablation with manual-control protocols.

RESULTS

A 1-mm band of homogeneous altered marrow signal distributed symmetrically parallel to the entire probe tract was seen earliest, at 1 day, in the femoral neck lesion treated with the 2-cm probe. The band was low signal on the T1 sequence and high signal on the STIR sequence, and the diameter of the zone was 27 mm. By 7 days, five of the seven treated bones showed a band of marrow signal alteration. By 28 days, all 10 treated bones had a band of marrow signal alteration. The interband distance at 90 degrees to the probe measured on STIR images at 28 days was a mean of 20.9 mm (confidence interval, 16.1-25.7 mm [p < 0.05]; range +/- measurement error, 10.5-35 +/- 1.64 mm) with a 1-cm probe and 30.5 mm (measurement error, +/- 0.78 mm) on T1 images without contrast material when a 2-cm exposed-tip probe was used. Higher-output generators with impedance-control software and internally cooled radiofrequency probes with longer exposed tips produce larger zones of marrow signal change than expected with manual-control protocols.

CONCLUSION

MRI allows detection of temporal marrow signal change after radiofrequency ablation. The marrow signal change with a high-energy delivery protocol is larger than manual-control protocols.

Ureterocutaneous fistula and urostomy exclusion with use of a covered wallstent

The present report describes a case of urostomy breakdown and failed urinary diversion with bilateral nephrostomy drainage treated with transrenal placement of a covered stent. Covered stents can be used successfully for the exclusion of ureterocutaneous fistulas and urostomies with the potential for ureteric occlusion.

CT guided radiofrequency ablation of intra-articular osteoid osteoma of the hip

BACKGROUND

Osteoid osteoma is a painful benign bone tumour. Previously the standard therapy was surgical excision. Image guided radiofrequency ablation can be clinically applied to ablate the tumour in a minimally invasive manner.

AIMS

We present a case of an 18-year-old boy who presented with features of chronic left hip arthropathy secondary to intra-articular osteoid osteoma, subsequently successfully treated by percutaneous CT guided radiofrequency ablation.

RESULTS

The CT guided radiofrequency ablation was technically successful as a day case procedure without complication. The patient returned to normal function within one week. No recurrence occurred in the three-year follow-up period.

CONCLUSION

Radiofrequency ablation is a safe, minimally invasive and effective technique for treatment of osteoid osteoma.

Current trends in treatment of osteoid osteoma with an emphasis on radiofrequency ablation

This article reviews current trends in the treatment of osteoid osteoma with an emphasis on the evolving use of radiofrequency thermoablation as a primary definitive treatment and for recurrent and residual lesions. In so doing, the article reviews merits and relative disadvantages of both surgical and non-surgical imaging-guided techniques in treatment. Radiofrequency ablation of osteoid osteoma is a highly effective, efficient, minimally invasive and safe method of treating osteoid osteoma. Clinical success range from 76 to 100%. Surgery remains the standard treatment in cases where histology of the lesion is in doubt, neurovascular structures are within 1.5 cm or in repeated failure of any other minimally invasive ablative technique or percutaneous resection. Clinical success of surgery ranges from 88 to 100%. Laser interstitial thermal therapy shares many of the advantages and much of the success of radiofrequency thermoablation but has not been as available. Clinical success ranges from 87 to 100%. Cryotherapy, ethanol therapy and imaging-guided excision remain second-line therapies. Clinical success ranges from 77 to 100% for imaging-guided resection and 100% for ethanol therapy.