Oncologic Interventions

Oncologic Interventions

Oncologic Interventions Poster No. 263 Transvenous and Direct Stick Sclerotherapy of Peripheral Vascular Malformations and Hemangiomas. p. Sahgal, Uni...

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Oncologic Interventions Poster No. 263 Transvenous and Direct Stick Sclerotherapy of Peripheral Vascular Malformations and Hemangiomas. p. Sahgal, University ofMinnesota, Minneapolis, MN. USA .1. Ross· D. W. Hunter

PURPOSE: To assess the clinical course of malformations

a~d hemangiomas following transvenous and direct stick sclerotherapy.

MATERIALS AND METHODS: From 1986 to 2001, 64 patients (33 female, 31 male) underwent 155 sclerotherapy treatments for a variety of peripheral vascular malformations as classified by Mulliken. Treatment groups included arteriovenous malformations (AVM), venous malformations (VM), capillovenous malformations (CVM), arteriocapillovenous malformations (ACVM), hemangiomas (H), Iymphohemangiomas (LH), and a final category titled venous dysplasia. Treatments were performed from a transvenous, direct stick, or a combination approach. Patient follow-up and clinical course were monitored via office visits, telephone follow-up, and chart review. Patient symptoms were graded on a 0 to 4 scale, based on any change compared to symptoms at presentation. A score of 0 indicated worsened symptoms and 4 indicated complete reliefofsymptoms. Short term and long term complications were evaluated. RESULTS: Results depended heavily on the lesion category. The lesions with slower flow tended to have better results. Most patients developed minor side effects including swelling and pain. Only one devastating complication occurred in a patient with an AVM in which the sclerosant inadvertently spilled over into adjacent normal vessels causing extensive tissue loss. Skin flaps were required in this patient. Most patients required repeat intervention and/or staged.procedures in order to relieve their symptoms. Of all the lesion types, the ACVM group had the greatest percentage of patients who required multiple treatments (85.7%). This group also had the least successful results. 65.2% ofVM patients, 44.4% of CVM patients, and 40% of AVM patients required multiple sclerotherapy treatments. 25 patients required surgical intervention as an adjunct to sclerotherapy in order to better control their symptoms. CONCLUSION: Careful selection of patients based on their lesion characteristics can lead to successful treatment of vascular malformations. A realistic goal must be set for close follow-up and repeat intervention in almost all patients. Poster No. 264 Comparison between Acetic Acid and Ethanol Tumor Ablation in VX2 Carcinoma. Ss. Shah, Hospital ofthe University ofPennsylvania, Philadelphia, PA, USA· DL Jacobs· E. Furth· T. W Clark

PURPOSE: Acetic acid has been employed as a chemical ablation agent for liver tumors owing to superior diffusion characteristics than ethanol, requiring smaller volumes and fewer sessions than ethanol. We sought to compare the efficacy ofacetic acid and ethanol for effects ofearly tumor necrosis in a rabbit model of hepatocellular carcinoma. MATERIALS AND METHODS: VX2 tumors were created in the left lobe of the liver in II male New Zealand rabbits. Each animal underwent a midline mini-laparotomy to expose the tumor-laden left lobe followed by injection of 1.0 cc of 100% ethanol (n = 5) or 50% acetic acid (n = 6) using a 20-gauge

Bernadino needle (Cook, Bloomington, IN). Animals were sacrificed 30 minutes following surgery; explanted livers were fixed in formalin and saline and evaluated for size and extent of tumor necrosis.

RESULTS: Injection of each agent produced rapid diffusion through tumor and surrounding hepatic parenChyma, with immediate protein precipitation manifested by induration of involved tissue. No discernable differences in the degree of necrosis were seen between each agent. The size ofthe necrosis zone, expressed as the mean product of the maximum perpendicular diameters of tumoral diffusion, was 13.0 ± 9.4 cm 2 vs. 1.3 ± 1.8 cm 2 for acetic acid and ethanol, respectively (P =0.049). No pathologic differences could be seen between injection-induced necrosis and biologic necrosis. CONCLUSION: Acetic acid produced significantly larger zones oftumor necrosis than ethanol when injected into VX2 carcinoma in equal volumes. Poster No. 265 Effects of Direct IntratumOJ:al Injection of Cisplatinl Epineprine Gel in a Rabbit Model of Liver Cancer. 1.F Geschwind, Johns Hopkins University School of Medicine, Baltimore, MD, USA· M. Torbenson • H.s. Kim· C.Are

PURPOSE: To assess the extent of tumor cell death in a rabbit model of liver cancer after therapy with direct intratumoral injection ofcisplatinlepinephrine gel and to compare the effects of single vs. multiple treatments on tumor cell death. MATERIALS AND METHODS: Tumors were first grown in the hindlegs of carrier rabbits for 14 days. Resultant tumors were harvested from each rabbit carrier. Tumor tissue was minced and injected directly into the liver of recipient rabbits. Liver tumors were allowed to grow for 14 days after which a contrast-enhanced CT scan was obtained for each animal. Animals were divided into 3 groups; group I (n=6) received a single injection, group 2 (n=6) received 2 injections I week apart and group 3 (n=7) did not receive any treatment (control). The volume injected was 0.25 ml ofgel percm J oftumor. Each rabbit underwent repeat contrast-enhanced CT scans after therapy to assess tumor response. Animals were euthanized, their livers explanted, and liver tissue submitted to histologic analysis. RESULTS: Percent tumor necrosis as measured at histology was 85% in group 2 (2 injections), 75% in group 1 (1 injection) and 52% in the control group. The difference between groups I and 2 was statistically significant, indicating that repeat therapy had a greater impact on tumor necrosis than single injection. The fraction oftumor necrosis estimated at contrastenhanced CT imaging correlated well with that found at histology. Viable cells were mostly found at the periphery of the tumor. CONCLUSION: Intratumoral injection of cisplatinl epinephrine gel caused significant tumor necrosis especially when injections are repeated. Estimates of tumor necrosis at CT imaging matched those obtained at histology.

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Poster No. 266 The Efficacy of Percutaneous Hot Saline Injection Therapy Combined with Transcatheter Arterial Embolization Using Lipiodol for Hepatocellular Carcinoma. H, Anai, Nara Medical University, Nara, Japan· H, Sakaguchi· r Tanaka· K. Yamamoto· H, Uchida· K. Kichikawa, et al. PURPOSE: Transcatheter arterial embolization using Lipiodol (Lp-TAB) for hepatocellular carcinoma (HCe) has been spread widely. However if tumor includes hypovascular lesion or selective catheterization is very difficult, Lp-TAE was performed insufficiently and poor accumulation of Lipiodol (Lp) in the tumor is obtained on CT after Lp-TAE. Additional Lp-TAE is not indicated for HCC in such cases and another treatment is required. The purpose of this study is to evaluate the efficacy of percutaneous hot saline injection therapy (PHSIT) for HCC with poor Lp accumulation after Lp-TAB. MATERiALS AND METHODS: Twenty five patients with HCCs with poor Lp accumulation after Lp-TAE underwent additional PHSlT. A Doppler US or CT guidance is used to identify the region ofLp deficit and to guide the needle to the location ofthe residual tumor to deliver the hot saline injection. The quantity of the hot saline injection is determined by the size ofthe region of poor Lp accwnulation indicated by contrast enhanced CT images. We evaluated the vascularity of the lesion of poor Lp accumulation on CT in all cases and the viability of malignancies by flOe needle biopsy (FNB) in 7 of all. PHSIT was performed with hot saline (15 -160 ml; mean 60 mJ). TIle period offollow up after PHSIT ranged ITom 6 to 70 months (mean 32 months). The therapeutic effect was evaluated with US Doppler, dynamic CT and dynamic MRI periodically. Also survival rate was evaluated. RESULTS: The lesion revealed hypervascular (Hyper) in 18 of 25, hypovascular (Hypo) in 7. Six of 7 in Hypo were diagnosed as well-differentiated adenocarcinoma and one was diagnosed as moderate differentiated adenocarcinoma by FNB. Cumulative local recurrence rate was 10, 17,31 and 31 % in I, 2, 3 and 5 years, respectively. Cumulative survival rate was 97,77,59 and 59% in 1,2,3 and 5 years, respectively. No complication was obtained in all cases. CONCLUSION: It is suggested that PHSlT combined with Lp-TAE is safe, less invasive and effective to control local recurrence and prolong survival time.

Poster No. 267 Chemoembolization for HepatoceUular Carcinoma: The Synergistic Role of Hepatitis C and Alcoholic Cirrhosis. CA. Hamasaki, Mallinckrodt Institute o/Radiology, St. Louis, MO, USA· D.B. Brown· M Lisker-Melman • J.s. Crippin • R. Satyanarayana· MA. Fallah, et at. PURPOSE: Recent trials ofhepatic artery chemoembolization (HACE) for hepatocellular carcinoma in American populations used either a combination of high dose chemotherapy, particulate agents, and ethiodol or particulate agents alone. We report our results using lower doses ofchemotherapy and gelfoam powder without ethiodol.

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MATERiALS AND METHODS: HACE was performed 105 times in 55 patients. Agents used were cisplatin 50 mg, doxorubicin 20 mg, and mitomycin-C 10 mg mixed with gelfoam powder. Survival was evaluated with attention to Childs and Okuda classes at initial treatment. Patient survival was quantitated regarding whether patients were viral hepatitis positive (HP), alcohol abuse positive (AP) or both HP and

AP. Thirty-day mortality and other complications were tracked.

RESULTS: Mean survival for all patients was 18.3 months. Mean survival was 20.4 months, 15.1 months, and 3.0 months for Childs class A, B, and C patients respectively. Mean survival was 20.2 months, 12.3 months, and 5.0 months for Okuda class I, 2, and 3 patients respectively. Ten patients received transplants and were censored at a mean of 12.1 months (range 1-27). Hepatitis and alcohol status was known for 46 patients. Thirty-three patients were HP and 22 were AP. Thirteen patients were both HP and AP. Mean survival for all HP patients was 18.2 months while for all AP patients it was 17.5 months. The survival of patients with both HP and AP was lower when compared with the other groups (8.8 vs. 18.0 months) despite similar initial mean Okuda scores (1.4 for HPI AP co-positive vs~ 1.5 for all others). One patient (Childs class B, Okuda 2) expired within 30 days from variceal hemorrhage after one HACE session. Thirty-day mortality was 1.8% per patient and 0.9% per session of HACE. No other major complications occurred. CONCLUSION: HACE with the described protocol is safe and has comparable survival and complication rates to other published American serics. Childs C and Okuda 3 patients have poor survival regardless of the etiology of cirrhosis. Patients who are both HP and AP have lower survival than individuals with HP or AP alone. The liver in these patients may be more vulnerable to arterial ischemia secondary to HACE.

Poster No. 268 Predisposing Factors of Acute Progressive Hepatic Insufficiency after Chemoemblization of HepatoceUular Carcinoma. H, G. Lee, Holy Family Hosp, The Catholic University 0/ Korea. KyungKi-Do, Korea· H,J. Chung· YJ. Kim· M.H, Chung· N.J. Han' YS. Lee PURPOSE: Acute progressive hepatic insufficiency (APHI) is one ofthe most severe complications oftranscatheter arterial chemoembolization (TACE) in treatment of hepatocellular carcinoma (HCe). We performed a retrospective analysis to find out predisposing factors for APHI after TACE. MATERIALS AND METHODS: A total of 44 patients who underwent TACE duc to HCC during I year of a period included in the analysis. Of these patients, 20 patients were uneventful after TACE, 15 experienced transient hepatic insufficiency and 9 showed APHI. We assessed survival rate with the Kaplan-Meier method, and preprocedural 15 factors including clinical data, TACE metho~ and image features with univariate and multivariate analyses. RESULTS: Median survival( 38 days) of APHl group was significantly shorter than that ofthe group without APHI(>500 days, P<0.05). At univariate analysis, serum bilirubin (~2.0 mgldl) and albumin ($ 3.0 mgldl), prothrombin time (>80 %), ascites (>moderate), and encephalopathy (>mild) were significantly related to APH!. Portal vein thrombosis as an imaging finding was another factor for APHI (P<0.05). Age, gender, AFP, embolization extent, arterioportal shunt, ratio of mass to the liver volume, and mass size, number, and type were not significant factors(P>0.05). Multivariate analysis showed serum bilirubin as only significant factor associated with APHI (P<0.05). CONCLUSION: Preprocedural serum bilirubin is the most important factor for APHI after TACE, but other factors such as Child-Pugh score and portal vein thrombosis should be considered.

Poster No. 269 Chemoembolization of Liver Thmors: Impact on Quality of Life. DE Ramsey, Johns Hopkins University School ofMedicine, Baltimore, MD, USA· HS Kim· H Kobeiter • J.F Geschwind PURPOSE: Chemoembolization has become the mainstay of therapy for unresectable liver cancer. Data are scarce or even nonexistent on the psychological impact and quality oflife of patients after treatment with chemoembolization. The purpose of our study was to assess the effects of chemoembol ization on patients quality of life. MATERIALS AND METHODS: Patients with hepatocellular carcinoma (n=30) completed quality of life questionnaires (Brief Symptom Inventory)before, 4 weeks and 6 months after each chemoemboJization procedure. Mean scores were calculated at each time point in order to calculate the general severity index (T value), which is the most sensitive single indicator of repondent's distress level. Each score was then compared to baseline values using Student's t test. RESULTS: The mean T value was 58.1 at baseline, which is within the range of values found in normal population. After the first chemoembolization procedure, the mean T score decreased slightly to 55.6 (not significant). This downward trend was maintained after the second (55.4) and third (53) chemoembolization indicating a reduction in overall psychological distress. Long-term follow-up revealed no significant change in the mean T value, although it was I standard deviation lower than the mean baseline value (47.8 vs. 58.1, respectively). CONCLUSION: Overall quality of life remained constant throughout therapy with chemoembolization and psychological distress was slightly reduced, indicating that chemoembolization did not impact negatively on patient's well-being. Poster No. 270 Immediate and Midterm Results of Combined Hepatic Artery Chemoembolization with RF Ablation for Hepatic Malignancy. R. Salem, Beaumont Hospital, Royal Oak, MI, USA· F.T. Lee· A. Shirkhoda PURPOSE: To assess the immediate and midterm safety and efficacy ofusing combined hepatic artery chemoembolization with radiofrequency ablation (RF) in the treatment ofhepatic malignancy. MA TERIALS AND METHODS: Between 1998-2001, II (17 lesions) patients underwent hepatic artery chemoembolization immediately followed by percutaneous radiofrequency ablation. Patients were treated for hepatoma (n=4), metastatic colon cancer (n=6) and bladder cancer (n=I). All patients were treated using mitomycin, adriamycin, cisplatinum, with PVA particles and ethiodol. Radiofrequency ablation was performed using the RITA medical device. All procedures were performed in the same setting using fluoroscopic, 'ultrasound or-Cr g'u"dance'- Ai least" 6 months of followup data was available for all patients. Either CT or MRI was performed as the followup imaging modality. RESULTS: There were no immediate post-operative complications. At followup imaging, 14 of the 17 lesions treated demonstrated persistent ethiodol within the lesion, implying necrosis and avascularity. For all 17 lesions, the mean drop in volume was 23%. In 3 cases, the hepatoma

could not be well visualized until the ethiodol had been instilled, suggesting these lesions are ethiodol avid. This allowed us to perform the ablation under fluoroscopic rather than CT or US guidance. The mean drop in AFP was 83% at 6 months in the patients with hepatoma. The mean drop in CEA was 73% at 6 months in the patients with metastatic colon cancer. Embolization was also helpful in the patient with a hypovascular bladder metastasis, as the lesion became surrounded by ethiodol, creating a negative shadow as seen fluoroscopically. CONCLUSION: A combined approach using chemoembolization and RF is an emerging treatment protocol for primary or metastatic hepatic malignancy. We present a small cohort of patients that demonstrates the safety and efficacy ofthis combined approach. Furthermore, we believe that chemoembolization in this context is analogous to the surgical Pringle maneuver, decreasing the vascularity of the ablated lesion. The use of ethiodol during embolization has reproducibly increased radioopacity and visualization of the lesion, allowing the use of fluoroscopy for RF ablation. Poster No. 271 An Experimental Study of Radiofrequency Ablation with Fine eedle Electrode. H. Anai, Nara Medical University, Nara, Japan· H Sakaguchi· T. Tanaka· K. Yamamoto· S Suzuki· K. Kichikawa, et al. PURPOSE: Radiofrequency (RF) ablation has been widely spread. However its electrode size is too large to perform RF safely. The purpose of this study is to evaluate the efficacy of RF ablation with fine needle electrode in the animal model. MATERIALS AND METHODS: RF was applied ex vivo and in vivo with use ofRF generator, RF-2000 and 21 gauge fine needle electrode (FNE). FNE with 3 side holes at the needle tip was completely insulated except for the last I or 2 em of the needle tip (I cm-, 2 cm-FNE). Ex vivo study; RF with 2 cm-FNE was applied in ex vivo calf liver with or without continuous saline injection. Generator output was 10 or 30 watts. In vivo study; RF with) cm-FNE or 2 cm-FNE was applied in in vivo six porcine liver with continuous saline injection. Generator output was lO watts. RESULTS: Ex vivo study; Coagulation areas in all conditions were spindle shape. Coagulation size measured 4 x 20 mm, 7 x 24 mm and 19 x 30 mm in ex vivo calfliver without saline injection with 30 watts, without saline injection with 10 watts and with continuous saline injection with 10watts, respectively. In vivo study; In I cm-FNE coagulation area was almost round shape and coagulation size measured 15 x 19 mm. In 2 cm-FNE coagulation area was spindle shape and coagulation size measured 14 x 24 mm. CONCLUSION: It is suggested that RF with FNE applied with continuous saline injection and with 10 watts might be appropriate and that RF with FNE might make larger coagulation size more safely with further inventions. Poster

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Coaccess Radiofrequency (RF) eedle for Treatment of Liver Tumors. T. de Baere, Institltt Gustave Roussy, France PURPOSE: To evaluate the usefulness of the Coaccess RF needle for treatment of liver tumors. MATERIALS AND METHODS: 15 patients bearing liver tumors underwent radiofrequency ablation using LeVeen

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CoAccess needles (Radiotherapeutics, Sunnyvale, CA, USA), The Coaccess needle was made of a trocart needle with an external insulated sheath in which any 18 Gauge or smaller needle can be placed including a specially designed 3.5 em LeVeen RF electrode. The CoAccess needle was used: to provide biopsy and RF treatment in a single puncture under US guidance (n=6), for RF treatment requiring multiple overlapping RF deliveries under US guidance (n=4), or to facilitate the easiness of placement ofthe RF needle under CT guidance (n=5).

RESULTS: In the six cases combining RF treatment and biopsy in a single puncture, the biopsy with a 18 Gauge 20 cm long cutting needle was always contributive. Due to pre-positioning of the sheath, post-biopsy modifications (bleeding or air artefacts) did not hinder subsequent RF treatment. The 4 large tumors requiring several RF applications were treated using 3 to 5 trocmt sheaths placed in the tumor before delivering any RF current. In this manner, the sheath could be precisely loaded in the tumor, avoiding repositioning of the RF needle under US guidance after a first treatment which generates very intense hyperechoic changes including a marked acoustic shadow that usually impedes accurate US guidance. The size of RF destruction obtained were 7 to 8.5 cm in their largest dimension. The absence of handle during CT guided puncture faci litated needle placement by avoiding contact betweem the handle and the gantry. CONCLUSION: The RF CoAccess needle allows more precise tumor targeting when treating large tumors requiring multiple RF deliveries, or when performing biopsies just before RF ablation. It facilitates puncture under CT. Poster No. 273 Radiofrequency Liver Lesion: Experimental Comparison of 4 Devices. AL Denys, Dept 0/ Interventionnal Radiology, CHUV, Lausanne, Switzerland· T De Baere • V Kuoch • F. Doenz • P. Schnyder

PURPOSE:. Compare experimentally the efficacy of4 different RFA devices. MATERJALSAND METHODS: Large swine pigs (80-100 kg) and calflivers were used for in-vivo and ex-vivo experiment. Radionics cluster, RITA starburst XL 5 cm, Radiotherapeutics Leveen 4 em needle, and Bertchold 14G 15 mm perfused needle were randomly used in each liver. Livers were immediately explanted and the lesion measured in the needle axis diameter and in two perpendicular diameters were measured. RESULTS: 8 in-vivo and 9 ex-vivo lesions were created for each unit except for Bertchold for which only 3 in-vivo lesions could be achicved because of death of 5 animals within the first 5 minutes of RFA lesion creation. Suspected cause of death is massive pulmonary embolism related to hepatic vein coagulation due to diffusion of hot saline along vein wall. Invivo lesion mean volume (±SD) were 29±ll, 42±10, 39±4,3 and 37±8 respectively for Radionics, Radiotherapeutics, RITA, and Bertchold respectively. Difference between anchor devices (RJTA and Radiotherapeutics) and Radionics is significant (p<0.05). Shape ofthe in-vivo lesion evaluated by the diameter ratio between transverse and needle axis diameter showed almost spherical lesions with a ratio of 1±{). I6 and 0.97±{).1 for Radiotherapeutics and RJTA. Lesions were ovoid for Bertchold and Radionics. SIze of ex-vivo lesions were not significantly different

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CONCL USJON: Anchor needle allow creation of larger and more reproductible lesions in-vivo than perfused and cooled

needles. Using these devices allows to produce more spherical and reproductible lesions than with Bertchold and Radionics Poster No. 274 Radiofrequency Ablation of Adrenal Tumors and Adrenocortical Carcinoma Metastases: An Update. B.J. Wood, National Institutes o/Health, Bethesda, MD, USA· 1.L. Hvizda .1. Abraham· R. Alexander· Z. Neeman • T Fojo

PURPOSE: To analyze the feasibility, safety, imaging appearance, and short-term cfficacy of image-guided percutaneous radiofrequency ablation (RFA) of primary and metastatic adrenal neoplasms including adrenocortical carcinoma. MATERJALSAND METHODS: RFA was performed with 42 treatment spheres on 17 adrenal tumors in 10 patients over 27 months. Tumors ranged from 15 mm to 90 nun diameter with a mean of43 mm. Eight patients had adrenocortical carcinoma, one patient had adenocarcinoma ofunknown origin metastatic to the adrenal gland, and one had pheochromocytoma metastatic to the rib. All patients were unresectable or poor operative candidates. Median and mean follow-up was II months. RESULTS: All patients were discharged or signed off-service 6 to 48 hours after the procedures without major complications. All treatments resulted in presumptive coagulative necrosis by imaging criteria, manifested as Joss of prior contrast enhancemcnt in tumor tissue. Ten of 17 posttreatment thermal lesions decreased in size on latest followup CT scan post treatment, with 4 showing some degree of interval growth, and 3 not changing in size. A total of 6 of 17 tumors showed interval growth and/or contrast enhancement on follow up imaging, suggestive of incomplete treatment or recurrence. In the subsets of smaller tumors, 5 of 7 tumors less than 4 cm were completely ablated at mean follow up of 15 months, and 7 of II tumors less than 5 cm were completely ablated with a mean follow up of 13 months. CONCLUSION: Percutaneous, image-guided RFA is a safe and well-tolerated procedure for the treatment of unresectable primary or metastatic adrenal tumors, including adrenocortical carcinoma. RFA is effective for the short-tenn local control of small adrenal tumors, and is more effective for tumors Jess than 4 cm. The survival rate for adrenocortical carcinoma is improved by radical excision, therefore aggressive local disease control could potentially influence survival as well. However, further study is required to examine survival impact, document long-term efficacy, and to detennine if RFA can obviate the need for repeated surgical intervention in specific clinical scenarios. Poster No. 275 Perfusion Effect on Radiofrequency Ablation in the Kidneys. I. Mikityansky, National Institutes o/Health, Bethesda, MD, USA·1. Chang· WF Pritchard· D. Wray-Cahen .1. Karanian .1.L. Hvizda • B.J. Wood, et al.

PURPOSE: To evaluate the effect of perfusion on the size of radiofrequency ablation (RFA) lesions and cooling curves in porcine kidneys. To assess thc prospect of using selective renal embolization to enhance RFA of renal tumors. MATERIALS AND METHODS: A total of 21 lesions were created in 10 porcine kidneys after surgical exposure. II lesions were created without flow obstruction, 7 after clamping of

renal vasculature, and three after complete renal artery embolization using 3 ml of 500-700 micron Embosphere embolization microsphere particles. Parenchymal flow was evaluated by Doppler ultrasound. A 200 watt Radionics Generator and a single probe with a 2 cm un insulated tip without saline perfusion were used at 98°C constant temperature for 10 minutes to create each lesion. Cooling curves were obtained using a thermistor at the active tip ofthe probe. The lesions were bisected. Maximum diameters were measured for each lesion. RESULTS: Maximum diameter ofeach RFA lesion increased with flow obstruction. Thermal lesion diameter with normal flow was 1 cm, but it increased to 1.5 cm after renal vasculature clamping or embolization. Cooling curves for lesions without flow interruption exhibited wide variability and were much steeper than the ones for lesions after vascular obstruction. Both post-clamping and post-embolization cooling curves were not significantly different, though post-embolization curves showed less variability than the post-clamping ones. CONCLUSION: Blood flow obstruction increases the size of RFA lesions in the kidneys, likely due to reduction of convective heat loss during ablation. In addition, embolization decreases variability of the convective heat Joss from the ablation, which should result in improved uniformity and predictability ofRFA lesions. Pre-RFA selective renal artery embolization may significantly enhance RFA ofrenal tumors by allowing ablation of larger tumors. In addition, pre-RFA embolization for large renal tumors could potentially decrease blood loss. Superior uniformity and predictability could facilitate treatment planning, and thus improve outcomes. Therefore, further evaluation ofcombination ofthese modalities is indicated.

Poster No. 276 Sensitivity of Semi-Automated Delineation of Paths of Blood Vessel for Planning Radio-Frequency Ablation of Thmors. P.J. Yim, National Institutes ofHealth, Bethesda, MD, USA· H.B. Marcos· P.L. Choyke· B.J. Wood PURPOSE: Radio-frequency ablation (RFA) of liver tumors may be impeded by blood flow in the vicinity of the tumor. Blood flowing through the larger vessels produces a heat-sink effect thus preventing burning of the tumor. If the presence and location oflarge blood vessels near to tumors is known, additional heating can be applied accordingly by modification of the needle placement and the current density. The purpose ofthis paper is to evaluate the accuracy of the Ordered Region Growing (ORG) computational algorithm for delineation of blood vessels in the liver from magnetic resonance angiography (MRA) and venography (MRV). MATERIALS AND METHODS: Contrast enhanced magnetic resonance (MR) images of the arteries, veins and liver tissue were obtained of a patient with liver cancer on a 1.5T MR system. 3D Coronal images were obtained after intravenous injection of0.05 mmol/kg ofa gadolinium chelate. The MRA and MRV were obtained during consecutive breath-hold acquisitions triggered by a bolus detection method. A seed point was manually placed at the celiac axis in the MRA, at the origin of the hepatic vein in the MRV and at the origin of the portal vein in the MRV The ORG connectivity graph was constructed for both the MRA and MRV The vessel skeletons were then obtained interactively by picking poinls at all the distal termini ofthe vessel trees. Tubular surface meshes were produced from all vessel paths and visualized as a shaded surface display.

RESULTS: The ORG algorithm detected 9 terminal segments of arteries in the liver while only 6 could be visually identified from the MIP of the MRA. 25 terminal segments of the portal vein were detected while 3 terminal segments of the bepatic vein were detected by the ORG algorithm. CONCLUSION: The ORG is a reliable semi-automated method for depiction of blood vessels in the liver for the purpose of radio-frequency ablation planning. Identification of blood vessels near a planned therrnallesion may assist with treatment planning to overcome the heat sink effect. The ORG algorithm needs to be compared to the source images of the MRA and MRV, as a measure of vessel detection sensitivity. The impact of detected vessels upon thermal lesion size and shape must also be assessed.

Poster No. 277 MRI-Guided Percutaneous Cryoablation of Hepatocellular Carcinoma. T Shimizu, Hokkaido University General Hospital, Hokkaido, Japan· H. Endo • N. Miyamoto· Y. Watanabe· M. Funakubo • K. Miyasaka PURPOSE: To evaluate the feasibility of MRI-guided percutaneous cryoablation ofhepatocellular carcinoma (HCC). MATERIALS AND METHODS: Using an MR-compatible, argon-based cryoablation system (CryoHit; Galil Medical, Israel) with 2 and 3mm diameter probes, MRI-guided percutaneous cryoablation is performed. Treatments are guided and monitored with a low magnetic field (0.3T) horizontal type open MRI (Aeris II; HITACHI Medico, Japan). Criteria for the candidates are as follows.

1. Good performance status. 2. Tumors are limited to the liver. 3. Has no other serious disease. 4. Number of tumors is less than or equal to 3. 5. The maximum diameter of the tumor is less than 10 cm when it is solitary. And the diameters are less than or equal to 3 em when the number of tumors is 2 or 3. RESULTS: From April to September 2001, 6 HCCs in 6 cases were treated. Ages ranged from 46 to 65 years old. The average age was 57.8. The maximum diameters of tumors ranged from 1.2 to 4.0 cm and the average was 2.3 cm. All HCCs were confirmed by CT, MRI and tumor markers (AFP or PIVKA-II). Superparamagnetic iron oxide (SPIO) was administered intravenously in 5 cases out of 6 for delineating the tumor clearly. The numbers of probes were I in 3 cases, 2 in 2 cases and 3 in one case. The follow up periods were from 2 weeks to 23 weeks. The mean was 13.3 weeks. In all cases, cryoprobes were located safely and accurately using MRI guidance and all tumors were contained inside ice balls on the MR images. The entire area of five tumors was ablated and there was no residual viability oftumors in short term follow up. In the last case, the follow up period was too short to evaluate the viability. The serum level of AST, ALT, LDH and CRP were elevated but they returned to normal within 2 or 3 weeks. The adverse reactions were mild fever in all cases and temporary pleuritis in one case. CONCLUSION: MRl-guided percutaneous cryoablation is a safe, accurate and effective modality for HCC.

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Poster No. 278 Role of Diagnostic Angiography and Embolization in the Delivery of Y-90 Microspheres. R. Salem, Beaumont Hospital, Royal Oak, MI, U!:>'A • V. Gates· H. Dworkin· C. Brancaleone • D. Martin PURPOSE: Yttrium-90 is a beta emitter. It is available as a glass microsphere brachytherapy device that is infused through the hepatic arterial route. We assessed the need for pretreatment visceral angiography and embolization prior to the administration ofY-90 for hepatic malignancies. MATERIALS AND METHODS: 24 patients underwent preoperative visceral angiography prior to the infusion ofY-90. Patients were being evaluated for the treatment of hepatoma (n=7) and metastatic disease (n=17). All available percutaneous techniques (coil embolization) were used to minimize the risk of radiation-induced bowel toxicity. RESULTS: 17 of the 24 patients had classic arterial anatomy, with one right and one left hepatic artery. All patients with classic anatomy underwent therapy to the right and left hepatic arteries at 30-day intervals. 7 patients had variant anatomy that altered treatment approach. In order to minimize radiationinduced bowel injury, 5 patients required gastroduodenal artery embolization and 2 patients required right gastric artery embolization prior to Y-90 administration. 2 patients required 3 treatments because of variant anatomy: one accessory right hepatic and one middle hepatic artery. Both of these patients underwent 3 treatments successfully. One patient requiring gastroduodenal artery embolization suffered radiation-induced bowel toxicity. CONCLUSION: Pre-treatment visceral angiography is essential in the evaluation of patients being evaluated for Y90. Arterial variants are common, requiring either percutaneous intervention with embolization or alternate dose fractionation. Furthermore, in cases of complex anatomy, percutaneous catheter techniques can be used to convert patients who might othelwise not be amenable to Y-90 into suitable candidates. Cases of these variants will be demonstrated.

Embolization· UAE Poster No. 280 Interest of Calibrated Microspheres To Perform Uterine Fibroid Embolization. F Joffre, Hopital Ranguiel, Toulouse, France' J.M. Tubiana • J.P Pelage, • A. FEMIC Group PURPOSE: To evaluate the efficacy and safety of uterine artery embolization in women with symptomatic fibroids. To study the effects of uterine artery embolization using large calibrated microspheres. MATERIALS AND METHODS: Eighty five women (Mean age 42 y.o., range 26-56) entered the study between January and December 2000. Indications for treatment were menorrhagia, menstrual pain or bulk-related symptoms. Calibrated microspheres larger than 500mu were used in all women and the main uterine artery was left patent. Ultrasound or Magnetic Resonance Imaging was performed before embolization and at 6 months. Clinical evaluation was made at regular intervals after embolization to assess patient outcome with focus on complications.

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RESULTS: With a mean clinical follow-up of 9.3 months, menorrhagia was improved in 87% of women. There was a significant reduction in uterine and dominant fibroid volumes

6 after treatment. No infective complications occured. Five (6%) warnen had clinical failure or recurrence leading to hysterectomy (performed 2 to 5 months after embolization). Five (5%) women had transient or permanent amenorrhea after embolization. All these women were over the age of 45.

CONCLUSION: Large calibrated microspheres seem to be an effective alternative to polyvinyl alcohol particles to perform uterine fibroid embolization. Targetted embolization of the perifibroid arterial plexus with incomplete embolization of the uterine artery is a promising strategy.

Poster No. 281 Uterine Artery Embolization for Symptomatic Fibroids in Young Females: Failure, Complication and Hormonal Changes. H.s. Kim, The Johns Hopkins Medical Institutes, Baltimore, MD, USA· A.N. Wadhwani· A.C. Venbrux' A. Arepally' J.F Geschwind

PURPOSE: To analyze the effectiveness of uterine artery embolization (UAE) procedure for symptomatic fibroid in young females between 20 to 39 years-old and to access failure, complication and hormonal changes. MATERIALS AND METHODS: Twenty-nine young women between the age of twenty to thirty five with symptomatic uterine fibroid undelwent uterine artery embolization at our institution during a 31 month period between 1998 and 2000. Four patients were in their twenties and twenty five patients were in their thirties. Bilateral uterine arteries were embolized using 500 to 710 microns PYA particles (Contour, Boston Scientific, Boston, MA). All of the patients were followed for a period of six months up to one year by follow-up clinic visits and follow-up pelvic MRI examinations. Hormone levels including follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol were obtained pre and post UAE. The patients' symptoms and follow-up MRI were closely followed, and repeat angiography was performed, ifindicated. RESULTS: Main symptoms of our patients include menorrhagia, metrorrhagia, menometrorrhagia and infertility. 100% initial technical success was noted. 8% (2/25) of the patients experienced recurrent or persistent menorrhagia after UAE. One patient was restudied by angiography, demonstrating recruitment by ovarian arteries, which were successfully embolized for symptomatic relief. One patient developed recurrent menometrorrhagia which subsequently resolved spontaneously. 4% (1/25) of patients developed post embolization syndrome, which was adequately treated by hospitalization and institution of intravenous antibiotics. None of the patients developed premature ovarian failure. No significant groin access site complication was seen. No symptoms attributed to non-target embolization was detected. No significant changes in FSH, LH and estradiol levels after the UAE procedure were observed. CONCLUSION: UAE is safe and effective procedure for symptomatic uterine fibroids in young patients with low rate ofcomplication and failure. Premature ovarian failure in young patients is rare. Initial failure from UAE can be treated effectively by repeat angiography and further selective embol ization.