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Abstract No. 327: Clinical and Imaging Outcomes of Radiofrequency Ablation of Osteoid Osteoma
RESULTS: 12 males and 18 females with a mean age of 50 were evaluated. Post-access Dyna-CT demonstrated 6 cases where access was different than expected by fluoroscopy and digital planar images, with 1 case requiring placement of a new access. Of the 21 post-procedural Dyna-CT cases, 16 showed residual stones greater than 3 mm. These stones were seen by planar imaging in only 10 of these 16 (63%). Comparing Dyna-CT with CT, 7 of 9 pre-procedural and 4 of 6 post-procedural comparisons demonstrated equivalent stone burden. In the remaining 4 cases where routine CT was superior, Dyna-CT images were significantly limited by patient motion. CONCLUSION: The current study demonstrates intra-procedural Dyna-CT aids in establishing accurate percutaneous access and assessing residual stone burden after PCNL. The current study also suggests Dyna-CT and routine crosssectional imaging are equivalent in assessing post-procedural stone burden in the absence of significant patient motion. These findings indicate that Dyna-CT may aid with intraprocedural management decisions during PCNL.
Non-vascular Interventions: Other Abstract No. 325 MR-Dacryocystography in Patients Treated with Balloon Dacryocystoplasty or Nasolacrimal Stent Placement. B. Coskun,1 E.T. Ilgit,1 B.A. Onal,1 N. Tokgoz,1 O. Konuk,2 M. Unal;2 1Gazi University, School of Medicine, Department of Radiology, Ankara, Turkey; 2Gazi University, School of Medicine, Department of Ophthalmology, Ankara, Turkey PURPOSE: To evaluate the efficacy of topical contrast enhanced magnetic resonance dacryocystography (MRDCG) in patients with obstructive epiphora who underwent interventional radiological procedures such as balloon dacryocystoplasty and/or nasolacrimal polyurethane stent placement. MATERIALS AND METHODS: Thirty-six lacrimal drainage systems (LDS) of 21 patients treated with balloon dacryocystoplasty (n⫽11) or nasolacrimal polurethane stent placement (n⫽11) were examined with MR-DCG and digital subtraction dacryocystography (DS-DCG). DS-DSG examinations were performed one day to three months before MR-DCG. Otherwise healthy, contralateral LDSs (n⫽14) were also evaluated in patients with unilateral disease. A sterile 0.9 % NaCl solution containing 1/100 diluted Gadobutrol was instilled into conjunctival sacs. The 3D FSPGR sequence was used with a 1.5-T scanner. MR- and DS-DCG findings were scored and compared according to the diagnostic image quality, morphology of lacrimal sac, junction, nasolacrimal duct and presence of contrast medium in the nasal cavity. RESULTS: Comparison of MR-DCG and DS-DCG findings showed no significant statistical differences in the reference anatomical locations according to the Mc Nemar Test (p ⬎ 0,05). Good or very good agreement ( ⬎ 0,61) was observed according to the Kappa statistics. CONCLUSION: Our results suggest that topical contrast enhanced MR-DCG is an effective, noninvasive and reliable method in the evaluation of LDS in patients treated by means of interventional radiological procedures. Application of topical contrast media without the requirement of cannulation of the canaliculus and ionizing radiation are the main advantages. S120
Abstract No. 326 EE Utilization of an Advanced Tableside Console for Enhanced Intra-Procedural Visualization during CTGuided Procedures. E. de Kerviler,1 J. Yanof,2 C. de Bazelaire,1 C. Bauer,2 K. Read;2 1Saint-Louis Hospital, Paris, France; 2Philips Medical Systems, Cleveland, OH PURPOSE: To review the workflow, visualization, and computer input devices used with a CT table-side console during several CT-guided interventional applications. MATERIALS AND METHODS: The CT Table-side Interventionist’s Console consists of a table-side display screen placed side-by-side with the CT fluoroscopy screen and computer input devices. The intra-procedural visualization includes application dependent roadmaps and reference results processed from pre-procedure data sets such as 1) High resolution, contrast enhanced diagnostic scan, 2) Ablation treatment planning, 3) Fused multi-modality images. Visualization may also include easy access to results of intraprocedural scanning such as 1) Mini-bolus CT Angiography and 2) Previous CT fluoro series. Computer input devices such as a touchpad are used with a sterile drape as means for the physician or the CT technologist to intra-procedurally adjust key image review functions and scan parameters. A shuttle jog/wheel is also used to scroll through image stacks. The outer shuttle is used for fast forward/rewind and the jog-wheel is used for fine frame-by-frame control. Several CT interventional cases are reviewed including percutaneous biopsy and ablation of solid tumors. TEACHING POINTS: Table-side access to a visualization monitor, side-by-side with the CT fluoro screen, can facilitate improved safety and workflow of CT guided procedures and decrease procedure time of CT guided procedures. Adjustment of visualiziation and scan parameters at the CT table-side console may be performed more easily at the tableside than instructing the technologist in the control room. Additional pre- or intra-procedure visualization can be easily accessed for intra-procedural reference and roadmap viewing. Abstract No. 327 Clinical and Imaging Outcomes of Radiofrequency Ablation of Osteoid Osteoma. E.B. Hayeems, J.R. Kachura; University Health Network and Mount Sinai Hospital, Toronto, ON, Canada PURPOSE: To evaluate clinical effectiveness of Radiofrequency Ablation of Osteoid Osteoma. MATERIALS AND METHODS: From September 2004 to September 2007, 42 CT guided radiofrequency ablation procedures were performed on 40 patients (31M/9F) with symptomatic osteoid osteoma. Mean age was 25 (17-62). Thirty-six patients had lower extremity or pelvic lesions and 4 had upper extremity lesions. Clinical and imaging follow-up time ranged from 1 day to 3 years. Follow up imaging, if obtained, was performed with gadolinium enhanced MR. RESULTS: 100% (42/42) of the procedures were technically successful with CT evidence of the ablation probe centered within the nidus of the lesion. Four patients were lost to clinical or imaging follow-up. 92% (33/36) of patients had clinical resolution of their pain post procedure. Three patients (8%) had no significant reduction in their pain post procedure. One of these patients elected to have a repeat
radiofrequency ablation of her osteoid osteoma which resulted in resolution of pain. One patient returned 6 days post procedure with a subcutaneous abscess which resolved following drainage and a course of intravenous antibiotics. One patient had a persistent region of anesthesia in the region of percutaneous needle entry. One patient returned 2.5 years following a successful ablation with recurrence of symptoms and evidence of a new lesion which was successfully treated. 95% (19/20) patients who had a gadolinium enhanced MRI at 1 month post procedure had no evidence of enhancement of the nidus. All of these patients were symptom free at the time of their follow up imaging. CONCLUSION: Radiofrequency ablation is a safe and effective treatment for osteoid osteoma with low complication and recurrence rates.
Oncology: Ablation Abstract No. 328 Evaluation of Incidentally Detected Renal Tumors for Feasibility of Percutaneous Thermal Ablation. J.J. Arampulikan, M. Stifelman, T.W. Clark; New York University School of Medicine, New York, NY PURPOSE: Many RCC are currently identified during imaging performed for another reason. As experience with thermal ablation of RCC as an alternative to surgical resection continues to accumulate, further insight is needed into the proportion of incident RCC patients with anatomic characteristics that are potentially amenable to this minimally-invasive therapy. MATERIALS AND METHODS: Over a 33-month period, 58 patients were identified with imaging characteristics of RCC during CECT or Gd-MRI performed for an unrelated clinical indication (eg. AAA, diverticulitis). Among these 58 patients, 39 (67.2%) patients (mean age, range) had RCC less than 4 cm in diameter and these cross-sectional images were evaluated by current anatomic criteria to determine suitability for percutaneous thermal ablation (Gervais classification, size, proximity to the central collecting system and adjacent viscera).
CONCLUSION: Within this retrospective cohort the majority of incident RCC discovered through imaging performed for an unrelated clinical indication were T1a lesions with anatomic characteristics that would be amenable to percutaneous thermal ablation. Abstract No. 329 CT Guided Percutaneous Cryoablation of Renal Tumors. M.A. Gibson; Eastern Virginia Medical School, Norfolk, VA
MATERIALS AND METHODS: 27 patients underwent 30 cryoablation procedures of 27 renal tumors during a 3-year period. There were 14 men and 13 women with an average age of 67 years (range, 58-80). Biopsy of the renal lesion was performed under CT guidance immediately prior to cryoablation. Using CT imaging, 1-4 cryoprobes (mean 1.4) were placed and lesions were ablated by using real-time CT imaging for intraprocedural monitoring of the ice ball formation. Technical success was defined as complete coverage of the tumor with the ice ball with at least a 1 cm margin and elimination of areas of abnormal tumoral enhancement at imaging immediately following completion of the procedure. Effectiveness was defined as absence of suspicious enhancement on post contrast imaging and was evaluated during routine follow up CT or MRI (mean, 11 months; range, 0-30 months). RESULTS: 27 tumors were successfully ablated 24 of which required only one treatment session. Mean tumor size was 2.3 cm (range, 1.2-4.6 cm). Technical success was achieved in 27 of 27 cryoablation sessions. Biopsies performed in 27 patients showed 19 renal cell carcinomas (68%), 2 renal cell carcinomas vs. oncocytomas (7%), 2 oncocytomas (7%), 1 negative for tumor with rare atypical cells (3.5%), 1 dense fibrous tissue with chronic inflammation and remote hemorrhage (3.5%), 1 negative for malignancy with benign parenchyma with focal fibrosis, glomerulosclerosis and chronic inflammation (3.5%), 1 negative for malignancy/ normal renal parenchyma (3.5%). There were three cases of recurrent tumor on routine follow up imaging with a mean recurrence of 10 months (range, 6-12 months). All three recurrences were successfully retreated with repeat percutaneous cryoablation with no additional recurrences and mean follow up 9 months (range, 1-15 months). There were no major complications according to the SIR standardized grading system. CONCLUSION: CT-guided percutaneous cryoablation of renal tumors is a viable option for treatment of selected small renal cell tumors with good short term follow up results and no major complications. Abstract No. 330 Thermal Nerve Injury after Percutaneous Radiofrequency Ablation for Lung Tumor. H. Gobara, T. Hiraki, T. Mukai, K. Kobayashi, J. Sakurai, H. Fujiwara, T. Kurose, T. Iishi, D. Inoue, N. Tajiri, S. Norikane, M. Marunaka, H. Mimura, S. Kanazawa; Department of Radiology, Okayama University Medical School, Okayama, Japan
POSTER SESSIONS
RESULTS: 33 (84.6%) of the 39 presumed RCC were exophytic, 1 (2.6%) central and 5 (12.8%) had mixed (exophytic and central) characteristics. Mean RECIST RCC diameter was 1.8 cm (range 1.0 – 3.9 cm). Mean distance from the skin to the lesion via a posterior approach was 6.10 cm (range 2.5 – 15.2 cm). The mean distance from the lesion to the central collecting system was 0.7 cm (range 0 – 1.8 cm). 4 (10.2%) RCC had adjacent/overlying bowel that would be potentially injured and would be expected to require hydrodissection or other maneuvers for displacement.
PURPOSE: To retrospectively evaluate the success, efficacy and safety of percutaneous CT-guided cryoablation of solid renal masses.
PURPOSE: Various complications after percutaneous radiofrequency (RF) ablation for lung tumor has been known. The purpose of this study is to describe a rare complication of thermal nerve injury after RF ablation for lung tumor. MATERIALS AND METHODS: This study was based on four cases of thermal nerve injury following RF ablation of lung tumors, which occurred among 500 sessions in our institution from Jun 2000 to August 2007. The maximum tumor diameter was 15-30 mm. All procedures were performed percutaneously under CT fluoroscopic guidance using local anesthesia in 2 or epidural anesthesia in 2. The electrode used was expandable multitined electrode (LeVeen; Boston Scientific, Natick, MA) with 2-4 cm array S121
Non-vascular Interventions: Other Abstract No. 325 MR-Dacryocystography in Patients Treated with Balloon Dacryocystoplasty or Nasolacrimal Stent Placement. B. Coskun,1 E.T. Ilgit,1 B.A. Onal,1 N. Tokgoz,1 O. Konuk,2 M. Unal;2 1Gazi University, School of Medicine, Department of Radiology, Ankara, Turkey; 2Gazi University, School of Medicine, Department of Ophthalmology, Ankara, Turkey PURPOSE: To evaluate the efficacy of topical contrast enhanced magnetic resonance dacryocystography (MRDCG) in patients with obstructive epiphora who underwent interventional radiological procedures such as balloon dacryocystoplasty and/or nasolacrimal polyurethane stent placement. MATERIALS AND METHODS: Thirty-six lacrimal drainage systems (LDS) of 21 patients treated with balloon dacryocystoplasty (n⫽11) or nasolacrimal polurethane stent placement (n⫽11) were examined with MR-DCG and digital subtraction dacryocystography (DS-DCG). DS-DSG examinations were performed one day to three months before MR-DCG. Otherwise healthy, contralateral LDSs (n⫽14) were also evaluated in patients with unilateral disease. A sterile 0.9 % NaCl solution containing 1/100 diluted Gadobutrol was instilled into conjunctival sacs. The 3D FSPGR sequence was used with a 1.5-T scanner. MR- and DS-DCG findings were scored and compared according to the diagnostic image quality, morphology of lacrimal sac, junction, nasolacrimal duct and presence of contrast medium in the nasal cavity. RESULTS: Comparison of MR-DCG and DS-DCG findings showed no significant statistical differences in the reference anatomical locations according to the Mc Nemar Test (p ⬎ 0,05). Good or very good agreement ( ⬎ 0,61) was observed according to the Kappa statistics. CONCLUSION: Our results suggest that topical contrast enhanced MR-DCG is an effective, noninvasive and reliable method in the evaluation of LDS in patients treated by means of interventional radiological procedures. Application of topical contrast media without the requirement of cannulation of the canaliculus and ionizing radiation are the main advantages. S120
Abstract No. 326 EE Utilization of an Advanced Tableside Console for Enhanced Intra-Procedural Visualization during CTGuided Procedures. E. de Kerviler,1 J. Yanof,2 C. de Bazelaire,1 C. Bauer,2 K. Read;2 1Saint-Louis Hospital, Paris, France; 2Philips Medical Systems, Cleveland, OH PURPOSE: To review the workflow, visualization, and computer input devices used with a CT table-side console during several CT-guided interventional applications. MATERIALS AND METHODS: The CT Table-side Interventionist’s Console consists of a table-side display screen placed side-by-side with the CT fluoroscopy screen and computer input devices. The intra-procedural visualization includes application dependent roadmaps and reference results processed from pre-procedure data sets such as 1) High resolution, contrast enhanced diagnostic scan, 2) Ablation treatment planning, 3) Fused multi-modality images. Visualization may also include easy access to results of intraprocedural scanning such as 1) Mini-bolus CT Angiography and 2) Previous CT fluoro series. Computer input devices such as a touchpad are used with a sterile drape as means for the physician or the CT technologist to intra-procedurally adjust key image review functions and scan parameters. A shuttle jog/wheel is also used to scroll through image stacks. The outer shuttle is used for fast forward/rewind and the jog-wheel is used for fine frame-by-frame control. Several CT interventional cases are reviewed including percutaneous biopsy and ablation of solid tumors. TEACHING POINTS: Table-side access to a visualization monitor, side-by-side with the CT fluoro screen, can facilitate improved safety and workflow of CT guided procedures and decrease procedure time of CT guided procedures. Adjustment of visualiziation and scan parameters at the CT table-side console may be performed more easily at the tableside than instructing the technologist in the control room. Additional pre- or intra-procedure visualization can be easily accessed for intra-procedural reference and roadmap viewing. Abstract No. 327 Clinical and Imaging Outcomes of Radiofrequency Ablation of Osteoid Osteoma. E.B. Hayeems, J.R. Kachura; University Health Network and Mount Sinai Hospital, Toronto, ON, Canada PURPOSE: To evaluate clinical effectiveness of Radiofrequency Ablation of Osteoid Osteoma. MATERIALS AND METHODS: From September 2004 to September 2007, 42 CT guided radiofrequency ablation procedures were performed on 40 patients (31M/9F) with symptomatic osteoid osteoma. Mean age was 25 (17-62). Thirty-six patients had lower extremity or pelvic lesions and 4 had upper extremity lesions. Clinical and imaging follow-up time ranged from 1 day to 3 years. Follow up imaging, if obtained, was performed with gadolinium enhanced MR. RESULTS: 100% (42/42) of the procedures were technically successful with CT evidence of the ablation probe centered within the nidus of the lesion. Four patients were lost to clinical or imaging follow-up. 92% (33/36) of patients had clinical resolution of their pain post procedure. Three patients (8%) had no significant reduction in their pain post procedure. One of these patients elected to have a repeat
radiofrequency ablation of her osteoid osteoma which resulted in resolution of pain. One patient returned 6 days post procedure with a subcutaneous abscess which resolved following drainage and a course of intravenous antibiotics. One patient had a persistent region of anesthesia in the region of percutaneous needle entry. One patient returned 2.5 years following a successful ablation with recurrence of symptoms and evidence of a new lesion which was successfully treated. 95% (19/20) patients who had a gadolinium enhanced MRI at 1 month post procedure had no evidence of enhancement of the nidus. All of these patients were symptom free at the time of their follow up imaging. CONCLUSION: Radiofrequency ablation is a safe and effective treatment for osteoid osteoma with low complication and recurrence rates.
Oncology: Ablation Abstract No. 328 Evaluation of Incidentally Detected Renal Tumors for Feasibility of Percutaneous Thermal Ablation. J.J. Arampulikan, M. Stifelman, T.W. Clark; New York University School of Medicine, New York, NY PURPOSE: Many RCC are currently identified during imaging performed for another reason. As experience with thermal ablation of RCC as an alternative to surgical resection continues to accumulate, further insight is needed into the proportion of incident RCC patients with anatomic characteristics that are potentially amenable to this minimally-invasive therapy. MATERIALS AND METHODS: Over a 33-month period, 58 patients were identified with imaging characteristics of RCC during CECT or Gd-MRI performed for an unrelated clinical indication (eg. AAA, diverticulitis). Among these 58 patients, 39 (67.2%) patients (mean age, range) had RCC less than 4 cm in diameter and these cross-sectional images were evaluated by current anatomic criteria to determine suitability for percutaneous thermal ablation (Gervais classification, size, proximity to the central collecting system and adjacent viscera).
CONCLUSION: Within this retrospective cohort the majority of incident RCC discovered through imaging performed for an unrelated clinical indication were T1a lesions with anatomic characteristics that would be amenable to percutaneous thermal ablation. Abstract No. 329 CT Guided Percutaneous Cryoablation of Renal Tumors. M.A. Gibson; Eastern Virginia Medical School, Norfolk, VA
MATERIALS AND METHODS: 27 patients underwent 30 cryoablation procedures of 27 renal tumors during a 3-year period. There were 14 men and 13 women with an average age of 67 years (range, 58-80). Biopsy of the renal lesion was performed under CT guidance immediately prior to cryoablation. Using CT imaging, 1-4 cryoprobes (mean 1.4) were placed and lesions were ablated by using real-time CT imaging for intraprocedural monitoring of the ice ball formation. Technical success was defined as complete coverage of the tumor with the ice ball with at least a 1 cm margin and elimination of areas of abnormal tumoral enhancement at imaging immediately following completion of the procedure. Effectiveness was defined as absence of suspicious enhancement on post contrast imaging and was evaluated during routine follow up CT or MRI (mean, 11 months; range, 0-30 months). RESULTS: 27 tumors were successfully ablated 24 of which required only one treatment session. Mean tumor size was 2.3 cm (range, 1.2-4.6 cm). Technical success was achieved in 27 of 27 cryoablation sessions. Biopsies performed in 27 patients showed 19 renal cell carcinomas (68%), 2 renal cell carcinomas vs. oncocytomas (7%), 2 oncocytomas (7%), 1 negative for tumor with rare atypical cells (3.5%), 1 dense fibrous tissue with chronic inflammation and remote hemorrhage (3.5%), 1 negative for malignancy with benign parenchyma with focal fibrosis, glomerulosclerosis and chronic inflammation (3.5%), 1 negative for malignancy/ normal renal parenchyma (3.5%). There were three cases of recurrent tumor on routine follow up imaging with a mean recurrence of 10 months (range, 6-12 months). All three recurrences were successfully retreated with repeat percutaneous cryoablation with no additional recurrences and mean follow up 9 months (range, 1-15 months). There were no major complications according to the SIR standardized grading system. CONCLUSION: CT-guided percutaneous cryoablation of renal tumors is a viable option for treatment of selected small renal cell tumors with good short term follow up results and no major complications. Abstract No. 330 Thermal Nerve Injury after Percutaneous Radiofrequency Ablation for Lung Tumor. H. Gobara, T. Hiraki, T. Mukai, K. Kobayashi, J. Sakurai, H. Fujiwara, T. Kurose, T. Iishi, D. Inoue, N. Tajiri, S. Norikane, M. Marunaka, H. Mimura, S. Kanazawa; Department of Radiology, Okayama University Medical School, Okayama, Japan
POSTER SESSIONS
RESULTS: 33 (84.6%) of the 39 presumed RCC were exophytic, 1 (2.6%) central and 5 (12.8%) had mixed (exophytic and central) characteristics. Mean RECIST RCC diameter was 1.8 cm (range 1.0 – 3.9 cm). Mean distance from the skin to the lesion via a posterior approach was 6.10 cm (range 2.5 – 15.2 cm). The mean distance from the lesion to the central collecting system was 0.7 cm (range 0 – 1.8 cm). 4 (10.2%) RCC had adjacent/overlying bowel that would be potentially injured and would be expected to require hydrodissection or other maneuvers for displacement.
PURPOSE: To retrospectively evaluate the success, efficacy and safety of percutaneous CT-guided cryoablation of solid renal masses.
PURPOSE: Various complications after percutaneous radiofrequency (RF) ablation for lung tumor has been known. The purpose of this study is to describe a rare complication of thermal nerve injury after RF ablation for lung tumor. MATERIALS AND METHODS: This study was based on four cases of thermal nerve injury following RF ablation of lung tumors, which occurred among 500 sessions in our institution from Jun 2000 to August 2007. The maximum tumor diameter was 15-30 mm. All procedures were performed percutaneously under CT fluoroscopic guidance using local anesthesia in 2 or epidural anesthesia in 2. The electrode used was expandable multitined electrode (LeVeen; Boston Scientific, Natick, MA) with 2-4 cm array S121