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Abstract No. 328: Evaluation of Incidentally Detected Renal Tumors for Feasibility of Percutaneous Thermal Ablation
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
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