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Re: Can We Better Select Patients With Metastatic Renal Cell Carcinoma for Cytoreductive Nephrectomy?
RENAL, URETERAL AND RETROPERITONEAL TUMORS
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delayed images a hybrid SPECT/CT was performed. SPECT was fused with CT to determine the anatomical localization of the sentinel node. Surgery with sampling was performed the following day using a gamma probe and a portable mini gamma camera. Results: Eight patients, seven with right-sided renal cell carcinoma, were included with a mean age of 55 years (range: 45–77). The mean tumour size was 4 cm (range: 3.5– 6 cm). Six patients had sentinel nodes on scintigraphy (two retrocaval, four interaortocaval, including one hilar) with one extraretroperitoneal location along the internal mammary chain. All nodes could be mapped and sampled. In two patients no drainage was visualized. Renal cell carcinomas were of clear cell subtype with no lymph node metastases. Conclusion: Sentinel node identification using preoperative and intraoperative imaging to locate and sample the sentinel node at surgery in renal cell carcinoma is feasible. Sentinel node biopsy may clarify the pattern of lymphatic drainage and extent of lymphatic spread which may have diagnostic and therapeutic implications. Editorial Comment: Routine lymph node dissection without radiological lymphadenopathy in patients with renal cancer has been discouraged because of a lack of proven benefit in randomized trials. A fundamental shortcoming of the literature is the variability of the dissection templates among surgeons and the known widely variable lymphatic drainage of the kidney. These authors propose a novel approach to lymph node sampling in renal cancer through application of a technique historically used in other malignancies such as breast, melanoma and penis. While such an approach is appealing, I am skeptical that it could work for kidney cancer given the likely drainage of most tumors to multiple nodes, the difficulty in selecting a site for injection in larger tumors and the known low incidence of lymph node metastases in organ confined, early stage disease. A large clinical trial would likely be necessary to validate the clinical benefit. Samir S. Taneja, M.D.
Re: Can We Better Select Patients With Metastatic Renal Cell Carcinoma for Cytoreductive Nephrectomy? S. H. Culp, N. M. Tannir, E. J. Abel, V. Margulis, P. Tamboli, S. F. Matin and C. G. Wood Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston, Texas Cancer 2010; 116: 3378 –3388.
Background: The benefits of cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (mRCC) should outweigh surgical morbidity. Even when the generally agreed upon selection criteria for CN are met, some patients do poorly after surgery. The objective of this study was to identify preoperative factors that were prognostic of outcome in patients who were being considered for CN. Methods: The authors conducted a retrospective study to investigate the overall survival (OS) of patients who underwent CN using the OS of patients with mRCC who did not undergo CN as a referent group. Patients who underwent CN were divided into 2 groups based on when their OS diverged from that of nonsurgical patients. Chi-square analysis was used to identify variables that differed between the 2 surgical groups. Multivariate Cox proportional hazards regression was used to analyze those variables for the entire CN cohort. Risk factors were defined as preoperative variables that remained significant on multivariate analysis. The median OS and the overall risk of death were calculated based on the number of risk factors. Results: From 1991 to 2007, 566 patients who were eligible for or received systemic therapy underwent CN, and 110 patients received medical therapy alone. On multivariate analysis, independent preoperative predictors of inferior OS in surgical patients included a lactate dehydrogenase level greater than the upper limit of normal, an albumin level less than the lower limit of normal, symptoms at presentation caused by a metastatic site, liver metastasis, retroperitoneal adenopathy, supradiaphragmatic adenopathy, and clinical tumor classification ⱖT3. Inferior OS and an increased risk of death were correlated positively with the number of risk factors. Surgical patients who had ⱖ4 risk factors did not appear to benefit from CN. Conclusions: The authors of this report identified 7 preoperative variables that permitted them to identify patients who were unlikely to benefit from CN.
1226
IMAGING
Editorial Comment: The benefits of cytoreductive nephrectomy in the setting of systemic immunotherapy have been largely accepted, although justification of its implementation before systemic tyrosine kinase inhibitors has been largely extrapolated. The authors of this study demonstrate, importantly, that a group of patients may suffer more harm than benefit from nephrectomy. Intuitively patients who are deconditioned from the renal cancer, or those who have advanced disease, do not do well following cytoreductive nephrectomy. Often, rapid progression may preclude systemic therapy. Preoperative identification of these patients is imperative in current practice, given the unknown benefit of nephrectomy in the evolving systemic therapeutic paradigm. Samir S. Taneja, M.D.
Imaging Characterization of Contrast Enhancement in the Ablation Zone Immediately After Radiofrequency Ablation of Renal Tumors S. Javadi, J. U. Ahrar, E. Ninan, S. Gupta, S. F. Matin and K. Ahrar Department of Radiology, Section of Interventional Radiology, University of Texas M. D. Anderson Cancer Center, Houston, Texas J Vasc Interv Radiol 2010; 21: 690 – 695.
Purpose: To characterize the degree of contrast enhancement within the ablation zone immediately after radiofrequency (RF) ablation of renal tumors. Materials and Methods: Patients with renal tumors treated with percutaneous RF ablation at one institution between January 2004 and October 2007 were retrospectively reviewed. For each tumor, computed tomography (CT) density measurements were made at four phases (noncontrast, arterial phase, parenchymal phase, and excretory phase) in each of four CT examinations (before ablation, day 0, 1 month, and 6 months). Results: A total of 36 renal tumors in 34 patients were treated with CT-guided RF ablation in 35 sessions. Before RF ablation, all tumors exhibited enhancement after intravenous administration of contrast material. The peak density was reached during the parenchymal phase, with a partial washout of contrast agent in the excretory phase. On CT images acquired immediately after RF ablation (day 0), 28 of the 36 ablated tumors (78%) exhibited clinically significant homogeneous enhancement (ie, density change ⬎10 HU) within the ablation zone. However, contrast-enhanced CT studies performed at 1 and 6 months revealed no clinically significant enhancements in any of the 36 treated tumors (mean density changes of 4 HU at 1 month and 3 HU at 6 months). Conclusions: Contrast-enhanced CT studies revealed a mild, temporary homogenous contrast enhancement of the ablation zone immediately after RF ablation of renal tumors, which should not be mistaken for a residual, unablated tumor. This enhancement in the ablation zone eventually disappears in follow-up contrast-enhanced CT studies. Editorial Comment: Percutaneous CT guided RF ablation is increasingly being offered to patients with a renal mass who are poor surgical candidates. The tumor is treated in situ and there is no histopathological evaluation of the ablated tissue. The main diagnostic feature used by radiologists is residual enhancement of the ablated mass. Radiologists use an increase in enhancement of greater than 10 HU from the pre-contrast to the postcontrast scan as suspicious for residual or recurrent tumor. These authors studied 34 patients with a renal mass. Noncontrast, arterial phase, nephrographic phase and excretory phase scans were performed before ablation, as well as on day zero and at 1-month and 6-month followup. The region of interest was measured on the pre-contrast and post-contrast scans. The area that had the highest increase in enhancement was recorded.
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delayed images a hybrid SPECT/CT was performed. SPECT was fused with CT to determine the anatomical localization of the sentinel node. Surgery with sampling was performed the following day using a gamma probe and a portable mini gamma camera. Results: Eight patients, seven with right-sided renal cell carcinoma, were included with a mean age of 55 years (range: 45–77). The mean tumour size was 4 cm (range: 3.5– 6 cm). Six patients had sentinel nodes on scintigraphy (two retrocaval, four interaortocaval, including one hilar) with one extraretroperitoneal location along the internal mammary chain. All nodes could be mapped and sampled. In two patients no drainage was visualized. Renal cell carcinomas were of clear cell subtype with no lymph node metastases. Conclusion: Sentinel node identification using preoperative and intraoperative imaging to locate and sample the sentinel node at surgery in renal cell carcinoma is feasible. Sentinel node biopsy may clarify the pattern of lymphatic drainage and extent of lymphatic spread which may have diagnostic and therapeutic implications. Editorial Comment: Routine lymph node dissection without radiological lymphadenopathy in patients with renal cancer has been discouraged because of a lack of proven benefit in randomized trials. A fundamental shortcoming of the literature is the variability of the dissection templates among surgeons and the known widely variable lymphatic drainage of the kidney. These authors propose a novel approach to lymph node sampling in renal cancer through application of a technique historically used in other malignancies such as breast, melanoma and penis. While such an approach is appealing, I am skeptical that it could work for kidney cancer given the likely drainage of most tumors to multiple nodes, the difficulty in selecting a site for injection in larger tumors and the known low incidence of lymph node metastases in organ confined, early stage disease. A large clinical trial would likely be necessary to validate the clinical benefit. Samir S. Taneja, M.D.
Re: Can We Better Select Patients With Metastatic Renal Cell Carcinoma for Cytoreductive Nephrectomy? S. H. Culp, N. M. Tannir, E. J. Abel, V. Margulis, P. Tamboli, S. F. Matin and C. G. Wood Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston, Texas Cancer 2010; 116: 3378 –3388.
Background: The benefits of cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (mRCC) should outweigh surgical morbidity. Even when the generally agreed upon selection criteria for CN are met, some patients do poorly after surgery. The objective of this study was to identify preoperative factors that were prognostic of outcome in patients who were being considered for CN. Methods: The authors conducted a retrospective study to investigate the overall survival (OS) of patients who underwent CN using the OS of patients with mRCC who did not undergo CN as a referent group. Patients who underwent CN were divided into 2 groups based on when their OS diverged from that of nonsurgical patients. Chi-square analysis was used to identify variables that differed between the 2 surgical groups. Multivariate Cox proportional hazards regression was used to analyze those variables for the entire CN cohort. Risk factors were defined as preoperative variables that remained significant on multivariate analysis. The median OS and the overall risk of death were calculated based on the number of risk factors. Results: From 1991 to 2007, 566 patients who were eligible for or received systemic therapy underwent CN, and 110 patients received medical therapy alone. On multivariate analysis, independent preoperative predictors of inferior OS in surgical patients included a lactate dehydrogenase level greater than the upper limit of normal, an albumin level less than the lower limit of normal, symptoms at presentation caused by a metastatic site, liver metastasis, retroperitoneal adenopathy, supradiaphragmatic adenopathy, and clinical tumor classification ⱖT3. Inferior OS and an increased risk of death were correlated positively with the number of risk factors. Surgical patients who had ⱖ4 risk factors did not appear to benefit from CN. Conclusions: The authors of this report identified 7 preoperative variables that permitted them to identify patients who were unlikely to benefit from CN.
1226
IMAGING
Editorial Comment: The benefits of cytoreductive nephrectomy in the setting of systemic immunotherapy have been largely accepted, although justification of its implementation before systemic tyrosine kinase inhibitors has been largely extrapolated. The authors of this study demonstrate, importantly, that a group of patients may suffer more harm than benefit from nephrectomy. Intuitively patients who are deconditioned from the renal cancer, or those who have advanced disease, do not do well following cytoreductive nephrectomy. Often, rapid progression may preclude systemic therapy. Preoperative identification of these patients is imperative in current practice, given the unknown benefit of nephrectomy in the evolving systemic therapeutic paradigm. Samir S. Taneja, M.D.
Imaging Characterization of Contrast Enhancement in the Ablation Zone Immediately After Radiofrequency Ablation of Renal Tumors S. Javadi, J. U. Ahrar, E. Ninan, S. Gupta, S. F. Matin and K. Ahrar Department of Radiology, Section of Interventional Radiology, University of Texas M. D. Anderson Cancer Center, Houston, Texas J Vasc Interv Radiol 2010; 21: 690 – 695.
Purpose: To characterize the degree of contrast enhancement within the ablation zone immediately after radiofrequency (RF) ablation of renal tumors. Materials and Methods: Patients with renal tumors treated with percutaneous RF ablation at one institution between January 2004 and October 2007 were retrospectively reviewed. For each tumor, computed tomography (CT) density measurements were made at four phases (noncontrast, arterial phase, parenchymal phase, and excretory phase) in each of four CT examinations (before ablation, day 0, 1 month, and 6 months). Results: A total of 36 renal tumors in 34 patients were treated with CT-guided RF ablation in 35 sessions. Before RF ablation, all tumors exhibited enhancement after intravenous administration of contrast material. The peak density was reached during the parenchymal phase, with a partial washout of contrast agent in the excretory phase. On CT images acquired immediately after RF ablation (day 0), 28 of the 36 ablated tumors (78%) exhibited clinically significant homogeneous enhancement (ie, density change ⬎10 HU) within the ablation zone. However, contrast-enhanced CT studies performed at 1 and 6 months revealed no clinically significant enhancements in any of the 36 treated tumors (mean density changes of 4 HU at 1 month and 3 HU at 6 months). Conclusions: Contrast-enhanced CT studies revealed a mild, temporary homogenous contrast enhancement of the ablation zone immediately after RF ablation of renal tumors, which should not be mistaken for a residual, unablated tumor. This enhancement in the ablation zone eventually disappears in follow-up contrast-enhanced CT studies. Editorial Comment: Percutaneous CT guided RF ablation is increasingly being offered to patients with a renal mass who are poor surgical candidates. The tumor is treated in situ and there is no histopathological evaluation of the ablated tissue. The main diagnostic feature used by radiologists is residual enhancement of the ablated mass. Radiologists use an increase in enhancement of greater than 10 HU from the pre-contrast to the postcontrast scan as suspicious for residual or recurrent tumor. These authors studied 34 patients with a renal mass. Noncontrast, arterial phase, nephrographic phase and excretory phase scans were performed before ablation, as well as on day zero and at 1-month and 6-month followup. The region of interest was measured on the pre-contrast and post-contrast scans. The area that had the highest increase in enhancement was recorded.