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RE: A COMPARISON OF URETEROSCOPY TO IN SITU EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY FOR THE TREATMENT OF DISTAL URETERAL CALCULI
0022-5347/99/1626-2103/0 THE JOURNAL OF UROLOGY® Copyright © 1999 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 162, 2103–2107, December, 1999 Printed in U.S.A.
Letters to the Editor RE: IMAGING GUIDED BIOPSY OF RENAL MASSES: INDICATIONS, ACCURACY AND IMPACT ON CLINICAL MANAGEMENT B. J. Wood, M. A. Khan, F. McGovern, M. Harisinghani, P. F. Hahn and P. R. Mueller J. Urol., 161: 1470 –1474, 1999 To the Editor. The authors demonstrate 100% positive and 83% negative predictive value for diagnosis of renal malignancies in 79 patients. They report that 41% of biopsies led to a change in clinical management and the prevention of nephrectomy. Although these results are good, we believe that they should be interpreted with a degree of caution. In particular, the biopsies were taken from a highly select group of patients with renal masses ranging from 1 to 20 cm. Campbell et al in their series of 25 small (less than 5 cm.) renal carcinomas found that only 40% of preoperative aspirations yielded a sufficient quality of malignant cells for definitive diagnosis.1 We have also recently audited the accuracy of fine needle aspiration cytology in 49 patients with renal masses in our clinical practice and determined that, although sensitivity for large renal masses (greater than 5 cm.) was 89% and, therefore, reasonably comparable with this study, the sensitivity for small renal masses was only 64%, which is considerably less reliable. We agree that renal biopsy should be reserved for patients for whom nonsurgical treatment seems more appropriate. This population would include patients at poor operative risk, or those with possible disseminated extrarenal neoplasia or advanced renal malignancy. However, with the improving quality and accuracy of imaging in many cases suspicious radiological findings alone will usually determine whether surgery is appropriate. Indeed, the significant false-negative biopsy rate in this study emphasizes that the negative biopsy will always be difficult to handle and may even detract, rather than enhance, the overall diagnostic evaluation following suspicious imaging findings. For patients who do not belong to the aforementioned categories suspicious imaging will almost always lead to surgical exploration, regardless of the biopsy result. Respectfully, Robert D. Brierly and Philip J. Thomas Department of Urology Royal Sussex County Hospital Eastern Rd. East Sussex, BN2 5BE United Kingdom 1. Campbell, S. C., Novick, A. C., Herts, B., Fischler, D. F., Meyer, J., Levin, H. S. and Chen, R. N.: Prospective evaluation of fine needle aspiration of small, solid renal masses: accuracy and morbidity. Urology, 50: 25, 1997.
Reply by Authors. We agree that these results should be interpreted with caution in several respects. The urologist faced with the question of whether to biopsy must realize the team factor. The success of core biopsy and especially fine needle aspiration is extremely dependent on the specific expertise of the cytopathologist, cytology technician, pathologist and interventional radiologist. The strength of the team is dependent on all players. A retrospective evaluation of local results for a given procedure is invaluable. We agree that the sensitivity for biopsy of large renal masses may be higher. However, the mean size of masses in our study was 4.5 cm. (median 3.3). Of 79 masses biopsied 11 were 2 cm. or less in maximum diameter. The renal mass sizes and imaging characteristics varied. The take home message of our study was that suspicious imaging findings of renal masses should be analyzed in the context of clinical history. In our study renal mass biopsy was a safe and accurate intermediate step in the management of suspicious or indeterminate
renal masses and provided an option other than surgery or radiological followup. Surprisingly, 41% of biopsies were ultimately managed nonoperatively. Resorting to surgery simply to get a diagnosis may no longer be necessary in a select group of patients, as outlined, including those with a history of malignancy, solitary kidney, renal insufficiency, underlying medical illness, contraindication to surgery, planned nephrotoxic chemotherapy, known renal lymphoma (to assess response to therapy and for tissue characterization or subtyping after a positive biopsy or prior negative biopsy with highly suspicious imaging findings), or for those who have undergone partial nephrectomy. We are in no way suggesting that any other renal masses (in uncomplicated cases) that resemble renal cell carcinoma on a quality computerized tomography should be biopsied. We agree that most renal masses with suspicious imaging will require surgical exploration. We were only seeking exceptions to the rule, not to change the rule.
RE: A COMPARISON OF URETEROSCOPY TO IN SITU EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY FOR THE TREATMENT OF DISTAL URETERAL CALCULI T. M. T. Turk and A. D. Jenkins J. Urol., 161: 45– 47, 1999 To the Editor. Contrary to the results of the authors we believe that the optimal treatment for distal ureteral stones should be determined by stone size. Because of its excellent results in situ extracorporeal shock wave lithotripsy (ESWL*) should be the first choice for stones less than 6 mm. and considered for stones 6 to 10 mm. Stones greater than 10 mm. preferably should be treated with ureteroscopy. From January 1996 to June 1998 we treated 230 distal ureteral stones. ESWL was performed with the MFL 5000 with intravenous sedation in 70 patients. Stones were treated with 2,500 shocks 23 to 26 kV. Ureteroscopy was performed with a rigid tapered 6.5 to 8F or 8 to 10.5F scope using a video camera in 160 patients. Stone removal was done with a basket and laser or lithoclast lithotripsy. A Double-J† stent was placed at the end of treatment. Complete fragmentation (fragments less than 3 mm.) during ESWL was dependent on stone size. After 1 ESWL session complete destruction was achieved in 78% of the cases for stones less than 6 mm., 58% for stones 6 to 10 mm. and 18% for stones greater than 10 mm. After a second ESWL treatment the destruction rate was greater than 90% for stones less than 6 mm. and 83% for stones 6 to 10 mm. After ureteroscopy all patients were stone-free after 1 procedure. Ureteral perforation occurred in 4.3% of the patients. In addition, a second operation with intravenous sedation was necessary for stent removal. Therefore, informed consent regarding the difference in success and complication rates should be obtained. Respectfully, U. H. G. Michl, M. Graefen and H. Huland Department of Urology University Hospital Eppendorf Martinistrasse 52 20246 Hamburg Germany
Reply by Authors. We did not stratify our successes based on stone size and, thus, it is difficult to comment directly on the results listed by Michl et al. However, most of our failures in the ESWL and ureteroscopy groups were for stones greater than 10 mm. Their numbers are similar to ours in terms of success rates (78 versus 80% fragmentation after ESWL and greater than 90 versus 95% stonefree status after ureteroscopy). It appears that a number of their patients required a second ESWL session as well. At our institution
2103
* Dornier Medical Systems, Inc., Marietta, Georgia. † Medical Engineering Corp., New York, New York.
Vol. 162, 2103–2107, December, 1999 Printed in U.S.A.
Letters to the Editor RE: IMAGING GUIDED BIOPSY OF RENAL MASSES: INDICATIONS, ACCURACY AND IMPACT ON CLINICAL MANAGEMENT B. J. Wood, M. A. Khan, F. McGovern, M. Harisinghani, P. F. Hahn and P. R. Mueller J. Urol., 161: 1470 –1474, 1999 To the Editor. The authors demonstrate 100% positive and 83% negative predictive value for diagnosis of renal malignancies in 79 patients. They report that 41% of biopsies led to a change in clinical management and the prevention of nephrectomy. Although these results are good, we believe that they should be interpreted with a degree of caution. In particular, the biopsies were taken from a highly select group of patients with renal masses ranging from 1 to 20 cm. Campbell et al in their series of 25 small (less than 5 cm.) renal carcinomas found that only 40% of preoperative aspirations yielded a sufficient quality of malignant cells for definitive diagnosis.1 We have also recently audited the accuracy of fine needle aspiration cytology in 49 patients with renal masses in our clinical practice and determined that, although sensitivity for large renal masses (greater than 5 cm.) was 89% and, therefore, reasonably comparable with this study, the sensitivity for small renal masses was only 64%, which is considerably less reliable. We agree that renal biopsy should be reserved for patients for whom nonsurgical treatment seems more appropriate. This population would include patients at poor operative risk, or those with possible disseminated extrarenal neoplasia or advanced renal malignancy. However, with the improving quality and accuracy of imaging in many cases suspicious radiological findings alone will usually determine whether surgery is appropriate. Indeed, the significant false-negative biopsy rate in this study emphasizes that the negative biopsy will always be difficult to handle and may even detract, rather than enhance, the overall diagnostic evaluation following suspicious imaging findings. For patients who do not belong to the aforementioned categories suspicious imaging will almost always lead to surgical exploration, regardless of the biopsy result. Respectfully, Robert D. Brierly and Philip J. Thomas Department of Urology Royal Sussex County Hospital Eastern Rd. East Sussex, BN2 5BE United Kingdom 1. Campbell, S. C., Novick, A. C., Herts, B., Fischler, D. F., Meyer, J., Levin, H. S. and Chen, R. N.: Prospective evaluation of fine needle aspiration of small, solid renal masses: accuracy and morbidity. Urology, 50: 25, 1997.
Reply by Authors. We agree that these results should be interpreted with caution in several respects. The urologist faced with the question of whether to biopsy must realize the team factor. The success of core biopsy and especially fine needle aspiration is extremely dependent on the specific expertise of the cytopathologist, cytology technician, pathologist and interventional radiologist. The strength of the team is dependent on all players. A retrospective evaluation of local results for a given procedure is invaluable. We agree that the sensitivity for biopsy of large renal masses may be higher. However, the mean size of masses in our study was 4.5 cm. (median 3.3). Of 79 masses biopsied 11 were 2 cm. or less in maximum diameter. The renal mass sizes and imaging characteristics varied. The take home message of our study was that suspicious imaging findings of renal masses should be analyzed in the context of clinical history. In our study renal mass biopsy was a safe and accurate intermediate step in the management of suspicious or indeterminate
renal masses and provided an option other than surgery or radiological followup. Surprisingly, 41% of biopsies were ultimately managed nonoperatively. Resorting to surgery simply to get a diagnosis may no longer be necessary in a select group of patients, as outlined, including those with a history of malignancy, solitary kidney, renal insufficiency, underlying medical illness, contraindication to surgery, planned nephrotoxic chemotherapy, known renal lymphoma (to assess response to therapy and for tissue characterization or subtyping after a positive biopsy or prior negative biopsy with highly suspicious imaging findings), or for those who have undergone partial nephrectomy. We are in no way suggesting that any other renal masses (in uncomplicated cases) that resemble renal cell carcinoma on a quality computerized tomography should be biopsied. We agree that most renal masses with suspicious imaging will require surgical exploration. We were only seeking exceptions to the rule, not to change the rule.
RE: A COMPARISON OF URETEROSCOPY TO IN SITU EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY FOR THE TREATMENT OF DISTAL URETERAL CALCULI T. M. T. Turk and A. D. Jenkins J. Urol., 161: 45– 47, 1999 To the Editor. Contrary to the results of the authors we believe that the optimal treatment for distal ureteral stones should be determined by stone size. Because of its excellent results in situ extracorporeal shock wave lithotripsy (ESWL*) should be the first choice for stones less than 6 mm. and considered for stones 6 to 10 mm. Stones greater than 10 mm. preferably should be treated with ureteroscopy. From January 1996 to June 1998 we treated 230 distal ureteral stones. ESWL was performed with the MFL 5000 with intravenous sedation in 70 patients. Stones were treated with 2,500 shocks 23 to 26 kV. Ureteroscopy was performed with a rigid tapered 6.5 to 8F or 8 to 10.5F scope using a video camera in 160 patients. Stone removal was done with a basket and laser or lithoclast lithotripsy. A Double-J† stent was placed at the end of treatment. Complete fragmentation (fragments less than 3 mm.) during ESWL was dependent on stone size. After 1 ESWL session complete destruction was achieved in 78% of the cases for stones less than 6 mm., 58% for stones 6 to 10 mm. and 18% for stones greater than 10 mm. After a second ESWL treatment the destruction rate was greater than 90% for stones less than 6 mm. and 83% for stones 6 to 10 mm. After ureteroscopy all patients were stone-free after 1 procedure. Ureteral perforation occurred in 4.3% of the patients. In addition, a second operation with intravenous sedation was necessary for stent removal. Therefore, informed consent regarding the difference in success and complication rates should be obtained. Respectfully, U. H. G. Michl, M. Graefen and H. Huland Department of Urology University Hospital Eppendorf Martinistrasse 52 20246 Hamburg Germany
Reply by Authors. We did not stratify our successes based on stone size and, thus, it is difficult to comment directly on the results listed by Michl et al. However, most of our failures in the ESWL and ureteroscopy groups were for stones greater than 10 mm. Their numbers are similar to ours in terms of success rates (78 versus 80% fragmentation after ESWL and greater than 90 versus 95% stonefree status after ureteroscopy). It appears that a number of their patients required a second ESWL session as well. At our institution
2103
* Dornier Medical Systems, Inc., Marietta, Georgia. † Medical Engineering Corp., New York, New York.