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1051 UROLITHIASIS IN PATIENTS TREATED FOR CHILDHOOD CANCER: DOES ALTERED CALCIUM METABOLISM PLAY A ROLE?
Vol. 183, No. 4, Supplement, Monday, May 31, 2010
1050 PRIMARY HYPERPARATHYROIDISM IN PEDIATRIC STONE FORMERS Nicholas Cost*, Nicol Bush, Theodore Barber, Neel Srikishen, Seerath Basravi, Benjamin Brown, Linda Baker, Dallas, TX INTRODUCTION AND OBJECTIVES: Although the published incidence of primary hyperparathyroidism (phPTH) in adult stone formers is 1-2%, scant data exists to define the incidence in children. Being perceived as a rare entity in children, many physicians only screen children found to have hypercalcemia or hypophosphatemia after a diagnosis of urolithiasis. We hypothesized that pediatric somatic bone growth and the absence of long term phPTH might change the clinical picture from that seen in adults. In this study, we sought to determine the frequency of hPTH in our population of pediatric stone formers and assess the utility of other blood and urine tests to detect phPTH in children. METHODS: With IRB approval, we retrospectively reviewed a clinical laboratory database at the Children’s Medical Center of Dallas from 1996-2008, identifying all children with renal and/or ureteral stones by ICD9 coding who had a serum intact parathyroid hormone (iPTH) drawn. Demographical data, blood electrolytes, blood hormones, stone analyses, and urine stone risk assays were evaluated. All data was analyzed using SPSS version 17.0. RESULTS: Of the 119 children with stone disease and an available iPTH level, 21 (17.6%) were found to have an elevated iPTH. Of these, 7 (5.9%) were found to have primary hPTH with pathologically confirmed parathyroid adenomas after parathyroidectomy. The median age at diagnosis of phPTH was 14.4yr (12.6-17.6). However, only 4 of the 7 (57%) patients with phPTH had hypercalcemia or hypophosphatemia. These 4 patients with alterations in serum calcium or phosphorous had higher levels of iPTH, 34.3 vs. 9.8pmol/liter, p⫽0.08. All 7 children were found to have low serum 25-OH Vitamin D levels, hypercalciuria, and calcium stones (5 Calcium Oxalate; 2 Calcium Phosphate). Of the 7, 3 of 4 tested had hyperphosphaturia. All 7 patients manifested their phPTH with nephrolithiasis at a mean of 6.8mo before parathyroidectomy. CONCLUSIONS: The incidence of phPTH in this population of pediatric stone formers is 5.9% (7/119). Screening pediatric stone formers for hPTH only if hypercalcemia or hypophosphatemia are present would miss a significant portion of pediatric patients with phPTH. Like adults, hPTH stones in children are calcium based and urine stone risk profiles are similar. Given the potential for life-long recurrent stones and additional long term sequelae of phPTH, we recommend all stone-forming children be screened for hPTH with an iPTH, irrespective of their serum electrolytes. Source of Funding: None
1051 UROLITHIASIS IN PATIENTS TREATED FOR CHILDHOOD CANCER: DOES ALTERED CALCIUM METABOLISM PLAY A ROLE? Kathleen Kieran*, Dana W. Giel, Andrew M. Davidoff, Mark A. Williams, Memphis, TN INTRODUCTION AND OBJECTIVES: Kidney stones are known sequelae of chemotherapy, and may reflect elevated blood and urine levels of uric acid secondary to rapid tumor cell destruction. However, therapy-associated nephrotoxicity and alterations in bone mineral density (BMD) may also play a role. We reviewed our recent experience with nephrolithiasis in patients treated for malignancies in childhood.
THE JOURNAL OF UROLOGY姞
e409
METHODS: We reviewed the records of all patients at our institution with a history of cancer and a new diagnosis of urolithiasis from July 2004 to June 2009. Data were abstracted on patient demographics, malignancy characteristics, therapy type and duration, stone characteristics and treatment, and serum and urine electrolytes. RESULTS: 72 patients (40 male, 32 female, mean age 19.5 [range 1.2 to 46.7] years) were identified. The mean age at cancer diagnosis was 8.3 (range 0.7-18.9) years. 40 (55.6%) patients had leukemia, 8 (11.1%) had lymphoma, 15 (20.8%) had central nervous system tumors, and 9 (12.5%) had other solid tumors. 35 (48.6%) patients received chemotherapy, 4 (5.6%) received radiation, 31 (43.1%) received both, and 2 (2.8%) patients were treated with surgical resection alone. 12 (16.7%) patients were receiving therapy at the time of stone presentation. Stones were noted on routine imaging a mean of 10.7 years (range 1.3-35.3) following completion of therapy in the other 60 patients. Stones were ⬙punctate⬙ (ⱕ2 mm) in 65 (90.3%) patients. 3 patients (4%) had ureteral stones; 69 (95.8%) had only renal stones. 8 (11.1%) patients had bilateral intrarenal stones. No patient had an elevated creatinine at the time of stone presentation. Stones were asymptomatic in all but 4 (5.6%) patients; of these 4, 1 required lithotripsy, 1 underwent stone dissolution, 1 required stenting, and 1 passed the stone spontaneously. Urine chemistries were performed in 19 (26.4%) patients; of these, Ca/Cr ratios were elevated in 7 (36.8%). 28 patients (38.9%) had limited physical mobility secondary to their disease or prior therapy. In the 54 (75%) patients in whom BMD was assessed, the mean BMD was at the 13th percentile (z ⫽ -1.17). CONCLUSIONS: In our pediatric oncology patients, most stones developed after completion of treatment and were small and asymptomatic. Extremely low BMD measurements, high Ca/Cr ratios and a high prevalence of mobility disorders suggest a role for altered calcium metabolism in the pathogenesis of post-treatment nephrolithiasis. Further research is needed to elucidate the relative contributions of altered BMD, renal function, and direct effects of therapy to the development of stones. Source of Funding: None
1052 PEDIATRIC URETEROSCOPIC LITHOTRIPSY- EIGHT YEARS SINGLE CENTER RESULTS Yuval Bar-Yosef*, Rafael Gosalbez, Miguel Castellan, Andrew Labbie, Miami, FL INTRODUCTION AND OBJECTIVES: Endourologic techniques have revolutionized the treatment of urinary tract stones, and have assumed a greater role in the pediatric population. We present the results of ureteroscopic stone treatment, from a single center during an eight years period. METHODS: The charts of all patients who underwent ureteroscopic stone management between 2000 and 2008 were reviewed. Demographic data, stone size, operative details, and operative results were recorded. Only patients with recorded follow up and post operative data and an imaging study were included in the analysis. RESULTS: During the study period 134 ureteroscopic procedures for stone management were performed. Post operative data and an imaging study were available for 94 patients. The study cohort included 50 females and 44 males, with a mean age of 13 (range 10 months- 19 years). Stone location was in the distal ureter in 59 patients, mid ureter in 5, proximal ureter in 15 and renal in 15. Average stone burden was 8.6 (range 2-31) mm. In 22 patients a ureteral stent was placed pre-operatively. The ureteral orifice was dilated in 21 (22%) of the patients. A semi-rigid ureteroscope was used in 75 cases, a flexible ureteroscope in 16, and both in 3. A ureteral stent was placed at the end of the procedure in 74 patients (79%). Of the 94 patients, 81 (86%) were stone free after a single ureteroscopic procedure. Stone free rates were 98% (63 of 64) for distal stones, 60% (18 of 30) for proximal
1050 PRIMARY HYPERPARATHYROIDISM IN PEDIATRIC STONE FORMERS Nicholas Cost*, Nicol Bush, Theodore Barber, Neel Srikishen, Seerath Basravi, Benjamin Brown, Linda Baker, Dallas, TX INTRODUCTION AND OBJECTIVES: Although the published incidence of primary hyperparathyroidism (phPTH) in adult stone formers is 1-2%, scant data exists to define the incidence in children. Being perceived as a rare entity in children, many physicians only screen children found to have hypercalcemia or hypophosphatemia after a diagnosis of urolithiasis. We hypothesized that pediatric somatic bone growth and the absence of long term phPTH might change the clinical picture from that seen in adults. In this study, we sought to determine the frequency of hPTH in our population of pediatric stone formers and assess the utility of other blood and urine tests to detect phPTH in children. METHODS: With IRB approval, we retrospectively reviewed a clinical laboratory database at the Children’s Medical Center of Dallas from 1996-2008, identifying all children with renal and/or ureteral stones by ICD9 coding who had a serum intact parathyroid hormone (iPTH) drawn. Demographical data, blood electrolytes, blood hormones, stone analyses, and urine stone risk assays were evaluated. All data was analyzed using SPSS version 17.0. RESULTS: Of the 119 children with stone disease and an available iPTH level, 21 (17.6%) were found to have an elevated iPTH. Of these, 7 (5.9%) were found to have primary hPTH with pathologically confirmed parathyroid adenomas after parathyroidectomy. The median age at diagnosis of phPTH was 14.4yr (12.6-17.6). However, only 4 of the 7 (57%) patients with phPTH had hypercalcemia or hypophosphatemia. These 4 patients with alterations in serum calcium or phosphorous had higher levels of iPTH, 34.3 vs. 9.8pmol/liter, p⫽0.08. All 7 children were found to have low serum 25-OH Vitamin D levels, hypercalciuria, and calcium stones (5 Calcium Oxalate; 2 Calcium Phosphate). Of the 7, 3 of 4 tested had hyperphosphaturia. All 7 patients manifested their phPTH with nephrolithiasis at a mean of 6.8mo before parathyroidectomy. CONCLUSIONS: The incidence of phPTH in this population of pediatric stone formers is 5.9% (7/119). Screening pediatric stone formers for hPTH only if hypercalcemia or hypophosphatemia are present would miss a significant portion of pediatric patients with phPTH. Like adults, hPTH stones in children are calcium based and urine stone risk profiles are similar. Given the potential for life-long recurrent stones and additional long term sequelae of phPTH, we recommend all stone-forming children be screened for hPTH with an iPTH, irrespective of their serum electrolytes. Source of Funding: None
1051 UROLITHIASIS IN PATIENTS TREATED FOR CHILDHOOD CANCER: DOES ALTERED CALCIUM METABOLISM PLAY A ROLE? Kathleen Kieran*, Dana W. Giel, Andrew M. Davidoff, Mark A. Williams, Memphis, TN INTRODUCTION AND OBJECTIVES: Kidney stones are known sequelae of chemotherapy, and may reflect elevated blood and urine levels of uric acid secondary to rapid tumor cell destruction. However, therapy-associated nephrotoxicity and alterations in bone mineral density (BMD) may also play a role. We reviewed our recent experience with nephrolithiasis in patients treated for malignancies in childhood.
THE JOURNAL OF UROLOGY姞
e409
METHODS: We reviewed the records of all patients at our institution with a history of cancer and a new diagnosis of urolithiasis from July 2004 to June 2009. Data were abstracted on patient demographics, malignancy characteristics, therapy type and duration, stone characteristics and treatment, and serum and urine electrolytes. RESULTS: 72 patients (40 male, 32 female, mean age 19.5 [range 1.2 to 46.7] years) were identified. The mean age at cancer diagnosis was 8.3 (range 0.7-18.9) years. 40 (55.6%) patients had leukemia, 8 (11.1%) had lymphoma, 15 (20.8%) had central nervous system tumors, and 9 (12.5%) had other solid tumors. 35 (48.6%) patients received chemotherapy, 4 (5.6%) received radiation, 31 (43.1%) received both, and 2 (2.8%) patients were treated with surgical resection alone. 12 (16.7%) patients were receiving therapy at the time of stone presentation. Stones were noted on routine imaging a mean of 10.7 years (range 1.3-35.3) following completion of therapy in the other 60 patients. Stones were ⬙punctate⬙ (ⱕ2 mm) in 65 (90.3%) patients. 3 patients (4%) had ureteral stones; 69 (95.8%) had only renal stones. 8 (11.1%) patients had bilateral intrarenal stones. No patient had an elevated creatinine at the time of stone presentation. Stones were asymptomatic in all but 4 (5.6%) patients; of these 4, 1 required lithotripsy, 1 underwent stone dissolution, 1 required stenting, and 1 passed the stone spontaneously. Urine chemistries were performed in 19 (26.4%) patients; of these, Ca/Cr ratios were elevated in 7 (36.8%). 28 patients (38.9%) had limited physical mobility secondary to their disease or prior therapy. In the 54 (75%) patients in whom BMD was assessed, the mean BMD was at the 13th percentile (z ⫽ -1.17). CONCLUSIONS: In our pediatric oncology patients, most stones developed after completion of treatment and were small and asymptomatic. Extremely low BMD measurements, high Ca/Cr ratios and a high prevalence of mobility disorders suggest a role for altered calcium metabolism in the pathogenesis of post-treatment nephrolithiasis. Further research is needed to elucidate the relative contributions of altered BMD, renal function, and direct effects of therapy to the development of stones. Source of Funding: None
1052 PEDIATRIC URETEROSCOPIC LITHOTRIPSY- EIGHT YEARS SINGLE CENTER RESULTS Yuval Bar-Yosef*, Rafael Gosalbez, Miguel Castellan, Andrew Labbie, Miami, FL INTRODUCTION AND OBJECTIVES: Endourologic techniques have revolutionized the treatment of urinary tract stones, and have assumed a greater role in the pediatric population. We present the results of ureteroscopic stone treatment, from a single center during an eight years period. METHODS: The charts of all patients who underwent ureteroscopic stone management between 2000 and 2008 were reviewed. Demographic data, stone size, operative details, and operative results were recorded. Only patients with recorded follow up and post operative data and an imaging study were included in the analysis. RESULTS: During the study period 134 ureteroscopic procedures for stone management were performed. Post operative data and an imaging study were available for 94 patients. The study cohort included 50 females and 44 males, with a mean age of 13 (range 10 months- 19 years). Stone location was in the distal ureter in 59 patients, mid ureter in 5, proximal ureter in 15 and renal in 15. Average stone burden was 8.6 (range 2-31) mm. In 22 patients a ureteral stent was placed pre-operatively. The ureteral orifice was dilated in 21 (22%) of the patients. A semi-rigid ureteroscope was used in 75 cases, a flexible ureteroscope in 16, and both in 3. A ureteral stent was placed at the end of the procedure in 74 patients (79%). Of the 94 patients, 81 (86%) were stone free after a single ureteroscopic procedure. Stone free rates were 98% (63 of 64) for distal stones, 60% (18 of 30) for proximal