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821 Calculi localisation in extracorporeal shockwave lithotripsy. Reducing the radiation dose to the patient
821
Calculi localisation in extracorporeal shockwave lithotripsy. Reducing the radiation dose to the patient Eur Urol Suppl 2014;13;e821
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Bryant D.A., Smith H., Lewis G. City Hospital Sunderland, Dept. of Urology, Sunderland, United Kingdom INTRODUCTION & OBJECTIVES: The study was performed in order to demonstrate that Ultrasound [US] localisation of renal calculi for Extracorporeal Shockwave Lithotripsy [ESWL] calculi targeting is equivalent to fluoroscopic [x-ray] localisation. Comparison between 2 cohorts of patients treated on the same ESWL machine utilising electroconductive technology [Sonolith I-sys Lithotripter] was made. Two different modalities for calculi localisation was utilised, US and x-ray. MATERIAL & METHODS: Two Consecutive cohorts of patients with renal calculi treated in our unit using US (n=48 patients) or x-ray (n=47 patients) calculi localisation were identified. There was no statistical difference between either cohort with regards to age, Body mass Index [BMI], calculi size or calculi location within the kidney. All patients had radiolucent calculi and underwent an X-ray KUB before treatment and at follow up, 2 weeks after ESWL. Outcome measures were related to calculi clearance, as follows; 1] Complete calculi clearance - no visible calculi fragments; 2] Successful treatment - if any residual fragments were too small to warrant treatment, i.e. 1-2mm in size, or; 3] Unsuccessful treatment - if a surgical modality was required for calculi clearance. The patients were treated in 2012-2013. RESULTS: The table highlights the key findings;
Localisation Modality
Ultrasound
X-ray fluoroscopy
Number of patients
48
47
Average age [years]
59
58
Average BMI [Kg/m2 ]
28.6
28.1
Average calculi size [mm]
8.5mm [4-18]
9.3mm [5-16]
Calculi clearance rate with 1 ESWL treatment [%]
37.5
23.4
Successful outcome with 1 ESWL treatment [%]
22.9
21.2
Successful outcome with 2 ESWL treatments [%]
25
34
Successful outcome with 3 ESWL treatments [%]
2.1
6.4
Successful outcome with ESWL [%]
87.5
85.1
Unsuccessful treatment, i.e. surgical intervention required for calculi clearance [%] 12.5
14.9
Complications [%]
8.3
17
Average radiation dose [mGy/cm2 ]
103 [0-233]
2113 [241-7821]
The successful calculi treatment rate in our study was good [86.3% overall] and the reported complications were; pain requiring admission for analgesic administration and urgent endourological management was required in 5 patients [2 patients in the US cohort and 3 patients in the x-ray group]. No patients had any serious complications. The radiation dose in the US cohort was greatly reduced to that in the x-ray cohort.
CONCLUSIONS: In our study the data for US calculi localisation demonstrates equivalence to x-ray calculi localisation for successful treatment with ESWL [87.5% versus 85.1%]. It also appears that US localisation is more favourable in the calculi clearance rate with one treatment of ESWL to that of x-ray localisation [37.5% versus 23.4%], however, the study was not powered to demonstrate this. It is preferable for patients to have the lowest dose of radiation that is achievable. As US is free of ionising radiation it reduces the radiation dose that a calculi former is exposed to. This is important to the recurrent calculi forming population who will be exposed to repeated radiation doses throughout their lifetime. Our data supports the use of an US localisation system for ESWL and US should become standard practice in departments that use traditional x-ray localisation for calculi targeting.
Calculi localisation in extracorporeal shockwave lithotripsy. Reducing the radiation dose to the patient Eur Urol Suppl 2014;13;e821
Print! Print!
Bryant D.A., Smith H., Lewis G. City Hospital Sunderland, Dept. of Urology, Sunderland, United Kingdom INTRODUCTION & OBJECTIVES: The study was performed in order to demonstrate that Ultrasound [US] localisation of renal calculi for Extracorporeal Shockwave Lithotripsy [ESWL] calculi targeting is equivalent to fluoroscopic [x-ray] localisation. Comparison between 2 cohorts of patients treated on the same ESWL machine utilising electroconductive technology [Sonolith I-sys Lithotripter] was made. Two different modalities for calculi localisation was utilised, US and x-ray. MATERIAL & METHODS: Two Consecutive cohorts of patients with renal calculi treated in our unit using US (n=48 patients) or x-ray (n=47 patients) calculi localisation were identified. There was no statistical difference between either cohort with regards to age, Body mass Index [BMI], calculi size or calculi location within the kidney. All patients had radiolucent calculi and underwent an X-ray KUB before treatment and at follow up, 2 weeks after ESWL. Outcome measures were related to calculi clearance, as follows; 1] Complete calculi clearance - no visible calculi fragments; 2] Successful treatment - if any residual fragments were too small to warrant treatment, i.e. 1-2mm in size, or; 3] Unsuccessful treatment - if a surgical modality was required for calculi clearance. The patients were treated in 2012-2013. RESULTS: The table highlights the key findings;
Localisation Modality
Ultrasound
X-ray fluoroscopy
Number of patients
48
47
Average age [years]
59
58
Average BMI [Kg/m2 ]
28.6
28.1
Average calculi size [mm]
8.5mm [4-18]
9.3mm [5-16]
Calculi clearance rate with 1 ESWL treatment [%]
37.5
23.4
Successful outcome with 1 ESWL treatment [%]
22.9
21.2
Successful outcome with 2 ESWL treatments [%]
25
34
Successful outcome with 3 ESWL treatments [%]
2.1
6.4
Successful outcome with ESWL [%]
87.5
85.1
Unsuccessful treatment, i.e. surgical intervention required for calculi clearance [%] 12.5
14.9
Complications [%]
8.3
17
Average radiation dose [mGy/cm2 ]
103 [0-233]
2113 [241-7821]
The successful calculi treatment rate in our study was good [86.3% overall] and the reported complications were; pain requiring admission for analgesic administration and urgent endourological management was required in 5 patients [2 patients in the US cohort and 3 patients in the x-ray group]. No patients had any serious complications. The radiation dose in the US cohort was greatly reduced to that in the x-ray cohort.
CONCLUSIONS: In our study the data for US calculi localisation demonstrates equivalence to x-ray calculi localisation for successful treatment with ESWL [87.5% versus 85.1%]. It also appears that US localisation is more favourable in the calculi clearance rate with one treatment of ESWL to that of x-ray localisation [37.5% versus 23.4%], however, the study was not powered to demonstrate this. It is preferable for patients to have the lowest dose of radiation that is achievable. As US is free of ionising radiation it reduces the radiation dose that a calculi former is exposed to. This is important to the recurrent calculi forming population who will be exposed to repeated radiation doses throughout their lifetime. Our data supports the use of an US localisation system for ESWL and US should become standard practice in departments that use traditional x-ray localisation for calculi targeting.