Renography with a semiautomated algorithm for diuretic decision 7 min postradiopharmaceutical administration: a feasibility study

Abstract

Objective The F+10 method for diuretic renography (diuretics given 10 min after the radiopharmaceutical) could be a time-conserving method. This method involves a 30-min dynamic acquisition where diuretics are administered only when necessary by the Nuclear Medicine technologist performing the examination. The purpose of this study was to assess the method’s performance and to discover the optimal threshold of residual activity for a diuretic administration 7 min into the F+10 renography by reprocessing raw data from prior performed examinations with 20-min acquisitions without diuretics. Methods Retrospectively, raw data from 320 original examinations of adult patients performed from 2013 to 2015 were reprocessed into 7-min series and categorized as requiring diuretic or not. The diuretic decisions made by an expert panel were used as a reference. A receiver-operating characteristic curve was drawn to assess the optimal cutoff value for the residual renal activity. Sensitivity, specificity, positive and negative predictive values, as well as the Youden J index were calculated. Result The experts classified 50% (160 examinations) as in need of diuretics. The receiver-operating characteristic curve demonstrated the theoretical optimal cutoff value at 7 min to be 94% of maximum activity (sensitivity 0.93, specificity 0.81, Youden J index 0.73). A clinically acceptable threshold is suggested to be 85% (sensitivity 0.99, specificity 0.59, Youden J index 0.58). Conclusion 99mTc-mercaptoacetyltriglycine renography with the F+10 method and the threshold 85% for diuretic decision 7 min into the renography is a feasible and acceptable method in clinical practice.

Timing of diuretics in diuresis renography

“…However, a lower dose of diuretics was administered in the F + 10 method compared to the F − 15 method in this study [19]. Kandeel with the F + 20 method and reported the F + 10 method to be a feasible and acceptable method in clinical practice [24].…”

“…The included articles were published between the years 1978 and 2020 [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. The number of participants varied between 14 and 320.…”

“…The radiopharmaceutical 99m Tc-MAG3 was administered in six studies [11, 17-19, 24, 25], 99m Tc-DTPA in five studies [9,12,13,20,22], 123 I-OIH in four studies [15,16,21,23], 99m Tc-EC in one study [10] and one study did not mention which radiopharmaceutical had been administered [14]. Five studies had a retrospective study design [15,17,22,24,25] and 12 studies had a prospective study design [9-14, 16, 18-21, 23]. Four articles included both children and adults in their studies [16,17,20,22], Table 3.…”

“…Liu et al compared the F + 0 method with F − 15 method and reported that a greater part of the patients could complete the diuresis renography with the F + 0 method since more examinations were reported to be disrupted with the F − 15 method due to voiding issues [17]. Three articles reported results concerning administering the diuretics 10 min after the radiopharmaceutical i.e., the F + 10 method [19,20,24]. Tartaglione et al reported that the F + 10 method (in seated position) could reduce the equivocal findings of the F − 15 method (in supine position) and lead to fewer bladder filling related problems.…”

Advantages of gravity-assisted diuretic renogram: F + 10 (seated position) method

“…The F + 10(sp) method has several advantages: ( (15) Thanks to a better timing, diuretics may be administered only when necessary by the physician [58]. (16) A gamma camera with single-head flexibility allowing acquisition in all position is required.…”