Evaluation of pressure-controlled mammography compression paddles with respect to force-controlled compression paddles in clinical practice

OBJECTIVES: To reduce pain and discomfort associated with breast compression in mammography, a pressure-controlled compression paddle was recently introduced. The objective was to evaluate the pressure-controlled paddle by comparing it to the standard force-controlled paddle. METHODS: Differences of compressed breast thickness (CBT), compression force, compression pressure, and average glandular dose (AGD) between annual follow-up full-field digital mammography exams of 3188 patients were retrospectively examined. Two groups were compared: (1) force-force group (FF-group), both examinations were performed with the force-controlled paddle, and (2) force-pressure group (FP-group), only the follow-up examination was performed with the pressure-controlled paddle. In an additional group of patients, pain scores on a scale of 0 (no pain at all) to 10 (worst pain imaginable) were evaluated prospectively (n = 343) who were randomly assigned to either paddle. RESULTS: Median differences between follow-up exams in CBT, compression force, compression pressure, and AGD were for the FF- and FP-group respectively − 1.0 vs 0.0 mm (p < 0.001); 0.0 vs − 1.0 daN (p = 0.002); − 1.0 vs − 0.5 kPa (p = 0.005); and 0.05 vs − 0.02 mGy (p < 0.001). These differences were, although statistically significant, clinically non-relevant (defined as ΔCBT > ± 2 mm; Δforce > ± 2 daN; Δpressure > ± 1 kPa and ΔAGD > ± 0.1 mGy). The subanalysis dividing CBT into five categories revealed similar results. The median [interquartile range] pain scores were 6 [3, 7] and 5 [3, 7] for the force-controlled and pressure-controlled paddle, respectively, which was not significantly different (p = 0.113). CONCLUSIONS: We observed no clinically relevant differences in CBT, compression force, compression pressure, AGD, or pain score between the force- and pressure-controlled paddle. As such, we found no basis for preferring one paddle over the other. KEY POINTS: • The pressure-controlled paddle did not show any clinically relevant changes in breast compression parameters compared to the force-controlled paddle. • The pressure-controlled paddle did not lead to significant reduction in pain scores indicated by the patients compared to the force-controlled paddle. • A large variation in compression force and compression pressure was observed in mammography exams for the both the force- and pressure-controlled compression paddle. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00330-018-5953-6) contains supplementary material, which is available to authorized users.