In-house-prepared semisolid bolus for esophageal transit scintigraphy in normal volunteers and its comparison with liquid bolus

Background/Aims: Esophageal transit scintigraphy (ETS) is a useful tool for evaluating esophageal motility disorders, although conflicting results are seen due to lack of ideal bolus. Semisolid/solid boluses have shown superiority over liquid boluses, and the present study aims to establish the utility of in-house-prepared bolus in normal volunteers and its comparison with liquid bolus. Materials and Methods: Thirty-three healthy volunteers were selected for ETS with in-house-prepared semisolid bolus jelly containing^99mTc-sulfur colloid. Dynamic studies were acquired in anterior projection with single swallow for both supine and sitting positions. T90% esophageal emptying time (EET) was calculated for whole and three equally divided segments of esophagus and also done with liquid bolus on different day. Results: The median value of EET for semisolid bolus for whole esophagus in sitting and supine positions was 11.7 s (interquartile range [IQR]: 8.0-16.7) and 17.7 s (IQR: 12.0-33.0). EET of liquid bolus for whole esophagus in sitting and supine positions was 9.3 s (IQR: 8.0-13.3) and 13.0 s (IQR: 9.7-25.0), respectively. Significantly different EET for whole esophagus and lower one-third esophagus between sitting and supine positions was seen for semisolid (whole esophagus;P = 0.003, lower one-third esophagus; P = 0.025) and liquid boluses (whole esophagus; P = 0.032, lower one-third esophagus; P = 0.016). Comparing EET using semisolid and liquid boluses, only lower one-third esophagus in supine position showed significant difference (P = 0.033). Conclusions: In-house-prepared semisolid radiolabeled jelly is inexpensive, easy to prepare with good radiolabeling. Condensed dynamic images from semisolid bolus were better, sharper, and reproducible in comparison to liquid bolus without fragmentation. This study standardized semisolid bolus and verified its suitability for clinical use.