[Quantification of bone scintigraphy as an objective method in the follow-up of radioisotopic synoviorthesis]

This work tries to provide the clinicians an objective tool that can contribute to the assessment of the results of radioisotopic synoviorthesis (RS). This study aims to assess the value of the quantification of bone scintigraphy in blood pool and late phase of the affected joints treated with 90Y silicate, in order to observe the clinical improvement experienced by most of these patients. A total of 69 bone scintigraphies (BS) in blood pool and late phase have been quantified. They belonged to 23 patients who were treated with RS with 90Y. The first scintigraphy study was performed before the treatment, the second and the third ones were performed 2 and 6 months after treatment. In each BS we quantified the index: counts per pixel of healthy / affected joint. We also have calculated the fraction in the late phase: counts per pixel of healthy bone / counts per pixel of affected and healthy joint. For the comparative statistical analysis of the results we used the Student's t test. We considered statistical significance when p < 0.05. All the patients presented clinical improvement. If we compare the index obtained in BS 2 months after treatment and pre-treatment we find statistical significance (p < 0.05) in the increase of index in the anterior view and late phase. If we compare the index obtained in BS 6 month after treatment and pre-treatment, we find a statistically significant increase in the anterior (p < 0.01) and posterior (p < 0.05) view of the blood pool phase and the anterior view of late phase (p < 0.01). The fraction counts per pixel of healthy bone / counts per pixel of affected and healthy joint did not present a significant increase in any BS control (2 and 6 months). We recommend quantification using the index (counts per pixel healthy / affected joint ) proposed in this work, because it is easy to perform, cheap and reliable in the follow-up of patients treated with RS.