Center of Expertise on Gender Dysphoria, Amsterdam UMC, VU University, Amsterdam, the Netherlands.
Department of Endocrinology and Metabolism, Amsterdam UMC, VU University, Amsterdam, the Netherlands.
PLoS One. 2024 Jun 6;19(6):e0305059. doi: 10.1371/journal.pone.0305059. eCollection 2024.
Three-dimensional (3D) imaging techniques are promising new tools for measuring breast volume, for example in gender-affirming therapy. Transgender individuals can be treated with gender-affirming hormone therapy (GAHT). A robust method for monitoring breast volume changes is critical to be able to study the effects of feminizing GAHT. The primary aim of this study was to compare the accuracy of three 3D devices (Vectra XT, Artec LEO and iPhone XR) for measuring modest breast volume differences using a mannequin. The secondary aim of this study was to evaluate these methods in several performance domains. We used reference prostheses of increasing volumes and compared the volumes using GOM-inspect software. For Vectra XT 3D images, manufacturer-provided software was used to calculate volumes as well. The scanning methods were ranked based on their performance in a total of five categories: volume estimations, costs, user-friendliness, test subject-friendliness and technical aspects. The 3D models analyzed with GOM-inspect showed relative mean estimate differences from the actual volumes of 9.1% for the Vectra XT, 7.3% for the Artec LEO and 14% for the iPhone XR. For the Vectra XT models analyzed with the built-in software this was 6.2%. Root mean squared errors (RMSE) calculated based on the GOM-inspect volume analyses showed mean RMSEs of 2.27, 2.54 and 8.93 for the Vectra XT, Artec LEO and iPhone XR, respectively. The Vectra software had a mean RMSE of 3.00. In the combined performance ranking, the Vectra XT had the most favorable ranking, followed by the Artec LEO and the iPhone XR. The Vectra XT and Artec LEO are the preferred scanners to monitor breast development due to the combination of higher accuracy and overall performance. The current study shows that 3D techniques can be used to adequately measure modest breast volume differences and therefore will be useful to study for example breast changes in transgender individuals using feminizing GAHT. These observations may also be relevant in other fields of 3D imaging research.
三维（3D）成像技术是测量乳房体积的有前途的新工具，例如在性别肯定治疗中。跨性别者可以接受性别肯定激素治疗（GAHT）。一种可靠的监测乳房体积变化的方法对于研究女性化 GAHT 的效果至关重要。本研究的主要目的是比较三种 3D 设备（Vectra XT、Artec LEO 和 iPhone XR）测量假人中度乳房体积差异的准确性。本研究的次要目的是评估这些方法在几个性能领域的表现。我们使用体积逐渐增大的参考假体，并使用 GOM-inspect 软件比较体积。对于 Vectra XT 3D 图像，使用制造商提供的软件计算体积。根据五个类别的性能对扫描方法进行排名：体积估计、成本、用户友好性、测试对象友好性和技术方面。使用 GOM-inspect 分析的 3D 模型显示，Vectra XT 的相对平均估计差异为实际体积的 9.1%，Artec LEO 的为 7.3%，iPhone XR 的为 14%。使用内置软件分析的 Vectra XT 模型为 6.2%。基于 GOM-inspect 体积分析计算的均方根误差（RMSE）显示，Vectra XT、Artec LEO 和 iPhone XR 的平均 RMSE 分别为 2.27、2.54 和 8.93。Vectra 软件的平均 RMSE 为 3.00。在综合性能排名中，Vectra XT 排名最高，其次是 Artec LEO 和 iPhone XR。Vectra XT 和 Artec LEO 是首选的扫描仪，因为它们具有更高的准确性和整体性能，因此可用于监测乳房发育。目前的研究表明，3D 技术可用于充分测量适度的乳房体积差异，因此对于使用女性化 GAHT 的跨性别者研究乳房变化等将非常有用。这些观察结果在其他 3D 成像研究领域也可能具有相关性。
