Page 72 - JCTR-10-2

166 Ezenekwe et al. | Journal of Clinical and Translational Research 2024; 10(2): 165-171
while a small number of cases are caused by multiglandular disease There are other factors that might inform a provider’s decision
(MGD) (10%), or even more rarely parathyroid carcinoma [2]. on the selection of imaging modality. For example, despite the
PHPT may present asymptomatically or with a myriad of adverse low costs involved, ultrasounds provide poor imaging results
symptoms, classically including renal, cognitive, and/or skeletal for obese patients and have low sensitivity, and the quality of
abnormalities [3]. imaging findings is dependent on the technologist’s expertise [11].
Overall, PHPT is the third most common endocrine disorder Comparatively, 4D-CTs, similarly to sestamibi, expose patients
following diabetes and thyroid disorders [4], thus making it a research to ionizing radiation, involve higher upfront costs, and require
area of significant importance, holding promise for improvement specific radiologist expertise for interpretation.
of treatment and quality of life. At present, parathyroidectomy is To avoid the invasive path of BNE surgery, there is growing
the only curative treatment of PHPT and is recommended in all interest in developing the ability of 4D-CT to identify and localize
patients with symptoms [5]. The two common surgical approaches parathyroid adenomas. By exploring the depth of potential of
to parathyroidectomy are a bilateral neck exploration (BNE) and 4D-CT, it is possible to improve clinical outcomes by providing
a unilateral minimally invasive parathyroidectomy (MIP) [2]. In the necessary accurate pre-operative localization to allow for
recent years, the surgical approach has widely changed in favor MIP. Thus, 4D-CT texture analysis has arisen as a particularly
of MIP as this technique results in reduced surgical times, shorter promising methodology to non-invasively identify parathyroid
hospital stays, decreased cost, improved cosmetic appearance, and adenomas. For this reason, the purpose of this study is to
reduced post-operative fibrosis of the neck, which is beneficial in the correlate 4D-CT radiomic data to pathology-proven parathyroid
case of repeat surgery [1,6]. However, not all patients are candidates adenomas to identify and quantitate select texture features that
for this surgical approach. For example, in the case of MGD when predict parathyroid adenomas with a high degree of confidence.
all four glands may be involved, BNE is generally indicated [1]. This Ultimately, this study aims to improve the reliability of parathyroid
procedure involves a surgically intricate and demanding exploration adenoma detection using quantitative CT imaging analysis [2,12].
of the delicate neck tissue to examine all four parathyroid glands.
Given the shortcomings and complexities of BNE, MIP is the 2. Methods
preferred approach. Proceeding with MIP requires high-level, 2.1. Subjects
detailed imaging of the neck anatomy before surgery. At present,
sestamibi and/or ultrasound are the most common modalities A total of 144 subjects with a history of a parathyroidectomy
used for localization [7] but there is no universal protocol procedure for the removal of parathyroid adenoma between 2013
for pre-operative imaging. The modality used for imaging is and 2023 were selected for this study through a search of our
typically based on the surgeon’s and radiologist’s preferences and institution’s database using mPower. Patients who received the
knowledge. However, findings from past studies have underscored final pathological diagnosis of parathyroid adenoma, based on
the importance of using specific imaging modalities according to intraoperative pathology-proven results of frozen section, were
the actual clinical scenarios. A comprehensive meta-analysis of recruited. In addition, only subjects who received a 4D-CT scan of
patients using sestamibi SPECT/CT as a first-line approach for the neck for pre-operative detection and localization of parathyroid
pre-operative imaging has shown a significantly low sensitivity adenoma were selected. Patients who had undergone a single
and specificity of 65% and 80%, respectively, when compared parathyroidectomy as well as multiple gland parathyroidectomy
to 4D-CT with a sensitivity and specificity of 81% and 89%, were selected. Cases with unsuccessful parathyroidectomy,
respectively [8]. In addition, past studies have shown that 4D-CTs negative findings, inaccurate localization of parathyroid adenoma
have a concordance rate with intraoperative pathology results of on 4D-CT, thyroidectomy before preoperative 4D-CT, or
87%, which surpasses sestamibi and ultrasound with concordance unavailable pathology results were excluded. Fifty eligible cases
rates of 26.9% and 26.1%, respectively [9]. The high concordance were identified, of which 20 were randomly selected for inclusion.
rate of 4D-CTs with intraoperative pathology findings highlights Figure 1 shows the flow chart of this study featuring the inclusion
its increasing potential in PHPT detection because inaccurate pre- criteria. This study was approved by the institutional review board
operative localization necessitates exploration of all parathyroid at the University of Chicago.
glands, triggering a shift of surgical approach from MIP to 2.2. Image analysis
BNE. This data accords with recent studies showing that the
mean number of glands explored during parathyroidectomy was The 25-second arterial phase of each patient’s 4D-CT neck
significantly lower for patients who received a 4D-CT when scan (kVp: 120; mAs: 200; slice thickness: 3 mm) was used
compared to patients who were subjected to only nuclear imaging for analysis. Three anatomical structures (carotid artery, jugular
studies [10]. In the past, only difficult cases such as those with vein, and thyroid gland) were chosen to differentiate from the
negative or discordant ultrasound and sestamibi scans or failed parathyroid adenoma. An axial section of the 25-second arterial
surgery called for the use of 4D-CT scans [11], but with recent phases containing the largest area of each of the four structures
findings of the superior efficacy of 4D-CTs, some medical centers was selected. Segmentation of the carotid artery, jugular vein,
have found success transitioning to a new protocol warranting a thyroid, and parathyroid adenoma was completed on the selected
4D-CT in replacement of sestamibi in the case of an inconclusive axial series of each patient using the 3D Slicer image computing
ultrasound finding [10]. platform. Figure 2 displays a representative resultant image
DOI: https://doi.org/10.36922/jctr.23.00112