Preoperative parathyroid localization. Relevance of MIBI SPECT-CT in adverse scenarios.

PURPOSE: Selective parathyroidectomy, the treatment of choice for primary hyperparathyroidism, requires precise preoperative localization. Our purpose was to compare the accuracy and concordance of pre-surgical MIBI parathyroid scintigraphy and ultrasonography, as well as to assess the relevance of hybrid acquisition (SPECT/CT) in compromised circumstances: low-weight or ectopic adenomas, coexisting thyroid disease and re-interventions. METHODS: The study included 223 patients with primary hyperparathyroidism operated in a single Surgical Unit from August 2016 to March 2021. Preoperative ultrasonography and double-phase MIBI were performed with early SPECT/CT acquisition. A minimally invasive surgical approach was initially attempted, except in patients with concomitant thyroid surgery or multiglandular parathyroid disease. RESULTS: Selective parathyroidectomy was accomplished in 179 patients (80.2%); cervicotomy and/or thoracoscopy in 44. Removal of the parathyroid lesion was achieved in 211 patients (94.6%), corresponding 204 (96.7%) to adenomas (37 ectopic). The cure rate was 94.2%. Preoperative MIBI SPECT/CT showed higher sensitivity and accuracy (84%; 80%) compared to ultrasound (72%; 71%), being more precise in defining the exact anatomical location (75.8% vs 68.7%). These differences reached statistical significance in ectopic glands. The existence of concomitant thyroid pathology did not decrease the sensitivity of SPECT/CT (84.2%). Mean parathyroid weight was 692.2mg (95%CI: 443.5-941) in MIBI-negative cases and 1145.9mg (95%CI: 983.6-1308.3) in MIBI-positive (p=0.001). Re-intervention was successful in the 8 patients with previous surgery. CONCLUSION: MIBI SPECT/CT presents greater sensitivity, accuracy and anatomical precision than ultrasound for preoperative parathyroid localization, even in the case of ectopic glands or coexisting thyroid pathology. The weight of the pathological gland is a significantly limiting factor.

Análisis de los factores relacionados con la sobreestadificación y la positividad del ganglio centinela en las pacientes con diagnóstico inicial de carcinoma ductal in situ / Analysis of factors related to upstaging and sentinel node positivity in the initial diagnosis of ductal carcinoma in situ

Objetivo. Determinar el porcentaje de pacientes con diagnóstico inicial de carcinoma ductal in situ (CDIS) que presentó infiltración tras la excisión quirúrgica e identificar los factores relacionados tanto con la sobreestadificación como con la positividad del ganglio centinela (GC) en el estudio definitivo. Material y métodos. Análisis retrospectivo de 135 pacientes diagnosticadas mediante biopsia core de CDIS a las que se les realizó biopsia selectiva del GC de forma consecutiva de 2003 a 2011. La técnica fue mixta en el período inicial y posteriormente mediante administración intraperilesional de radiocoloides. En 2009 se introdujo una gammacámara portátil y se inició el estudio intraoperatorio molecular mediante amplificación de ácido nucleico de un solo paso. Resultados. Se produjo sobreestadificación en 45 de las 135 pacientes (33,3%), de las que 30 (22,2%) presentaron CDIS con microinfiltración y 15 (11,1%) carcinoma infiltrante. Los CDIS con microinfiltración mostraron mayor tamaño, mayor porcentaje de alto grado, de HER2 positivo y de Ki-67 alto que los CDIS (p < 0,001, p < 0,001, p = 0,002 y p = 0,031, respectivamente). Los porcentajes de positividad del GC fueron del 3,6% en el CDIS, del 6,9% en el CDIS con microinfiltración y del 20% en los carcinomas infiltrantes, correspondiendo a 8 pacientes, de las cuales 6 presentaron HER2 positivo y Ki-67 alto. Conclusiones. El porcentaje global de infraestimación fue alto, principalmente debido a la presencia de microinfiltración. Tanto esta como la afectación metastásica del GC mostró relación con el HER2 positivo y el Ki-67 alto, por tanto, disponer de estos datos en la biopsia percutánea podría ser relevante para establecer la indicación de realización de biopsia selectiva del GC en el CDIS

Objective. To determine the percentage of patients with ductal carcinoma in situ (DCIS) with infiltration after surgical excision and to identify the factors related to both upstaging and sentinel node (SN) positivity in the final study. Material and methods. A retrospective analysis was performed in 135 patients diagnosed with DCIS by core biopsy who subsequently underwent sentinel lymph node biopsy from 2003 to 2011. In the first period of the study, the technique was mixed and subsequently consisted of intra-perilesional radiocolloid administration. In 2009, a portable gamma camera was introduced and we began to use intraoperative one-step nucleic acid amplification. Results. Upstaging occurred in 45 of the 135 patients (33.3%), of which 30 (22.2%) had DCIS with microinfiltration and 15 (11.1%) had invasive carcinoma. Compared with DCIS, DCIS with microinfiltration were larger and showed a higher percentage of high grade, HER2 positivity and high Ki-67 (P < .001, P < .001, P = .002 and P = .031, respectively). SN positivity rates were 3.6% in DCIS, 6.9% in DCIS with microinfiltration, and 20% in invasive carcinomas, corresponding to 8 patients, of whom 6 showed HER2-positivity and high Ki-67. Conclusions. Overall underestimation was high, mainly due to the presence of microinfiltration. Both microinfiltration and metastatic SN involvement were associated with HER2-positivity and high Ki-67. Therefore, the availability of this information in core needle biopsy could be relevant in establishing the indication for sentinel lymph node biopsy in DCIS