Controversy in the initial nodal staging of rectal cancer (MRI or PET/CT?).

OBJECTIVE: To compare the usefulness of MRI and PET/CT in nodal staging (N) of patients with locally advanced rectal cancer (LARC). MATERIAL AND METHODS: Retrospective study of patients with LARC, who completed their initial staging with PET/CT, between January-20 and March-23. Regional nodes were assessed, and N was determined using both techniques according to TNM criteria. Concordance between MRI and PET/CT was analyzed. The accuracy of both techniques was calculated for those patients who underwent direct surgery. Non-regional pelvic lymph nodes were evaluated by both modalities. RESULTS: Among the 73 patients, 48 were ultimately diagnosed with a locally advanced stage. Of these, 39 underwent neoadjuvant treatment (chemoradiotherapy) followed by surgery, and 9 direct surgery. In 25, the PET/CT extension study revealed distant disease, leading to systemic treatment. Weak concordance was observed between MRI and PET/CT in determining N (k=0.286; p<0.005). Out of 73 patients, 31(42%) exhibited concordance, and 42(58%) showed discordance. In 83% of the discordant cases, MRI overstaged compared to PET/CT, with 17 cases indicating nodal involvement (N+) by MRI and N0 by PET/CT. Diagnostic accuracy was 78% for both techniques. Sensitivity, specificity, positive predictive value, and negative predictive value were 80%, 75%, 80%, and 75% for MRI, and 60%, 100%, 100%, and 67%, for PET/CT. PET/CT identified pelvic metastatic adenopathies in 8 patients that were not visible/doubtful by MRI. CONCLUSIONS: In the initial nodal staging of rectal cancer MRI overstages relative to PET/CT. Both modalities are complementary, PET/CT offers higher specificity and MRI higher sensitivity.

Prognostic 18F-FDG Radiomic Features in Advanced High-Grade Serous Ovarian Cancer.

High-grade serous ovarian cancer (HGSOC) is an aggressive disease with different clinical outcomes and poor prognosis. This could be due to tumor heterogeneity. The 18F-FDG PET radiomic parameters permit addressing tumor heterogeneity. Nevertheless, this has been not well studied in ovarian cancer. The aim of our work was to assess the prognostic value of pretreatment 18F-FDG PET radiomic features in patients with HGSOC. A review of 36 patients diagnosed with advanced HGSOC between 2016 and 2020 in our center was performed. Radiomic features were obtained from pretreatment 18F-FDGPET. Disease-free survival (DFS) and overall survival (OS) were calculated. Optimal cutoff values with receiver operating characteristic curve/median values were used. A correlation between radiomic features and DFS/OS was made. The mean DFS was 19.6 months and OS was 37.1 months. Total Lesion Glycolysis (TLG), GLSZM_ Zone Size Non-Uniformity (GLSZM_ZSNU), and GLRLM_Run Length Non-Uniformity (GLRLM_RLNU) were significantly associated with DFS. The survival-curves analysis showed a significant difference of DSF in patients with GLRLM_RLNU > 7388.3 versus patients with lower values (19.7 months vs. 31.7 months, p = 0.035), maintaining signification in the multivariate analysis (p = 0.048). Moreover, Intensity-based Kurtosis was associated with OS (p = 0.027). Pretreatment 18F-FDG PET radiomic features GLRLM_RLNU, GLSZM_ZSNU, and Kurtosis may have prognostic value in patients with advanced HGSOC.

NP-59 test for preoperative localization of primary hyperaldosteronism.

PURPOSE: Adrenal venous sampling is generally considered the gold standard to identify unilateral hormone production in cases of primary hyperaldosteronism. The aim of this study is to evaluate whether the iodine-131-6-ß-iodomethyl-19-norcholesterol (NP-59) test may represent an alternative in selected cases. METHODS: Patients submitted to laparoscopic adrenalectomy for suspected primary hyperaldosteronism (n = 27) were retrospectively reviewed. When nuclear medicine tests were preoperatively performed, their results were compared with the histopathologic findings and clinical improvement. RESULTS: Nuclear medicine tests were realized in 13 patients. In 11 (84.6%), a planar anterior and posterior NP-59 scintigraphy was performed and a SPECT/TC in two (15.4%). Scintigraphy indicated a preoperative lateralization in 12 out of 13 patients (92.3%). When the value of NP-59 tests was based on pathologic results, it showed a sensitivity of 90.9% and a positive predictive value of 83.3%. When the nuclear medicine test's performance was based on postoperative blood pressure control, both sensitivity and positive predictive value were 91.6%. CONCLUSIONS: Nuclear medicine tests represent a useful tool in the preoperative localisation of primary hyperaldosteronism with a high sensitivity and positive predictive value. In patients with contraindications to adrenal venous sampling like contrast allergies, or when it is inconclusive, scintigraphy can represent a useful and non-invasive alternative.

Decontamination of radioisotopes.

Contaminations with radioactive material may occur in several situations related to medicine, industry or research. Seriousness of the incident depends mainly on the radioactive element involved; usually there are no major acute health effects, but in the long term can cause malignancies, leukemia, genetic defects and teratogenic anomalies. The most common is superficial contamination, but the radioactive material can get into the body and be retained by the cells of target organs, injuring directly and permanently sensitive elements of the body. Rapid intervention is very important to remove the radioactive material without spreading it. Work must be performed in a specially prepared area and personnel involved should wear special protective clothing. For external decontamination general cleaning techniques are used, usually do not require chemical techniques. For internal decontamination is necessary to use specific agents, according to the causative element, as well physiological interventions to enhance elimination and excretion.

Etomidate accurately localizes the epileptic area in patients with temporal lobe epilepsy.

PURPOSE: A variety of drugs have been used to activate and identify the epileptogenic area in patients during presurgical evaluation. We have evaluated the safety and usefulness of etomidate in identifying the epileptic zone by measuring bioelectrical brain activity and cerebral blood flow (CBF). METHODS: We studied 13 men and 9 women under presurgical evaluation for temporal lobe epilepsy. We applied etomidate (0.1 mg/kg) while patients were monitored by video-electroencephalography (VEEG) with foramen ovale electrodes. In a subset of 15 patients, we also measured CBF with single photon emission computed tomography (SPECT). RESULTS: (1) Etomidate induced seizures in 2 of 22 patients. (2) The main side-effects observed were myoclonus (14 of 20) and moderate pain (3 of 20). (3) No changes in capillary oxygen saturation, respiration, or heart rate were observed. (4) Irritative activity specifically increased in the temporal mesial and lateral areas. No spikes were observed in other areas, aside from those observed under baseline conditions. (5) Irritative activity induced by etomidate correctly lateralized the ictal onset zone in 19 of 20 patients. In addition, the two etomidate-induced seizures appeared in the same regions as spontaneous ones. (6) The kinetics of pharmacologically induced activity was higher in the region of the ictal-onset zone. (7) Etomidate increased the CBF in the basal ganglia and especially in the posterior hippocampus of the temporal mesial region contralateral to the ictal-onset zone. DISCUSSION: Etomidate activation is a safe, specific, and quick test that can be used to identify the epileptic region in patients evaluated as candidates for temporal lobe epilepsy surgery.

What Do Changes in Brain Perfusion Induced by Etomidate Suggest about Epilepsy in Human Patients?

Epilepsy is one of the major neurological disorders, affecting roughly 1-2% of the world's population, of which approximately 20-25% of patients are drug resistant. A variety of drugs have been used to activate and identify the epileptic area in patients during presurgical evaluation. We studied the cerebral blood flow (CBF) by single photon-emission computed tomography (SPECT) and bioelectrical brain activity responses to etomidate in 11 patients. Etomidate (0.1 mg/kg) was administered while patients were monitored by video-electroencephalography with foramen ovale electrodes (FOEs). After etomidate administration, a brief period of high-frequency activity was observed, followed by a generalized, high-voltage delta pattern. Increased regional CBF was observed bilaterally in thalamus, putamen, and posterior hippocampus. Besides, the only interhemispheric difference was observed in the posterior hippocampus, where CBF decreased in the epileptic temporal lobe. Activation by etomidate induces a specific and repetitive response in the bioelectrical activity. In addition, CBF changes induced by etomidate may serve as a diagnostic tool in the near future.

[Surgical treatment and localization techniques in primary hyperparathyroidism]. / Tratamiento quirúrgico y técnicas de localización en el hiperparatiroidismo primario.

Parathyroidectomy is the only definitive cure for primary hyperparathyroidism (PHPT). While bilateral neck exploration has been the conventional surgical approach and the mainstay of therapy, recent advances in technology have revolutionized the field, making a focused or minimally invasive approach to parathyroidectomy a reality. This change has taken place because of the development of accurate preoperative localization techniques able to select patients who have single-gland parathyroid disease (single adenoma) and can be managed by a minimally invasive parathyroidectomy. Currently, the most reliable and practical diagnostic procedure is (99m)TC-sestamibi parathyroid scintigraphy, using different protocols depending on the institution's logistics and experience (classical dual-phase, oblique projections, various subtraction techniques and/or single photon-emission computed tomography or SPECT). Ultrasound has emerged as a complementary technique in the preoperative evaluation of PHPT, which can be used when scintigraphy is negative or as a confirmatory test. When these procedures fail to identify the enlarged gland, other non-invasive procedures such as computed tomographic scanning or magnetic resonance imaging are used in selected cases. A variety of surgical techniques have been employed to achieve a safe and effective minimally invasive procedure. These techniques include mini-incision unilateral parathyroid exploration and endoscopic, video-assisted and radio-guided parathyroidectomy. With optimized preoperative mapping, the success rate of these less invasive techniques equals that of the traditional bilateral approach. This review summarizes the imaging techniques and rationale for preoperative localization studies that are used before parathyroidectomy, as well as the current surgical approaches.

Tratamiento quirúrgico y técnicas de localización en el hiperparatiroidismo primario / Surgical treatment and localization techniques in primary hyperparathyroidism

La paratiroidectomía es el único tratamiento definitivo del hiperparatiroidismo primario (HP). Aunque la exploración cervical bilateral ha sido el tratamiento de elección tradicional de esta enfermedad, avances tecnológicos recientes han revolucionado el campo de la paratiroidectomía y han hecho posible una intervención focalizada o mínimamente invasiva. Este cambio se ha debido, sobre todo, al desarrollo de técnicas de localización preoperatoria precisas capaces de seleccionar a pacientes con enfermedad de una sola glándula paratiroidea (adenoma único) y que pueden tratarse mediante paratiroidectomía mínimamente invasiva (PMI). En la actualidad, el test diagnóstico más fiable y práctico es la gammagrafía paratiroidea con tecnecio 99m sestamibi, con el uso de distintos protocolos, dependiendo de la logística y la experiencia del centro (técnica dual clásica, proyecciones oblicuas, técnicas de sustracción, tomografía computarizada o tomografía computarizada por emisión de fotones simples). La ecografía ha surgido como una técnica complementaria, que puede utilizarse tanto cuando la gammagrafía es negativa, como prueba de confirmación. Cuando estos procedimientos fracasan en identificar una glándula aumentada de tamaño, en casos seleccionados pueden emplearse otros procedimientos no invasivos, como la tomografía computarizada o la resonancia magnética. Para realizar un procedimiento mínimamente invasivo, se han utilizado varias técnicas quirúrgicas, incluida una exploración paratiroidea unilateral con incisión mínima, que es la más utilizada, así como también paratiroidectomía endoscópica, videoasistida y radioguiada. Con una localización preoperatoria óptima, las tasas de curación con procedimientos menos invasivos son similares a las de la exploración bilateral. Este trabajo resume las técnicas diagnósticas de localización previas a la patiroidectomía, así como las técnicas quirúrgicas empleadas en la actualidad (AU)

Parathyroidectomy is the only definitive cure for primary hyperparathyroidism (PHPT). While bilateral neck exploration has been the conventional surgical approach and the mainstay of therapy, recent advances in technology have revolutionized the field, making a focused or minimally invasive approach to parathyroidectomy a reality. This change has taken place because of the development of accurate preoperative localization techniques able to select patients who have single-gland parathyroid disease (single adenoma) and can be managed by a minimally invasive parathyroidectomy. Currently, the most reliable and practical diagnostic procedure is 99mTC-sestamibi parathyroid scintigraphy, using different protocols depending on the institution’s logistics and experience (classical dual-phase, oblique projections, various subtraction techniques and/or single photon-emission computed tomography or SPECT). Ultrasound has emerged as a complementary technique in the preoperative evaluation of PHPT, which can be used when scintigraphy is negative or as a confirmatory test. When these procedures fail to identify the enlarged gland, other non-invasive procedures such as computed tomographic scanning or magnetic resonance imaging are used in selected cases. A variety of surgical techniques have been employed to achieve a safe and effective minimally invasive procedure. These techniques include mini-incision unilateral parathyroid exploration and endoscopic, video-assisted and radio-guided parathyroidectomy. With optimized preoperative mapping, the success rate of these less invasive techniques equals that of the traditional bilateral approach. This review summarizes the imaging techniques and rationale for preoperative localization studies that are used before parathyroidectomy, as well as the current surgical approaches (AU)

99MTc-sestamibi as sole technique in selection of primary hyperparathyroidism patients for unilateral neck exploration.

BACKGROUND: Unilateral neck exploration (UNE) is becoming the procedure of choice for treatment of primary hyperparathyroidism (PHPT). The aim of this study was to evaluate the role of (99m)Tc-sestamibi (MIBI) parathyroid scintigraphy as the sole technique in selecting patients for UNE. METHOD: We selected 136 consecutive PHPT patients who had only 1 solitary uptake at a MIBI were for UNE. The technique was a single dual-phase using MIBI and a subtraction technique with (99m)Tc-pertechnetate. Imaging data were correlated with surgical results. RESULTS: In 3 cases, the sestamibi scan was falsely positive, 1 had a contralateral location relative to the uptake, and 2 had multiglandular hyperplasia. Overall, the positive predictive value (PPV) of MIBI for detecting a solitary parathyroid adenoma in patients with 1 solitary uptake was 97.8. Sixteen patients (12%) had evidence of multinodular goiter. Overall, the PPV of MIBI was 98.4% (2 false positive among 120 cases) in patients with no multinodular thyroid disease (MNG) and 93.7% (1 false negative among 16 cases) in patients with MNG. The mean duration of the surgical procedure was 34.17 minutes. Mean hospitalization was 0.6 days. Conversion to bilateral neck exploration was performed in 5 patients. After a period of follow-up of 40 months (range, 6-72 months), the cure rate was 98%. CONCLUSION: Patients with PHPT and unequivocally positive preoperative (99m)Tc-sestamibi can safely be managed with UNE without additional localizing techniques.

First true initial ictal SPECT in partial epilepsy verified by electroencephalography.

Drug-resistant epilepsy can sometimes be treated by surgery. In these cases, an accurate identification of the epileptogenic area must be addressed before resection. Ictal SPECT is one of the presurgical evaluations that can be performed, but usually, the increase in the regional cerebral perfusion observed is produced by diffusion of ictal activity. Here we describe a patient studied with v-EEG and foramen ovale electrodes that suffered a seizure after intravenous infusion of etomidate. The sequence of etomidate administration, followed by radiotracer and seizure was good enough for us to suspect that a true initial ictal SPECT was observed. We have implemented a kinetic model with four compartments, previously described (Andersen 1989), in order to estimate the fraction of hydrophilic radiotracer in the brain during the pre-ictal and ictal periods. This model has shown that the fraction of hydrophilic radiotracer during the seizure into the brain would be between 18.9% and 42.3% of total infused. We show the first true initial ictal SPECT demonstrated by bioelectrical recordings of the brain activity, obtained by a correct succession of events and compatible with theoretical data obtained from the kinetic model.