RESUMEN
Two independent equations were recently proposed for estimating 177Lu-cetuximab cumulative activity, in a preclinical situation, from an initial 64Cu-cetuximab diagnostic scan acquired at peak time of decay-uncorrected (tpeak-uncorr) or decay-corrected (tpeak-corr) time-activity curve of trapped 64Cu-cetuximab, respectively. The standard uptake ratio (SUR) measured at tpeak-uncorr or tpeak-corr turned out to be a key metric in each equation, respectively. However, acquiring the diagnostic scan at tpeak-uncorr or tpeak-corr might be a limitation of the proposed method. Therefore, in an attempt to overcome this limitation, this note aims at theoretically investigating whether SUR(tpeak-uncorr) and/or SUR(tpeak-corr) could be derived from a diagnostic scan acquired at any time postinjection.
Asunto(s)
Medicina de Precisión , Humanos , Cetuximab/efectos adversos , Cobre/química , LutecioRESUMEN
Background: This study aimed at investigating whether a single diagnostic 64Cu-cetuximab scan might predict therapeutic 177Lu-cetuximab cumulative activity in a preclinical study. Methods: The framework of the reversible Patlak-Blasberg analysis was used to derive two independent equations of 177Lu-cetuximab cumulative activity that involve the tumor-to-blood standard uptake value ratio (i.e., the SUR) assessed at peak-time of either decay-uncorrected or decay-corrected activity concentration of trapped 64Cu-cetuximab, respectively. Applied to published data in TE-8 tumor-bearing mice, the two peak times and corresponding SUR values were assessed. Two estimates of 177Lu-cetuximab cumulative activity were then computed for comparison with two previously published values obtained from different methods. Results: The two estimates of 177Lu-cetuximab cumulative activity, computed at 14 and 59 h postinjection, were consistent with the previously published values: 4.7 × 1012 and 5.5 × 1012 versus 4.1 × 1012 and 5.3 × 1012 disintegrations/g. Conclusion: Two independent equations are proposed for estimating 177Lu-cetuximab cumulative activity from an initial diagnostic 64Cu-cetuximab scan, when acquired at two relevant injection acquisition times, respectively. Applied to published tumor-bearing mouse data, the 64Cu-cetuximab SUR assessed at either 14 or 59 h postinjection turns out to be key metrics.
Asunto(s)
Tomografía de Emisión de Positrones , Tomografía Computarizada de Emisión de Fotón Único , Animales , Cetuximab/uso terapéutico , Humanos , Ratones , Tomografía de Emisión de Positrones/métodos , Cintigrafía , Distribución TisularRESUMEN
In a preclinical model of neuroblastoma, Dearling et al. recently demonstrated the potential interest for a theranostic approach of [64/67Cu]Cu-SARTATE for the detection and treatment of SSTR2-positive neuroblastoma lesions in pediatric patients whose widespread metastases survive initial therapy as minimal residual disease (MRD). MRD may be detected by [64Cu]Cu-SARTATE and subsequently treated by [67Cu]Cu-SARTATE. Since therapeutic dosimetry estimation of the latter agent from the uptake of the former one in the initial diagnostic scan was not addressed, the present theoretical commentary proposes the derivation of an abbreviated therapy-dosimetric equation for the companion diagnostic/therapeutic [64/67Cu]Cu-SARTATE that might be of interest for future clinical theranostic practice.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Antígeno B7-H1 , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Radioisótopos de Flúor , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de PositronesAsunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Ganglios Linfáticos/diagnóstico por imagen , Mediastino/diagnóstico por imagenAsunto(s)
Neoplasias de la Mama , Neoplasias de la Mama Triple Negativas , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/terapia , Fluorodesoxiglucosa F18 , Xenoinjertos , Humanos , Tomografía de Emisión de Positrones , Radiofármacos , Neoplasias de la Mama Triple Negativas/diagnóstico por imagen , Neoplasias de la Mama Triple Negativas/terapiaRESUMEN
Previously published experiments established the time-course of olfactory habituation in humans, and extracted 3 centroid curves from clustering analysis that reflected high, middle and low habituation. The aim of the current theoretical study was to further analyse these previous experimental data by developing a mathematical modelling analysis designed for fitting the 3 curves from a general equation. After adjusting equation parameters for each curve, fitting equation outcomes on experimental data yielded high correlation coefficients of 0.9997 - 0.9995 - 0.9962, respectively. A model-based interpretation of olfactory-habituation centroid curves is proposed suggesting that they result from the effect of 2 separate processes that act simultaneously. We suggest that the first process is unlikely related to the olfactory habituation itself, and, rather, is of unclear origin. The second process seems to play a major role in the degree of OH and cannot be assigned, a priori, to either peripheral or central adaptation, respectively.
