Advances in radioguided surgery in oncology Valdés Olmos, Renato A; Vidal-Sicart, Sergi; Manca, Gianpiero ...
The quarterly journal of nuclear medicine and molecular imaging,
09/2017, Volume:
61, Issue:
3
Journal Article
Peer reviewed
The sentinel lymph node (SLN) biopsy is probably the most well-known radioguided technique in surgical oncology. Today SLN biopsy reduces the morbidity associated with lymphadenectomy and increases ...the identification rate of occult lymphatic metastases by offering the pathologist the lymph nodes with the highest probability of containing metastatic cells. These advantages may result in a change in clinical management both in melanoma and breast cancer patients. The SLN evaluation by pathology currently implies tumor burden stratification for further prognostic information. The concept of SLN biopsy includes pre-surgical lymphoscintigraphy as a "roadmap" to guide the surgeon toward the SLNs and to localize unpredictable lymphatic drainage patterns. In addition to planar images, SPECT/CT improves SLN detection, especially in sites closer to the injection site, providing anatomic landmarks which are helpful in localizing SLNs in difficult to interpret studies. The use of intraoperative imaging devices allows a better surgical approach and SLN localization. Several studies report the value of such devices for excision of additional sentinel nodes and for monitoring the whole procedure. The combination of preoperative imaging and radioguided localization constitutes the basis for a whole spectrum of basic and advanced nuclear medicine procedures, which recently have been encompassed under the term "guided intraoperative scintigraphic tumor targeting" (GOSTT). Excepting SLN biopsy, GOSTT includes procedures based on the detection of target lesions with visible uptake of tumor-seeking radiotracers on SPECT/CT or PET/CT enabling their subsequent radioguided excisional biopsy for diagnostic of therapeutic purposes. The incorporation of new PET-tracers into nuclear medicine has reinforced this field delineating new strategies for radioguided excision. In cases with insufficient lesion uptake after systemic radiotracer administration, intralesional injection of a tracer without migration may enable subsequent excision of the targeted tissue. This approach has been helpful in non-palpable breast cancer and in solitary pulmonary nodules. The introduction of allied technologies like fluorescence constitutes a recent advance aimed to refine the search for SLNs and tracer-avid lesions in the operation theatre in combination with radioguidance.
In endometrial cancer (EC), sentinel lymph node (SLN) mapping has emerged as an alternative to systematic lymphadenectomy. Little is known about factors that might influence SLN preoperative ...detection. The aim of our study was to evaluate the clinical and technical variables that may influence on the success of SLN detection in preoperative lymphatic mapping in patients with intermediate and high-risk EC when performing transvaginal ultrasound-guided myometrial injection of radiotracer (TUMIR).
Between March 2006 and March 2017, we prospectively enrolled patients with histologically confirmed EC with intermediate or high-risk of lymphatic involvement. All women underwent SLN detection by using TUMIR approach. After radiotracer injection, pelvic and abdominal planar and SPECT/CT images were acquired to obtain a preoperative lymphoscintigraphic mapping. Pattern of drainage was registered and analyzed to identify the factors directly involved in drainage. Sonographer learning curves to perform TUMIR approach were created following Cumulative Sum and Wright methods. Univariate and multivariate analyses were performed using logistic regression.
During study period, 123 patients were included. SLN preoperative detection rate was 70.7%. Age under 75 years at diagnosis (P<0.01), radiotracer injection above 4 mL -high-volume- (P<0.01), and tumoral size below 2 cm (P=0.04) were associated with higher SLN preoperative detection rate. Twenty-five procedures were necessary to attain an adequate performance in TUMIR approach.
The higher SLN preoperative detection rate in women with intermediate and high-risk endometrial cancer after TUMIR approach was related with younger age, smaller tumors and high-volume injection of radiotracer. Sonographers are required to perform 25 procedures before acquiring an expertise in radiotracer injection.
To compare the agreement between whole-body (WB) magnetic resonance (MR) imaging, 18F-FDG PET/CT, and skeletal survey (SS) in patients with multiple myeloma (MM) for diagnosis, initial staging, ...response evaluation, and early detection of complications.
This is a retrospective cohort study including MM patients who were diagnosed, treated, and followed in 2 institutions. These patients were studied with SS, WB-MR, and/or 18F-FDG PET/CT. We studied bone lesions by anatomical locations and analyzed the concordance between SS and a tomographic technique (WB-MR or 18F-FDG PET/CT) and between both tomographic techniques (WB-MR and PET/CT).
Forty-four MM patients with a mean age of 62.6 years (range, 38-85 years) were included from January 2012 to February 2016. Whole-body MR and 18F-FDG PET/CT found more lesions than SS in every location except in the skull. Concordance between WB-MR and 18F-FDG PET/CT was either good or excellent in most of the locations and in plasmacytoma studies. However, WB-MR was better than 18F-FDG PET/CT in the study of complications (medullar compression and vascular necrosis).
Our results suggest the study of MM patients should include WB-MR and/or 18F-FDG PET/CT, whereas SS is only useful for the skull. Whole-body MR and 18F-FDG PET/CT are complementary techniques, because both of them show good concordance in almost every location. It is still necessary to individualize the indication of each technique according to patient characteristics.
The estimated seroprevalence of hepatitis C virus (HCV) in Spain is 1.7%, but is much higher in the at-risk population. The most efficient national screening strategy is unclear.
To estimate the ...prevalence of HCV among the at-risk population seen in primary care (PC), and to determine their epidemiological profile.
Cross-sectional descriptive prevalence study that included adult patients with risk factors for HCV infection seen in PC in the southwest Madrid region between 2010 and 2012.
A total of 158 patients (men=51.3%), mean age 46 years (SD=16.6), were included. The most common risk factors were hypertransaminasaemia (44.3%) and major surgery (13.3%). Immigration, unsafe sexual practices, and tattoos or body piercing were more prevalent in patients younger than 45 years of age. Fifteen patients (9.5%) were positive for anti-HCV; 9 of these (5.7%) were HCV-ARN positive. Of the positive patients, 4 (44.4%) had significant fibrosis at diagnosis (F3-F4). Male patients had a higher rate of positive anti-HCV results (13.8 vs. 5.3%; P=.072), as did patients older than 45 years of age (12.8 vs. 6.3%; P=.167). Intravenous and intranasal drug use were associated with a higher rate of positive anti-HCV results (50 vs. 8.5%; P=.005 and 66.7 vs. 8.4%; P=.001, respectively).
Patients with risk factors for HCV infection have high seroprevalence. Screening programmes must therefore be implemented to detect HCV infection in this population in PC.
Neuroimaging studies often quantify tau burden in standardized brain regions to assess Alzheimer disease (AD) progression. However, this method ignores another key biological process in which tau ...spreads to additional brain regions. We have developed a metric for calculating the extent tau pathology has spread throughout the brain and evaluate the relationship between this metric and tau burden across early stages of AD.
445 cross-sectional participants (aged ≥ 50) who had MRI, amyloid PET, tau PET, and clinical testing were separated into disease-stage groups based on amyloid positivity and cognitive status (older cognitively normal control, preclinical AD, and symptomatic AD). Tau burden and tau spatial spread were calculated for all participants.
We found both tau metrics significantly elevated across increasing disease stages (p < 0.0001) and as a function of increasing amyloid burden for participants with preclinical (p < 0.0001, p = 0.0056) and symptomatic (p = 0.010, p = 0.0021) AD. An interaction was found between tau burden and tau spatial spread when predicting amyloid burden (p = 0.00013). Analyses of slope between tau metrics demonstrated more spread than burden in preclinical AD (β = 0.59), but then tau burden elevated relative to spread (β = 0.42) once participants had symptomatic AD, when the tau metrics became highly correlated (R = 0.83).
Tau burden and tau spatial spread are both strong biomarkers for early AD but provide unique information, particularly at the preclinical stage. Tau spatial spread may demonstrate earlier changes than tau burden which could have broad impact in clinical trial design.
This research was supported by the Knight Alzheimer Disease Research Center (Knight ADRC, NIH grants P30AG066444, P01AG026276, P01AG003991), Dominantly Inherited Alzheimer Network (DIAN, NIH grants U01AG042791, U19AG03243808, R01AG052550-01A1, R01AG05255003), and the Barnes-Jewish Hospital Foundation Willman Scholar Fund.
Steroid 21-hydroxylase deficiency is the underlying cause in over 90% of patients with congenital adrenal hyperplasia, an inherited metabolic disorder of adrenal steroidogenesis. We have ...characterized 94 mutant alleles from 47 unrelated Mexican patients and the corresponding mutant alleles in their parents by amplification of the functional CYP21 gene by PCR, followed by direct sequence analysis. The study included patients diagnosed with the three clinical forms of the disease. Our results revealed: (1) the presence of relatively few mutations or combinations of mutations associated with particular phenotypes; (2) the presence of putative new mutations; (3) the finding of identical genotypes in patients displaying discordant phenotypes; (4) the identification of patients lacking all previous reported mutations; and (5) an apparent high frequency of germ-line mutations. The absence of previously reported mutations in about 22% of the disease alleles, the finding of putative new mutations in some of the patients lacking previously known mutations, and the apparent high prevalence of germ-line mutations make evident the differences in the genetic background leading to this disorder between the Caucasian and the Mexican populations.
Steroid 21-hydroxylase deficiency is caused by mutations in the CYP21 gene. Approximately 95% of mutant alleles are generated by recombination events between the active gene CYP21 and its highly ...homologous pseudogene, CYP21P. Deletion alleles are generated by unequal crossing over, while point mutations are the result of gene conversion events. Deletions account for 20-25% of the 21-hydroxylase deficiency alleles in most populations studied. We have looked for deletions among 53 unrelated Mexican patients with steroid 21-hydroxylase deficiency and found that deletions represent less than 1% of the disease alleles. These findings suggest that nearly all mutant alleles in our patient population contain point mutations and that the low representation of deletion alleles among clinically diagnosed patients may be due to missing detection of salt wasters, mainly males, who may die during the neonatal period.
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