María Nieves Cabrera Martín

Predictive value of PET-CT for pathological response in stages II and III breast cancer patients following neoadjuvant chemotherapy with docetaxel

PURPOSE To prospectively study the value of PET-CT with fluorine-18 fluorodeoxyglucose (FDG) to predict neoadjuvant chemotherapy (NAC) response of locoregional disease of stages II and III breast cancer patients. MATERIAL AND METHODS A written informed consent and approval were obtained from the Ethics Committee. PET-CT accuracy in the prediction of pathologic complete response (pCR) after NAC was studied in primary tumors and lymph node metastasis in 43 women (mean age: 50 years: range: 27-71 years) with histologically proven breast cancer between December 2009 and January 2011. PET-CT was performed at baseline and after NAC. SUV(max) percentage changes (ΔSUV(max)) were compared with pathology findings at surgery. Receiver-operator characteristic (ROC) analysis was used to discriminate between locoregional pCR and non-pCR. In patients not achieving pCR, it was investigated if ΔSUV(max) could accurately identify the residual cancer burden (RCB) classes: RCB-I (minimal residual disease (MRD)), RCB-II (moderate RD), and RCB-III (extensive RD). RESULTS pCR was obtained in 11 patients (25.6%). Residual disease was found in 32 patients (74.4%): 16 (37.2%) RCB-I, 15 (35.6%) RCB-II and 2 (4.7%) RCB-III. Sensitivity, specificity, and accuracy to predict pCR were 90.9%, 90.6%, and 90.7%, respectively. Specificity was 94.1% in the identification of a subset of patients who had either pCR or MRD. CONCLUSION Accuracy of ΔSUV(max) in the locoregional disease of stages II and III breast cancer patients after NAC is high for the identification of pCR cases. Its specificity is potentially sufficient to identify a subgroup of patients who could be managed with conservative surgery.

[Systematic review and meta-analysis of diagnostic accuracy of 18F-FDG PET in suspected recurrent head and neck cancer].

Abstract Objectives Ameta-analysis of the literature was performed in this article in order to evaluate the diagnostic accuracy of 18 F-FDG PET in suspected recurrent head and neck cancer. Material and methods Asystematic review of the literature was performed using 1987 to 2007 MEDLINE and CANCERLIT databases, applying selection criteria to the studies found. Sensitivity, specificity, positive and negative likelihood ratios, and odds ratio were calculated. The diagnostic accuracy was evaluated with ROC (receiveoperating- characteristics) curves. Results Nineteen articles were included in the meta-analysis. Sensitivity of 18 F-FDG PET was 94%, specificity 80%, and the summary ROC curve showed a good trade-off between sensitivity and specificity. Conclusions 18 F-FDG PET was useful in patients with suspected recurrence of head and neck cancer, showing a high sensitivity and intermediate-high specificity.

Revisión sistemática y metaanálisis de la eficacia diagnóstica de la PET 18F-FDG en recurrencia tumoral de cánceres de cabeza y cuello

Objetivos En este trabajo se realizo un metaanalisis de la literatura para evaluar la exactitud diagnostica de la PET 18 F-FDG en la sospecha de recurrencia de canceres de cabeza y cuello. Material y metodos Inicialmente se realizo una busqueda sistematica de la literatura en las fuentes MEDLINE y CANCERLITE hasta mayo de 2007, aplicando unos criterios de cribado a los estudios hallados. Se calcularon los valores de sensibilidad, especificidad, cocientes de probabilidad positivo y negativo y la odds ratio diagnostica. El rendimiento diagnostico se valoro mediante curvas ROC (receive-operating-characteristic). Resultados Fueron incluidos 19 articulos en el metaanalisis. La sensibilidad de la PET 18 F-FDG fue del 94 %, la especificidad del 80 % y la curva ROC mostro una buena relacion entre sensibilidad y especificidad. Conclusiones La PET 18 F-FDG fue util en pacientes con sospecha de recurrencia tumoral por cancer de cabeza y cuello; mostro una sensibilidad alta y una especificidad intermedia-alta.

Impacto de la tomografía por emisión de positrones en el tratamiento de pacientes con sospecha de enfermedad residual o recurrente de cáncer diferenciado de tiroides

Objetivo Valorar las modificaciones en el tratamiento inducidas por la tomografia por emision de positrones con 18 F-desoxiglucosa (PET-FDG) en pacientes con sospecha de enfermedad residual o recurrente de cancer diferenciado de tiroides (CDT) con tiroglobulina (Tg) elevada y rastreo corporal total (RCT) con 131 I negativo. Pacientes y metodo Se analizo de forma retrospectiva a un grupo de 50 pacientes (35 mujeres y 15 varones) tratados de CDT, a los que se hizo estudio PET-FDG (51 exploraciones) por elevacion de Tg con RCT con 131 I negativo. La comprobacion de resultados se hizo segun la anatomia patologica, respuesta al tratamiento o seguimiento clinico. Valoraron el impacto los medicos, que indicaron como influyo esta tecnica en las decisiones terapeuticas, y se clasifico como alto, moderado, bajo o sin impacto, segun los criterios de Hicks modificados. Resultados La PET-FDG tuvo alto impacto en 18 (35,3%) pacientes, en los que se modifico la estrategia terapeutica; en 2 (3,9%) el impacto fue moderado, ya que no se aplico tratamiento pero el resultado negativo de la PET-FDG evito la realizacion de otros metodos diagnosticos; en 18 (35,3%), el impacto fue bajo, ya que no modifico el tratamiento; en 13 (25,5%) no tuvo impacto, pues no se tuvo en cuenta a la hora de decidir el tratamiento. Conclusiones La PET-FDG resulta una tecnica diagnostica util para la toma de decisiones terapeuticas en pacientes con sospecha de enfermedad residual o recurrente de CDT que presentan Tg elevada y RCT con 131 I negativo.

Adrenocortical Carcinoma: False Positive in an I-123 Metaiodobenzylguanedine Scan

A 55-year-old man with a personal history of left pheochromocytoma 2 years previously presented with an abdominal mass. Tumor relapse was suspected.Abdominal ultrasound showed a large left upper quadrant solid mass (calipers), with heterogeneous echogenicity and central cystic degeneration areas or necrosis (Fig. 1a). A computed tomography (CT) scan showed surgical clips of left adrenalectomy and multiple confluent left upper quadrant masses with a maximal diameter of 19 cm and heterogeneous enhancement (Fig. 1b). Both CT scan and ultrasound images were suspicious of adrenocortical carcinoma (ACC): size, heterogeneity and diaphragm invasion among other radiological features. Clinically, the mass grew in a few months and there were no paroxysmal hypertension episodes, nor elevation of catecholamines (cathecholamine urine test: 37.2 μg/g creatinine, normal range 0.1-260). F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT was performed as ACC was suspected (2). ACC is an uncommon malignant neoplasm of unknown cause; however, smoking and oral contraceptives may be risk factors [1, 2]. Patients usually present with advanced-stage disease and have poor prognosis [3], with a 2-year recurrence rate that ranges from 73 to 86 % [4]. CT or magnetic resonance (MR) is most often used for initial staging of ACC and usually shows heterogeneous adrenal mass with variable enhancement of solid components [4]. F-18 FDG PET has been used successfully for detection of adrenal metastases and for staging ACC [5]. Most ACCs accumulate and retain FDG [2, 6]. However, FDG PET cannot differentiate among malignant lesions (metastases, ACC, malignant pheochromocytoma, and lymphoma). Also, most pheochromocytomas (benign or malignant) are metabolically active and might accumulate FDG [7, 8]. A whole-body FDG PET scan (coronal and axial view) shows increased irregular FDG uptake in the abdominal masses (Fig. 2). An I-123 metaiodobenzylguanedine (MIBG) scan was requested to rule out pheochromocytoma because, although conventional image methods (ultrasound and CT) and also PET/CT scan were suspicious of ACC, the primary histology of the tumor was consistent with pheochromocytoma. An MIBG scan was performed after injection of 185 MBq of I123 MIBG intravenously. Single photon emission tomography (SPECT)/CT scan showed abnormal isotope accumulation in the tumor region. The patient underwent total resection of the tumor. The histology was of ACC, with areas of necrosis and cystic areas, so the result of the MIBG scan was a false positive. No positive chromaffin staining or chromogranin ISSN (print) 1869-3474 ISSN (online) 1869-3482

Head and Neck Cancer

Head and neck neoplasms are an important and frequent condition, where squamous cell carcinomas are the most common subtype, accounting for 5 % of all cancers. CT or MRI is mandatory performed in pretherapeutic staging and monitoring treatment in patients with head and neck cancers. Morphologic imaging techniques are often insufficient for themselves to discriminate small recurrences from vascularized scar tissue. In those cases, CT or MRI requires to be integrated with functional imaging techniques (perfusion CT, dynamic contrast-enhanced MRI, MRS, and DWI). PET/CT offers valuable opportunities for the assessment of head and neck cancer in all phases of the disease. It emerges, beyond doubt, as a useful and cost-effective tool in pretreatment staging and in recurrent disease detection. FDG imaging shows great promise in treatment planning and assessment of treatment response. Alternative tracers are yielding information on tumor biology and new imaging techniques associated to MRI which could be crucial in the clinical management of head and neck cancer patients.