[Diagnosis of COVID-19 pneumonia in asymptomatic patients after an oncological PET/CT]. / Diagnóstico de neumonía COVID-19 en pacientes asintomáticos tras la realización de un PET/TC oncológico.

INTRODUCTION: On January 30, 2020, the World Health Organization (WHO) declared an international emergency due to the pandemic caused by a new coronavirus. There are some oncological indications that have special priority and studies are still being carried out despite the current situation. In these studies we have found suspicious findings of COVID-19 pneumonia in asymptomatic patients. The objective of this work is to assess the incidence of these findings, describe their characteristics and the evolution of suspected patients. MATERIAL AND METHODS: Oncological PET studies carried out in asymptomatic patients between March 18 and April 8, 2020 have been reviewed. Patients who presented findings suggestive of corresponding to an pulmonary infectious process were selected. Clinical findings have been reviewed to confirm or rule out SARS-CoV-2 infection. RESULTS: During the specified period, a total of 129 PET/CT studies were performed. Of these, 11 (8.5%) found suspicious findings of a pulmonary infectious process. These were 8 men and 3 women aged between 30 and 79 years (mean 62.2). CONCLUSIONS: Patients with COVID-19 can present few symptoms of the disease, and in PET/CT studies both presymptomatic and almost asymptomatic patients can be detected, so nuclear medicine physicians should take special attention to the pulmonary evaluation of PET/CT studies.

18F-Choline PET/CT scan in staging and biochemical recurrence in prostate cancer patients: Changes in classification and radiotherapy planning. / La PET/TC con 18F-Colina en la estadificación y recidiva bioquímica de pacientes con cáncer de próstata: cambios en la clasificación y planificación de radioterapia.

OBJECTIVE: To evaluate the role of the 18F-Choline PET/CT in prostate cancer management when detecting distant disease in planning radiotherapy and staging and to evaluate the therapy changes guided by PET/TC results. MATERIAL AND METHODS: A retrospective evaluation was performed on 18F-Choline PET/CT scans of patients with prostate cancer. Staging and planning radiotherapy scans were selected in patients with at least 9 months follow up. There was a total of 56 studies, 33 (58.93%) for staging, and 23 (41.07%) for planning radiotherapy. All scans were obtained using a hybrid PET/CT scanner. The PET/CT acquisition protocol consisted of a dual-phase procedure after the administration of an intravenous injection of 296-370MBq of 18F-Choline. RESULTS: There were 43 out of 56 (76.8%) scans considered as positive, and 13 (23.2%) were negative. The TNM staging was changed in 13 (23.2%) scans. The PET/CT findings ruled out distant disease in 4 out of 13 scans, and unknown distant disease was detected in 9 (69.3%) scans. CONCLUSIONS: 18F-Choline PET/CT is a useful technique for detecting unknown distant disease in prostate cancer when staging and planning radiotherapy. The inclusion of 18F-choline PET/CT should be considered in prostate cancer management protocols.

Clinical relevance of incidental finding of focal uptakes in the colon during 18F-FDG PET/CT studies in oncology patients without known colorectal carcinoma and evaluation of the impact on management.

AIMS: To assess the significance and the impact of focal FDG uptake in the colon in oncology patients without known colorectal carcinoma. MATERIALS AND METHODS: A retrospective study was undertaken on 2,220 (18)F-FDG PET/CT studies carried out consecutively in the Nuclear Medicine Department in our hospital from 2 December 2008 to 31 May 2010. Inclusion criteria were patients with abnormal (18)F-FDG uptake in colorectal area that could not be explained (or not previously known) by their clinical histories. Patients previously diagnosed with colorectal carcinoma were excluded. A total of 86 patients (57 male, average age 63.4, range 46-85) were finally included. Colonoscopy with biopsy was established as a reference test. The impact of these findings on the diagnostic-therapeutic management in these patients was evaluated. RESULTS: A colonoscopy was performed in 54 of the 86 patients, this examination not having been done up-to-date in the remaining 32 patients. Biopsy was obtained in 43 lesions of the 54 patient in whom a colonoscopy was performed. Colon disease was detected in 49 of these 54 patients, obtaining 54 FDG incidental foci which corresponded to 10 previously unsuspected primary colorectal carcinoma, 3 metastases, 27 adenomatous polyps with different degrees of dysplasia and 14 inflammatory processes. In the remaining 5 patients, the colonoscopy was normal. PET/CT modified the diagnostic and treatment management in most of the patients (49/54, that is 91%). CONCLUSIONS: These results confirm the need to determine the cause of abnormal (18)F-FDG colorectal uptakes in the PET/CT studies by using colonoscopy and biopsy. This approach allows for the detection and early treatment of malignant and premalignant lesions.

Contribution of the portable gamma camera to detect the sentinel node in breast cancer during surgery.

AIM: To show our experience using the portable gamma camera during surgery in the detection of the sentinel node in breast cancer. MATERIAL AND METHODS: A total of 46 women diagnosed with breast cancer were included. This study was carried out by means of the periareolar intradermal injection. Planar images and SPECT/CT were acquired. On the following day, the sentinel nodes were localized intraoperatively with a portable gamma camera and a gamma probe. Images of the anterior axillary line projection and lateral axillary line projection were acquired before and after extraction of all the sentinel nodes. RESULTS: The images acquired with the portable gamma-camera during the operation showed no activity in all of the patients after the removal of the sentinel nodes. In four out of the 46 cases, the portable gamma camera provided relevant information during the procedure (it detected a sentinel node in two cases in which it had not been detected prior to the surgery and it oriented the surgeon in the localization of low activity nodes when the probe screening had been negative). CONCLUSIONS: The use of the intraoperative portable gamma camera to detect the sentinel node in breast cancer patients is useful in order to ensure, independently of the surgeon, that all the sentinel nodes have been removed. It can also help guide the surgeon in the event of a single low activity sentinel node.

[SPECT-CT in sentinel node detection in patients with melanoma]. / SPECT-TAC en la localización del ganglio centinela en pacientes con melanoma.

INTRODUCTION: The prognosis of patients with cutaneous melanoma is greatly influenced by the presence of lymph node metastases. One of the most innovative and fascinating concepts to emerge in the field of oncology in recent years is the use of sentinel lymph node biopsy (SLNB). AIM: The aim of this study was to determine what SPECT-CT images contribute to the search for sentinel nodes in patients with melanoma. METHODS: From March 2007 to October 2008, 18 patients were examined for sentinel nodes using dynamic scintigraphy, planar images, and SPECT-CT in the Nuclear Medicine Department of San Carlos University Hospital. The group contained 10 women and 8 men, age range 14-83 years, mean age 57 years (57+/-20.1). RESULTS: The sentinel node was located by conventional imaging techniques (dynamic scintigraphy and planar images) in 16 of 18 patients (88.88%). SPECT-CT identified the sentinel node in 18 of 18 patients (100%) and detected clinically relevant findings in 6 of 18 patients (33.33%) CONCLUSIONS: SPECT-CT imaging contributed clinically relevant information on sentinel nodes of melanoma, which is particularly important in patients with melanoma of the trunk or head and neck.

[SPECT-CT: a new tool for localisation of sentinel lymph nodes in breast cancer patients]. / SPECT-TAC: una nueva herramienta para la localización del ganglio centinela en pacientes con cáncer de mama.

INTRODUCTION: Sentinel lymph node biopsy has become a widely accepted procedure for axillary lymph node staging in patients with breast cancer. AIM: The aim of this study was to determine the advantages of using SPECT-CT instead of planar scintigraphy in the presurgical localisation of sentinel lymph nodes. METHODS: We prospectively included 25 consecutive patients with breast cancer who were admitted to our department for SLN localisation. Patients were divided into two groups, depending on whether neoadjuvant chemotherapy had been received (B, n = 6) or not (A, n = 19). Four doses (1.0 mCi each) of 99mTc-nanocolloid were injected intradermallly in all patients, and SPECT-CT and planar images were acquired. All patients underwent surgery and SLN localisation with a hand-held gamma probe. Any axillary "hot spots" were resected. The kappa index (ki) was calculated using surgical findings as the gold standard. RESULTS: In group A, the SLN was correctly detected in 17/19 patients (89.5 %) with SPECT-CT and in 12/19 (63.2 %) with planar images. The correlation between SPECT-CT and surgical findings (ki 0.91) was better than between planar images and surgical findings (ki 0.57). In group B, the results of SPECT-CT and planar images were identical, with accurate localisation of the SLN in 5/6 patients (ki 0.76). CONCLUSIONS: The results of this study suggest that SPECT-CT may be useful for locating the SLN in breast cancer patients, as it provides accurate localization of the SLN with useful anatomical information. This may allow the surgeon to search exclusively for SLN viewed on SPECT-CT, and avoid false negative and false positive results.