Purandare Nilendu C, Prakash Anjali, Shah Sneha, Agrawal Archi, Puranik Ameya D, Rangarajan Venkatesh
Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India.
Indian J Nucl Med. 2021 Oct-Dec;36(4):357-361. doi: 10.4103/ijnm.ijnm_94_21. Epub 2021 Dec 15.
The objective is to evaluate incidental detection of COVID-19 lung involvement in asymptomatic individuals who undergo fluorodeoxyglucose (FDG) positron emission tomography-computerized tomography (PET/CT) scans for oncologic indications.
The study was conducted in a tertiary care oncology hospital and included patients who were asymptomatic for COVID-19 infection and underwent FDG PET/CT scans for standard oncologic indications between April 15, 2020, and September 30, 2020. Patients who showed CO-RADS category 4/5 changes (high level of suspicion) on the CT chest component of the PET/CT study were considered for analysis. CT severity score, presence of FDG uptake, and maximum standardized uptake value of FDG avid lung involvement were noted and correlated with reverse transcriptase-polymerase chain reaction (RT-PCR) test.
1982 PET/CT scans were performed, 78 (3.9%) patients showed lung changes with high degree of suspicion of COVID-19 pneumonia (CO-RADS 4/5). Hematolymphoid and head-neck cancer were the most common tumor types (23%), and restaging/response evaluation was the most common PET/CT indication. Of the patients who underwent RT-PCR testing, 70% showed a positive result. The mean CT severity score was 6 (standard deviation 5.9) with no significant difference seen between the RT-PCR positive and negative groups. FDG avidity in lung lesions was noted in 41 out 57 (72%) patients. A significant correlation was seen between the RT-PCR positivity and FDG uptake in lung lesions.
A small but significant proportion of patients undergoing routine oncologic PET/CT scans showed incidental COVID-19 lung involvement. Lung involvement in these asymptomatic patients showed a low CT severity score in all patients and FDG avidity in majority. Timely detection of such incidental cases can initiate further confirmatory RT-PCR testing and isolation measures that not only influence patient's cancer treatment protocols but also have a larger community impact of limiting the spread of infection.
评估因肿瘤指征接受氟脱氧葡萄糖（FDG）正电子发射断层扫描 - 计算机断层扫描（PET/CT）的无症状个体中COVID-19肺部受累的偶然发现情况。
本研究在一家三级肿瘤专科医院进行，纳入了2020年4月15日至2020年9月30日期间因标准肿瘤指征接受FDG PET/CT扫描且无COVID-19感染症状的患者。PET/CT检查胸部CT部分显示CO-RADS分类为4/5级变化（高度怀疑）的患者纳入分析。记录CT严重程度评分、FDG摄取情况以及FDG摄取阳性的肺部受累的最大标准化摄取值，并与逆转录聚合酶链反应（RT-PCR）检测结果进行关联分析。
共进行了1982例PET/CT扫描，78例（3.9%）患者显示肺部变化，高度怀疑为COVID-19肺炎（CO-RADS 4/5）。血液淋巴系统和头颈癌是最常见的肿瘤类型（23%），重新分期/疗效评估是最常见的PET/CT检查指征。在接受RT-PCR检测的患者中，70%结果呈阳性。平均CT严重程度评分为6分（标准差5.9），RT-PCR阳性组和阴性组之间无显著差异。57例患者中有41例（72%）肺部病变有FDG摄取。RT-PCR阳性与肺部病变的FDG摄取之间存在显著相关性。
在接受常规肿瘤PET/CT扫描的患者中，有一小部分但比例可观的患者偶然出现了COVID-19肺部受累情况。这些无症状患者的肺部受累在所有患者中CT严重程度评分较低，且大多数有FDG摄取。及时发现此类偶然病例可启动进一步的确诊RT-PCR检测和隔离措施，这不仅会影响患者的癌症治疗方案，还会对限制感染传播产生更大的社区影响。
