Evaluation of 18FDG PET-CT-positive mediastinal-hilar lymph nodes in extrathoracic malignancies by EBUS-TBNA; correlation of SUVmax, and short-axis diameter with the final diagnosis

Introduction: Intrathoracic lymph node metastasis from extrathoracic neoplasms are rare. Primary malignancies that metastasize to mediastinal-hilar lymph nodes are head and neck , carcinoma breast ,and genitourinary. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)/endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is currently the preferred modality for mediastinal lymph node sampling. Methods: Fifty seven patients with extrathoracic malignancies with maximum standardized uptake value (SUVmax) of mediastinal-hilar lymph nodes greater than or equal to 2.5 were taken up for EBUS-TBNA. The histo-cytopathological results obtained from EBUS-TBNA were compared with SUVmax value and short-axis diameter of a lymph node as noted on EBUS. Results: Out of 74 sampled nodes, 49 (66.2%) were benign and 25 (33.8%) were malignant. The SUVmax range of benign nodes was 2.8� as compared to 3� of malignant nodes. The size range of malignant and benign nodes were 8� mm and 8� mm, respectively. The mean size of abnormal nodes (metastatic + granulomatous) was 17.5 (8� mm) and the mean SUVmax was 9.1 (3.4�), and it was a statistically significant difference when compared to reactive (normal) nodes. At SUVmax cut-off 7.5, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) were 78.5%, 81.2%, 84.6%, and 74.2%, respectively for detecting abnormal nodes. At 13 mm size cut-off, sensitivity, specificity, PPV, NPV were 75.5%, 65%, 75%, and 72%, respectively, for detecting abnormal nodes. Conclusion: The majority of mediastinal-hilar nodes with increased metabolic activity are benign in nature. Size and SUVmax are poor predictors of metastasis in tuberculosis endemic region. There should be a restrictive attitude toward invasive diagnostic testing for mediastinal-hilar nodes in extrathoracic malignancies.

Role of early dynamic PET/CT scan imaging with 18F-PSMA-1007 in staging and restaging prostate cancer in a tertiary private hospital

Introduction@#18F-PSMA-1007 is a novel prostate-specific membrane antigen (PSMA)-based radiopharmaceutical for imaging prostate cancer. The recommended imaging time is 60 minutes post-injection of the radiotracer. However, during this time there is a physiologic accumulation of the radiotracer in the urinary bladder which sometimes may obscure lesions adjacent to it. @*Objective@#This study aims to determine if early dynamic imaging in addition to the recommended 60-minute postinjection static imaging can improve the detection of PSMA-avid lesions in the staging and restaging of prostate cancer. @*Methods@#This is a retrospective cross-sectional study of the detection rate of early dynamic and static imaging using 18F-PSMA-1007 PET/CT scan in patients with prostate cancer (PCa) who were referred for initial staging or restaging. The McNemar test was used to compare the detection rate between the two imaging. Spearman correlation was used to determine the correlation of Gleason score (GS), PSA, and SUVmax values.@*Results@#18F-PSMA-1007 PET/CT scans of 53 patients with prostate cancer, were referred for either staging (22/53) or restaging (31/53), all of whom had undergone both early dynamic and static imaging. Among the 53 patients, 5 had 2 lesions each, for a total of 58 lesions were included in the analysis. There were 48/58 lesions detected on both early dynamic and static imaging, 2/58 lesions were only detected in the early imaging, 1/58 lesions was only detected in the static imaging, and 7/58 were not detected on both imaging. McNemar the test was not statistically significant (p = 1.000) in the detection rate of the two methods. There is a positive correlation between serum PSA levels and SUVmax measurements for all the patients. Only the correlation between the GS and SUVmax in the static imaging of the staging group was statistically significant. @*Conclusion@#Early dynamic imaging may be an adjunctive procedure in detecting PSMA-avid lesions, particularly in the basal segment of the prostate gland near the urinary bladder. However, it is not recommended as a standard component of the comprehensive protocol for imaging using 18F-PSMA-1007 PET/CT in patients with PCa.

Role of 18F-FDG PET/CT in the diagnostic work-up of renal cell carcinoma presenting as low back pain

@#Low back pain is common among adults, but back pain secondary to a metastatic carcinoma is rare. We present a case of a 71-year-old male with low back pain who was referred for a 18F-FDG PET/CT scan due to suspicious-looking skeletal lesions on MRI. On PET/CT, multiple foci of increased FDG uptake were noted in the axial and appendicular skeleton. When correlated with a non-contrast CT stonogram done 2 months prior, an exophytic lesion in the right kidney did not show FDG update; rather, it was in the left kidney where an FDG-avid focus was seen. A concomitant bone scan revealed fewer bone lesions when compared with the PET/CT findings. Biopsies of the left renal mass and a vertebral lession were consistent with metastatic renal cell carcinoma. While not a first-line diagnostic test in the management of low back pain, 18F-FDG PET/CT scan can be valuable in cases where metasis highly suspected without a known primary carcinoma site.

Predictors of Distant Metastasis after Radical Surgery Followed by Postoperative Radiotherapy with or without Chemotherapy for Oropharyngeal Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: We investigated the prognostic factors for distant metastasis (DM) in patients with locally advanced oropharyngeal cancer (OPC) treated with surgery and adjuvant radiotherapy with or without concurrent chemotherapy. MATERIALS AND METHODS: Eighty-five patients treated between January 1995 and August 2014 were evaluated retrospectively. Data regarding the pathological tumour and nodal status, human papillomavirus (HPV) status, treatment characteristics, and pretreatment maximum standardized uptake value (SUVmax) of 18-fluoro-2-deoxyglucose positron emission tomography–computed tomography scan (¹⁸F-FDG PET-CT) were evaluated, and their influence on DM and survival outcomes were analyzed. RESULTS: Median follow-up period was 48.0 months. Recurrence was observed in 20 patients, including locoregional recurrence and DM. DM was observed in 13 patients. A multivariate analysis confirmed that the presence of lymphovascular invasion (p=0.031), lower neck lymph node (LN) involvement (p=0.006), SUVmax ≥ 9.7 (p=0.014), and tumour size ≥ 3 cm (p=0.037) significantly affected DM. HPV status was not associated with DM. Perineural invasion (p=0.048), lower neck LNinvolvement (p=0.008), SUVmax ≥ 9.7 (p=0.019), and tumour size ≥ 3 cm (p=0.033) were also significant factors for the DM-free survival rate. CONCLUSION: Lower neck LN involvement, high SUVmax in pretreatment ¹⁸F-FDG PET-CT, and large tumour size were predictive factors for DM in patients of OPC.

The Role of 18F-FDG PET/CT in the Evaluation of Gastric Cancer Recurrence after Curative Gastrectomy

PURPOSE: 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scans are frequently performed for the screening or staging of malignant tumors. This study aimed to assess the usefulness of 18F-FDG PET/CT in detection of gastric cancer recurrence after curative gastrectomy. MATERIALS AND METHODS: Eighty nine patients who had undergone curative gastrectomy due to gastric cancer and had 18F-FDG PET/CT and contrast CT scans within 2 weeks for surveillance in asymptomatic patients (n = 11) or to clarify suspected recurrence (n = 78) were consecutively collected and retrospectively analyzed. They had clinical follow-up for at least 12 months after PET/CT and CT scans. RESULTS: Fifteen of the 89 patients (16.9%) were diagnosed with recurrent gastric cancer in 21 organs. Forty one organs showed an increase in FDG uptake, and only 9 of these organs were diagnosed with recurrent gastric cancer by 18F-FDG PET/CT. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the 18F-FDG PET/CT were 42.9%, 59.7%, 29.3%, 78.2%, and 57.3%, respectively. On the CT scan, 18 of 21 recurrent gastric cancers were detected, and 7 cases were in agreement with the 18F-FDG PET/CT. The sensitivity and specificity of the CT scan were 85.8% and 87.3%, respectively, which are superior to the 18F-FDG PET/CT. When we diagnosed a recurrence based on either 18F-FDG PET/CT or CT scans, the sensitivity increased to 95.2% and the specificity decreased to 45.6%, when compared with the contrast CT scan alone. CONCLUSION: 18F-FDG PET/CT is an insufficient diagnostic method in detection of recurrence after curative gastrectomy, and even less accurate than contrast CT scan alone.

Diagnostic Efficacy of PET/CT Plus Brain MR Imaging for Detection of Extrathoracic Metastases in Patients with Lung Adenocarcinoma

We aimed to evaluate prospectively the efficacy of positron emission tomography (PET)/computed tomography (CT) plus brain magnetic resonance imaging (MRI) for detecting extrathoracic metastases in lung adenocarcinoma. Metastatic evaluations were feasible for 442 consecutive patients (M:F=238:204; mean age, 54 yr) with a lung adenocarcinoma who underwent PET/CT (CT, without IV contrast medium injection) plus contrast-enhanced brain MRI. The presence of metastases in the brain was evaluated by assessing brain MRI or PET/CT, and in other organs by PET/CT. Diagnostic efficacies for metastasis detection with PET/CT plus brain MRI and with PET/CT only were calculated on a per-patient basis and compared from each other. Of 442 patients, 88 (20%, including 50 [11.3%] with brain metastasis) had metastasis. Regarding sensitivity of overall extrathoracic metastasis detection, a significant difference was found between PET/CT and PET/CT plus brain MRI (68% vs. 84%; P=0.03). As for brain metastasis detection sensitivity, brain MRI was significantly higher than PET/CT (88% vs. 24%; P<0.001). By adding MRI to PET/CT, brain metastases were detected in additional 32 (7% of 442 patients) patients. In lung adenocarcinoma patients, significant increase in sensitivity can be achieved for detecting extrathoracic metastases by adding dedicated brain MRI to PET/CT and thus enhancing brain metastasis detection.