Assessment of a single-pass venous phase CT chest, abdomen and pelvis and dual-energy CT in general oncology outpatients.

INTRODUCTION: This study assessed replacing traditional protocol CT-arterial chest and venous abdomen and pelvis, with a single-pass, single-bolus, venous phase CT chest, abdomen and pelvis (CAP) protocol in general oncology outpatients at a single centre. METHODS: A traditional protocol is an arterial phase chest followed by venous phase abdomen and pelvis. A venous CAP (vCAP) protocol is a single acquisition 60 s after contrast injection, with optional arterial phase upper abdomen based on the primary tumour. Consecutive eligible patients were assessed, using each patient's prior study as a comparator. Attenuation for various structures, lesion conspicuity and dose were compared. Subset analysis of dual-energy (DE) CT scans in the vCAP protocol performed for lesion conspicuity on 50 keV virtual monoenergetic (VME) images. RESULTS: One hundred and eleven patients were assessed with both protocols. Forty-six patients had their vCAP scans using DECT. The vCAP protocol had no significant difference in the attenuation of abdominal structures, with reduced attenuation of mediastinal structures. There was a significant improvement in the visibility of pleural lesions (p < 0.001), a trend for improved mediastinal nodes assessment, and no significant difference for abdominal lesions. A significant increase in liver lesion conspicuity on 50 keV VME reconstructions was noted for both readers (p < 0.001). There were significant dose reductions with the vCAP protocol. CONCLUSION: A single-pass vCAP protocol offered an improved thoracic assessment with no loss of abdominal diagnostic confidence and significant dose reductions compared to traditional protocol. Improved liver lesion conspicuity on 50 keV VME images across a range of cancers is promising.

Radiological analysis of orbital lymphoma histological subtypes.

PURPOSE: To characterise the radiological features of orbital lymphoma subtypes. METHODS: This was a multicentre, retrospective study to analyse radiological and clinical characteristics of orbital lymphoma by histological subtype across two sites within Australia and the United States. RESULTS: A total of eighty-eight patients were included. The most common subtypes were extranodal marginal zone lymphoma [EMZL] (48, 54.5%), follicular lymphoma [FL] (16, 18.2%), and diffuse large B-cell lymphoma [DLBCL] (15, 17.0%). Clinically, significant associations were found between DLBCL and vision change (p < .01), pain (p < .01), extraocular movement limitation (p = .01), and optic neuropathy (p = .01). Radiologically, there was no significant difference between the individual histopathological sub-groups with respect to bone destruction (p = .30), optic nerve involvement (p = .30) and diffuse appearance (p = .84). However, if categorised as either aggressive or indolent, aggressive lymphoma subtypes were significantly more likely to demonstrate globe indentation radiologically than indolent subtypes (Odds Ratio = 5.5, 95% CI: 1.3, 23.3; p = .02). CONCLUSIONS: DLBCL was significantly associated with vision change, pain, extraocular movement limitation and optic neuropathy clinically. Aggressive lymphoma subtypes were significantly more likely to demonstrate globe indentation radiologically. Otherwise, there were no significant differences between lymphoma subtypes and radiological findings on MRI and CT.

Predictive value of computed tomography in identifying extracapsular spread of cervical lymph node metastases in p16 positive oropharyngeal squamous cell carcinoma.

BACKGROUND: Extracapsular spread (ECS) of lymph node metastases is associated with poor prognosis and is an indication for adjuvant chemoradiotherapy. Accurately identifying ECS using imaging may allow us to recommend primary chemoradiotherapy to avoid trimodality treatment. We investigated the accuracy of staging CT in diagnosing ECS in P16 + oropharyngeal squamous cell carcinoma (OPSCC). METHODS: Patients with pathologically determined cervical nodal metastases from P16 + OPSCC were included. Two blinded radiologists scored images to predict the presence of ECS in comparison to histopathology. RESULTS: Eighty patients with a total of 91 specimens were evaluated. Pathologic ECS was identified in 53.8% of the patients. Sensitivity and specificity of CT for the two observers were 56.5% and 60.9%, and 73.3% and 66.7%, respectively. The presence of perinodal stranding was found to be significantly associated with pathological ECS. CONCLUSION: Computed tomography displays consistently high specificity, which may be used to rule out the presence of extracapsular spread in cervical nodal metastases of P16 + oropharyngeal squamous cell carcinoma.