Diagnostic accuracy of whole-body MRI versus standard imaging pathways for metastatic disease in newly diagnosed non-small-cell lung cancer: the prospective Streamline L trial

Abstract

Summary Background Whole-body magnetic resonance imaging (WB-MRI) could be an alternative to multi-modality staging of non-small-cell lung cancer (NSCLC), but its diagnostic accuracy, effect on staging times, number of tests needed, cost, and effect on treatment decisions are unknown. We aimed to prospectively compare the diagnostic accuracy and efficiency of WB-MRI-based staging pathways with standard pathways in NSCLC. Methods The Streamline L trial was a prospective, multicentre trial done in 16 hospitals in England. Eligible patients were 18 years or older, with newly diagnosed NSCLC that was potentially radically treatable on diagnostic chest CT (defined as stage IIIb or less). Exclusion criteria were severe systemic disease, pregnancy, contraindications to MRI, or histologies other than NSCLC. Patients underwent WB-MRI, the result of which was withheld until standard staging investigations were complete and the first treatment decision made. The multidisciplinary team recorded its treatment decision based on standard investigations, then on the WB-MRI staging pathway (WB-MRI plus additional tests generated), and finally on all tests. The primary outcome was difference in per-patient sensitivity for metastases between standard and WB-MRI staging pathways against a consensus reference standard at 12 months, in the per-protocol population. Secondary outcomes were difference in per-patient specificity for metastatic disease detection between standard and WB-MRI staging pathways, differences in treatment decisions, staging efficiency (time taken, test number, and costs) and per-organ sensitivity and specificity for metastases and per-patient agreement for local T and N stage. This trial is registered with the International Standard Randomised Controlled Trial registry, number ISRCTN50436483, and is complete. Findings Between Feb 26, 2013, and Sept 5, 2016, 976 patients were screened for eligibility. 353 patients were recruited, 187 of whom completed the trial; 52 (28%) had metastasis at baseline. Pathway sensitivity was 50% (95% CI 37–63) for WB-MRI and 54% (41–67) for standard pathways, a difference of 4% (−7 to 15, p=0·73). No adverse events related to imaging were reported. Specificity did not differ between WB-MRI (93% [88–96]) and standard pathways (95% [91–98], p=0·45). Agreement with the multidisciplinary team's final treatment decision was 98% for WB-MRI and 99% for the standard pathway. Time to complete staging was shorter for WB-MRI (13 days [12–14]) than for the standard pathway (19 days [17–21]); a 6-day (4–8) difference. The number of tests required was similar WB-MRI (one [1–1]) and standard pathways (one [1–2]). Mean per-patient costs were £317 (273–361) for WBI-MRI and £620 (574–666) for standard pathways. Interpretation WB-MRI staging pathways have similar accuracy to standard pathways, and reduce the staging time and costs. Funding UK National Institute...

Whole-body MRI compared with standard pathways for staging metastatic disease in lung and colorectal cancer: the Streamline diagnostic accuracy studies

“…Thereafter, radiologists with experience of < 100 WB-MRI data sets underwent a period of 'buddy' reporting with a more experienced radiologist (experience of > 100 WB-MRI data sets) and were only permitted to report alone once deemed competent by the more experienced radiologist. 25,26 This process was specifically designed to mirror how WB-MRI would be reported in standard NHS practice were it to become disseminated. We specifically avoided using a small number of highly experienced subspecialty radiologists who would not be representative of the NHS radiological workforce.…”

“…Reporting radiologists were instructed to interpret the WB-MRI as they would in their routine clinical practice, taking into account the known morphology and characteristics of potential metastatic disease across the various sequences. 22,25,26 Following completion of the CRF, the reporting radiologist produced a free-text clinical report as per their usual clinical practice (using all available sequences and based on the TNM 7th edition) 27 for subsequent release to the clinical team. This report contained information relating to the local T and N stage of the tumour, together with the presence, location, number and size of metastatic deposits as well as important 'incidental' findings, for example a second malignancy.…”

“…Multidisciplinary consensus panel review is the standard methodology for diagnostic test accuracy studies where an independent reference standard does not exist or is impossible because of incorporation bias. 23,25,26,28 The Streamline trials applied this methodology. Specifically, each recruitment site convened a series of consensus panels to derive the reference standard for the cancer TNM stage at recruitment for their participants.…”

“…Given the variable follow-up period (e.g. owing to participant death) and the potential for primary tumours left in situ to seed new metastatic disease after cancer diagnosis (which would unfairly penalise diagnostic accuracy estimates of initial staging investigations), the following criteria were applied by the panel when opining on metastatic status (defined upfront as part of the trial protocols): 25,26 l For participants in whom the primary tumour was completely removed within 3 months of diagnosis, all new metastatic sites identified over the follow-up period were be assumed to have been present at diagnosis. l If the primary tumour was left in situ for > 3 months after diagnosis ( The presence of metastatic disease was recorded overall, and then on a per-organ basis.…”

Whole-body MRI for lung cancer staging: a step in the right direction

“…For both patients and health-care providers, it would be desirable to have a single and accurate imaging modality for staging. In The Lancet Respiratory Medicine, Stuart A Taylor and colleagues report the Streamline L study, 4 providing evidence that whole-body MRI (WB-MRI) might represent such an imaging modality.…”