Avoiding Errors in Head and Neck Cancer Imaging Lawrence E. Ginsberg, M.D. Departments of Diagnostic Imaging and Head and Neck Surgery University of Texas M.D. Anderson Cancer Center Houston, Texas You Can t Avoid Errors But for fun we can dream about it I will offer some strategies but none are foolproof because we are human No solution or prevention for just missed it Employing every suggestion I propose won t prevent every error or misdiagnosis Sharing, review of misses and error, analysis and self-forgiveness are crucial Suggestions will be accompanied by case material in which a mistake was or easily could have been made, usually by me Ginsberg s Suggestions to Avoid Errors Live in a perfect world and be perfect, know everything Live in a world where there is no variation or pitfall, and if there variations and pitfalls, know them all (which requires missing them previously) Live in a world where you have every conceivable bit of clinical data you need Live in a world where things are fair Cherry-pick, mistakes less likely on easy cases Retire If you re gonna do extra sequences or recons, look at them Never have a bad day or a distraction, never be in a rush Ginsberg s Suggestions to Avoid Errors Avoid satisfaction of search by being extra vigilant right after making key observations. Ignore the obvious tumor for a while; it's not going anywhere Once you have a diagnosis, consider for a moment that it s a trap. Force yourself to consider alternatives even if you then reject them Remember that successfully treated H&N cancer patients get new malignancies, so look elsewhere Like when playing chess, avoid blunders Expertise (you published, you lecture, etc.) does not confer immunity to error Don t hallucinate findings, but be vigilant for what may be subtle, early lesions, and if unsure consider bringing patient back for repeat imaging earlier Ginsberg s Suggestions to Avoid Errors Don t forget to look at the brain and lungs Remember on PET hot cancer Learn some PET, including body PETfalls Protocol the case correctly even if they order it incorrectly Have others look at the scans, colleagues, clinicians, the more the better-clinician often knows something you don t Make sure you re comparing with the most recent exam, not the most recent of same modality Don t accept the history as accurate. EVER. Read only 4 scans/day If the patient had Bx or surgery prior to the scan, know it Live in a world where there is no variation, and Aunt Minnie always looks like her old self 30-y/o woman with intermittent bouts of ptosis ultimately diagnosed as Horner s, leading to imaging and diagnosis of skull base lesion IS THAT FAIR?
Or is this fair? 41-y/o man with stabbing right facial pain, no underlying history 54-y/o woman with 3 year history of gradually enlarging intraoral mass, left facial sensory loss, and recent dizziness 44-y/o man with CML with new right facial discomfort Life s not fair. Deal with it. If you re gonna do extra sequences or recons, look at them 57-y/o woman with PTC Avoid blunders 80-y/o-man referred for nasopharyngeal mass Know everything, miss nothing, have all history, all priors, not every modality sees every lesion 51-y/o man, s/p resection of left eyelid invasive sebaceous carcinoma, and subsequent left parotidectomy for nodal metastasis (seen only on US, 4mm, invisible on CT). at Dx Blunder: I forgot to look at the rest of the body!!
Several post-op CTs negative, but 18 months post-op, patient experiencing left facial discomfort and imaged closer to home. Presence of trismus not conveyed to radiologist who read this CT, and symptoms of left V 3 neuropathy might not even have begun yet. MDACC 7/16 Outside 12/6 Possible outside reader had no knowledge of resection of parotid met 3/17, with progressive trismus and now mandibular neuropathy Don t hallucinate findings, but be vigilant for what may be subtle/early lesions, consider bringing patient back for repeat imaging earlier 63-y/o man being surveilled after XRT for left glottic Ca 5/14 8/14 11/14 Left cord deemed worrisome, recommended early re-imaging 1/15 Have lots of people looking at the scan, ignore the obvious tumor for a while; it's not going anywhere 80-y/o man, new patient with big ulcerated left parietal scalp basal cell Just never miss anything. Big new lesions are a huge uh-oh moment. If the thing wasn t called previously, was it visible, could/ should it have been seen, and were you the one who missed it? Often the key comparison is the previous study and the one prior to it. I m all over it, until I get an e mail an hour later yes
EVOLUTION OF A MISS 54-y/o man being surveilled after TL for recurrent larynx Ca. Last several post-rx scans read neg. Answer: -it was there -it was callable -it was read no lesion -I read it 3/17 Uh-oh. Questions: What did last scan look like, was this thing there, was it callable, how was it read, and who read it? 3/17 12/16 Know everything, hot cancer, learn some PET including body PETfalls 54-y/o man, s/p chemorads for NPC, now being staged for new oral tongue Ca with contralateral nodal mets 3/29/17? my miss 3/29/17 3/23/17 9/16 5/16 If the patient had Bx or surgery prior to the scan, know it, otherwise you just look bad Same patient, pre-op CT, PET/CT 6 days later Why? Because the PET was postglossectomy!
If the patient had Bx or surgery prior to the scan, know it, otherwise you just look bad. Want another? 66-y/o woman with recurrent orbital large B cell lymphoma Know everything, expertise confers no immunity from error 67-y/o man, 7 years s/p chemoradiation for right tonsil Ca. Follow-up PET/CT read by me. 4/24/17 3/7/17 I check for XRT, none, assume patient had received chemo and this scan reflects response to therapy. Good thing I kept digging: No therapy! Don t accept the history as gospel. EVER. 56-y/o woman, MR obtained, requisition said NPC. Had recurrent ear infections, likely serous otitis, outside physician made Dx of NPC, allegedly Bx proven, and patient referred to us
CT obtained one week later Re-review of MR Remember hot cancer Clinician ordered contrast enhanced CT for further evaluation 63-y/o man, 4 years s/p composite resection, free flap, neck dissection and XRT for treatment of right RMT/gingival SCCa. Interim scans had been read as negative, PET/CT obtained, apparently as routine follow up. Pre-Rx Pretty reasonable? So what s wrong with this diagnosis? January, 2017 June, 2016
Different conspicuity for different modalities, get input from the clinician who examined the patient, don t accept Hx as gospel 54-y/o man, no cancer history, self palpates right neck mass, referred to MDACC Suspicion of Cancer clinic, CT ordered, requisition says lymphadenopathy, but I can t find any. Clinician I never met walks up to clinic, politely introduces herself, and points on her own neck to where a hard mass is palpable on this man, so I look again. Since you can t prevent errors, Ginsberg s Suggestions on Dealing With Errors Your clinicians don t expect you to be perfect Forgive yourself, because it won t be the last error Own your mistakes, addend the report immediately, use the QA process. I routinely ding myself. Take solace that many misses are either insignificant or won t impact outcome; in many cases there are few good treatment options, and seeing a recurrence earlier won t necessarily improve survival Never take pleasure in someone else s error because you very possibly missed the same lesion previously