RESUMEN
INTRODUCTION: There is recent evidence advocating the use of post-chemotherapy MRI for safe resection of primary bone sarcoma in providing a clear margin of disease. This paper challenges this view by providing evidence obtained from comparing surgical resection margin measurements calculated off the pre- and post-chemotherapy MRIs to the post-operative histological analysis. METHOD: A retrospective patho-radiological analysis of 10 patients treated for long bone Ewing's sarcoma. The pre- and post-chemotherapy MRI radiological measurements were correlated with the post-operative gross and microscopic histological specimens with the principle aim of determining which represented the accurate histological extent of disease and therefore which image set should be used in determining the surgical resection margins. RESULTS: In the 10 cases there was a discrepancy in the extent of pathological disease on comparative histological and radiological assessment. The mean age at presentation was 19.5years [4-45 years], with a female bias (n = 7/10). The lower limbs were more commonly involved than the upper limb (femur n = 2/10, tibia n = 3/10, fibula n = 2/10, humerus n = 2/10, ulna n = 1/10). There was no correlation between the percentage reduction in measured volume/length of pathological bone on sequential MRI and the percentage necrosis on histology. The average discrepancy between the length of pathological bone on histology and on MRI was 2.7 cm. Using the baseline pre-chemotherapy MRI to plan the surgical resection margins, 7/10 patients had their surgical resection margins through radiologically clear but pathologically abnormal bone (without histological evidence of residual tumour). Had the post-chemotherapy MRI been used a further 3 patients would have had their tumour resected through pathologically abnormal bone. No patients had or would have had tumour resected through residual tumour. CONCLUSIONS: The use of the post-chemotherapy MRI for planning surgical resection margins increases the risk of resecting through histologically abnormal bone that may have been previously contaminated by tumour, without significant benefit of preserving sufficient bone to facilitate joint or physeal sparing surgery. The evidence from this study supports current guidelines recommending the use of pre-chemotherapy MRI to plan safe surgical resection margins in Ewing's sarcoma.
Asunto(s)
Neoplasias Óseas , Sarcoma de Ewing , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/cirugía , Femenino , Humanos , Márgenes de Escisión , Neoplasia Residual , Estudios Retrospectivos , Sarcoma de Ewing/diagnóstico por imagen , Sarcoma de Ewing/cirugíaRESUMEN
The way in which we learn anatomy has changed exponentially over the decades and students now have access to lecture notes, textbooks, computer-assisted programmes, and a wide variety of internet based information. This study explored which resources were the most (and least) useful for a group of first year, undergraduate, medical students, with minimal prior content exposure (aged 18 and 19 years old, n = 76), over an 18 month period. Anatomy websites were found to be the most useful (30%), followed by tutorials (20%) and lectures (19%). A total of 13% found the university computer-assisted learning (CAL) platform least useful. We subsequently enhanced our 'urogenital' CAL anatomy module, with inclusion of new and updated images, videos and tutorials, as well as, digital and printed 3D-models. A post-intervention survey (n = 81) showed an increase from 12% to 27% for CAL as being most useful, and a decrease from 13% to 3% as being least useful. Our results provided a snapshot of students' preferences in studying anatomy, and highlighted the importance of digital platforms and the need for evaluating our own learning resources. We must be mindful that there is an increasing tendency for students to rely on the Internet for information, which may expose them to unfiltered and unreliable content. We conclude that educators must be aware of the spectrum of learning resources used by students, to ensure that our own Institutional eLearning platforms are optimised to meet the diverse needs of learners.