TY - JOUR
T1 - Can errors in reconstructing pre-chemotherapy target volumes contribute to the inferiority of sequential chemoradiation in stage III non-small cell lung cancer (NSCLC)?
AU - Lagerwaard, Frank J.
AU - Van de Vaart, Paul J M
AU - Voet, Peter W J
AU - Nijssen-Visser, Margriet R J
AU - Schuchhard-Schipper, Regine H.
AU - Joosten, Hans P J
AU - Oei, Swie Swat
AU - Senan, Suresh
PY - 2002/12/1
Y1 - 2002/12/1
N2 - Concurrent chemo-radiotherapy (CT-RT) has been shown to be superior to sequential CT-RT for stage III non-small cell lung cancer (NSCLC). Pre-chemotherapy gross tumor volumes (GTV) are commonly contoured for sequential CT-RT and, as significant inter-clinician variability exists in defining GTV's for lung cancer, we postulated that the poorer local control observed with sequential CT-RT may partly be due to the larger errors in defining GTV after chemotherapy-induced tumor regression. Pre-and post-chemotherapy CT scans for RT planning (RTP) were performed in ten patients who received induction chemotherapy for NSCLC. Image registration of pre- and post-chemotherapy RTP scans was performed for all patients. GTV's were first contoured in the conventional manner by two clinicians, i.e. by visual reconstruction from hard copies of the pre-chemotherapy diagnostic CT scans ('GTV-visual'). A 'GTV-match' was then contoured after image-registration, and the 'gold standard' volume was considered to be the overlap of the 'GTV-match' generated by both clinicians. The 'GTV-match' was on average 31-40% larger than 'GTV-visual'. The mean percentage of the 'gold standard', which was not covered by the 'GTV-visual' was similar for both clinicians, i.e. 26.3±12.5 and 28.0±15.0%. The inter-clinician agreement in contouring improved after image registration. These data suggest that conventional visual contouring of pre-chemotherapy GTV's may fail to treat the actual pre-chemotherapy tumor volume, and thus confound studies evaluating optimal sequencing of chemo-radiotherapy in NSCLC.
AB - Concurrent chemo-radiotherapy (CT-RT) has been shown to be superior to sequential CT-RT for stage III non-small cell lung cancer (NSCLC). Pre-chemotherapy gross tumor volumes (GTV) are commonly contoured for sequential CT-RT and, as significant inter-clinician variability exists in defining GTV's for lung cancer, we postulated that the poorer local control observed with sequential CT-RT may partly be due to the larger errors in defining GTV after chemotherapy-induced tumor regression. Pre-and post-chemotherapy CT scans for RT planning (RTP) were performed in ten patients who received induction chemotherapy for NSCLC. Image registration of pre- and post-chemotherapy RTP scans was performed for all patients. GTV's were first contoured in the conventional manner by two clinicians, i.e. by visual reconstruction from hard copies of the pre-chemotherapy diagnostic CT scans ('GTV-visual'). A 'GTV-match' was then contoured after image-registration, and the 'gold standard' volume was considered to be the overlap of the 'GTV-match' generated by both clinicians. The 'GTV-match' was on average 31-40% larger than 'GTV-visual'. The mean percentage of the 'gold standard', which was not covered by the 'GTV-visual' was similar for both clinicians, i.e. 26.3±12.5 and 28.0±15.0%. The inter-clinician agreement in contouring improved after image registration. These data suggest that conventional visual contouring of pre-chemotherapy GTV's may fail to treat the actual pre-chemotherapy tumor volume, and thus confound studies evaluating optimal sequencing of chemo-radiotherapy in NSCLC.
KW - CT scan
KW - Image registration
KW - Induction chemotherapy
KW - NSCLC
KW - Radiotherapy planning
UR - http://www.scopus.com/inward/record.url?scp=0036890205&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/S0169-5002(02)00225-8
DO - https://doi.org/10.1016/S0169-5002(02)00225-8
M3 - Article
SN - 0169-5002
VL - 38
SP - 297
EP - 301
JO - Lung Cancer
JF - Lung Cancer
IS - 3
ER -