BACKGROUND: Cervical cancer inter-observer delineation variation has been demonstrated. This article addresses its dosimetric impact. METHODS: 21 centres outlined two INTERLACE trial quality assurance test cases. A gold standard clinical target volume (GSCTV) was created from a consensus and STAPLE outline. RapidArc plans were created for all centres' planning target volumes (PTVs; PTV1+2). Gold standard PTVs (GSPTVs) were created for each plan by applying each centre's CTV-PTV margins to GSCTV. DVH parameters including D95% and Dmean for each PTV1+2 and GSPTV were compared, representing planned versus GSPTV delivered dose. PTV1+2 and GSPTV V95% was also calculated. RESULTS: Reviewing all parameters, no plans achieved acceptable GSPTV coverage. GSPTV V95%⩾95% was not achieved for any plan. GSPTV V95%<90% in 15/21 (case 1) and 14/22 (case 2) and <80% in 2 plans from both cases. GSPTV V95% is on average 10-15% lower than planned and GSPTV D95% is 10-20% lower than planned. Most common GSCTV anatomical areas not receiving 95% dose were vagina, obturator and external iliac nodes and, in case 1, the superior nodal aspect. CONCLUSION: Cervical cancer CTV delineation variation leads to significant reductions in dose delivered to GSPTV. This highlights the ongoing importance of standardising delineation in the IMRT era.
BACKGROUND:Cervical cancer inter-observer delineation variation has been demonstrated. This article addresses its dosimetric impact. METHODS: 21 centres outlined two INTERLACE trial quality assurance test cases. A gold standard clinical target volume (GSCTV) was created from a consensus and STAPLE outline. RapidArc plans were created for all centres' planning target volumes (PTVs; PTV1+2). Gold standard PTVs (GSPTVs) were created for each plan by applying each centre's CTV-PTV margins to GSCTV. DVH parameters including D95% and Dmean for each PTV1+2 and GSPTV were compared, representing planned versus GSPTV delivered dose. PTV1+2 and GSPTV V95% was also calculated. RESULTS: Reviewing all parameters, no plans achieved acceptable GSPTV coverage. GSPTV V95%⩾95% was not achieved for any plan. GSPTV V95%<90% in 15/21 (case 1) and 14/22 (case 2) and <80% in 2 plans from both cases. GSPTV V95% is on average 10-15% lower than planned and GSPTV D95% is 10-20% lower than planned. Most common GSCTV anatomical areas not receiving 95% dose were vagina, obturator and external iliac nodes and, in case 1, the superior nodal aspect. CONCLUSION:Cervical cancer CTV delineation variation leads to significant reductions in dose delivered to GSPTV. This highlights the ongoing importance of standardising delineation in the IMRT era.
Authors: Robert Poel; Elias Rüfenacht; Ekin Ermis; Michael Müller; Michael K Fix; Daniel M Aebersold; Peter Manser; Mauricio Reyes Journal: Radiat Oncol Date: 2022-10-22 Impact factor: 4.309
Authors: Richard Pötter; Kari Tanderup; Christian Kirisits; Astrid de Leeuw; Kathrin Kirchheiner; Remi Nout; Li Tee Tan; Christine Haie-Meder; Umesh Mahantshetty; Barbara Segedin; Peter Hoskin; Kjersti Bruheim; Bhavana Rai; Fleur Huang; Erik Van Limbergen; Max Schmid; Nicole Nesvacil; Alina Sturdza; Lars Fokdal; Nina Boje Kibsgaard Jensen; Dietmar Georg; Marianne Assenholt; Yvette Seppenwoolde; Christel Nomden; Israel Fortin; Supriya Chopra; Uulke van der Heide; Tamara Rumpold; Jacob Christian Lindegaard; Ina Jürgenliemk-Schulz Journal: Clin Transl Radiat Oncol Date: 2018-01-11
Authors: Jan Hofmaier; Franziska Walter; Indrawati Hadi; Maya Rottler; Rieke von Bestenbostel; George Dedes; Katia Parodi; Maximilian Niyazi; Claus Belka; Florian Kamp Journal: Phys Imaging Radiat Oncol Date: 2021-12-02