Wiviann Ottosson1, Fatma Rahma2, David Sjöström2, Claus F Behrens2, Patrik Sibolt3. 1. Department of Oncology, Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen, Denmark; Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark. Electronic address: wivott01@heh.regionh.dk. 2. Department of Oncology, Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen, Denmark. 3. Department of Oncology, Radiotherapy Research Unit, Herlev Hospital, University of Copenhagen, Denmark; Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark.
Abstract
BACKGROUND AND PURPOSE: Three cone-beam computed tomography (CBCT) registration strategies combined with deep-inspiration breath-hold (DIBH) and free-breathing (FB) were explored, in terms of obtaining the smallest planning target volume (PTV). MATERIAL AND METHODS: CBCT images were acquired pre- and post-treatment in FB and DIBH, for 17 locally advanced lung cancer patients. Bony registration on the spine, and soft-tissue registrations on the primary gross tumor volume (GTV-T) and GTV-Total, including malignant lymph nodes (GTV-N), were retrospectively analyzed. Setup-margins and resulting PTVs were calculated. RESULTS: For the spine, the smallest residual misalignments were observed in FB, independently of registration method. For GTV-T and GTV-N, soft-tissue registrations were superior to bony registration, independently of FB or DIBH. Compared to FB, PTV-Totals were during DIBH reduced by 13% and 8% for the soft-tissue and bony registrations, respectively. If intra-fractional motion was included, the corresponding gain of DIBH was reduced to 9% and 7%, respectively. Superiority of DIBH was mainly due to larger clinical target volumes in FB. CONCLUSIONS: Despite larger setup uncertainties compared to FB, DIBH resulted in smaller PTV-Totals for all registration methods. Soft-tissue registrations were superior to bony registration, independently of FB and DIBH. During DIBH, undesirable arching of the back was identified. Daily CBCT pre-treatment target verification is advised.
BACKGROUND AND PURPOSE: Three cone-beam computed tomography (CBCT) registration strategies combined with deep-inspiration breath-hold (DIBH) and free-breathing (FB) were explored, in terms of obtaining the smallest planning target volume (PTV). MATERIAL AND METHODS: CBCT images were acquired pre- and post-treatment in FB and DIBH, for 17 locally advanced lung cancerpatients. Bony registration on the spine, and soft-tissue registrations on the primary gross tumor volume (GTV-T) and GTV-Total, including malignant lymph nodes (GTV-N), were retrospectively analyzed. Setup-margins and resulting PTVs were calculated. RESULTS: For the spine, the smallest residual misalignments were observed in FB, independently of registration method. For GTV-T and GTV-N, soft-tissue registrations were superior to bony registration, independently of FB or DIBH. Compared to FB, PTV-Totals were during DIBH reduced by 13% and 8% for the soft-tissue and bony registrations, respectively. If intra-fractional motion was included, the corresponding gain of DIBH was reduced to 9% and 7%, respectively. Superiority of DIBH was mainly due to larger clinical target volumes in FB. CONCLUSIONS: Despite larger setup uncertainties compared to FB, DIBH resulted in smaller PTV-Totals for all registration methods. Soft-tissue registrations were superior to bony registration, independently of FB and DIBH. During DIBH, undesirable arching of the back was identified. Daily CBCT pre-treatment target verification is advised.
Authors: Manuel Blessing; Julian Hofmann; Lena Vogel; Judit Boda-Heggemann; Frank Lohr; Frederik Wenz; Florian Stieler; Anna Simeonova-Chergou Journal: Strahlenther Onkol Date: 2018-05-22 Impact factor: 3.621
Authors: Alejandro Prado; Daniel Zucca; Miguel Ángel De la Casa; Jaime Martí; Leyre Alonso; Paz García de Acilu; Juan García; Ovidio Hernando; Pedro Fernández-Letón; Carmen Rubio Journal: Phys Imaging Radiat Oncol Date: 2022-04-29
Authors: Mirjana Josipovic; Marianne C Aznar; Jakob B Thomsen; Jonas Scherman; Sidsel Ms Damkjaer; Lotte Nygård; Lena Specht; Mette Pøhl; Gitte F Persson Journal: Br J Radiol Date: 2019-09-26 Impact factor: 3.039