case_images: PMC10413634_01
case_images: Clinical target volumes (CTVs) and the field-specific targets used for the fields at gantry angles of 0 , 25 , and 45  in Plan B The metallic port template in high-resolution CT image is also shown at the left-bottom corner of the figure.
case_images: fonc-13-1132178-g001.jpg
case_images: PMC10413634_01_fonc-13-1132178-g001.jpg
case_images: f1
case_images: The MP structure template on a high-resolution CT image is shown in  Figure 1 . A) and the first vCT (Plan B), respectively, for the fractional dose of 1.8 Gy(RBE) using Eclipse treatment planning system (TPS) (Varian Medical System, Palo Alto, CA, USA, version 15.6). Additional fields and different gantry angles were used in Plan B to improve the overall robustness of Plan A (a total four different gantry angles using five different FSTs).  Figure 1  shows the FSTs with 5-mm geometrical margin from the magnet to avoid heavily weighted protons passing through the high-Z material in Plan B.
case_images: The reconstructed fractional doses on the day of 19 July 2021 for a prescription of 180 cGy(RBE) per fraction. The kV X-ray images and CBCT show the dislocation of the treated MP versus the planned MP.
case_images: fonc-13-1132178-g002.jpg
case_images: PMC10413634_01_fonc-13-1132178-g002.jpg
case_images: f2
case_images: A) and the first vCT (Plan B), respectively, for the fractional dose of 1.8 Gy(RBE) using Eclipse treatment planning system (TPS) (Varian Medical System, Palo Alto, CA, USA, version 15.6). Additional fields and different gantry angles were used in Plan B to improve the overall robustness of Plan A (a total four different gantry angles using five different FSTs).  Figure 1  shows the FSTs with 5-mm geometrical margin from the magnet to avoid heavily weighted protons passing through the high-Z material in Plan B.
case_images: The reconstructed cumulative doses as the sum of deformed fractional doses (17 fractions from Plan A and 11 fractions from Plan B) on pCT.
case_images: fonc-13-1132178-g003.jpg
case_images: PMC10413634_01_fonc-13-1132178-g003.jpg
case_images: f3
case_images: A) and the first vCT (Plan B), respectively, for the fractional dose of 1.8 Gy(RBE) using Eclipse treatment planning system (TPS) (Varian Medical System, Palo Alto, CA, USA, version 15.6). Additional fields and different gantry angles were used in Plan B to improve the overall robustness of Plan A (a total four different gantry angles using five different FSTs).  Figure 1  shows the FSTs with 5-mm geometrical margin from the magnet to avoid heavily weighted protons passing through the high-Z material in Plan B.