Respiratory Impact on Gastric MALT Lymphoma Radiotherapy

Tadashi Matsumoto and the team aimed to investigate the effect of respiratory motion on planned radiotherapy (RT) dose for gastric mucosa-associated lymphoid tissue (MALT) lymphoma using four-dimensional dose (4D-dose) accumulation.

Researchers performed an inclusive analysis utilizing 4D-computed tomography (4D-CT) images of 10 patients diagnosed with gastric MALT lymphomas. These images were divided into 10 respiratory phases. Subsequently, the 3D dose was computed employing 3D conformal RT (3D-CRT) and volumetric modulated arc therapy (VMAT) plans based on average intensity projection (AIP) images.

Plans were recalculated for each phase image. Furthermore, dose distributions for each phase were registered to the AIP images using deformable image registration. The 4D dose distribution was then calculated by summing the doses of each phase and comparing them with the dosimetric parameters of the 3D dose distribution.

For 3D-CRT, the D95 and D99 of the 4D-dose in the planning target volume (PTV) were significantly lower than those of the 3D-dose, with mean differences of 0.2 (P=0.009) and 0.1 Gy (P=0.021), respectively. There were no significant differences in the other PTV and organ-at-risk dosimetric parameters of 3D-CRT or in any dosimetric parameters of VMAT between the 3D- and 4D-dose distributions.

The study concluded that respiratory motion has a minimal and clinically negligible effect on the planned 3D-CRT and VMAT dose distributions for gastric MALT lymphoma.

The study received no funds.

Source: https://pubmed.ncbi.nlm.nih.gov/38307577/

Matsumoto T, Toya R, Shimohigashi Y, et al. (2024). “Influence of Respiratory Motion on Dose Distribution in Gastric Mucosa-associated Lymphoid Tissue Lymphoma Radiotherapy.” Anticancer Res. 2024 Feb;44(2):687-694. doi: 10.21873/anticanres.16859. PMID: 38307577.