Surface-Guided Patient Setup Versus Traditional Tattoo Markers for Radiation Therapy: Is Tattoo-Less Setup Feasible for Thorax, Abdomen and Pelvis Treatment?

Abstract

Purpose: In this study, patient setup accuracy was compared between surface guidance and tattoo markers for radiation therapy treatment sites of the thorax, abdomen and pelvis.Methods and materials: A total of 608 setups performed on 59 patients using both surface-guided and tattoo-based patient setups were analyzed. During treatment setup, patients were aligned to room lasers using their tattoos, and then the six-degree-of-freedom (6DOF) surface-guided offsets were calculated and recorded using AlignRT system. While the patient remained in the same post-tattoo setup position, target localization imaging (radiographic or ultrasound) was performed and these image-guided shifts were recorded. Finally, surface-guided vs tattoo-based offsets were compared to the final treatment position (based on radiographic or ultrasound imaging) to evaluate the accuracy of the two setup methods.Results: The overall average offsets of tattoo-based and surface-guidance-based patient setups were comparable within 3.2 mm in three principal directions, with offsets from tattoo-based setups being slightly less. The maximum offset for tattoo setups was 2.2 cm vs. 4.3 cm for surface-guidance setups. Larger offsets (ranging from 2.0 to 4.3 cm) were observed for surface-guided setups in 14/608 setups (2.3%). For these same cases, the maximum observed tattoo-based offset was 0.7 cm. Of the cases with larger surface-guided offsets, 13/14 were for abdominal/pelvic treatment sites. Additionally, larger rotations (>3°) were recorded in 18.6% of surface-guided setups. The majority of these larger rotations were observed for abdominal and pelvic sites (~84%).Conclusions: The small average differences observed between tattoo-based and surface-guidance-based patient setups confirm the general equivalence of the two potential methods, and the feasibility of tattooless patient setup. However, a significant number of larger surface-guided offsets (translational and rotational) were observed, especially in the abdominal and pelvic regions. These cases should be anticipated and contingency setup methods planned for.

Feasibility assessment of real-time surface-guided intrafraction radiotherapy for prostate cancer without immobilization

“…Several clinical studies have demonstrated the wide usage of OSMS in radiotherapy positioning and realtime monitoring of tumours in the head, neck, chest, abdomen, and breast [23,[27][28][29][30].Optical guidance has proven to provide a stable system for patient positioning and real-time position tracking. In 2004, Keall reported successful clinical treatment using continuous kV image intrafraction monitoring, achieving submillimeter treatment accuracy and precision [31].The application of orthogonal kV imaging and cone beam CT (CBCT) further enhances the positioning ability.…”

Prospective evaluation of patient-reported outcomes of invisible ink tattoos for the delivery of external beam radiation therapy: the PREFER trial

“…Zhao et al. showed larger rotations (>3° in any yaw, roll or pitch direction) in 18.6% of surface-guided setups, with the majority observed for abdominal and pelvic targets, highlighting the importance of checking a patient’s entire body pose ( 7 ). Naidoo et al.…”

“…Giantsoudi et al showed no difference in setup shifts or average treatment time per fraction in patients receiving tattooless regional nodal irradiation (RNI) with volumetric modulated arc therapy (VMAT) versus those receiving three-dimensional conformal RT RNI with VITs (6). Zhao et al showed larger rotations (>3°in any yaw, roll or pitch direction) in 18.6% of surface-guided setups, with the majority observed for abdominal and pelvic targets, highlighting the importance of checking a patient's entire body pose (7). Naidoo et al performed a systematic review of 13 studies evaluating the accuracy and reproducibility of patient setup with SGRT versus conventional tattoo-based methods and showed SGRT mean systematic errors in the 3 translational directions were reduced relative to tattoo setups alone, and mean rotational errors were equivalent, thereby concluding that SGRT could improve setup accuracy and efficiency (16).…”

“…Recognizing the negative impact of visible permanent ink tattoos on patient quality of life (QoL), alternative approaches are under study, including tattooless setup and the use of alternative inks such as temporary tattoos (NCT05248009) or IITs ( 5 – 7 ). Validating the feasibility of these methods is imperative to ensure treatment setup accuracy and efficiency, while also systematically assessing patient preference in pursuing VITs alternatives and their impact on QoL.…”

“…Recognizing the negative impact of visible permanent ink tattoos on patient quality of life (QoL), alternative approaches are under study, including tattooless setup and the use of alternative inks such as temporary tattoos (NCT05248009) or IITs (5)(6)(7).…”