Three-dimensional (3D) printing involves preparing 3D objects from a digital model. These models can be used to plan and practice surgery. We used 3D printing to plan for a rare complicated surgery involving the removal of a renal tumor and neoplastic mass, which reached the heart atrium. A printed kidney model was an essential element of communication for physicians with different specializations.

Background: This study describes the possibility of implemen ng threedimensional prin ng technology to create a precise construc on of a planned bolus, based on computed tomography informa on stored in the Digital Imaging and Communica ons in Medicine (DICOM) format file. Materials and Methods: To create the bolus with a 3D printer, we converted data in the DICOM format to the stereolithography (STL) format. In addi on, we produced a paraffin bolus that, tradi onally, is manually placed directly on the pa ent. CT scans were acquired for both boluses, and the images were superimposed onto the pa ent CT scans that were used to design the bolus. The superimposi on of images was performed to compare the fit of the bolus printed on a 3D printer to that of the paraffin bolus made in the tradi onal way. In addi on, for both models, the dose distribu on was simulated. To quan fy the level of matching ML, special formula was used. The ML parameter had a value between 0 and 100%, where 100% indicated a perfect fit between the model and the 3D printed bolus. Results: We verified that 100% of the volume of the 3D printed bolus was located within the contour of the designed model. The ML of the bolus was 94%. For the classical paraffin bolus the ML was only 28%. Conclusion: A bolus printed on a threedimensional printer can faithfully reproduce the structure specified in the project plan. Compared to the classical paraffin bolus, the three-dimensional printed bolus more closely matched the planned model and possessed greater material uniformity.

This work describes the use of 3D printing technology to create individualized boluses for patients treated with electron beam therapy for skin lesions of the eye canthi. It aimed to demonstrate the effectiveness of 3D‐printed over manually fabricated paraffin boluses. The study involved 11 patients for whom the construction of individual boluses were required. CT scans of the fabricated 3D‐printed boluses and paraffin boluses were acquired and superimposed onto patient CT scans to compare their fitting, bolus homogeneity, and underlying dose distribution. To quantify the level of matching, multiple metrics were utilized. Matching Level Index (ML) values ranged from 0 to 100%, where 100% indicated a perfect fit between the reference bolus (planned in treatment planning system) and 3D‐printed and paraffin bolus. The average ML (± 1 SD) of the 3D‐printed boluses was 95.1 ± 2.1%, compared to 46.0 ± 10.1% for the manually fabricated paraffin bolus. Correspondingly, mean doses were closer to the prescribed doses, and dose spreads were less for the dose distributions from the 3D‐printed boluses, as compared to those for the manually fabricated paraffin boluses. It was concluded that 3D‐printing technology is a viable method for fabricating boluses for small eye lesions and provides boluses superior to our boluses manually fabricated from paraffin sheets.

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Background: Surface brachytherapy, usually characterized by a high dose gradient, allows the dose to be precisely deposited in the irradiated area while protecting critical organs. When the lesion is located in the nasal or ocular region, the organ of vision must be protected. The aim of this study was to verify the dose distributions near critical organs in the head and neck region during a brachytherapy procedure using lead shielding of the eye. Methods: Anthropomorphic phantom using 3D-printing technology was prepared. The doses deposited at a point in the lens of the eye and on the surface of the eyelid, directly under the lead shield were calculated and measured using EBT3 radiochromic films. Comparison of doses planned in the treatment planning system using the TG-43 formalism, TG-186 formalism, and measured were also performed. Results: Comparing the planned and calculated doses with TG186 formalism it can be assumed that the use of lead shields is a method for protecting the organ of vision from the adverse effects of ionizing radiation. Conclusions: The decision to use a lead shield during facial surface brachytherapy procedures should be made on a patient-by-patient basis and based on model-based calculation methods recommended by TG186.