Prog Med Phys.  2024 Dec;35(4):172-177. 10.14316/pmp.2024.35.4.172.

Clinical Applications of Thermoplastic Sheets as Patient-Specific Gonadal Shields During Computed Tomography Simulation

• Jegal J
• Park H
• Kang S
• Choi CH
• Kim Ji

• KMID: 2564156
• DOI: http://doi.org/10.14316/pmp.2024.35.4.172

Abstract

Purpose
Conventional gonadal shields are manufactured in standardized sizes and shapes and do not conform to individual testicular contours, causing discomfort. We developed a novel patientspecific gonadal shield using thermoplastic sheets and tested its feasibility through dosimetric evaluations.
Methods
During the computed tomography simulation, custom lead shields were fabricated using thermoplastic sheets that were molded to the testicular shape of the patient. The shielding efficacy was evaluated using optically stimulated luminescent dosimeters (OSLDs) for point dose measurements.
Results
The thermoplastic sheet was molded to fit closely to the skin with a minimal air gap of approximately 8.4 cm³, providing comfort to the patient during treatment. The patient-specific shield effectively reduced the surface dose from 28 cGy to less than 15 cGy. By combining the OSLDs located in the same row and calculating the mean dose value, a shielding effect was achieved with a maximum dose reduction of 56.1%.
Conclusions
Customized gonadal shields were successfully created using thermoplastic sheets to minimize patient discomfort during application. However, further improvements in lead shield fabrication are needed to ensure full conformity.

Keyword

Radiation shield; Patient-specific gonadal shield; Thermoplastic sheet

Figure

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  Fig. 1 Step-by-step creation of a patient-specific gonadal shield. CT, computed tomography.

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  Fig. 2 (a) Overall, (b) axial, and (c) sagittal views of a computed tomography image obtained using the thermo plastic sheet during the radiation treatment simulation. The air gaps between the body and the sheet were minimal.

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  Fig. 3 A patient-specific gonad shield created using a thermoplastic sheet.

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  Fig. 4 Images showing the placement of the optically stimulated luminescent dosimeters (OSLDs): behind the (a) posterior and (b) anterior shields. (c) Positions of the OSLDs used for dose measurement.

Reference

References

1. Bortfeld T. 2006; IMRT: a review and preview. Phys Med Biol. 51:R363–R379. DOI: 10.1088/0031-9155/51/13/R21. PMID: 16790913.

2. Teh BS, Woo SY, Butler EB. 1999; Intensity modulated radiation therapy (IMRT): a new promising technology in radiation oncology. Oncologist. 4:433–442. DOI: 10.1634/theoncologist.4-6-433. PMID: 10631687.

3. Khurana KK, Alukal JP. Demographics of cancer in the reproductive age male. 2016. Cancer and fertility. Springer International Publishing;p. 1–10. DOI: 10.1007/978-3-319-27711-0_1. PMCID: PMC4705060.

4. Buchli C, Martling A, Arver S, Holm T. 2011; Testicular function after radiotherapy for rectal cancer-a review. J Sex Med. 8:3220–3226. DOI: 10.1111/j.1743-6109.2011.02455.x. PMID: 21951391.

5. Kesari KK, Agarwal A, Henkel R. 2018; Radiations and male fertility. Reprod Biol Endocrinol. 16:118. DOI: 10.1186/s12958-018-0431-1. PMID: 30445985. PMCID: PMC6240172.

6. Fukunaga H, Yokoya A, Prise KM. 2022; A brief overview of radiation-induced effects on spermatogenesis and oncofertility. Cancers (Basel). 14:805. DOI: 10.3390/cancers14030805. PMID: 35159072. PMCID: PMC8834293.

7. Ravichandran R, Binukumar JP, Kannadhasan S, Shariff MH, Ghamrawy KE. 2008; Testicular shield for para-aortic radiotherapy and estimation of gonad doses. J Med Phys. 33:158–161. DOI: 10.4103/0971-6203.44477. PMID: 19893710. PMCID: PMC2772052.

8. Fraass BA, Kinsella TJ, Harrington FS, Glatstein E. 1985; Peripheral dose to the testes: the design and clinical use of a practical and effective gonadal shield. Int J Radiat Oncol Biol Phys. 11:609–615. DOI: 10.1016/0360-3016(85)90196-8. PMID: 3972670.

9. Gandini L, Sgrò P, Lombardo F, Paoli D, Culasso F, Toselli L, et al. 2006; Effect of chemo- or radiotherapy on sperm parameters of testicular cancer patients. Hum Reprod. 21:2882–2889. DOI: 10.1093/humrep/del167. PMID: 16997940.

10. Hahn EW, Feingold SM, Simpson L, Batata M. 1982; Recovery from aspermia induced by low-dose radiation in seminoma patients. Cancer. 50:337–340. DOI: 10.1002/1097-0142(19820715)50:2<337::AID-CNCR2820500229>3.0.CO;2-6. PMID: 7083140.

11. Munteanu A, Moldoveanu S, Manea E. 2016; Thermoplastic materials applications in radiation therapy. Rev Med Chir Soc Med Nat Iasi. 120:197–200.

12. Sakai Y, Tanooka M, Okada W, Sano K, Nakamura K, Shibata M, et al. 2021; Characteristics of a bolus created using thermoplastic sheets for postmastectomy radiation therapy. Radiol Phys Technol. 14:179–185. DOI: 10.1007/s12194-021-00618-2. PMID: 33837911.

13. Sharp L, Lewin F, Johansson H, Payne D, Gerhardsson A, Rutqvist LE. 2005; Randomized trial on two types of thermoplastic masks for patient immobilization during radiation therapy for head-and-neck cancer. Int J Radiat Oncol Biol Phys. 61:250–256. DOI: 10.1016/j.ijrobp.2004.04.047. PMID: 15629618.

14. Bahl A, Ghosal S, Kapoor R, Bhattacharya T, Sharma SC. 2012; Clinical implications of thermoplastic mask immobilization on acute effects of radiotherapy in head and neck cancers. J Postgrad Med Edu Res. 46:187–189. DOI: 10.5005/jp-journals-10028-1042.