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SU‐FF‐T‐368: Radioprotective Effect of the Bolus On Testicular Dose Following Radiation Therapy
Author(s) -
Chung J,
Ye S,
Kim J,
Kim I,
Seok J,
Lee J,
Suh T
Publication year - 2007
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2761093
Subject(s) - nuclear medicine , dosimeter , medicine , bolus (digestion) , imaging phantom , dosimetry , isocenter , testicle , thermoluminescent dosimetry , radiation therapy , cumulative dose , thermoluminescent dosimeter , radiology , surgery , anatomy
Purpose: To estimate the radioprotective effect of the bolus on testicular radiation dose following radiation therapy for testicular seminoma. Methods and Materials: Testicular dose measurements were performed with thermoluminescent dosimeters (TLDs) between three and seven times on two patients and anthropomorphic phantom. All treatments were taken with L‐shaped fields administered as two parallel‐opposed AP and PA equally weighted fields of 15 MV X‐rays. One fraction of 180 cGy was delivered to the same isocenter with 120 multi‐leaf collimations from a Varian 21EX linear accelerator. In two patients, a round testicle shield device was used to protect the testes during treatment period. To reduce an additional testicular dose, we inserted the bolus (0.5, 1 cm thickness) in the shield device. In phantom, the comparison measurement was performed with and without the shield device added the bolus. Results: The testicular dose ranged from <1 cGy to 6 cGy (range 0.6–3.3%, mean 1.1% of the prescribed dose at the reference point). With only the shield device, the measured dose to the testicles ranged from 1.9–3.2 cGy (mean 2.2 cGy). The absorbed dose was reduced to 1%–2% of the prescribed dose relative to that of without the shield device. Mean testicular dose of the shield device added the bolus was 1.1 cGy (range 0.8–1.4). By using the bolus of 0.5 and 1 cm thickness, 10%–50% of the absorbed dose to testicle decreased. This was due to the reduction of scattered testicular radiation dose by the bolus in shield device. Conclusion: This study observed the shielding benefit of the bolus on testicular dose during radiation treatment with 15 MV X‐rays. Decreasing the undesired irradiation on testicle by using the bolus shoud be pursued in an effort to reduce the genetic risk.