title: Comparison of testicular dose delivered by intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) in patients with prostate cancer.
abstract: A small decrease in testosterone level has been documented after prostate irradiation, possibly owing to the incidental dose to the testes. Testicular doses from prostate external beam radiation plans with either intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) were calculated to investigate any difference. Testicles were contoured for 16 patients being treated for localized prostate cancer. For each patient, 2 plans were created: 1 with IMRT and 1 with VMAT. No specific attempt was made to reduce testicular dose. Minimum, maximum, and mean doses to the testicles were recorded for each plan. Of the 16 patients, 4 received a total dose of 7800 cGy to the prostate alone, 7 received 8000 cGy to the prostate alone, and 5 received 8000 cGy to the prostate and pelvic lymph nodes. The mean (range) of testicular dose with an IMRT plan was 54.7 cGy (21.1 to 91.9) and 59.0 cGy (25.1 to 93.4) with a VMAT plan. In 12 cases, the mean VMAT dose was higher than the mean IMRT dose, with a mean difference of 4.3 cGy (p = 0.019). There was a small but statistically significant increase in mean testicular dose delivered by VMAT compared with IMRT. Despite this, it unlikely that there is a clinically meaningful difference in testicular doses from either modality.
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Martin
authors.affiliation: Department of Biostatistics, Fox Chase Cancer Center, Philadelphia, PA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Handorf
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Price
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA.
authors.forename: George
authors.initials: G
authors.lastname: Cherian
authors.affiliation: Department of Radiation Oncology, Stanford University, Stanford, CA.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Buyyounouski
authors.affiliation: Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, PA.
authors.forename: David Y
authors.initials: DY
authors.lastname: Chen
authors.affiliation: Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, PA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kutikov
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Johnson
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA.
authors.forename: Chung-Ming Charlie
authors.initials: CM
authors.lastname: Ma
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA. Electronic address: eric.horwitz@fccc.edu.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Horwitz
mesh_terms: D065638:Absorption, Radiation; D006801:Humans; D008297:Male; D059351:Organ Sparing Treatments / Q000379:methods; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D000069079:Radiation Exposure / Q000032:analysis; D011835:Radiation Protection / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D013737:Testis / Q000528:radiation effects*; D016896:Treatment Outcome
keywords: Intensity-modulated radiation therapy; Prostate cancer; Testicle dose; Volumetric-modulated arc therapy