Erectile Dysfunction and Absorbed Dose to Penile Base Structures in a Randomized Trial Comparing Ultrahypofractionated and Conventionally Fractionated Radiation Therapy for Prostate Cancer

Rasmusson, Elisabeth; Gunnlaugsson, Adalsteinn; Wieslander, Elinore; Höglund, Peter; Widmark, Anders; Fransson, Per; Kjellén, Elisabeth; Nilsson, Per

Erectile Dysfunction and Absorbed Dose to Penile Base Structures in a Randomized Trial Comparing Ultrahypofractionated and Conventionally Fractionated Radiation Therapy for Prostate Cancer

Mark

Rasmusson, Elisabeth ^LU ; Gunnlaugsson, Adalsteinn ^LU ; Wieslander, Elinore ^LU ; Höglund, Peter ^LU ; Widmark, Anders ; Fransson, Per ; Kjellén, Elisabeth ^LU and Nilsson, Per ^LU

(2020) In International Journal of Radiation Oncology Biology Physics 107(1). p.143-151

Abstract: Purpose: To study the relationships between absorbed dose to penile base structures and erectile dysfunction (ED) in patients treated with ultrahypofractionated (UHF) radiation therapy (RT) or conventionally fractionated (CF) RT for prostate cancer. Methods and Materials: This dose-response study comprises 673 patients (57%) of the 1180 per-protocol patients included in the HYPO-RT-PC trial (median follow-up 5, years), where patients were randomized to CF (39 × 2.0 Gy, 8 weeks) or UHF (7 × 6.1 Gy, 2.5 weeks). No androgen deprivation therapy was allowed. Only patients with erectile function sufficient for intercourse at baseline and complete RT data were included in this study. Erectile function was assessed by physician at regular... (More); Purpose: To study the relationships between absorbed dose to penile base structures and erectile dysfunction (ED) in patients treated with ultrahypofractionated (UHF) radiation therapy (RT) or conventionally fractionated (CF) RT for prostate cancer. Methods and Materials: This dose-response study comprises 673 patients (57%) of the 1180 per-protocol patients included in the HYPO-RT-PC trial (median follow-up 5, years), where patients were randomized to CF (39 × 2.0 Gy, 8 weeks) or UHF (7 × 6.1 Gy, 2.5 weeks). No androgen deprivation therapy was allowed. Only patients with erectile function sufficient for intercourse at baseline and complete RT data were included in this study. Erectile function was assessed by physician at regular follow-ups. The main endpoint was severe ED (ED_s). The penile bulb (PB) and crus were retrospectively delineated on the treatment planning computed tomography scans. Dose-volume descriptors were derived from EQD2 converted dose matrices (α/β = 3 Gy). Univariable and multivariable Cox proportional hazard regression and logistic regression were used to find predictors for ED_S. Results: No significant difference in ED_s was found between CF and UHF. During the follow-up period, ED_s occurred in 27% of the patients in both treatment groups. Average (median) PB mean dose, D_mean, was 24.5 (20.2) in CF and 18.7 (13.1) Gy₃ in UHF. Age was the only significant predictor for ED_s in Cox analyses. All dose-volume variables contributed significantly in univariable logistic regression at 2-year follow-up. Age and near maximum dose (D_2%) were significant predictors for ED_s in multivariable logistic regression analyses at both 1 and 2 years. Conclusions: The frequency of ED_S was similar in the CF and UHF treatment groups. Age at radiation therapy was the strongest predictor for ED_s, followed by dose to PB, and was most evident for younger patients. We propose D_{2 %} <50 Gy₃ and D_mean <20 Gy₃ to the PB as the primary objectives to be applied in the treatment planning process.
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Please use this url to cite or link to this publication: https://lup.lub.lu.se/record/798e11ac-e077-46c6-bbe5-2c31e25614aa

author

Rasmusson, Elisabeth ^LU ; Gunnlaugsson, Adalsteinn ^LU ; Wieslander, Elinore ^LU ; Höglund, Peter ^LU ; Widmark, Anders ; Fransson, Per ; Kjellén, Elisabeth ^LU and Nilsson, Per ^LU

organization

publishing date

2020-05-01

type

Contribution to journal

publication status

published

subject

Radiology, Nuclear Medicine and Medical Imaging

in

International Journal of Radiation Oncology Biology Physics

volume

107

issue

1

pages

9 pages

publisher

Elsevier

external identifiers

pmid:32004582
scopus:85080138653

ISSN

0360-3016

DOI

10.1016/j.ijrobp.2020.01.022

language

English

LU publication?

yes

id

798e11ac-e077-46c6-bbe5-2c31e25614aa

date added to LUP

2020-06-26 14:07:08

date last changed

2024-03-20 11:41:48

@article{798e11ac-e077-46c6-bbe5-2c31e25614aa,
  abstract     = {{<p>Purpose: To study the relationships between absorbed dose to penile base structures and erectile dysfunction (ED) in patients treated with ultrahypofractionated (UHF) radiation therapy (RT) or conventionally fractionated (CF) RT for prostate cancer. Methods and Materials: This dose-response study comprises 673 patients (57%) of the 1180 per-protocol patients included in the HYPO-RT-PC trial (median follow-up 5, years), where patients were randomized to CF (39 × 2.0 Gy, 8 weeks) or UHF (7 × 6.1 Gy, 2.5 weeks). No androgen deprivation therapy was allowed. Only patients with erectile function sufficient for intercourse at baseline and complete RT data were included in this study. Erectile function was assessed by physician at regular follow-ups. The main endpoint was severe ED (ED<sub>s</sub>). The penile bulb (PB) and crus were retrospectively delineated on the treatment planning computed tomography scans. Dose-volume descriptors were derived from EQD2 converted dose matrices (α/β = 3 Gy). Univariable and multivariable Cox proportional hazard regression and logistic regression were used to find predictors for ED<sub>S</sub>. Results: No significant difference in ED<sub>s</sub> was found between CF and UHF. During the follow-up period, ED<sub>s</sub> occurred in 27% of the patients in both treatment groups. Average (median) PB mean dose, D<sub>mean</sub>, was 24.5 (20.2) in CF and 18.7 (13.1) Gy<sub>3</sub> in UHF. Age was the only significant predictor for ED<sub>s</sub> in Cox analyses. All dose-volume variables contributed significantly in univariable logistic regression at 2-year follow-up. Age and near maximum dose (D<sub>2%</sub>) were significant predictors for ED<sub>s</sub> in multivariable logistic regression analyses at both 1 and 2 years. Conclusions: The frequency of ED<sub>S</sub> was similar in the CF and UHF treatment groups. Age at radiation therapy was the strongest predictor for ED<sub>s</sub>, followed by dose to PB, and was most evident for younger patients. We propose D<sub>2 %</sub> &lt;50 Gy<sub>3</sub> and D<sub>mean</sub> &lt;20 Gy<sub>3</sub> to the PB as the primary objectives to be applied in the treatment planning process.</p>}},
  author       = {{Rasmusson, Elisabeth and Gunnlaugsson, Adalsteinn and Wieslander, Elinore and Höglund, Peter and Widmark, Anders and Fransson, Per and Kjellén, Elisabeth and Nilsson, Per}},
  issn         = {{0360-3016}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{1}},
  pages        = {{143--151}},
  publisher    = {{Elsevier}},
  series       = {{International Journal of Radiation Oncology Biology Physics}},
  title        = {{Erectile Dysfunction and Absorbed Dose to Penile Base Structures in a Randomized Trial Comparing Ultrahypofractionated and Conventionally Fractionated Radiation Therapy for Prostate Cancer}},
  url          = {{http://dx.doi.org/10.1016/j.ijrobp.2020.01.022}},
  doi          = {{10.1016/j.ijrobp.2020.01.022}},
  volume       = {{107}},
  year         = {{2020}},
}

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Erectile Dysfunction and Absorbed Dose to Penile Base Structures in a Randomized Trial Comparing Ultrahypofractionated and Conventionally Fractionated Radiation Therapy for Prostate Cancer