Dataset Information

Salvage reirradiation for local failure of prostate cancer after curative radiation therapy: Association of rectal toxicity with dose distribution and normal-tissue complication probability models.

ABSTRACT:

Purpose

This study aimed to assess the impact of radiation dose on rectal toxicity after salvage external beam radiation therapy (EBRT) with or without a brachytherapy boost for exclusive local failures after the primary EBRT for prostate cancer.

Methods and materials

Fourteen patients with no severe residual late toxicity after primary EBRT ± brachytherapy were reirradiated after a median time interval of 6.1 years. The median normalized total dose in 2 Gy fractions (NTD_2Gy, α/β ratio = 1.5 Gy for prostate cancer cells) was 74 Gy at primary EBRT and 85.1 Gy at reirradiation. Rectal dose-volume histograms (converted to NTD_{2Gy_alpha/beta = 3 Gy}) and the corresponding normal-tissue complication probability (NTCP) values for gastrointestinal (GI) toxicity were evaluated for 2 groups: High GI toxicity (grade ≥3) and low GI toxicity (grade ≤2).

Results

The 5-year grade ≥3 GI toxicity-free survival rate was 57.1%. The median rectal V_70Gy and maximum dose to 1 cm³ (D1cc_rect) at primary EBRT were both predictive for grade ≥3 GI toxicity (9% vs 0%; P = .04 and 72.2 Gy vs 66.8 Gy; P < .01, respectively). When adding primary radiation therapy (RT) and reirradiation plans, the median D1cc_rect was 139.8 Gy versus 126.7 Gy (P < .01) for high and low GI toxicity groups. NTCP >10% at primary RT was predictive for high GI toxicity at reirradiation (P < .05).

Conclusions

Even in the absence of residual toxicity after primary RT, rectal doses >70 Gy and NTCP >10% calculated for a first irradiation may be associated with a higher risk of developing high GI toxicity at reirradiation with a possible D1cc_rect threshold of 130 Gy.

SUBMITTER: Dipasquale G

PROVIDER: S-EPMC6200893 | biostudies-literature | 2018 Oct-Dec

REPOSITORIES: biostudies-literature

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Publications

Salvage reirradiation for local failure of prostate cancer after curative radiation therapy: Association of rectal toxicity with dose distribution and normal-tissue complication probability models.

Dipasquale Giovanna G Zilli Thomas T Fiorino Claudio C Rouzaud Michel M Miralbell Raymond R

Advances in radiation oncology 20180615 4

<h4>Purpose</h4>This study aimed to assess the impact of radiation dose on rectal toxicity after salvage external beam radiation therapy (EBRT) with or without a brachytherapy boost for exclusive local failures after the primary EBRT for prostate cancer.<h4>Methods and materials</h4>Fourteen patients with no severe residual late toxicity after primary EBRT ± brachytherapy were reirradiated after a median time interval of 6.1 years. The median normalized total dose in 2 Gy fractions (NTD<sub>2Gy< ...[more]

PMID: 30370369

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Dataset Information

Salvage reirradiation for local failure of prostate cancer after curative radiation therapy: Association of rectal toxicity with dose distribution and normal-tissue complication probability models.

Purpose

Methods and materials

Results

Conclusions

Publications

Salvage reirradiation for local failure of prostate cancer after curative radiation therapy: Association of rectal toxicity with dose distribution and normal-tissue complication probability models.

Similar Datasets

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