Late Effects After Radiotherapy for Locally Advanced Cervical Cancer: Comparison of Two Brachytherapy Schedules and Effect of Dose Delivered Weekly

Journal Article · Mon Mar 01 00:00:00 EST 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2009.02.024· OSTI ID:21372091

Kristensen, Gunnar B ^[1]; Olsen, Dag Rune ^[2]

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1. Department of Gynaecological Oncology, Division of Obstetrics and Gynaecology, Institute for Cancer Research, Radiumhospitalet, Rikshospitalet University Hospital, Oslo (Norway)
2. Department of Physics, University of Oslo, Oslo (Norway)

Purpose: To compare the severe late effects (Grade 3 or greater) for two groups of cervical cancer patients treated with the same external beam radiotherapy and two high-dose-rate intracavitary brachytherapy regimens and to investigate the influence of the dose delivered each week. Methods and Materials: For 120 patients, intracavitary brachytherapy was delivered with 33.6 Gy in eight fractions to Point A (HD group), and for 119, intracavitary brachytherapy was delivered with 29.4 Gy in seven fractions to Point A (LD group). The cumulative incidence of severe gastrointestinal and genitourinary late effects were calculated for both dose groups using Kaplan-Meier survival analysis. This method was also used to explore whether the number of weeks with different dose levels could predict the cumulative incidence of late effects. Results: The actuarial rate of developing severe gastrointestinal morbidity at 7 years was 10.7% and 8.3% for HD and LD groups, respectively. The rate for genitourinary morbidity was 6.6% for the HD group and 5.0% for the LD group, respectively. No significant difference was found between the two groups. The analyses showed that a marginally significant increase occurred in severe gastrointestinal complications as the number of weeks with a physical dose >20 Gy increased in the HD group (p = .047). Conclusion: To establish dose-response relationships for late complications, three-dimensional imaging and dose-volume histogram parameters are needed. We found some indications that 20 Gy/wk is an upper tolerance level when the dose to the International Commission on Radiation Units and Measurements rectum point is 81 Gy{sub {alpha}/{beta}=3} (isoeffective [equivalent] dose of 2-Gy fractions). However, additional investigations using three-dimensional data are needed.

• OSTI ID: 21372091
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 76, Issue 3; Other Information: DOI: 10.1016/j.ijrobp.2009.02.024; PII: S0360-3016(09)00255-7; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BRACHYTHERAPY
DELAYED RADIATION EFFECTS
DOSE RATES
DOSE-RESPONSE RELATIONSHIPS
FRACTIONATED IRRADIATION
NEOPLASMS
THREE-DIMENSIONAL CALCULATIONS
UROGENITAL SYSTEM DISEASES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
DISEASES
IRRADIATION
MEDICINE
NUCLEAR MEDICINE
RADIATION EFFECTS
RADIOLOGY
RADIOTHERAPY
THERAPY