Patient-Assessed Late Toxicity Rates and Principal Component Analysis After Image-Guided Radiation Therapy for Prostate Cancer

Journal Article · Sun Jul 01 04:00:00 EDT 2007 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2006.12.064· OSTI ID:20951694

Skala, Marketa ^[1]; Rosewall, Tara ^[2]; Dawson, Laura ^[1]; Divanbeigi, Lorella ^[2]; Lockwood, Gina ^[3]; Thomas, Christopher ^[4]; Crook, Juanita ^[1]; Chung, Peter ^[1]; Warde, Padraig ^[1]; Catton, Charles ^[1]

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1. Department of Radiation Oncology, Princess Margaret Hospital and University of Toronto, Toronto, ON (Canada)
2. Department of Radiation Therapy, Princess Margaret Hospital and University of Toronto, Toronto, ON (Canada)
3. Department of Biostatistics, Princess Margaret Hospital and University of Toronto, Toronto, ON (Canada)
4. Department of Medical Physics, Princess Margaret Hospital and University of Toronto, Toronto, ON (Canada)

Purpose: The aims of this study were to determine the incidence of patient-assessed late toxicity after high-dose, image-guided radiation therapy in a cohort of men with prostate cancer; and to correlate toxicity with conventional dosimetric parameters and rectal and bladder dose-volume histograms (DVH) reduced using principal component analysis. Methods and Materials: Toxicity questionnaires were sent to 690 men treated for localized prostate cancer to 75.6 Gy or 79.8 Gy using three-dimensional conformal radiation therapy (3DCRT) or intensity-modulated radiation therapy (IMRT) between 1997 and 2003 at the Princess Margaret Hospital. Toxicity was graded according to the modified Radiation Therapy Oncology Group (RTOG)-late effects normal tissue (LENT) scoring system. Late rectal and bladder toxicity scores were dichotomized as < Grade 2 and {>=} Grade 2, and correlated with dosimetric parameters and with the first three principal components of rectal and bladder DVHs. Results: In all, 63% of the patients completed the questionnaire. At a median follow-up of 37 months, the incidence of late rectal toxicity RTOG Grades 1, 2, and 3 was 25.2%, 2.5%, and 0.7% respectively. The incidence of late urinary toxicity RTOG Grade 1, 2, and 3 was 16.5%, 8.8%, and 0.9% respectively. Maintenance of erectile function sufficient for intercourse was reported in 68%. No dosimetric parameter analyzed, including principal component analysis reduction of DVHs, correlated with late toxicity. Conclusions: Postal questionnaire was effective for collection of patient-assessed late toxicity data. The incidence of late toxicity was low, with a lack of correlation to dosimetric parameters. We attribute this to the use of conformal techniques and daily image guidance.

• OSTI ID: 20951694
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 3 Vol. 68; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BLADDER
CARCINOMAS
DISEASE INCIDENCE
HOSPITALS
IMAGES
PATIENTS
PROSTATE
RADIATION DOSES
RADIOTHERAPY
RECTUM
TOXICITY