Acute toxicity in prostate cancer patients treated with and without image-guided radiotherapy

Abstract

BackgroundImage-guided radiotherapy (IGRT) increases the accuracy of treatment delivery through daily target localisation. We report on toxicity symptoms experienced during radiotherapy treatment, with and without IGRT in prostate cancer patients treated radically.MethodsBetween 2006 and 2009, acute toxicity data for ten symptoms were collected prospectively onto standardized assessment forms. Toxicity was scored during radiotherapy, according to the Common Terminology Criteria Adverse Events V3.0, for 275 prostate cancer patients before and after the implementation of a fiducial marker IGRT program and dose escalation from 74Gy in 37 fractions, to 78Gy in 39 fractions. Margins and planning constraints were maintained the same during the study period. The symptoms scored were urinary frequency, cystitis, bladder spasm, urinary incontinence, urinary retention, diarrhoea, haemorrhoids, proctitis, anal skin discomfort and fatigue. Analysis was conducted for the maximum grade of toxicity and the median number of days from the onset of that toxicity to the end of treatment.ResultsIn the IGRT group, 14228 toxicity scores were analysed from 249 patients. In the non-IGRT group, 1893 toxicity scores were analysed from 26 patients. Urinary frequency ≥G3 affected 23% and 7% in the non-IGRT and IGRT group respectively (p = 0.0188). Diarrhoea ≥G2 affected 15% and 3% of patients in the non-IGRT and IGRT groups (p = 0.0174). Fatigue ≥G2 affected 23% and 8% of patients in the non-IGRT and IGRT groups (p = 0.0271). The median number of days with a toxicity was higher for ≥G2 (p = 0.0179) and ≥G3 frequency (p = 0.0027), ≥G2 diarrhoea (p = 0.0033) and ≥G2 fatigue (p = 0.0088) in the non-IGRT group compared to the IGRT group. Other toxicities were not of significant statistical difference.ConclusionsIn this study, prostate cancer patients treated radically with IGRT had less severe urinary frequency, diarrhoea and fatigue during treatment compared to patients treated with non-IGRT. Onset of these symptoms was earlier in the non-IGRT group. IGRT results in less acute toxicity during radiotherapy in prostate cancer.

Reducing radiation-associated toxicity using online image guidance (IGRT) in prostate cancer patients undergoing dose-escalated radiation therapy

“…These results corresponded with published data. 4,9,25,26 The incidence of late grade ≥2 GI toxicity was 17% (IGRT) vs. 11% (non-IGRT), and only one patient suffered from rectal bleeding 12 months after treatment. There were no significant differences between treatment groups in regard to late grade ≥2 GU toxicity.…”

“…3,9,19,25,26 These data are limited in terms of the quantifiable benefits of IGRT due to differences in the number of patients, the protocols and the dose constraints. Contradictory to our results, the incidence of grade 2 GI effects was 30%, compared to 35% in the non-IGRT group, in the study by Gill et al 9 after delivering a total dose of 78 Gy. Lips et al 26 evaluated 330 patients treated by IMRT/IGRT with a total dose of 76 Gy.…”

“…8 Image-guided radiotherapy enables an immediate correction of target movement by online imaging. 6,9 A geographical miss of the prostate may result in increased dose-volume effects on the organs at risk. Higher mean doses to the rectum and bladder are more likely to increase treatment-related side effects, such as proctitis or cystitis.…”

“…In addition, missing the target volume might result in higher rates of local failure. 7,9,10 In 2009, image guidance for dose-escalated irradiation of prostate cancer was implemented in our clinic as the standard of care.…”

Image-guided radiation therapy: looking beyond what we currently see

“…The incorporation of image guidance in this context has largely focused on assuring consistent positioning of the patient and tumor. These efforts have been reported to improve clinical outcomes including increased tumor control and reduced normal tissue toxicity for various tumor sites [3][4][5][6].…”