High-dose intensity-modulated radiotherapy for prostate cancer using daily fiducial marker-based position verification: acute and late toxicity in 331 patients

Abstract

We evaluated the acute and late toxicity after high-dose intensity-modulated radiotherapy (IMRT) with fiducial marker-based position verification for prostate cancer. Between 2001 and 2004, 331 patients with prostate cancer received 76 Gy in 35 fractions using IMRT combined with fiducial marker-based position verification. The symptoms before treatment (pre-treatment) and weekly during treatment (acute toxicity) were scored using the Common Toxicity Criteria (CTC). The goal was to score late toxicity according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) scale with a follow-up time of at least three years. Twenty-two percent of the patients experienced pre-treatment grade ≥ 2 genitourinary (GU) complaints and 2% experienced grade 2 gastrointestinal (GI) complaints. Acute grade 2 GU and GI toxicity occurred in 47% and 30%, respectively. Only 3% of the patients developed acute grade 3 GU and no grade ≥ 3 GI toxicity occurred. After a mean follow-up time of 47 months with a minimum of 31 months for all patients, the incidence of late grade 2 GU and GI toxicity was 21% and 9%, respectively. Grade ≥ 3 GU and GI toxicity rates were 4% and 1%, respectively, including one patient with a rectal fistula and one patient with a severe hemorrhagic cystitis (both grade 4). In conclusion, high-dose intensity-modulated radiotherapy with fiducial marker-based position verification is well tolerated. The low grade ≥ 3 toxicity allows further dose escalation if the same dose constraints for the organs at risk will be used.

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

“…According to published data, the majority of later rectal side effects manifest during a follow-up period of 36 months. 26,29 Nevertheless, these data compare well to those from the randomized trial published by Zietman et al, 29 which reported late grade 2 GI side effects in 17% of the patients and grade 3 reactions in 1% of the patients (total dose of 79.2 Gy). In addition, acute toxicity is predictive of late rectal and GU side effects.…”

“…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.…”

“…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. Acute grade 2 GU and GI toxicities occurred in 47% and 30% of the cases, respectively, but the data were not compared to those for non-IGRT cases.…”

Overestimation of Low-Dose Radiation in Intensity-Modulated Radiotherapy with Sliding-Window Technique

“…Dynamic intensity-modulated radiotherapy (IMRT) using the sliding-window technique is currently applied for treatment in many clinical cases, particularly for patients with head-and-neck cancer or prostate cancer [1,3,7,15,16,19]. Dose distributions with improved conformity to the target can be obtained with this technique, leading to a reduced dose to the surrounding healthy tissue and critical organs [1].…”