| dc.description | PURPOSE: A clinical complete response is seen after neoadjuvant chemoradiation for rectal tumors
in 15%e20% of patients. These patients can potentially be spared mutilating total mesorectal
excision surgery through a watch-and-wait policy. Recent studies show that dose escalation by a
radiation boost increases the clinical complete response rate. The boost dose to the tumor can be
administered through external beam radiotherapy or through internal radiotherapy using techniques
like contact therapy, low-dose-rate or high-dose-rate brachytherapy (BT). However, limited information
is available concerning treatment-related toxicity of these techniques. With this systematic
review, we aim to summarize and compare published data concerning acute and late toxicity after
contact X-ray therapy (CXT) and BT for rectal cancer.
METHODS AND MATERIALS/RESULTS: Thirty-eight studies reporting toxicity after endorectal
radiation techniques for rectal cancer were included, resulting in 3682 patients for analysis.
Direct comparison of toxicity by the different radiation modes was hampered by various combinations
of endorectal techniques, a lack of clear reporting of toxicity scores, dose prescription, technique
used, and treated volumes. $ Grade 3 rectal toxicity was reported in 2.9% of patients having
received only CXT; 6.3% of patients who received only BT had Grade 3 rectal toxicity, and BT also
caused Grade 3 urinary toxicity in 1 patient.
CONCLUSION: All techniques reported some$Grade 3 toxicity. Toxicity after CXTwas confined
to the rectum, whereas after BT, urogenital toxicity and skin toxicity were seen as well. Unfortunately,
few specific conclusions could be drawn regarding the dose-related risk of toxicity for the various
techniques due to nonuniform reporting strategies and missing information. To enable future comparisons
and improvements, the endorectal radiation field urgently needs consensus guidelines on dose
reporting, dose prescription, treatment volume specification, and toxicity reporting. 2018 American
Brachytherapy Society. Published by Elsevier Inc. All rights reserved. | |
