Unit:
Faculty of MedicineLibrary of the School of Health Sciences
Author:
Kougioumtzopoulou Andromachi
Dissertation committee:
Βασίλειος Κουλουλίας, Καθηγητής (επιβλέπων), Ιατρική Σχολή, ΕΚΠΑ
Κωνσταντίνος Συρίγος, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Νικόλαος Κελέκης, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Αριστοτέλης Μπάμιας, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Άννα Ζυγογιάννη, Αν. Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Καλλιόπη Πλατώνη, Αν. Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Ιωάννης Γεωργακόπουλος, Επ. Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Original Title:
Υποκλασματοποιημένο σχήμα εξωτερικής ακτινοθεραπείας (EBRT) σε ασθενείς με αδενοκαρκίνωμα προστάτη αδένα: αξιολόγηση αποτελεσματικότητας και τοξικότητας
Translated title:
Moderate hypofractionated radiotherapy in prostate cancer patients: efficacy and toxicity
Summary:
Background: Moderate hypofractionated radiotherapy (MHRT) has emerged as the preferred treatment modality for localized prostate cancer based on randomized controlled studies regarding efficacy and toxicity, using contemporary radiotherapy techniques. In the setting of MHRT, available data on dosimetric parameters and late rectal toxicity are limited.
Aim: To present the effects of MHRT on late rectal toxicity while conducting an extensive dosimetric analysis in conjunction to rectoscopy results.
Methods: This is a prospective study including patients with intermediate risk prostate adenocarcinoma. All patients were treated with MHRT 44 Gy in 16 fractions to the seminal vesicles and to the prostate followed by a sequential boost to the prostate alone of 16.5 Gy in 6 fractions delivered with three-dimensional conformal radiation therapy (3DCRT). Acute and late toxicity were assessed. Endoscopy was performed at baseline, every 3 months post-therapy for the first year and every 6 months for the year after. The Vienna Rectoscopy Score (VRS) was used to assess rectal mucosal injury related to radiotherapy. Dosimetric analysis for the rectum, rectal wall and its subsegments (upper, mid, and low 1/3) was performed.
Results: Between September 2015 and December 2019, 20 patients enrolled. Grade 1 late gastrointestinal toxicity occurred in 10 % of the patients whereas 5% had grade ≥2. 12 months post radiotherapy: 4 (20%) patients had VRS 1; 2 (10%) patients had VRS 2; 1(5%) patient had VRS 3. 24 months post radiotherapy, VRS 1 was observed in 4 patients (20%) and VRS 2 in 3 (15%) patients. The dosimetric analysis demonstrated noticeable variations between the rectum, rectal wall, and rectal wall subsegments. The dosimetric analysis of rectum, rectal wall
and its mid and low segments with respect to rectoscopy findings showed that the higher dose endpoints V52.17Gy and V56.52Gy are associated to rectal mucosal injury.
Conclusion: A thorough delineation of the rectal wall and its subsegments together with the dosimetric analysis of these structures may reduce late rectal toxicity. Dosimetric parameters such as V52.17Gy and V56.52Gy were identified to have a significant impact to rectal mucosal injury; additional dose endpoint validation and its relation to late GI toxicity is needed.
Main subject category:
Health Sciences
Keywords:
Moderate hypofractionated radiotherapy, Prostate cancer, Intensity-modulated radiation therapy (IMRT), Three-dimensional conformal radiation therapy (3DCRT), Dosimetry, Rectoscopy, Rectal wall, Vienna rectoscopy score (VRS), Dose volume histogram (DVH)
Number of references:
159
File:
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