Chronic radiation effects on dental hard tissue (radiation caries). Classification and therapeutic strategies

Universitätsklinik und -poliklinik für Mund-, Kiefer- und Gesichtschirurgie, Mainz.
Strahlentherapie und Onkologie (Impact Factor: 2.91). 03/2001; 177(2):96-104.
Source: PubMed


Since the first description of rapid destruction of dental hard tissues following head and neck radiotherapy 80 years ago, "radiation caries" is an established clinical finding. The internationally accepted clinical evaluation score RTOG/EORTC however is lacking a classification of this frequent radiogenic alteration.
Medical records, data and images of radiation effects on the teeth of more than 1,500 patients, who underwent periradiotherapeutic care, were analyzed. Macroscopic alterations regarding the grade of late lesions of tooth crowns were used for a classification into 4 grades according to the RTOG/EORTC guidelines.
No early radiation effects were found by macroscopic inspection. In the first 90 days following radiotherapy 1/3 of the patients complained of reversible hypersensitivity, which may be related to a temporary hyperemia of the pulp. It was possible to classify radiation caries as a late radiation effect on a graded scale as known from RTOG/EORTC for other organ systems. This is a prerequisite for the integration of radiation caries into the international nomenclature of the RTOG/EORTC classification.
The documentation of early radiation effects on dental hard tissues seems to be neglectable. On the other hand the documentation of Late radiation effects has a high clinical impact. The identification of an initial lesion at the high-risk areas of the neck and incisal part of the tooth can lead to a successful therapy as a major prerequisite for orofacial rehabilitation. An internationally standardized documentation is a basis for the evaluation of the side effects of radiooncotic therapy as well as the effectiveness of protective and supportive procedures.

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    ABSTRACT: Hintergrund: Patienten mit Plattenepithelkarzinomen im Kopf- und Halsbereich werden zumeist multimodal strahlen-, chemotherapeutisch und/oder chirurgisch behandelt. Die Erfolgsrate einer mikrovaskulren Hart- und Weichgeweberekonstruktion nach vorausgegangener Radiotherapie ist neben anderen Faktoren limitiert durch die strahleninduzierten Vernderungen der mikrochirurgisch genutzten Anschlussgefe im Kopf- und Halsbereich. Ziel der Untersuchungen war es daher, das Ausma pathomorphologischer Gefvernderungen in Abhngigkeit von der Gesamtreferenzdosis und dem Intervall zwischen Radiotherapie und/oder Chemotherapie zu erfassen. Patienten und Methoden: Im Zeitraum von Oktover 1995 bis Mrz 2002 wurden insgesamt 348 Patienten mit 356 freien mikrovaskulren Hart- und Weichgewebetransplantaten primr oder sekundr rekonstruiert. In Abhngigkeit von der strahlentherapeutischen Vorbehandlung wurde folgende Gruppeneinteilung vorgenommen: Gruppe 1 = Patienten (n = 27) mit ausschlielich chirurgischer Behandlung. Gruppe 2 = Patienten (n = 29) mit einer neoadjuvanten Radiochemotherapie (40-50 Gy; 800 mg/m2 5-Fluorouracil [5-FU] und 20 mg/g2 Cisplatin) und primrer Rekonstruktion. Grupp3 = Patienten (n = 20) mit vorausgegangener Radiotherapie (60-70 Gy) und sekundrer Rekonstruktion. 209 Gefproben der Anschluss- und Transplantatgefe wurden qualitativ histologisch auf Vernderungen der Media und Intima sowie quantitativ histomorphometrisch (NIH-Image) auf eine anteilige Zu- oder Abnahme der Media, der Intima oder des Lumens am Gesamtquerschnitt des Gefes untersucht (ANOVA SPSS V9). Ergebnisse: Die Ergebnisse zeigten ein signifikantes berwiegen von Gefvernderungen des Grade II (Hyalinose der Media und Intima und eine Intimaablsung, p = 0,009) an den Anschlussarterien in der Gruppe 3 (properative Radiotherapie mit 60-70 Gy). An Transplantatarterien (p = 0,127), Anschluss- (p = 0,43) und Transplantatvenen (p = 0,54) wurden keine signifikanten qualitativen Gefwandvernderungen zwischen einer vorausgegangenen Radiotherapie und keiner Bestrahlung gesehen. Bei der Analyse der Anschlussarterien war die Ratio Media/Gesamtflche in Gruppe 3 (Median 0,51; IQR 0,10) signifikant kleiner als in Gruppe 1 (p = 0,02) (Median 0,61; IQR 0,29) und Gruppe 2 (p = 0,046) (Median 0,58; IQR 0,19). Ein signifikanter Unterschied der Ratio Lumen/Gesamtflche zeigte sich zwischen Gruppe 1 und 3 (p = 0,01) (Gruppe 1: Median 0,24; IQR 0,15; Gruppe 2: Median 0,34; IQR 0,15; Gruppe 3; Median 0,40; IQR 0,18). Schlussfolgerung: Nach einer Vorbestrahlung mit 60-70 Gy wurden signifikante qualitative und quantitative Gefwandvernderungen an den Anschlussarterien, nicht aber an den Anschlussvenen, den Transplantatarterien oder den Transplantatvenen festgestellt. Im Gegensatz zeigte eine neoadjuvante Radiochemotherapie (40-50 Gy, 5-FU und Cisplatin) bei der primren vaskulren Rekonstruktion 1,5 Monate nach neoadjuvanter Vorbehandlung keine signifikanten histologischen Gefvernderungen der vorbestrahlten Anschlussgefe. Background: Patients with squamous cell carcinomas of the oral cavity are being increasingly treated by multimodal interdisciplinary regimes using a combination of surgery, chemo- and radiotherapy. Inflammatory alterations of the vascular endothelium following preoperative radiotherapy frequently cause healing delays of free flaps in the irradiated graft bed. The aim of the study was to investigate quantitative and qualitative changes of irradiated neck recipient vessels and transplant vessels used for microsurgical anastomoses in free flaps in patients undergoing preoperative radiotherapy or radiochemotherapy. Patients and Methods: In 348 patients (October 1995-March 2002) receiving primarly or secondarly 356 microvascular hard- and soft tissue reconstruction, a total of 209 vessels were obtained from neck recipient vessels and transplant vessels during anastomosis. Three groups were analysed: group 1 (27 patients) treated with no radiotherapy or chemotherapy; group 2 (29 patients) treated with preoperative irradiation (60-70 Gy) and chemotherapy (800 mg/m2/day 5-FU and 20 mg/m2/day cisplatin) 1.5 months prior to surgery; group 3 (20 patients) treated with radiotherapy (60-70 Gy) (median interval 78.7 months; IQR: 31.3 months) prior to surgery. From each of the 209 vessel specimens, 3 sections were investigated histomorphometrically, qualitatively and quantitatively (ratio media area/total vessel area) by NIH-Image-digitized measurements. To evaluate these changes as a function of age, radiation dose and chemotherapy, a statistical analysis was performed using an analysis of covariance and 2tests (p > 0.05, SPSS V10). Results: In group 3, qualitative changes (intima dehiscence, hyalinosis) were found in recipient arteries significantly more frequently than in groups 1 and 2. For group 3 recipient arteries, histomorphometry revealed a significant decrease in the ratio media area/total vessel area (median 0.51, IQR 0.10) in comparison with groups 1 (p = 0.02) (median 0.61, IQR 0.29) and 2 (p = 0.046) (mdeian 0.58, IQR 0.19). No significant difference was found between the vessels of groups 1 and 2 (p = 0.48). There were no significant differences in transplant arteries and recipient or tansplant veins between the groups. Age and chemotherapy did not appear to have a significant influence on vessel changes in this study (p > 0.05). Conclusions: Following irradiation with 60-70 Gy, significant qualitative and quantitative histological changes to the recipient arteries, but not to the recipient veins, could be observed. In contrast, irradiation at a dose of 40-50 Gy and chemotherapy given at a median interval of 1.5 months prior to operation did not lead to significant histological changes to the recipient vessels.
    Strahlentherapie und Onkologie 04/2002; 178(6):299-306. DOI:10.1007/s00066-002-0953-4 · 2.91 Impact Factor
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    Strahlentherapie und Onkologie 01/2003; 178(12):722-6. DOI:10.1007/s00066-002-0961-4 · 2.91 Impact Factor
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