Pre-radiotherapy dental extractions in patients with head and neck cancer: a Delphi study

A survey on oral health-related standard of care for head and neck cancer patients in the EU

OBJECTIVE

To map oral health-related standard of care in the context of head and neck cancer (HNC) treatment across the European Union (EU).

MATERIALS AND METHODS

Six hundred and ninety centers across the European Union were contacted. The questionnaire contained questions focusing on the team/department structure, HNC treatment planning routines, and assessment and handling of dental treatment needs prior to cancer treatment.

RESULTS

Eighty-seven centers across the EU responded. Department structure and number of HNC patients treated per year varied widely and dental professionals are included as part of the team in about 25% of the centers. Standard of care, in terms of dental assessment and preventive dentistry routines, such as recording an orthopantomogram, offering dental treatment, and providing a radiation protection splint and splint for fluoride application, differed significantly among the European regions. Independent of the region, these aspects are positively affected if dental professionals are part of the interdisciplinary treatment team and if dental treatment is offered within the center.

CONCLUSION

Dental professionals are still only to a very limited extent included in interdisciplinary treatment planning teams of HNC patients. However, their inclusion and/or offering dental treatment within the same hospital/center appears to improve oral health-related standard of care.

CLINICAL RELEVANCE

Inclusion of dental professionals in treatment planning teams of HNC patients appears to improve oral health-related standard of care within HNC treatment.

Backscatter from therapeutic doses of ionizing irradiation does not impair cell migration on titanium implants in vitro

OBJECTIVE

The influence of radiation backscatter from titanium on DNA damage and migration capacity of human osteoblasts (OBs) and mesenchymal stem cells (MSCs) may be critical for the osseointegration of dental implants placed prior to radiotherapy. In order to evaluate effects of radiation backscatter, the immediate DNA damage and migration capacity of OBs and MSCs cultured on titanium or plastic were compared after exposure to ionizing irradiation.

MATERIALS AND METHODS

Human OBs and MSCs were seeded on machined titanium, moderately rough fluoride-modified titanium, or tissue culture polystyrene, and irradiated with nominal doses of 2, 6, 10, or 14 Gy. Comet assay was performed immediately after irradiation, while a scratch wound healing assay was initiated 24 h post-irradiation. Fluorescent live cell imaging documented the migration.

RESULTS

DNA damage increased with higher dose and with backscatter from titanium, and MSCs were significantly more affected than OBs. All doses of radiation accelerated the cell migration on plastic, while only the highest dose of 10 Gy inhibited the migration of both cell types on titanium.

CONCLUSIONS

High doses (10 Gy) of radiation inhibited the migration capacity of both cell types on titanium, whereas lower doses (2 and 6 Gy) did not affect the migration of either OBs or MSCs.

CLINICAL RELEVANCE

Fractionated doses of 2 Gy/day, as distributed in conventional radiotherapy, appear not to cause severe DNA damage or disturb the migration of OBs or MSCs during osseointegration of dental implants.

Proposal of a Decision-Making Model for the Provisional Restoration Alternatives in Single-Tooth Implant Treatment

Background The decision-making of the most appropriate provisional restoration option in single-tooth implant practice is complex under multi-criteria conditions. The aim of our study is to conduct a case study on the determination of the appropriate provisional treatment option to be used in a single-tooth dental implant interim period after placement with the help of an entropy-based additive ratio assessment. Methodology Eight important criteria for fulfilling this purpose have been extracted from the literature search: "esthetic potential," "patient comfort," "treatment time," "laboratory cost," "occlusal clearance," "ease of removal," "durability," and "ease of modification." Provisional treatment alternatives are "removable partial denture," "vacuum-formed appliances," "bonded extracted tooth or denture," "metal or fiber-reinforced resin-bonded fixed partial denture," "wire-retained resin-bonded fixed partial denture," "acrylic resin provisional fixed partial denture," and "implant-supported fixed provisional restoration." It has been examined which of these alternatives is most appropriate in terms of both reported specifications and artificially generated dominance scenarios. The scenarios employed are S0 (criteria are equal-weighted), S1 (the criterion is tri-fold dominant), and S2 (the criterion is two-fold dominant). Results "Patient comfort" was the most important criterion (wj = 0.19). The remaining criteria were ranked as "modifications," "treatment time," "durability," "esthetic potential," "laboratory cost," "occlusal clearance," and "ease of removal." The "implant-supported fixed provisional restoration" treatment option had the maximum degree of utility in the S0 (Ki = 0.782) and S2 (Ki = 0.80) categories. If "treatment time" or "occlusal clearance" is the dominant variable, "vacuum-formed appliances" had the highest degree of utility (Ki = 0.69) in S1. Conclusions According to the rankings and scenarios created utilizing entropy-based additive ratio assessment methods, the "implant-supported fixed provisional restoration" is the appropriate provisional option for a single-tooth implant treatment. If "treatment time" or "occlusal clearance" is an absolute criterion, the "vacuum-formed provisional appliance" will replace the appropriate option.

Determinants of Clinical Decision Making under Uncertainty in Dentistry: A Scoping Review

Clinical decision-making for diagnosing and treating oral and dental diseases consolidates multiple sources of complex information, yet individual clinical judgements are often made intuitively on limited heuristics to simplify decision making, which may lead to errors harmful to patients. This study aimed at systematically evaluating dental practitioners’ clinical decision-making processes during diagnosis and treatment planning under uncertainty. A scoping review was chosen as the optimal study design due to the heterogeneity and complexity of the topic. Key terms and a search strategy were defined, and the articles published in the repository of the National Library of Medicine (MEDLINE/PubMed) were searched, selected, and analysed in accordance with PRISMA-ScR guidelines. Of the 478 studies returned, 64 relevant articles were included in the qualitative synthesis. Studies that were included were based in 27 countries, with the majority from the UK and USA. Articles were dated from 1991 to 2022, with all being observational studies except four, which were experimental studies. Six major recurring themes were identified: clinical factors, clinical experience, patient preferences and perceptions, heuristics and biases, artificial intelligence and informatics, and existing guidelines. These results suggest that inconsistency in treatment recommendations is a real possibility and despite great advancements in dental science, evidence-based practice is but one of a multitude of complex determinants driving clinical decision making in dentistry. In conclusion, clinical decisions, particularly those made individually by a dental practitioner, are potentially prone to sub-optimal treatment and poorer patient outcomes.

Systematic dosimetric evaluation of risk of osteoradionecrosis (DERO): First results of dose reporting for preventing teeth osteoradionecrosis after head and neck irradiation

PURPOSE

OsteoRadioNecrosis (ORN) is a late complication of radiation for head and neck cancer. Predicting ORN is a major challenge. We developed DERO (Dosimetric Evaluation of Risk of ORN), a semi-automatic tool which reports doses delivered to tooth-bearing sectors, to guide post-therapeutic dental care. We present the method and the first results of a 125-patient prospective cohort.

MATERIAL AND METHODS

Dosimetric data of patients treated with IMRT for head and neck cancer were prospectively segmented to the DERO algorithm. Four arches corresponding to 8-tooth sectors were semi-automatically generated. Thirty-two cylindrical Regions Of Interest (ROI) corresponding to each tooth and surrounding periodontium were created by linear interpolation. Mean doses (Dmean) of ROI were extracted and included in a database, along with data about primary tumor site, laterality and dose values from organs at risk. Dmean to tooth sectors were computed for molar sectors, (teeth X5 to X8) and anterior sectors (teeth X1 to X4). An individual dose map was generated and delivered to patients and dentists.

RESULTS

Dosimetric data from 125 patients treated with Tomotherapy® were prospectively collected and analyzed: 9 parotid tumors (PA), 41 Sub-Hyoid tumors (larynx, hypopharynx) (SH), 43 Oropharynx tumors (OR), 32 Oral Cavity tumors (OC). Irradiation was unilateral for 100% of PA tumors (9), 12% of OR tumors (5) and 47% of OC tumors (15). For unilateral cervical irradiation, Dmean in ipsilateral molar sectors was 54Gy for OC tumors, 45Gy for OR tumors, 20Gy for PA tumors. For Oral Cavity bilateral irradiation, Dmean was high in all tooth sectors, 49 to 55Gy. For SH tumors, Dmean in molar sectors was 27Gy. A dose gradient of 10 to 20Gy was observed between molar and anterior sectors whether radiation was uni or bilateral.

CONCLUSION

Mandibular molar sectors of Oropharynx and Oral Cavity tumors were exposed to high Dmean of 40 to 50Gy. On the other hand, tooth sectors received lower doses for SH radiation. The DERO tool guide post-radiation dental care with a personalized dosimetric cartography to patient. With data update and patient follow-up, we will be able to determine ORN risk after head and neck radiation.

Dental management before radiotherapy of the head and neck region: 4-year single-center experience

OBJECTIVE

To review our experience with a standardized dental management approach in patients with planned radiotherapy of the head and neck region based on preradiation and follow-up data.

MATERIAL AND METHODS

Records of patients who underwent radiotherapy between June 2016 and November 2020 were reviewed. Data on dental findings and therapeutic recommendations were extracted from a prospectively managed database. Hospital records were used to obtain follow-up data.

RESULTS

Two hundred eighty-one patient records were identified. After the exclusion of 81 patients because of incomplete data, 200 patients were included in the study. Dental findings relevant to radiotherapy were found in 144 cases (72.0%). Teeth extractions were recommended in 112 (56.0%) patients. Follow-up data were available for 172 (86.0%) patients (mean follow-up: 16.8 ± 10.7 months). Radiodermatitis was the most frequently observed sequela of radiotherapy (42.4%), followed by dysphagia (38.4%) and stomatitis (36.6%). Osteoradionecrosis was observed in only 2.3% of the patients.

CONCLUSION

Dental findings relevant to planned radiotherapy were frequent and in many cases resulted in recommendations for teeth extraction. Based on our standardized dental management protocol, we observed low rates of late oral complications after radiotherapy of the head and neck region.

Undergraduate Teaching and Assessment Methods in Prosthodontics Curriculum: An International Delphi Survey

OBJECTIVES

To achieve consensus amongst an expert panel of prosthodontics/restorative dentistry academics on the best undergraduate teaching and assessments, and to develop recommendations regarding teaching and assessment of undergraduate prosthodontics.

METHODS

Semi-structured electronic questionnaires were used to collect data from senior clinical academics involved in the teaching of prosthodontics on three consecutive occasions (Delphi method). The questionnaires asked the experts' opinion on best teaching and assessment methods in the undergraduate prosthodontics curriculum. Invitation emails, with a hyperlink to the Round 1 questionnaire, were sent to 36 international dental academic experts. In later rounds, panellists were invited to consider their previous responses in light of the overall group response in attempt to bring the panel to a consensus. The group response was summarized using simple descriptive statistics, and the target level of consensus for each question was set at ≥ 70%. A response rate of at least 70% between rounds was deemed appropriate to maintain rigour.

RESULTS

Twenty-three senior academic experts from eleven countries agreed to participate. Eighteen (representing nine different countries) completed the questionnaires in its entirety (response rate 78.3%). The number of statements that attained consensus agreement was much higher than the number of non-consensus statements-92.6%, 175 statements out of 189 over three iterative rounds. Only 14 statements did not obtain a consensus during this Delphi study.

CONCLUSIONS

A total of 175 consensus statements represent the agreement expert views of participated senior academics in prosthodontics from nine different countries and across four continents. These consensus statements could be considered detailed guidelines and recommendations to improve future undergraduates' curriculum in prosthodontics.

CLINICAL SIGNIFICANCE

This Delphi study achieved a high consensus among a panel of senior academics in the teaching and assessment of undergraduate prosthodontics. This consensus could help minimise the current international and national divergence in dental schools' prosthodontics curricula, which could benefit future dentists and, subsequently, the patients.

Dental management in head and neck cancers: from intensity-modulated radiotherapy with photons to proton therapy

INTRODUCTION

Despite reduction of xerostomia with intensity-modulated compared to conformal X-ray radiotherapy, radiation-induced dental complications continue to occur. Proton therapy is promising in head and neck cancers to further reduce radiation-induced side-effects, but the optimal dental management has not been defined.

MATERIAL AND METHODS

Dental management before proton therapy was assessed compared to intensity-modulated radiotherapy based on a bicentric experience, a literature review and illustrative cases.

RESULTS

Preserved teeth frequently contain metallic dental restorations (amalgams, crowns, implants). Metals blur CT images, introducing errors in tumour and organ contour during radiotherapy planning. Due to their physical interactions with matter, protons are more sensitive than photons to tissue composition. The composition of restorative materials is rarely documented during radiotherapy planning, introducing dose errors. Manual artefact recontouring, metal artefact-reduction CT algorithms, dual or multi-energy CT and appropriate dose calculation algorithms insufficiently compensate for contour and dose errors during proton therapy. Physical uncertainties may be associated with lower tumour control probability and more side-effects after proton therapy. Metal-induced errors should be quantified and removal of metal restorations discussed on a case by case basis between dental care specialists, radiation oncologists and physicists. Metallic amalgams can be replaced with water-equivalent materials and crowns temporarily removed depending on rehabilitation potential, dental condition and cost. Implants might contraindicate proton therapy if they are in the proton beam path.

CONCLUSION

Metallic restorations may more severely affect proton than photon radiotherapy quality. Personalized dental care prior to proton therapy requires multidisciplinary assessment of metal-induced errors before choice of conservation/removal of dental metals and optimal radiotherapy.

An audit of dental assessments including orthopantomography and timing of dental extractions before radiotherapy for head and neck cancer

Introduction Head and neck cancer (HNC) patients should receive a dental assessment at an appropriate time before commencing radiotherapy (RT), to prevent complications such as osteoradionecrosis (ORN) if extractions are required. A recent orthopantomogram radiograph (OPG) is part of this assessment.Aim To compare the delivery of pre-RT dental assessment at the Regional Oncology Centre against national guidelines in regard to OPG assessments and timing of extractions.Materials and methods A consecutive cohort of patients treated curatively were selected within two timeframes (January to March 2018 and January to March 2019) using multidisciplinary team records at Liverpool University Hospital. Patient notes, x-ray images and records were examined.Results In total, 145 patients were identified. Eighty-nine percent (129) had an OPG radiograph and 72% (104) had a pre-RT dental assessment. Oral and laryngeal sites had the highest number of missed assessments. Altogether, 54 patients had dental treatment, with 47 undergoing extractions. Extractions were completed a median 13 days before RT started. By November 2020, no patients had been diagnosed with ORN.Conclusions Three-quarters of patients received a pre-RT assessment but there is scope for improvement. OPGs should be part of initial HNC staging and referral to Regional Oncology Centre dental services should be made as part of the pre-RT workup.

Artificial Intelligence-Guided Prediction of Dental Doses Before Planning of Radiation Therapy for Oropharyngeal Cancer: Technical Development and Initial Feasibility of Implementation

Purpose

The aim was to develop a novel artificial intelligence (AI)-guided clinical decision support system, to predict radiation doses to subsites of the mandible using diagnostic computed tomography scans acquired before any planning of head and neck radiation therapy (RT).

Methods and Materials

A dose classifier was trained using RT plans from 86 patients with oropharyngeal cancer; the test set consisted of an additional 20 plans. The classifier was trained to predict whether mandible subsites would receive a mean dose >50 Gy. The AI predictions were prospectively evaluated and compared with those of a specialist head and neck radiation oncologist for 9 patients. Positive predictive value (PPV), negative predictive value (NPV), Pearson correlation coefficient, and Lin concordance correlation coefficient were calculated to compare the AI predictions to those of the physician.

Results

In the test data set, the AI predictions had a PPV of 0.95 and NPV of 0.88. For 9 patients evaluated prospectively, there was a strong correlation between the predictions of the AI algorithm and physician (P = .72, P < .001). Comparing the AI algorithm versus the physician, the PPVs were 0.82 versus 0.25, and the NPVs were 0.94 versus 1.0, respectively. Concordance between physician estimates and final planned doses was 0.62; this was 0.71 between AI-based estimates and final planned doses.

Conclusion

AI-guided decision support increased precision and accuracy of pre-RT dental dose estimates.

Including dental professionals in the multidisciplinary treatment team of head and neck cancer patients improves long-term oral health status

Objective

To assess in a cross-sectional study the impact of including dental professionals in the multidisciplinary treatment team of head and neck squamous cell carcinoma (HNSCC) patients on the long-term oral health status.

Materials and methods

Oral health status, dental care behaviours, and oral health–related quality of life were assessed based on a clinical and radiographic examination, interview, and medical records in patients treated for HNSCC ≥ 6 months ago. This patient group (‘cohort 2’) was treated in a multidisciplinary treatment team including dental professionals and compared to a group of HNSCC patients previously treated at the same university, but without dental professionals included in the multidisciplinary treatment team (‘cohort 1’).

Results

Cohort 2 consisted of 34 patients, who had received a dental check-up and if necessary, treatment by dental professionals prior to the initiation of cancer treatment. This cohort showed significantly improved oral hygiene habits and a better periodontal health status compared to cohort 1. However, cohort 2 still presented high demand for treatment due to active carious lesions; only a few, statistically insignificant improvements were detected compared to cohort 1.

Conclusion

Including dental professionals in the multidisciplinary treatment team of HNSCC patients has a positive impact on patient oral health status—primarily in terms of periodontal disease—6 months and longer after finishing cancer therapy.

Clinical relevance

A team-based approach including dental professionals specialised in head and neck cancer improves oral health status.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04276-x.