Risk profile for osteoradionecrosis of the mandible in the IMRT era

Timing of development of osteoradionecrosis post head and neck radiotherapy: does a safe time interval exist for dental extraction?

INTRODUCTION

Risk factors for developing osteoradionecrosis (ORN) are well known, but less is known about factors influencing the interval between radiotherapy and the onset of ORN. Also, it is unknown whether there is any specific period post-radiotherapy with a reduced probability of ORN when irradiated teeth require extraction.

PURPOSE

The primary aim of this study was to identify factors influencing the interval in developing ORN in the following subgroups of patients: (1) patients who spontaneously developed ORN, (2) surgical-intervention-related ORN with a particular focus on patients after mandibulectomy. The secondary aim was to attempt to identify a possible time for safer dental intervention after primary treatment.

MATERIALS AND METHODS

The authors retrospectively analysed 1608 head and neck cancer (HNC) patients treated in a single centre. Time intervals were measured from the end of radiotherapy to the development of ORN and further analysed in the subgroups listed above.

RESULTS

In all, 141 patients (8.8%) developed intra-oral ORN. Median time from radiotherapy to ORN development in the whole cohort was 9 months. Median interval for spontaneous ORN was 8 months, 6.5 months for intervention-related ORN, and 15 months for patients post-mandibulectomy. In patients who required dental extraction preradiotherapy, median interval of ORN onset was 5 months.

CONCLUSION

In our study, a slightly higher proportion of patients with intervention developed ORN earlier in comparison with spontaneous ORN. The period from 12-18 months after radiotherapy was identified as having the highest probability of developing ORN in patients after mandibulectomy. A time for safer dental intervention after primary treatment was not identified.

The incidence of osteoradionecrosis of the jaws in oral cavity cancer patients treated with intensity-modulated radiotherapy: a systematic review and meta-analysis

OBJECTIVE

A systematic review with meta-analysis was conducted to define the incidence of osteoradionecrosis (ORN) in patients with oral cavity cancer (OCC) treated with intensity-modulated radiotherapy (IMRT), and to identify the risk factors influencing its development.

STUDY DESIGN

Six databases were searched systematically. A meta-analysis was performed to determine overall, spontaneous, and dental extraction-attributed incidences of ORN. The Grading of Recommendations Assessment, Development, and Evaluation tool evaluated evidence certainty.

RESULTS

Out of 11 eligible studies, 6 underwent meta-analysis for the overall aggregated ORN incidence in OCC patients receiving IMRT, resulting in an incidence rate of 8% (95% CI: 6%-11%). Regarding development reasons, 2 studies were assessed, revealing an incidence of 36% (95% CI: 1%-98%) for spontaneous ORN, and 17% (95% CI: 5%-44%) ensued from dental extraction exclusively pre-RT. All rates had very low certainty of evidence. Factors significantly correlated with ORN development included postoperative RT use (78%), employment of therapeutic doses above 50 Gy, and mandibular involvement (80.5%).

CONCLUSION

The findings suggest that IMRT alone is not sufficient to decrease ORN rates in OCC patients, underscoring the importance of precisely identifying the involved risk factors. However, further detailed primary studies will be necessary.

Development and Standardization of an Osteoradionecrosis Classification System in Head and Neck Cancer: Implementation of a Risk-Based Model

PURPOSE

Osteoradionecrosis of the jaw (ORN) can manifest in varying severity. The aim of this study is to identify ORN risk factors and develop a novel classification to depict the severity of ORN.

METHODS

Consecutive patients with head and neck cancer (HNC) treated with curative-intent intensity-modulated radiation therapy (IMRT) (≥45 Gy) from 2011 to 2017 were included. Occurrence of ORN was identified from in-house prospective dental and clinical databases and charts. Multivariable logistic regression model was used to identify risk factors and stratify patients into high-risk and low-risk groups. A novel ORN classification system was developed to depict ORN severity by modifying existing systems and incorporating expert opinion. The performance of the novel system was compared with 15 existing systems for their ability to identify and predict serious ORN event (jaw fracture or requiring jaw resection).

RESULTS

ORN was identified in 219 of 2,732 (8%) consecutive patients with HNC. Factors associated with high risk of ORN were oral cavity or oropharyngeal primaries, received IMRT dose ≥60 Gy, current/ex-smokers, and/or stage III to IV periodontal condition. The ORN rate for high-risk versus low-risk patients was 12.7% versus 3.1% (P < .001) with an AUC of 0.71. Existing ORN systems overclassified serious ORN events and failed to recognize maxillary ORN. A novel ORN classification system, ClinRad, was proposed on the basis of vertical extent of bone necrosis and presence/absence of exposed bone/fistula. This system detected serious ORN events in 5.7% of patients and statistically outperformed existing systems.

CONCLUSION

We identified risk factors for ORN and proposed a novel ORN classification system on the basis of vertical extent of bone necrosis and presence/absence of exposed bone/fistula. It outperformed existing systems in depicting the seriousness of ORN and may facilitate clinical care and clinical trials.

Osteoradionecrosis incidence in pre-radiation teeth extractions: A prospective study

AIMS

To evaluate osteoradionecrosis (ORN) incidence in a cohort of patients undergoing tooth extraction (TE) before radiotherapy (RT) for head and neck cancers.

METHODS

The study protocol was approved by the Ethics Committee of Università Cattolica del Sacro Cuore (ID-2132) and registered at clinicaltrials.gov (ID: NCT04009161). TE was performed in case of signs of pericoronitis, periapical lesions, restorative impossibility, severe periodontitis. ORN was defined as exposed bone at an unhealed post-extraction socket in the absence of oncological recurrence. The RT plans were reviewed, and each post-extractive socket was contoured to calculate the received radiation dose.

RESULTS

In total, 156 patients with 610 TE were enrolled. The mean follow-up was 567 days. ORN was diagnosed in four patients (2.6% of patients and 0.7% of TE). Need for osteotomy and radiation dose at the extraction site were associated with ORN (OR for osteotomy: 21.9, 95% CI: 2.17-222.2, p = 0.009; OR for RT dose: 1.1, 95% CI: 1-1.15, p = 0.05).

CONCLUSIONS

TE appears to be a significant risk factor for ORN, particularly when osteotomy is required, and post-extraction sockets receive a high RT dosage. This study proposes a decision-making algorithm for TE and outlines a straightforward surgical protocol.

Prophylactic Use of Pentoxifylline and Tocopherol for Prevention of Osteoradionecrosis of the Jaw after Dental Extraction in Post-Radiated Oral and Oropharyngeal Cancer Patients: An Initial Case Series

Osteoradionecrosis of the jaw is a morbid complication of radiotherapy in patients with oral and oropharyngeal cancers that may be precipitated by dental extractions. Pentoxifylline and tocopherol (PENTO) has been utilized in the management of osteoradionecrosis and as prophylaxis for post-radiated head and neck oncology patients requiring an invasive dental procedure. This observational study aims to report the outcome of the prophylactic use of PENTO in the prevention of osteoradionecrosis of the jaw after dental extractions in post-radiated oral and oropharyngeal cancer patients and to review the current literature on this topic. Four post-radiated oral and oropharyngeal oncology patients were referred to the dental oncology clinic of the University Dental Practice, University of Tennessee Health Sciences Center for dental extractions. All four patients were prescribed pentoxifylline 400 mg BID (twice a day) and tocopherol 400 IU BID (oral tablets) for 2 weeks before extraction(s) and for 6 weeks after extraction(s). All patients were followed up every week after the second week post-extraction if feasible until the extraction site(s) healed (covered by mucosa). The assessment endpoint was defined as 6 weeks post-extraction with the outcomes assessed as using four categories determined by the area of exposed bone: complete healing (complete mucosal coverage of extraction site); partial healing (reduction in size of extraction site); no change; and progression (increase in size of the extraction site). At the assessment endpoint, all patients had complete healing of all extraction sites. The ORN rate at the patient level (0/4) and individual tooth level (0/8) was 0%. All patients tolerated the PENTO medications and no adverse effects from the use of these medications were reported. This limited study in addition to the other reviewed studies estimates the rate of ORN at the patient level as 3.2% (14/436) for post-radiated head and neck oncology patients after dental extractions/invasive oral procedures. In conclusion, this PENTO regimen can reduce/prevent the incidence of ORN in post-radiated head and neck oncology patients. This safe and cost-effective protocol (PENTO regimen) should be further evaluated as prophylaxis for post-radiated head and neck oncology patients requiring an invasive dental procedure. We recommend large prospective studies to be carried out to further validate these findings.

Osteoradionecrosis - an old problem with new consequences

PURPOSE OF REVIEW

Osteoradionecrosis (ORN) is a devasting complication of radiation therapy (RT), especially in head and neck cancers (HNC), and is still poorly understood. The aim of this review is to report its incidence and consider the risk factors associated with ORN to highlight prevention strategies to decrease its incidence.

RECENT FINDINGS

The average incidence of ORN is between 2% and 23%, with incidence decreasing in more recent years with the introduction of modern RT technology and better oral health care. Smoking, diabetes mellitus, oropharyngeal and oral cavity cancers, pre- and post-RT dental extractions and a total radiation dose of over 60 Gy were all identified as risk factors for ORN. In prevention, strategies were mainly structured around minimising risk factors or targeting possible mechanisms of ORN's pathophysiology.

SUMMARY

At present, the controversy surrounding the risk factors and pathogenesis of ORN makes it difficult to establish a set of prevention guidelines for its incidence. In order to achieve this, more research examining its aetiology must be conducted as well as a universal staging system within which ORN may be classified.

A systematic review and meta-analysis of osteoradionecrosis following proton therapy in patients with head and neck cancer

INTRODUCTION

Head and neck cancer ranks as the seventh most common cancer worldwide. Proton therapy is widely used in head and neck cancer. Osteoradionecrosis(ORN) is currently a commonly investigated side effect of proton therapy. A meta-analysis is needed to investigate this topic.

MATERIAL/METHODS

Two authors searched three databases, including PubMed, Embase, and Cochrane Library; the search period was from inception to June 2023. The search keyword was set to be ((("osteoradionecrosis") OR ("osteonecrosis")) AND ("proton")).

RESULTS

We initially collected 410 articles, and after article selections, 22 articles remained in our systematic reviews. Due to the overlapping of patient populations, 17 studies were finally included in our meta-analysis. The pooled grade 3 or more ORN rate is 0.01(95 % CI = 0.01-0.03). Subgroup analysis showed that IMPT didn't reduce grade 3 or more ORN compared with 3DCPT (p = 0.15).

CONCLUSIONS

Our meta-analysis showed that severe ORN rarely occurred in proton therapy for head and neck cancer patients.

Development and Standardization of a Classification System for Osteoradionecrosis: Implementation of a Risk-Based Model

Purpose

Osteoradionecrosis of the jaw (ORN) can manifest in varying severity. The aim of this study is to identify ORN risk factors and develop a novel classification to depict the severity of ORN.

Methods

Consecutive head-and-neck cancer (HNC) patients treated with curative-intent IMRT (≥ 45Gy) in 2011-2018 were included. Occurrence of ORN was identified from in-house prospective dental and clinical databases and charts. Multivariable logistic regression model was used to identify risk factors and stratify patients into high-risk and low-risk groups. A novel ORN classification system was developed to depict ORN severity by modifying existing systems and incorporating expert opinion. The performance of the novel system was compared to fifteen existing systems for their ability to identify and predict serious ORN event (jaw fracture or requiring jaw resection).

Results

ORN was identified in 219 out of 2732 (8%) consecutive HNC patients. Factors associated with high-risk of ORN were: oral-cavity or oropharyngeal primaries, received IMRT dose ≥60Gy, current/ex-smokers, and/or stage III-IV periodontal disease. The ORN rate for high-risk vs low-risk patients was 12.7% vs 3.1% (p<0.001) with an area-under-the-receiver-operating-curve (AUC) of 0.71. Existing ORN systems overclassified serious ORN events and failed to recognize maxillary ORN. A novel ORN classification system, RadORN, was proposed based on vertical extent of bone necrosis and presence/absence of exposed bone/fistula. This system detected serious ORN events in 5.7% of patients and statistically outperformed existing systems.

Conclusion

We identified risk factors for ORN, and proposed a novel ORN classification system based on vertical extent of bone necrosis and presence/absence of exposed bone/fistula. It outperformed existing systems in depicting the seriousness of ORN, and may facilitate clinical care and clinical trials.

The Role of Dental Practitioners in the Management of Oncology Patients: The Head and Neck Radiation Oncology Patient and the Medical Oncology Patient

This narrative review addresses the role of a dentist in the management of oncology patients, highlighting the oral complications that arise in head and neck radiation oncology patients and medical oncology patients. The prevention and management of these complications are discussed.

Planned dose of intensity modulated proton beam therapy versus volumetric modulated arch therapy to tooth-bearing regions

BACKGROUND

Intensity modulated proton beam therapy (IMPT) for head and neck cancer offers dosimetric benefits for the organs at risk when compared to photon-based volumetric modulated arch therapy (VMAT). However, limited data exists about the potential benefits of IMPT for tooth-bearing regions. The aim of this study was to compare the IMPT and VMAT radiation dosimetrics of the tooth-bearing regions in head and neck cancer patients. Also, we aimed to identify prognostic factors for a cumulative radiation dose of ≥40 Gy on the tooth-bearing areas, which is considered the threshold dose for prophylactic dental extractions.

METHODS

A total of 121 head and neck cancer patients were included in this retrospective analysis of prospectively collected data. We compared the average Dmean values of IMPT versus VMAT of multiple tooth-bearing regions in the same patients. Multivariate logistic regression analysis was performed for receiving a cumulative radiation dose of ≥40 Gy to the tooth-bearing regions (primary endpoint) in both VMAT and IMPT.

RESULTS

A lower Dmean was seen after applying IMPT to the tooth-bearing tumour regions (p < 0.001). Regarding VMAT, oral cavity tumours, T3-T4 tumours, molar regions in the mandible, and regions ipsilateral to the tumour were risk factors for receiving a cumulative radiation dose of ≥40 Gy.

CONCLUSIONS

IMPT significantly reduces the radiation dose to the tooth-bearing regions.

Osteoradionecrosis of the Jaw Following Proton Radiation Therapy for Patients With Head and Neck Cancer

Importance

Proton radiation therapy (PRT) has reduced radiation-induced toxic effects, such as mucositis and xerostomia, over conventional photon radiation therapy, leading to significantly improved quality of life in patients with head and neck cancers. However, the prevalence of osteoradionecrosis (ORN) of the jaw following PRT in these patients is less clear.

Objective

To report the prevalence and clinical characteristics of ORN in patients with oral and oropharyngeal cancer (OOPC) treated with PRT.

Design, Setting, and Participants

This case series reports a single-institution experience (Memorial Sloan Kettering Cancer Center, New York, New York) between November 2013 and September 2019 and included 122 radiation therapy-naive patients with OOPC treated with PRT. Data were analyzed from 2013 to 2019.

Main Outcomes and Measures

Clinical parameters, including sex, age, comorbidities, tumor histology, concurrent chemotherapy, smoking, comorbidities, and preradiation dental evaluation, were obtained from the medical record. Patients with clinical or radiographic signs of ORN were identified and graded using the adopted modified Glanzmann and Grätz grading system. Characteristics of ORN, such as location, clinical presentation, initial stage at diagnosis, etiology, time to diagnosis, management, and clinical outcome at the last follow-up, were also collected.

Results

Of the 122 patients (mean [SD] age, 63 [13] years; 45 [36.9%] women and 77 [63.1%] men) included in this study, 13 (10.6%) developed ORN following PRT during a median (range) follow-up time of 40.6 (<1-101) months. All patients had spontaneous development of ORN. At the time of initial diagnosis, grade 0, grade 1, grade 2, and grade 3 ORN were seen in 2, 1, 9, and 1 patient, respectively. The posterior ipsilateral mandible within the radiation field that received the full planned PRT dose was the most involved ORN site. At a median (range) follow-up of 13.5 (0.2-58.0) months from the time of ORN diagnosis, complete resolution, stable condition, and progression of ORN were seen in 3, 6, and 4 patients, respectively. The 3-year rates of ORN and death in the total cohort were 5.2% and 21.5%, while the 5-year rates of ORN and death were 11.5% and 34.4%, respectively.

Conclusions and Relevance

In this case series, the prevalence of ORN following PRT was found to be 10.6%, indicating that ORN remains a clinical challenge even in the era of highly conformal PRT. Clinicians treating patients with OOPC with PRT should be mindful of this complication.

Osteoradionecrosis of the jaw: A mini review

Osteoradionecrosis (ORN) of the jaw is one of the most dreaded complications of head and neck radiation therapy. Despite the evolution of radiation treatment modalities, ORN continues to remain a therapeutic challenge and its etiopathogenesis still remains unclear. It is clinically characterized by exposed necrotic bone within the head and neck radiation field. Over the past years, several studies have reported on the definition, staging, incidence, etiology, and management of this oral complication. In this review, we summarize the literature on ORN and discuss our institutional experience and management strategies that aim to predict and mitigate risk for ORN.

Progression and postoperative complications of osteoradionecrosis of the jaw: a 20-year retrospective study of 124 non-nasopharyngeal cancer cases and meta-analysis

BACKGROUND

To assess the contributing risk factors for the progression of, and the postoperative poor prognosis associated with, osteoradionecrosis of jaw (ORNJ) following non-nasopharyngeal cancer treatment in head and neck.

METHODS

A retrospective study of 124 non-nasopharyngeal carcinoma patients in head and neck treated at one institution between 2001 and 2020 was conducted. A cumulative meta-analysis was conducted according to PRISMA protocol and the electronic search was performed on the following search engines: PubMed, Embase, and Web of Science. After assessing surgery with jaw lesions as a risk factor for the occurrence of ORNJ, 124 cases were categorized into two groups according to the "BS" classification, after which jaw lesions, chemotherapy, flap reconstruction and onset time of ORNJ were analyzed through the chi-square test and t-test to demonstrate the potential association between them and the progression of ORNJ. Postoperative outcomes of wound healing, occlusal disorders, and nerve injury were statistically analyzed.

RESULTS

With the statistically significant results of the meta-analysis (odds ratio = 3.07, 95% CI: 1.84-5.13, p < 0.0001), the chi-square test and t-test were used to validate our hypotheses and identified that surgery with jaw lesions could aggravate the progression and accelerate the appearance of ORNJ. Patients who underwent chemotherapy tended to suffer from severe-to-advanced osteonecrosis but did not shorten the onset time of ORNJ. Flap reconstruction presented obvious advantages in wound healing (p < 0.001) and disordered occlusion (p < 0.005). The mean onset time of ORNJ in non-nasopharyngeal cancer patients (4.5 years) was less than that in patients with nasopharyngeal cancer (NPC) (6.8 years).

CONCLUSIONS

Iatrogenic jaw lesions are evaluated as a significant risk factor in the occurrence and progression of ORNJ in non-nasopharyngeal carcinoma patients who tend to have more severe and earlier osteonecrosis after radiotherapy than NPC patients. Flap reconstruction is a better choice for protecting the remaining bone tissue and reducing postoperative complications of ORNJ.

Three-Dimensional Evaluation of Isodose Radiation Volumes in Cases of Severe Mandibular Osteoradionecrosis for the Prediction of Recurrence after Segmental Resection

Background: Pre-operative margin planning for the segmental resection of affected bone in mandibular osteoradionecrosis (ORN) is difficult. The aim of this study was to identify a possible relation between the received RT dose, exposed bone volume and the progression of ORN after segmental mandibular resection. Method: Patients diagnosed with grade 3-4 ORN for which a segmental resection was performed were included in the study. Three-dimensional reconstructions of RT isodose volumes were fused with postoperative imaging. The primary outcome was the recurrence of ORN after segmental resection. Subsequently, RT exposed mandibular bone volumes were calculated and the location of the bone cuts relative to the isodose volumes were assessed. Results: Five out of thirty-three patients developed recurrent ORN after segmental mandibular resection. All cases with recurrent ORN were resected inside an isodose volume of ≥56 Gy. The absolute mandibular volume radiated with 56 Gy was significantly smaller in the recurrent group (10.9 mL vs. 30.7 mL, p = 0.006), as was the proportion of the mandible radiated with 56 Gy (23% vs. 45%, p = 0.013). Conclusion: The volume of radiated bone was not predictive for risk of progression. The finding that recurrent ORN occurred with bone resection margins within the 56 Gy isodose volume suggests that this could serve as a starting point for the pre-operative planning of reducing the risk of ORN recurrence.

Frequency of osteoradionecrosis of the lower jaw after radiotherapy of oral cancer patients correlated with dosimetric parameters and other risk factors

Objectives

Osteoradionecrosis (ORN) of the lower jaw is a serious late complication after radiotherapy in patients with oral cavity cancer. The aim of this study is to generate more insight into which patient- and treatment-related factors are associated with the development of ORN in oral cavity cancer patients undergoing postoperative radiotherapy.

Material and methods

Retrospective evaluation and comparison of 44 patients with ORN (event group 1) matched according to 45 patients without ORN (control group 2) who received postoperative radiotherapy of oral cavity squamous cell carcinoma at our institution between 2012 and 2020. Dosimetric factors that favor the occurrence of ORN should be detected. The cumulative occurrence rate of ORN was calculated according to the Kaplan–Meier method and analyzed by Cox regression and log-rank test.

Results

The median time to develop ORN was 18 months (3–93 months) after radiotherapy. Dental status before radiotherapy (RT) treatment (HR 4.5; 1.8–11.5) and dosimetric parameters including Dmean > 45 Gy (HR 2.4; 1.0–5.7), Dmax > 60 Gy (HR 1.3; 1.1–2.8) and planning target volume (PTV) proportion > 40% intersection with the lower jaw (HR 1.1; 1.0–1.1) were significantly associated with ORN.

Conclusion

The results of this retrospective study reveal that oral cavity cancer patients who underwent pre-RT dental surgery as well as dosimetric parameters using Dmax > 60 Gy, higher mean doses > 45 Gy and more than 40% PTV intersection with the lower jaw bone are independent risk factors for ORN. These findings can assist in the management of patients undergoing RT for head and neck cancer regarding ORN prevention.

Clinical relevance

Poor oral hygiene and desolate dental status as well as high radiation doses to the mandibular bone significantly increase the risk of developing osteoradionecrosis. Before irradiating a patient with oral cavity cancer, an appointment with the dentist should be made and teeth sanitized if necessary. Likewise, maximum radiation doses to the lower jaw should be minimized.

Temporal Bone Osteoradionecrosis: An 18-year, Single-Institution Experience

OBJECTIVES/HYPOTHESIS

To report the largest single-institution review of temporal bone osteoradionecrosis (TBORN), and characterize the disease's natural history, prognostic factors, management, and outcomes.

STUDY DESIGN

Retrospective chart review.

METHODS

Retrospective review was conducted to identify patients with TBORN. Pertinent data were extracted. Descriptive statistics were used to summarize patient, tumor, and treatment characteristics. Multivariable analyses were conducted to explore associations between these characteristics and time to TBORN diagnosis and risk of developing diffuse disease.

RESULTS

TBORN was identified in 145 temporal bones from 128 patients. Mean age at diagnosis was 62 years, and mean time to diagnosis after radiotherapy was 10 years. Age greater than 50 years was associated with earlier diagnosis. According to the Ramsden criteria, 76% of TBs had localized and 24% had diffuse disease at initial diagnosis; 37% had diffuse disease at last follow-up. On multivariable analysis, diabetes, three-dimensional conformal radiotherapy (3D-CRT), and periauricular skin malignancy were significant risk factors for developing diffuse disease. Localized disease was successfully managed with conservative measures, whereas surgery was often necessary for diffuse disease. When TBORN spread outside the mastoid or infratemporal fossa, conservative measures were always unsuccessful.

CONCLUSIONS

TBORN occurs earlier in older patients. While diffuse disease is less common than localized disease, it occurs more frequently in patients with diabetes, history of 3D-CRT, and periauricular skin malignancies. Conservative management is appropriate for localized disease, while surgery is often necessary for diffuse disease. The prognostic factors identified helped propose a TBORN staging system and treatment guidelines which may improve patient risk stratification and disease management.

LEVEL OF EVIDENCE

IV Laryngoscope, 2021.

Predictors of osteoradionecrosis following irradiated tooth extraction

Background

Tooth extraction post radiotherapy is one of the most important risk factors of osteoradionecrosis of the jawbones. The objective of this study was to determine the predictors of osteoradionecrosis (ORN) which were associated with a dental extraction post radiotherapy.

Methods

A retrospective analysis of medical records and dental panoramic tomogram (DPT) of patients with a history of head and neck radiotherapy who underwent dental extraction between August 2005 to October 2019 was conducted.

Results

Seventy-three patients fulfilled the inclusion criteria. 16 (21.9%) had ORN post dental extraction and 389 teeth were extracted. 33 sockets (8.5%) developed ORN. Univariate analyses showed significant associations with ORN for the following factors: tooth type, tooth pathology, surgical procedure, primary closure, target volume, total dose, timing of extraction post radiotherapy, bony changes at extraction site and visibility of lower and upper cortical line of mandibular canal. Using multivariate analysis, the odds of developing an ORN from a surgical procedure was 6.50 (CI 1.37–30.91, p = 0.02). Dental extraction of more than 5 years after radiotherapy and invisible upper cortical line of mandibular canal on the DPT have the odds of 0.06 (CI 0.01–0.25, p < 0.001) and 9.47 (CI 1.61–55.88, p = 0.01), respectively.

Conclusion

Extraction more than 5 years after radiotherapy, surgical removal procedure and invisible upper cortical line of mandibular canal on the DPT were the predictors of ORN.

Brachytherapy with 198Au grains for cancer of the floor of the mouth: relationships between radiation dose and complications

OBJECTIVE

This study aimed to retrospectively evaluate the radiation dose and complications in soft tissue and mandible caused by ¹⁹⁸Au grain brachytherapy alone or the combination with other modalities in patients with the cancer of the floor of the mouth.

MATERIALS AND METHODS

Twelve patients with T1 (n = 5) and T2 (n = 7) squamous cell carcinoma of the floor of the mouth, who were treated with ¹⁹⁸Au grain brachytherapy alone (n = 5) or the combination of external beam radiotherapy (EBRT) and/or chemotherapy and ¹⁹⁸Au grain brachytherapy (n = 7) from January 2005 to December 2016, were included. The relationships between the radiation dose and the complications of the soft tissue or mandible were investigated.

RESULTS

Seven of 12 patients had died. Of these 7 patients, one with T1 and 2 with T2 had died of the causes related to the cancer of the floor of the mouth. Two with T1 and 2 with T2 had died of other diseases. Two patients had grade 2 complications of the soft tissue and mandible. These patients were treated by the combination of EBRT and/or chemotherapy and ¹⁹⁸Au grain brachytherapy and irradiated with 123 or 139 Gy in total dose, respectively. And one of these patients was treated by the chemotherapy in addition to EBRT.

CONCLUSION

Our study showed that the combination of EBRT and ¹⁹⁸Au grains brachytherapy for the floor of the mouth cancer patients might be associated with risks of developing complications of soft tissue ulcer and mandibular bone necrosis.

Osteoradionecrosis after treatment of head and neck cancer: a comprehensive analysis of risk factors with a particular focus on role of dental extractions

In head and cancer (HNC), osteoradionecrosis (ORN) is one of the most significant complications of radiotherapy (RT). With an absence of effective non-surgical treatment, prevention of the development of ORN is the best approach. The purpose of this study was to identify the risk factors for the development of ORN in HNC. Records of 1,118 patients with HNC treated with radical RT (≥55Gy) from January 2010 to December 2019 were reviewed. After applying the exclusion criteria, 935 patients were included in the final analysis. In patients with confirmed ORN, exact RT doses were mapped. In total, 91 patients were found (9.7%) with a median (range) time of eight (3-89) months to the development of ORN. Smoking, having a primary site in the oropharynx, bone surgery before adjuvant RT, the addition of concurrent chemotherapy, the presence of xerostomia, dental extraction pre-RT, the time ≤20 days between dental extraction and start of RT, and receiving >55Gy RT dose were significant factors for its development. This comprehensive analysis including the precise RT dose mapping has shown the risk factors for the development of ORN. In practice, every effort should be made to avoid these risk factors without compromising the oncology treatment. The findings of this analysis may provide a basis for future prospective research on this topic.

Risk factors for osteoradionecrosis of the jaw in patients with head and neck squamous cell carcinoma

BACKGROUND

To evaluate factors associated with osteoradionecrosis of the jaw (ORNJ) in patients with head and neck squamous cell carcinoma (HNSCC), focusing on jaw-related dose-volume histogram (DVH) parameters.

METHODS

We retrospectively reviewed the medical records of 616 patients with HNSCC treated with curative-intent or postoperative radiation therapy (RT) during 2008-2018. Patient-related (age, sex, history of smoking or alcohol use, diabetes mellitus, performance status, pre-RT dental evaluation, pre- or post-RT tooth extraction), tumor-related (primary tumor site, T-stage, nodal status), and treatment-related (pre-RT surgery, pre-RT mandible surgery, induction or concurrent chemotherapy, RT technique) variables and DVH parameters (relative volumes of the jaw exposed to doses of 10 Gy-70 Gy [V10-70]) were investigated and compared between patients with and without ORNJ. The Mann-Whitney U test was used to compare RT dose parameters. Univariate and multivariate Cox regression analyses were used to assess factors associated with ORNJ development. Kaplan-Meier analyses were performed for cumulative ORNJ incidence estimation.

RESULTS

Forty-six patients (7.5%) developed ORNJ. The median follow-up duration was 40 (range 3-145) months. The median time to ORNJ development was 27 (range 2-127) months. DVH analysis revealed that V30-V70 values were significantly higher in patients with than in those without ORNJ. In univariate analyses, primary tumor site, pre-RT mandible surgery, post-RT tooth extraction, and V60 > 14% were identified as important factors. In multivariate analyses, V60 > 14% (p = 0.0065) and primary tumor site (p = 0.0059) remained significant. The 3-year cumulative ORNJ incidence rates were 2.5% and 8.6% in patients with V60 ≤ 14% and > 14%, respectively (p < 0.0001), and 9.3% and 1.4% in patients with oropharyngeal or oral cancer and other cancers, respectively (p < 0.0001).

CONCLUSIONS

V60 > 14% and oropharyngeal or oral cancer were found to be independent risk factors for ORNJ. These findings might be useful to minimize ORNJ incidence in HNSCC treated with curative RT.

Osteoradionecrosis: Exposing the Evidence Not the Bone

Osteoradionecrosis is a relatively rare but potentially morbid and costly complication of radiation therapy for head and neck cancer. Multidisciplinary diagnosis and treatment are essential. Despite evidence guiding individual aspects of care for osteoradionecrosis, there is a lack of broad consensus on the overall diagnosis and management of this condition. This study comprehensively reviews the literature, with a focus on the past 10 years, to guide evaluation and treatment.

Marginal Mandibulectomy Defect Reconstruction with Pectoralis Major Myocutaneous (PMMC) Flap in Cases of Carcinoma Buccal Mucosa: Experience from a Tertiary Cancer Institute

Patients with carcinoma buccal mucosa requiring marginal mandibulectomy pose various key challenges with regard to reconstruction. To study the role and feasibility of the PMMC flap reconstruction in patients of carcinoma buccal mucosa with intact mandible. Study design: retrospective analysis of prospectively maintained data at a tertiary cancer institute in India. Inclusion criteria: all patients of carcinoma buccal mucosa undergoing marginal mandibulectomy at our institute from 1st Jan 2015 to 31st March 2018 with reconstruction done by the PMMC flap. The retrospective analysis showed 82 patients satisfied the inclusion criteria. Median age of the patients was 46 years. Seventy-seven (93.90%) patients were male while 5 (6.09%) patients were female. Median Ryle's tube dependency was 13 days. Median follow-up period was 28 months. All the patients had acceptable cosmesis and mouth opening with minimal morbidity. PMMC flap reconstruction after marginal mandibulectomy in patients with carcinoma buccal mucosa is a robust, cosmetically, and functionally acceptable option.

Risk assessment of osteoradionecrosis associated with periodontitis using 18F-FDG PET/CT

PURPOSE

Osteoradionecrosis (ORN) is a serious complication after radiotherapy (RT), even in the era of intensity modulated radiation therapy (IMRT). The purpose of this study was to evaluate whether ¹⁸F-FDG PET/CT can predict ORN associated with periodontal disease in patients with oropharyngeal or oral cavity squamous cell carcinoma (OP/OC SCC) undergoing RT.

METHODS

One hundred and five OP/OC SCC patients treated with RT who underwent pretreatment ¹⁸F-FDG PET/CT between October 2007 and June 2016 were retrospectively reviewed. A post-treatment diagnosis of ORN was made clinically based on presence of exposed irradiated mandibular bone that failed to heal after a period of three months without persistent or recurrent tumor. The maximum standardized uptake value (SUVmax) of periodontal regions identified on PET/CT was measured for all patients. Image-based staging of periodontitis was also performed using American Academy of Periodontology staging system on CT.

RESULTS

Among 105 patients, 14 (13.3 %) developed ORN. The SUVmax of the periodontal region in patients with ORN (3.35 ± 1.23) was significantly higher than patients without ORN (1.92 ± 0.66) (P <  .01). The corresponding CT stage of periodontitis in patients with ORN was significantly higher (2.71±0.47) than patients without ORN (1.80±0.73) (P <  .01). ROC analysis revealed the cut-off values of developing ORN were 2.1 in SUVmax, and II in CT stage of periodontitis. The corresponding AUC was 0.86 and 0.82, respectively.

CONCLUSIONS

Pretreatment ¹⁸F-FDG PET/CT identification of periodontitis may be helpful to predict the future development of ORN in patients with OP/OC SCC undergoing RT.

Tooth extraction before radiotherapy is a risk factor for developing osteoradionecrosis of the jaws: A systematic review

OBJECTIVES

The aim of this systematic review was to estimate the osteoradionecrosis rate in patients with head and neck cancer due to teeth extraction performed before radiotherapy and to identify possible risk factors.

MATERIAL AND METHODS

PRISMA protocol was used to evaluate and present the results. PubMed, Scopus and Web of Science were used as search engines: English full-length papers of clinical studies, in peer-reviewed journals, were investigated. Cumulative meta-analysis was performed with a random effects model (PROSPERO registration code: CRD42018079986).

RESULTS

Among 2,020 records screened, 8 were included in this review. Sixteen of 494 patients who underwent tooth extraction before radiotherapy developed osteoradionecrosis, with an osteoradionecrosis incidence of 2.2% (95% Confidence of Interval = 0.6-3.9, p < .185, I²  = 3,044%). All cases were reported in the mandible. No other clinical risk factor for osteoradionecrosis was detected.

CONCLUSIONS

Even if it is generally recommended to remove oral foci before radiotherapy, this systematic review confirmed that teeth extractions before radiotherapy represent a risk factor for osteoradionecrosis; the considerable amount of missing data prevented us from identifying other possible risk factors for osteoradionecrosis onset. Major efforts should be done to perform sounder methodological clinical investigations.

Chinese expert group consensus on diagnosis and clinical management of osteoradionecrosis of the mandible

Osteoradionecrosis of the mandible (MORN) is one of the most devastating complications caused by radiation therapy in the head and neck region. It is characterized by infection and chronic necrosis of the mandible as the main manifestation. Clinically, MORN-related symptoms include swelling, pain, dysphagia, trismus, masticatory or speech disorders, refractory orocutaneous fistula, bone exposure, and even pathological fracture. MORN has become a challenging clinical problem for oral and maxillofacial surgeons to deal with, but thus far, this problem has not been solved due to the lack of widely accepted treatment algorithms or guidelines. Because of the nonexistence of standardized treatment criteria, most clinical treatment against MORN nowadays is largely based on controversial empirical understandings, while recommendations on post-therapeutic evaluations are scarce. Therefore, to further unify and standardize the diagnosis and treatment of MORN, to decrease the huge waste of medical resources, and ultimately, to improve the wellbeing of the patients, the Chinese Society of Oral and Maxillofacial Surgery (CSOMS) convened an expert panel specialized in MORN from 16 domestic medical colleges and affiliated hospitals to discuss the spectrum of diagnosis and and formulate treatment. In addition, consensus recommendations were also revised with a comprehensive literature review of the previous treatment experiences and research pearls. This 'expert consensus statement on diagnosis and clinical management of MORN' is for clinical reference.

Research Frontiers in Oral Toxicities of Cancer Therapies: Osteoradionecrosis of the Jaws

The deleterious effects of head and neck radiation on bone, with osteoradionecrosis (ORN) as the major disabling side effect of head and neck cancer treatment, are difficult to prevent and hard to treat. This review focuses on the current state of the science regarding the pathobiology, clinical impact, and management of ORN. With regard to the pathobiology underlying ORN, it is not yet confirmed whether the current radiation schedules by 3-dimensional conformal radiotherapy and intensity modified radiotherapy result in an unchanged, decreased, or increased risk of developing ORN when compared with conventional radiation treatment, the main risk factor being the total radiation dose delivered on any clinically significant surface of the mandible.

With regard to the prevention of ORN, a thorough, early pre-irradiation dental assessment is still considered the first step to reduce the hazard of developing ORN post-radiotherapy, and hyperbaric oxygen (HBO) treatment reduces the risk of developing ORN in case of dental surgery in an irradiated field.

With regard to the treatment of ORN, the focus is bidirectional: elimination of the necrotic bone and improving the vascularity of the normal tissues that were included in the radiation portal. The cure rate of limited ORN by conservative therapy is approximately 50%, and the cure rate of surgical approaches when conservative therapy has failed is approximately 40%.

Whether it is effective to support conservative or surgical treatment with HBO as an adjuvant is not set. HBO treatment is shown to increase the vascularity of hard and soft tissues and has been reported to be beneficial in selected cases. However, in randomized clinical trials comparing the preventive effect of HBO on developing ORN with, eg, antibiotic coverage in patients needing dental surgery, the preventive effect of HBO was not shown to surpass that of a more conservative approach.

More recently, pharmacologic management was introduced in the treatment of ORN with success, but its efficacy has to be confirmed in randomized clinical trials. The major problem of performing well-designed randomized clinical trials in ORN is having access to large numbers of patients with well-defined, comparable cases of ORN. Because many institutions will not have large numbers of such ORN cases, national and international scientific societies must be approached to join multicenter trials. Fortunately, the interest of funding organizations and the number researchers with an interest in healthy aging is growing. Research aimed at prevention and reduction of the morbidity of cancer treatment fits well within these programs.

Predicting radiation dosimetric distribution in different regions of the jaw in patients receiving radiotherapy for squamous cell carcinoma of the tonsil

BACKGROUND

Radiotherapy (RT), the main treatment for patients with head and neck cancer, can lead to dental complications.

METHODS

We identified 244 patients with squamous cell carcinoma of the tonsil treated with RT from 2004 to 2013. For each patient, we contoured the 10 tooth-bearing regions and calculated the radiation dose (gray, Gy) to each region. From this data set, we built two predictive models to determine the expected maximum radiation dose, one for the non-molar regions and another for the molar regions.

RESULTS

For the non-molars, the final model included location, T-classification, and overall stage, with a median absolute prediction error of 7.0 Gy. For the molars, the final model included location, T-classification, overall stage, and treatment year, with a median absolute error of 6.0 Gy.

CONCLUSIONS

Our current model offers a good estimation of the maximum radiation dose delivered to different regions of the jaw; future work will independently validate these models.

Definitive radiotherapy vs. postoperative radiotherapy for lower gingival carcinomas of the mandible : A single-center report about outcome and toxicity

PURPOSE

To assess radiotherapy (RT) outcomes in patients with gingival carcinoma and growth up to or involvement of the lower jaw bone.

METHODS

This was a retrospective analysis of 51 patients with squamous cell carcinomas of the gingiva. Patients received definitive (group 1, 31.4%) or postoperative (group 2, 66.7%) RT between 2005 and 2017 at the Department of Radiation Oncology, University Hospital Heidelberg. The primary endpoint was overall survival (OS) in both treatment groups. Other endpoints were local-disease-free survival (LDFS), progression-free survival (PFS) and treatment-related toxicity (Common Terminology Criteria for Adverse Events, CTCAE, Version 4.03).

RESULTS

Median age at first diagnosis was 63 years. All patients had a local advanced disease (American Joint Commission on Cancer [AJCC] stage III-IV). After a median follow-up of 22 months (range 3-145 months), 20 patients (39.2%) were still alive. At 5 years, OS rate was 36.6%. No significant differences in OS (p = 0.773), PFS (p = 0.350) and LDFS (p = 0.399) were observed between the two groups. Most common higher-grade acute RT-related complications (≥ grade 3) were dermatitis (78.2%), oral mucositis (61.7%), xerostomia (51.5%), and loss of taste (74.6%). Three cases (5.8%) of osteoradionecrosis (ORN) of the lower jaw were detected after 15-31 months.

CONCLUSIONS

Definitive and postoperative RT have similar treatment outcomes for patients with lower gingiva carcinomas of the lower jaw. The most common acute complications (grade ≥3) were dermatitis, oral mucositis, xerostomia and loss of taste.

A nomogram to predict osteoradionecrosis in oral cancer after marginal mandibulectomy and radiotherapy

OBJECTIVE

There is no useful tool to clinically predict the occurrence of osteoradionecrosis (ORN) of the mandible quantitatively. The aim was to investigate the risk factors, including different modalities of radiotherapy, for developing mandibular ORN in patients undergoing marginal mandibulectomy and postoperative radiotherapy.

METHODS

Between January 2006 and December 2012, 167 subjects who underwent marginal mandibulectomy and postoperative radiotherapy with different modalities were enrolled. The association of ORN with mandibular bone measurements and patient variables was analyzed, and a nomogram was established.

RESULTS

Fifteen (8.98%) of the 167 patients developed ORN during the follow-up period, and ORN was significantly associated with diabetes mellitus (DM), body mass index (BMI), remaining bone height, remaining bone height to original bone height ratio, resected bone height to original bone height ratio, and mandibular dose (P: < 0.001, 0.004, 0.042, 0.018, 0.010, 0.020, respectively). Interestingly, the risk of ORN had no significant difference between conformal and intensity modulation radiation therapy (P = 0.407). Multivariate analysis revealed that DM and resected bone height to original bone height ratio ≥ 50% were independent risk factors for postoperative ORN. A nomogram consisting of BMI, DM, resected bone height to original bone height ratio, mandibulotomy, and mandibular dose for predicting the ORN-free probability was established; and the c-index of the nomogram for ORN status was 0.803.

CONCLUSION

A nomogram based on the risk factors was plotted to strengthen the prediction of ORN quantitatively. Surgeons should be more discrete regarding the treatment plan for patients with higher probability of ORN.

LEVEL OF EVIDENCE

3b Laryngoscope, 130:101-107, 2020.

Is there a patient population with squamous cell carcinoma of the head and neck region who might benefit from de-intensification of postoperative radiotherapy? : A monocentric retrospective analysis of a previously defined low-risk patient population treated with standard-of-care radiotherapy

PURPOSE

The aim of this retrospective study was to evaluate the clinical outcome of a previously defined low-risk patient population with completely resected (R0) squamous cell carcinoma of the oral cavity, oropharynx, larynx (pT1-3, pN0-pN2b), hypopharynx (pT1-2, pN0-pN1), and the indication for postoperative radio(chemo)therapy.

PATIENTS AND METHODS

According to predefined criteria, 99 patients with head and neck squamous cell carcinoma (SCC) who were treated at our institution from January 1, 2005 to December 31, 2014, were available for analysis. The Kaplan-Meier method was used for calculating survival and incidence rates. For univariate comparative analysis, the log-rank test was used for analyzing prognostic clinicopathologic parameters.

RESULTS

Median follow-up was 67 months. Cumulative overall (OS) and disease-free survival (DFS) were 97.9%/94.7%/88.0% and 96.9%/92.6%/84.7% after 1, 2, and 5 years, respectively. Cumulative incidence of loco-regional recurrence (LRR), distant metastases (DM), and second cancer (SC) were 1.0%/1.0%/4.9%, 0.0%/3.4%/5.8%, and 2.1%/4.2%/13.1%, respectively. In univariate comparative analysis, location of the primary tumor in the oropharynx was a significant predictor for increased OS (p = 0.043) and DFS (p = 0.048).

CONCLUSION

Considering the low disease relapse rates and high rates of therapy-induced late side effects, as well as the increased risk of developing SC, a prospective multicentric trial investigating de-escalation of radiotherapy in this clearly defined low-risk patient population was started and is still recruiting patients (DIREKHT-Trial, NCT02528955).

Modern management of osteoradionecrosis

PURPOSE OF REVIEW

Despite recent advances in radiotherapy, osteoradionecrosis (ORN) remains a common and difficult complication of radiation therapy in head and neck cancer patients. Available treatment options are complementary to its complex pathophysiology and the currently available theories of ORN development. The efficacy of hyperbaric oxygen therapy has recently been questioned, and therapies targeting the fibroatrophic process have become a focus of ORN treatment. The objective of this review is to evaluate the literature regarding ORN of the mandible, with a focus on available treatment options.

RECENT FINDINGS

The recently proposed fibroatrophic theory has challenged the traditional hypovascular-hypoxic-hypocellular theory as the mechanism of ORN. Medical management targeting this fibroatrophic process offers promising results, but has yet to be confirmed with robust clinical trials. The routine use of hyperbaric oxygen therapy is not substantiated in the literature, but may be justified for select patients. Systemic steroids may also have a role, though data are limited.

SUMMARY

The fibroatrophic process has gained acceptance as a main mechanism of ORN. No gold standard treatment or consensus guidelines exist, though a combination of therapeutic strategies should be considered, taking into account the severity of disease and individual patient characteristics.

Treatment of late sequelae after radiotherapy for head and neck cancer

Radiotherapy (RT) is used to treat approximately 80% of patients with cancer of the head and neck. Despite enormous advances in RT planning and delivery, a significant number of patients will experience radiation-associated toxicities, especially those treated with concurrent systemic agents. Many effective management options are available for acute RT-associated toxicities, but treatment options are much more limited and of variable benefit among patients who develop late sequelae after RT. The adverse impact of developing late tissue damage in irradiated patients may range from bothersome symptoms that negatively affect their quality of life to severe life-threatening complications. In the region of the head and neck, among the most problematic late effects are impaired function of the salivary glands and swallowing apparatus. Other tissues and structures in the region may be at risk, depending mainly on the location of the irradiated tumor relative to the mandible and hearing apparatus. Here, we review the available evidence on the use of different therapeutic strategies to alleviate common late sequelae of RT in head and neck cancer patients, with a focus on the critical assessment of the treatment options for xerostomia, dysphagia, mandibular osteoradionecrosis, trismus, and hearing loss.

Outcomes of oral cavity cancer patients treated with surgery followed by postoperative intensity modulated radiation therapy

OBJECTIVES

Although treatment paradigms have not changed significantly, radiotherapy, surgery, and imaging techniques have improved, leading us to investigate oncologic and survival outcomes for oral cavity squamous cell cancer (OCSCC) patients treated with surgery followed by postoperative IMRT.

MATERIAL AND METHODS

Records of patients with pathological diagnosis of OCSCC treated between 2000 and 2012 were retrospectively reviewed. Patients' demographic, disease, and treatment criteria were extracted. Kaplan-Meier method was used to calculate survival curves.

RESULTS

Two hundred eighty-nine patients were analyzed. Median follow-up was 35months. Two hundred sixty-eight had neck dissections (93%), of which 66% had nodal involvement, and 51% of those positive dissections had extracapsular extension. Forty patients received induction chemotherapy and 107 received concurrent chemotherapy. Median dose to high risk clinical target volume was 60Gy/30 fractions. The 5-year locoregional control and overall survival rates were 76% and 57%, respectively. Tumors with >1.5cm depth of invasion had significantly higher risk of local failure compared with ≤1.5cm (p<0.001). In multivariate analysis, positive and no neck dissection (p=0.01), positive lymphovascular invasion (p=0.006) and >1.5cm depth of invasion (p=0.003) were independent predictors of poorer survival.

CONCLUSIONS

Disease outcomes were consistent with historical data and did not appear compromised by the use of IMRT.

Osteoradionecrosis of the mandible in patients with oropharyngeal carcinoma treated with intensity-modulated radiotherapy

BACKGROUND

Osteoradionecrosis (ORN) of the mandible is a late toxicity affecting patients treated with radiotherapy for head and neck malignancies. To the authors' knowledge, ORN has no standardized grading system and its reporting is based on retrospective findings in heterogeneous patient populations. The rate of ORN in the era of intensity-modulated radiotherapy (IMRT) still is unknown.

METHODS

The authors report the incidence of ORN from prospectively collected data regarding 1196 patients who were diagnosed with squamous cell carcinoma of the oropharynx and treated with curative-intent IMRT, with or without concomitant systemic treatment, from January 2005 to December 2014. Each case of ORN was graded according to its severity. Clinical and dosimetric comparisons were performed between patients with ORN and a matched control cohort of patients without ORN.

RESULTS

The actuarial rate of ORN of the mandible was 3% at 1 year, 5% at 3 years, and 7% at 5 years. On multivariable analysis, smoking (hazard ratio, 1.9; 95% confidence interval, 1.07-3.4 [P = .03]) and T classification (hazard ratio, 1.78; 95% confidence interval, 1.02-3.1 [P = .041]) were found to be statistically significant risk factors. The presence of cardiovascular comorbidities, use of bisphosphonates, and pre-IMRT dental extractions were found to be different between the matched cohorts. The mandibular volume receiving 50 grays (Gy) (in cm³ ) and the volume receiving 60 Gy (in cm³ ) were found to be associated with ORN on multivariable analysis in the matched cohort patients receiving an IMRT regimen of 2 Gy per fraction.

CONCLUSIONS

ORN is relatively uncommon among patients with oropharyngeal carcinoma who are treated with IMRT, but continues to occur beyond 5 years after treatment. Modifiable risk factors that are associated with higher rates of ORN include smoking and the use of bisphosphonates. Minimizing the volumes of the mandible receiving >50 Gy or > 60 Gy also may have an effect on the ORN rate. Cancer 2017;123:3691-3700. © 2017 American Cancer Society.

The prevalence and risk factors associated with osteoradionecrosis of the jaw in oral and oropharyngeal cancer patients treated with intensity-modulated radiation therapy (IMRT): The Memorial Sloan Kettering Cancer Center experience

OBJECTIVE

To determine the prevalence and correlation of various risk factors [radiation dose, periodontal status, alcohol and smoking] to the development of osteoradionecrosis (ORN).

PATIENTS AND METHODS

The records of 1023 patients treated with IMRT for oral cavity cancer (OCC) and oropharyngeal cancer (OPC) between 2004 and 2013 were retrospectively reviewed to identify patients who developed ORN. Fisher exact tests were used to analyze patient characteristics between ORN patients with OCC and OPC. Paired Wilcoxon tests were used to compare the dose volumes to the ORN and contralateral non-ORN sites. To evaluate an association between ORN and risk factors, a case-control comparison was performed. One to 2 ORN-free patients were selected to match each ORN patient by gender, tumor site and size. General estimation equations models were used to compare the risk factors in ORN cases and matched controls.

RESULTS

44 (4.3%) patients developed ORN during a median follow-up time of 52.5months. In 82% of patients, ORN occurred spontaneously. Patients with OPC are prone to develop ORN earlier compared to patients with OCC (P=0.03). OPC patients received a higher Dmax compared to OCC patients (P=0.01). In the matched case-control analysis the significant risk factors on univariate analysis were poor periodontal status, history of alcohol use and radiation dose (P=0.03, 0.002 and 0.009, respectively) and on multivariate analysis were alcohol use and radiation dose (P=0.004 and 0.026, respectively).

CONCLUSION

In our study, higher radiation dose, poor periodontal status and alcohol use are significantly related to the risk of developing ORN.

Potential risk factors for jaw osteoradionecrosis after radiotherapy for head and neck cancer

INTRODUCTION

To identify potential risk factors for the development of jaw osteoradionecrosis (ORN) after 3D-conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) among patients with newly diagnosed head and neck cancer.

MATERIAL AND METHODS

This study included 776 patients who underwent 3D-CRT or IMRT for head and neck cancer at the Department of Radiotherapy at the University Hospital Halle-Wittenberg between 2003 and 2013. Sex, dental status prior to radiotherapy, tumor site, bone surgery during tumor resection, concomitant chemotherapy, and the development of advanced ORN were documented for each patient. ORN was classified as grade 3, 4, or 5 according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer classification or grade 3 or 4 according to the late effects in normal tissues/subjective, objective, management, and analytic scale. The cumulative incidence of ORN was estimated. Cox regression analysis was used to identify prognostic risk factors for the development of ORN.

RESULTS

Fifty-one patients developed advanced ORN (relative frequency 6.6 %, cumulative incidence 12.4 %). The highest risk was found in patients who had undergone primary bone surgery during tumor resection (hazard ratio [HR] = 5.87; 95 % confidence interval [CI]: 3.09-11.19) and in patients with tumors located in the oral cavity (HR = 4.69; 95 % CI: 1.33-16.52). Sex, dentition (dentulous vs. edentulous), and chemotherapy had no clinically relevant influence.

DISCUSSION AND CONCLUSION

In contrast to most previous studies, we noted a low cumulative incidence of advanced ORN. Patients with tumors located in the oral cavity and those who undergo bone surgery during tumor resection prior to RT may be considered a high-risk group for the development of ORN.

Comparison of mean radiation dose and dosimetric distribution to tooth-bearing regions of the mandible associated with proton beam radiation therapy and intensity-modulated radiation therapy for ipsilateral head and neck tumor

OBJECTIVE

The purpose of this study was to compare the dosimetric distribution of ipsilateral proton beam radiation therapy (PBRT) with intensity-modulated radiation therapy (IMRT) in the tooth-bearing region of the mandible in patients with head and neck cancer (HNC).

STUDY DESIGN

The mandibular dosimetric distribution in patients with head and neck cancer treated with ≥60 Gy relative biologic equivalent PBRT was evaluated. The mean radiation doses were calculated in 5 regions: ipsilateral molar, ipsilateral premolar, anterior, contralateral premolar, and contralateral molar (CM) regions. CM was used as the reference region for comparative analysis. The mandibular dosimetric distribution in patients treated with PBRT was compared with that in IMRT patients with similar tumor sites and planning target volumes.

RESULTS

The mean radiation dose to the contralateral regions was lower in patients treated with PBRT compared with those treated with IMRT. The average mean radiation doses to the reference region (CM) in patients treated with PBRT (relative biologic equivalent) versus IMRT were oropharynx (2.2 Gy vs 23.2 Gy; P < .00002), parotid (0 Gy vs 11.8 Gy; P = .01), and oral cavity (0.4 Gy vs 15.6 Gy; P = .006).

CONCLUSIONS

This study revealed the effective tissue-sparing capability of PBRT compared with IMRT. Utilization of PBRT could translate to less radiation-related toxicity.

Healing of a soft tissue wound of the neck and jaw osteoradionecrosis using platelet gel

AIM

Bone osteoradionecrosis is a serious complication of radiation treatment. Current treatment approaches are not curative and treatment response is often poor leading to high social and healthcare costs.

CASE REPORT

We report on the first case of osteoradionecrosis with successful restitutio ab integro by repeated administration of platelet gel (PLT-gel) and surgery in a critically ill patient. The administration of PLT-gel during a severe septic episode helped regeneration of bone and soft tissues, shortening the hospital stay of the patient. It was also noted that following applications of PLT-gel, both the use of morphine and the numbers of infective episodes were reduced.

CONCLUSION

Additional studies are needed to confirm the promising effect of PLT-gel for the treatment of osteoradionecrosis.