Osteoradionecrosis: a new concept of its pathophysiology

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

OBJECTIVES

To gain a consensus from consultants in restorative dentistry about the types of teeth that should be extracted from head and neck cancer patients (HNC) pre-radiotherapy.

MATERIALS

Literature- and clinician-informed questionnaires were emailed to an 'expert panel' of consultants (n = 24/28; 86%) in the United Kingdom (UK) and Ireland on three consecutive occasions (Delphi rounds). The results of Round 1 were used to revise the questionnaire that was distributed in Round 2, and this procedure was repeated for Round 3. During Rounds 2 and 3, participants were asked to indicate, on a 5-point Likert scale, their level of agreement with a series of statements on the types of teeth that should be extracted pre-radiotherapy. The target level of consensus for each statement was 70%.

RESULTS

In Round 2, there was consensus-agreement for 69 of 102 statements (i.e. ≥ 70% of participants rated 'agree' or 'strongly agree' to the relevant statement). Consensus agreement was also achieved for 20 of 28 statements in Round 3. Therefore, a total of 89 consensus statements are presented that illuminate the decision-making process for the pre-radiotherapy extraction of molar, premolar, and anterior teeth with periodontal pocketing, furcation disease, mobility, caries, tooth-wear, apical disease, or other pathology.

CONCLUSION

The statements represent the consensus professional views of participated consultants in restorative dentistry in the UK and Ireland regarding the types of teeth that should be extracted from HNC patients pre-radiotherapy. The results provide a platform for the development of future guidelines.

CLINICAL SIGNIFICANCE

Pre-radiotherapy dental assessments for head and neck cancer patients are considered mandatory. This study presents different criteria that should be considered for the treatment planning of these patients in relation to pre-radiotherapy extractions, according to the collective consensus opinion of participated consultants in restorative dentistry in the UK and Ireland.

Leukocyte- and platelet-rich fibrin as an adjuvant to the surgical approach for osteoradionecrosis: a case report

We present a case of osteoradionecrosis treated with leukocyte- and platelet-rich fibrin (LPRF) and surgery and followed up with clinical and tomographic investigations. A 65-year-old woman presented with pain in the posterior region of the right palate. Her medical history included cardiovascular disease and squamous cell carcinoma in the anterior region of the floor of the mouth that had been treated with intensity-modulated radiation therapy. Measurements of isodose curves showed a full dosage of 6,462.6 cGy in the anterior mandibular region, whereas that in the posterior region on the right side of the maxilla reached 5,708.1 cGy. Osteotomy was performed using rotary instruments, and debridement and placement of two LPRF membranes were also carried out. New gum tissue with no bone exposure was noted 14 days postoperatively. Tissue repair was complete, and the patient had no further complaints. During a 39-month follow-up period, the oral mucosa remained intact, and the patient was rehabilitated with a new upper denture. Since there is no consensus regarding the best protocol to treat osteoradionecrosis, LPRF might be an interesting adjuvant to a surgical approach. The use of LPRF is simple and reduces operational costs, time of handling, probability of technical failure, and associated morbidities for patients with osteoradionecrosis.

Effect of α2‑macroglobulin in the early stage of jaw osteoradionecrosis

Advanced osteoradionecrosis (ORN) is one of the most serious complications in patients with head and neck cancer, resulting in poor prognosis. Numerous studies have therefore focused on the pathogenesis and interventions of ORN early stage. The present study aimed to investigate whether α2-macroglobulin (α2M) could prevent early-stage jaw osteoradionecrosis caused by radiotherapy (RT). Following local injection of α2M, a single dose of 30 Gy was delivered to rats for pathological exploration. For 28 days, the irradiated mandible and soft tissues were examined for potential changes. Furthermore, primary human bone marrow mesenchymal stem cells pretreated with α2M followed by 8 Gy irradiation (IR) were also used. Tartrate-resistant acid phosphatase assay, terminal uridine deoxynucleotidyl nick end labeling assay and immunohistochemical staining were performed on irradiated mandibular bone, tongue or buccal mucosa tissues from rats. Cell proliferation was assessed by evaluating the cell morphology by microscopy and by using the cell counting kit-8. Fluorescence staining, flow cytometry and western blotting were conducted to detect the reactive oxygen species level, cell apoptosis and protein expression of superoxide dismutase 2 (SOD2), heme oxygenase-1 (HO-1) and phosphorylated Akt following irradiation. The results demonstrated that α2M attenuated physical inflammation, osteoclasts number and fat vacuole accumulation in mandibular bone marrow and bone marrow cell apoptosis following IR in vivo. Furthermore, α2M pretreatment suppressed the expression of 8-hydroxy-2′-deoxyguanosine in mandibular bone and tongue paraffin embedded sections, which is a marker of oxidative damage, and increased SOD2 expression in mucosa and tongue paraffin embedded sections. The present study demonstrated the efficient regulation of antioxidative enzymes, including SOD2 and heme oxygenase-1, and reduction in oxidative damage by α2M. In addition, in vitro results confirmed that α2M may protect cells from apoptosis and suppress reactive oxygen species accumulation. Overall, the present study demonstrated that α2M treatment may exert some radioprotective effects in early-stage ORN via antioxidant mechanisms, and may therefore be considered as a potential alternative molecule in clinical prophylactic treatments.

Risk assessment for osteoradionecrosis of the jaws in patients with head and neck cancer

Objectives

To identify the potential risk factors for the occurrence of osteoradionecrosis (ORN) of the jaws among patients who have been treated with radiotherapy for head and neck malignancy.

Methods

The study comprised of 231 patients treated with radiotherapy for head and neck malignancy at a tertiary referral center. The following details were recorded for each patient: age, gender, histopathological diagnosis, clinical staging, tumor site, treatment modality, radiation dose, radiation field, number of fractions, type of accelerator used, radiation area and duration of follow-up. Patient’s tobacco, alcohol habit history, and history of extraction of teeth before/during/after radiotherapy were also noted.

Results

Thirteen patients had osteoradionecrosis (frequency 5.62%). Among the radiotherapy variables assessed, increased radiation area was found to be significantly associated with the occurrence of osteoradionecrosis. Among the 13 ORN cases, 10 (76.9%) had a history of tobacco consumption, 8 (61.5%) had a time interval between radiotherapy and occurrence of ORN of less than 1-year duration.

Conclusions

We found a low cumulative incidence of osteoradionecrosis and a tendency to occur within a year of starting radiotherapy. Patients of older age, those with a prior tobacco habit may be considered more liable to develop osteoradionecrosis. A larger radiation field may also put patients at hazard for developing osteoradionecrosis.

Effect of relevant factors on radiation-induced nasopharyngeal ulcer in patients with primary nasopharyngeal carcinoma treated with intensity-modulated radiation therapy

OBJECTIVE

To analyze the correlation between relevant factors and radiation-induced nasopharyngeal ulcer (RINU) in primary nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT).

METHODS

Clinical data were collected for 599 patients with newly diagnosed NPC who had completed IMRT. The entire cohort was randomly divided into two subgroups. The relationship between RINU and IMRT dose-volume were statistically analyzed with ROC curves and the Chi-square test. Nutritional status during and after treatment was compared between patients with vs without RINU.

RESULTS

The results obtained showed that dose-volume had no effect on the incidence of RINU (P > .05). Nutrition-related parameters differed significantly between patients with vs without RINU (P < .05).

CONCLUSION

The results obtained show that the incidence of RINU is not related to IMRT dose-volume in the treatment of primary NPC. The incidence of RINU was found to be related to nutritional status during and after radiation therapy.

LEVEL OF EVIDENCE

2a.

Osteoradionecrosis of the Occipitocervical Junction After Radiation for Head and Neck Cancer: A Report of 8 Cases

BACKGROUND

Osteoradionecrosis (ORN) refers to the degenerative changes seen in bone after local radiation, particularly in head and neck cancer. ORN can present as neck or facial pain and may be confused with tumor recurrence. Magnetic resonance imaging (MRI) and positron emission tomography (PET) scans are often inconclusive, requiring percutaneous biopsy to differentiate ORN from infection and recurrent disease. We reviewed the utility of preprocedural imaging in guiding the decision to biopsy in cases of ORN.

CASE DESCRIPTION

Eight patients with a history of prior head and neck cancer, radiation therapy, and suspected ORN at the skull base, occipitocervical junction, and atlantoaxial spine were identified retrospectively from a single academic medical center. In 4 cases, MRI findings and PET imaging were negative for recurrence. One patient in this group underwent an aborted biopsy. Four patients had MRI concerning for infection or recurrent tumor with PET-positive lesions. Three patients in this group underwent biopsy that was negative for recurrent tumor. One patient developed an arteriovenous fistula after biopsy. The fourth patient was observed and did not demonstrate progression at 5 months. At last follow-up for all patients, there was no evidence of tumor recurrence or metastasis at the index site to indicate a misdiagnosis for recurrent tumor.

CONCLUSIONS

This case series highlights that PET scanning may not be useful in predicting which patients will benefit from biopsy for ORN because no patients with PET-positive lesions had histopathologic evidence of tumor recurrence or metastasis on biopsy.

Osteoradionecrosis of the Chest Wall

We present the case of a 48-year-old woman with a chronic ulcer with bony erosion over the right chest wall who had undergone adjuvant chemoradiotherapy for right breast cancer 18 years previously. Preoperative computed tomography revealed a large soft tissue ulcerative lesion with bony destruction of the anterolateral aspect of the right fifth and sixth ribs. Biopsy showed no evidence of recurrent malignancy. En bloc resection including the necrotic ulcer and partial resection of the fourth to sixth ribs was performed, resulting in a chest wall defect that exposed the right diaphragm and the right, middle, and lower lobes of the lung. Synthetic mesh was used to reconstruct the rib defect and prevent paradoxical respiration. A pedicle transverse rectus abdominis musculocutaneous flap was used for soft tissue and skin reconstruction.

Effects of pentoxifylline and tocopherol on an osteoradionecrosis animal model

PURPOSE

Osteoradionecrosis (ORN) is known to be a refractory disease in the oral and maxillofacial field. The purpose of this study was to examine the effects of pentoxifylline (PTX) and tocopherol (TP) on an ORN animal model focused on bone healing.

MATERIALS AND METHODS

A total of 48 Sprague-Dawley rats were used: 40 received a single irradiation dose of 35 Gy on the left mandible, and eight were used as the nonirradiated control group. The rats received PTX (T1, C1), TP (T2, C2), a combination of PTX and TP (T3, C3), or normal saline (T4, C4). Three weeks after irradiation, the mandibular posterior teeth were extracted. The rats were sacrificed 4 weeks after extraction.

RESULTS

In the T3 group, bone volume/tissue volume was 19.62 ± 16.03 (%), bone mineral density was as 0.31 ± 0.16 (g/cm³) in the micro-CT analysis, which were higher than that of other groups (p = 0.025, p = 0.012, respectively). In the histological analysis, bone regeneration was the most prominent in the T3 group. The ratio of empty lacunae was the highest in the T4 group, 68.77 ± 15.47 (%, p = 0.004). Immunohistochemistry showed that the expression of TNF-α was relatively lower in the T3 than in the T4 or T2 groups. The RT-qPCR showed the expression level of PECAM, VEGF-A, and osteocalcin was more than twofold as high as in the T3 group compared to the other groups.

CONCLUSION

The combination of PTX and TP appears to promote angiogenesis and osteogenesis in a rat ORN model. Therefore, PTX and TP might be useful in the treatment and prevention of ORN.

The Outcome of Primary Root Canal Treatment in Postirradiated Patients: A Case Series

Osteoradionecrosis (ORN) of the jaw is considered the most severe long-term adverse effect that can occur in radiation therapy patients. Teeth extractions and dental diseases are the main risk factors for ORN in irradiated patients. The aim of this case series was to evaluate the outcome of primary root canal treatments performed on patients who underwent head and neck radiotherapy and to evaluate any ORN related to the endodontic treatment. In this case series, primary root canal therapies (absence of radiolucency) were performed on 10 teeth of 8 patients who underwent radiotherapy for head and neck cancers. Radiation doses to the periapical area were calculated using the radiotherapy planning computed tomographic scan. After a 277-day mean follow-up, all patients were asymptomatic, no teeth showed periapical radiolucency, and no ORN was observed. Even if a limitation of buccal opening occurred after radiotherapy and complicated the endodontic procedures, root canal therapy seemed to be safe and a valid alternative to tooth extraction.

Oral management strategies for radiotherapy of head and neck cancer

Radiotherapy, often with concomitant chemotherapy, has a significant role in the management of head and neck cancer, however, radiotherapy induces adverse events include oral mucositis, hyposalivation, loss of taste, dental caries, osteoradionecrosis, and trismus, all of which have an impact on patients’ quality of life. Therefore, it is necessary to implement oral management strategies prior to the initiation of radiotherapy in patients with head and neck cancer. Since 2014, the National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology (NCCN Guidelines) have enumerated the “Principles of Dental Evaluation and Management (DENT-A)” in the section on head and neck cancers, however, oral management was not explained in detail. Oral management has not been achieved a consensus protocol. The aim of this literature is to show that oral management strategy include removal infected teeth before the start of radiotherapy to prevent osteoradionecrosis, oral care for preventing severe oral mucositis to support patient complete radiotherapy during radiotherapy, and prevent of dental caries followed by osteoradionecrosis after radiotherapy.

Bench to Bedside: Animal Models of Radiation Induced Musculoskeletal Toxicity

Ionizing radiation is a critical aspect of current cancer therapy. While classically mature bone was thought to be relatively radio-resistant, more recent data have shown this to not be the case. Radiation therapy (RT)-induced bone loss leading to fracture is a source of substantial morbidity. The mechanisms of RT likely involve multiple pathways, including changes in angiogenesis and bone vasculature, osteoblast damage/suppression, and increased osteoclast activity. The majority of bone loss appears to occur rapidly after exposure to ionizing RT, with significant changes in cortical thickness being detectable on computed tomography (CT) within three to four months. Additionally, there is a dose–response relationship. Cortical thinning is especially notable in areas of bone that receive >40 gray (Gy). Methods to mitigate toxicity due to RT-induced bone loss is an area of active investigation. There is an accruing clinical trial investigating the use of risderonate, a bisphosphonate, to prevent rib bone loss in patients undergoing lung stereotactic body radiation therapy (SBRT). Additionally, several other promising therapeutic/preventative approaches are being explored in preclinical studies, including parathyroid hormone (PTH), amifostine, and mechanical loading of irradiated bones.

Microbial etiology, susceptibility profile of postradiation nasopharyngeal necrosis patients with nasopharyngeal carcinoma

OBJECTIVE

Postradiation nasopharyngeal necrosis (PRNN) is a notorious complication after radiotherapy that affects prognosis in patients with nasopharyngeal carcinoma (NPC). It is important for clinical doctors to realize this problem in order to cope with this severe clinical situation. The aim of our study was to assess the bacteriology of PRNN and to demonstrate the antimicrobial susceptibility pattern that should guide the clinicians towards more appropriate antibiotic use.

METHODS

Sixty-nine NPC patients with PRNN in our department between March 2013 and December 2017 were retrospectively enrolled. Pathogenic culture and drug sensitivity test were performed in these 69 NPC patients with PRNN. The infection rate of Pathogens and the sensitivity of the drugs were analyzed based on these results.

RESULTS

Sixty-nine NPC patients with PRNN were enrolled in our study. Pathogens were identified in 58 (84%) patients. Of the 58 patients, Staphylococcus aureus was isolated in 34 (58.6%) patients. And the second most common group of bacterial isolates was Pseudomonas aeruginosa. Antibiotic sensitivity showed that Levofloxacin was the highest (88.5%), followed by Ciprofloxacin (85.2%) and Gentamicin (80.3%). The only pathologic fungus was Candidaalbicans, about 6.8%. The positive rates of bacterial and fungal culture in PRNN patients were not significantly different from the patients' gender, age, stage, number of radiotherapy courses (P>0.05), but the cure rate was statistically higher in culture-negative patients in comparison with culture-positive patients (63.6% vs 20.7%, P=0.011).

CONCLUSION

Our results provide an overall picture of the microbiology and drug susceptibility patterns for NPC patients with PRNN and could help implement guidelines for more rational treatment and improve therapeutic outcome.

Bisphosphonate-induced reactive oxygen species inhibit proliferation and migration of oral fibroblasts: A pathogenesis of bisphosphonate-related osteonecrosis of the jaw

BACKGROUND

The onset mechanism for bisphosphonate-related osteonecrosis of the jaw (BRONJ) has been reported, with a focus on bone remodeling, biofilm formation, and epithelial cell proliferation and migration. However, the involvement of stromal cells, especially fibroblasts, in the oral cavity is unclear. Therefore, this study was focused on how bisphosphonates (BPs) affect orthotopic periodontal ligament fibroblasts from the viewpoint of oxidative stress compared with ectopically obtained fibroblasts.

METHODS

Normal human periodontal ligament fibroblasts (HPdLFs) and normal human dermal fibroblasts (NHDFs) were used to gain insight into the functional differences in sensitivity and reactions to BPs. Cell growth assay, measurement of reactive oxygen species (ROS) and nitric oxide (NO) production, and wound-healing assay in vitro were performed. Maxillary first molars were extracted in C57BL/6 mice and either BP, N-acetyl-cysteine (NAC), and BP or saline were administered.

RESULTS

BP-induced IC₅₀ values were significantly lower in HPdLFs (30.6 µM) than in NHDFs (109.7 µM). BP resulted in an increase in ROS, but not NO generation in HPdLFs. BPs also inhibited proliferation and migration of HPdLFs but not NHDFs, while the addition of a ROS inhibitor, NAC, reversed those inhibitions. A BRONJ mouse model in which BP was administered and then the tooth was extracted, impaired wound healing of the socket was observed. When NAC was administered before tooth extraction, wound healing was significantly improved.

CONCLUSION

These results suggest that BP causes fibroblasts obtained from the oral cavity but not from skin to generate ROS and that the subsequent ROS-mediated inhibition of fibroblast growth and migration definitely delays wound healing, thereby contributing to BRONJ pathogenesis.

Development and Characterization of a Rabbit Model of Compromised Maxillofacial Wound Healing

IMPACT STATEMENT

Maxillofacial defects often present the clinical challenge of a compromised wound bed. Preclinical evaluation of tissue engineering techniques developed to facilitate healing and reconstruction typically involves animal models with ideal wound beds. The healthy wound bed scenario does not fully mimic the complex clinical environment in patients, which can lead to technology failure when translating from preclinical in vivo research to clinical use. The reported preclinical animal model of compromised wound healing enables investigation of tissue engineering technologies in a more clinically relevant scenario, potentially fostering translation of promising results in preclinical research to patients.

Interventions for preventing osteoradionecrosis of the jaws in adults receiving head and neck radiotherapy

BACKGROUND

Osteoradionecrosis (ORN) of the jaws is among the most serious oral complications of head and neck cancer radiotherapy, arising from radiation-induced fibro-atrophic tissue injury, manifested by necrosis of osseous tissues and failure to heal, often secondary to operative interventions in the oral cavity. It is associated with considerable morbidity and has important quality of life ramifications. Since ORN is very difficult to treat effectively, preventive measures to limit the onset of this disease are needed; however, the effects of various preventive interventions has not been adequately quantified.

OBJECTIVES

To assess the effects of interventions for preventing ORN of the jaws in adult patients with head and neck cancer undergoing curative or adjuvant (i.e. non-palliative) radiotherapy.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 5 November 2019), the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 10) in the Cochrane Library (searched 5 November 2019), MEDLINE Ovid (1946 to 5 November 2019), Embase Ovid (1980 to 5 November 2019), Allied and Complementary Medicine (AMED) Ovid (1985 to 5 November 2019), Scopus (1966 to 5 November 2019), Proquest Dissertations and Theses International (1861 to 5 November 2019) and Web of Science Conference Proceedings (1990 to 5 November 2019). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) or quasi-RCTs of adult patients 18 years or older with head and neck cancer who had undergone curative or adjuvant radiotherapy to the head and neck, who had received an intervention to prevent the onset of ORN. Eligible patients were those subjected to pre- or post-irradiation dental evaluation. Management of these patients was to be with interventions independent of their cancer therapy, including but not limited to local, systemic, or behavioural interventions.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials from search results, assessed risk of bias, and extracted relevant data for inclusion in the review. Authors of included studies were contacted to request missing data. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Four studies were identified that met pre-determined eligibility criteria, evaluating a total of 342 adults. From the four studies, all assessed as at high risk of bias, three broad interventions were identified that may potentially reduce the risk of ORN development: one study showed no reduction in ORN when using platelet-rich plasma placed in the extraction sockets of prophylactically removed healthy mandibular molar teeth prior to radiotherapy (odds ratio (OR) 3.32, 95% confidence interval (CI) 0.58 to 19.09; one trial, 44 participants; very low-certainty evidence). Another study involved comparing fluoride gel and high-content fluoride toothpaste (1350 parts per million (ppm)) in prevention of post-radiation caries, and found no difference between their use as no cases of ORN were reported (one trial, 220 participants; very low-certainty evidence). The other two studies involved the use of perioperative hyperbaric oxygen (HBO) therapy and antibiotics. One study showed that treatment with HBO caused a reduction in the development of ORN in comparison to patients treated with antibiotics following dental extractions (risk ratio (RR) 0.18, 95% CI 0.43 to 0.76; one trial, 74 participants; very low-certainty evidence). Another study found no difference between combined HBO and antibiotics compared to antibiotics alone prior to dental implant placement (RR 3.00, 95% CI 0.14 to 65.16; one trial, 26 participants; very low-certainty evidence). Adverse effects of the different interventions were not reported clearly or were not important.

AUTHORS' CONCLUSIONS

Given the suboptimal reporting and inadequate sample sizes of the included studies, evidence regarding the interventions evaluated by the trials included in this review is uncertain. More well-designed RCTs with larger samples are required to make conclusive statements regarding the efficacy of these interventions.

Rotational Tibio-Pelvic Constrained Hip Arthroplasty: A Surgical Technique: A Case Report

CASE

A 25-year-old man presented with chronic bone and soft tissue infection of the right thigh following resection and radiation of epithelioid sarcoma. Multiple revisions and debridement procedures had failed to control the infection and left him unable to ambulate. We describe a modified Van Nes rotationplasty using a constrained, prosthetic hip between the tibia and pelvis following femur resection. With 18 months of follow-up, the patient was able to walk with a prosthetic device without evidence of recurrent infection.

CONCLUSIONS

We report this rotationplasty as a potential approach to avoid hip disarticulation in cases requiring extensive debridement for incurable infection.

Osteoradionecrosis of the Temporal Bone: An Evidence-Based Approach

OBJECTIVES

To perform a systematic review evaluating etiologies, associated complications, and management of osteoradionecrosis of the temporal bone (ORNTB).

METHODS

The authors searched the PubMed, Embase, and Cochrane Library databases for relevant literature. Patient demographics, etiologies, treatments, and other clinical characteristics were obtained. Treatment success was defined as resolution of symptoms at last follow-up. Results were reported using the preferred reporting systems for systematic reviews and meta-analysis (PRISMA) guidelines.

RESULTS

Thirty-eight studies encompassing 364 patients with ORNTB were identified. The most common etiologies necessitating radiotherapy included: nasopharyngeal carcinoma (n = 133 [36.8%]), parotid tumors (n = 73 [20.2%]), and external auditory canal pathology (n = 59 [16.3%]). The mean dose of radiation was 58.0 Gy. The mean lag time between radiotherapy and osteoradionecrosis (ORN) symptoms was 7.9 years. The most common presenting symptoms were purulent otorrhea (33.3%), hearing loss (29.1%), and otalgia (17%). ORNTB complications included tympanic membrane perforation (n = 102 [63.8%]) and chronic otitis media (n = 16 [10%]). Treatments included lateral temporal bone resection (n = 99 [28.3%]), conservative treatment (n = 92 [26.3%]), and mastoidectomy (n = 82 [23.5%]) with 90.9, 89.13, and 59.76% considered successful, respectively.

CONCLUSIONS

ORNTB is a rare complication of radiotherapy that may present years after initial radiation exposure. Management should be aimed at relief of presenting symptoms and treatment of ORNTB associated complications. Both conservative and surgical measures may adequately control the disease process and symptomatology; however, randomized controlled studies comparing treatments would serve to further corroborate these findings.

New Therapeutic Approaches to Osteoradionecrosis: Literature Review

AbstractRadiotherapy is an important treatment of oral and maxillofacial malignancies. Among the various effects of this locoregional therapy, osteoradionecrosis (ORN) plays a prominent role due to its physical and psychological impact on cancer patients. In the literature, the therapeutic approach of ORN varies from a conservative to invasive surgery treatment. Objective: collect in the scientific literature, concise and current information about the benefits of using these therapies in the ORN. The present literature review selected articles based on the titles that addressed osteoradionecrosis treatment, as well as the evaluation systems adopted. After previous analysis, 22 relevant articles were included on the proposed theme. According to the literature, several hypotheses have been established to explain the etiopathogenesis of ORN, as numerous evaluation systems have been developed in the last years. Regarding the main therapeutic modalities used, new less invasive therapies have acquired space, such as ozone therapy, laser therapy associated with photodynamic therapy and drugs, such as vitamin, antifibrotic and anti-resorptive. However, in spite of the promising results, new randomized clinical trials have to be performed in an attempt to discover the real effectiveness of these therapies in the ORN. Therefore, it becomes a challenging issue for dental surgeons, since it requires the constant monitoring and long term of these patients, due to the risk of progression or recurrence of this condition.Keywords: Radiotherapy. Osteoradionecrosis. Conservative Treatment. Ozone. Photochemotherapy.ResumoA radioterapia compreende um tratamento importante no tratamento de tumores malignos orais e maxilofaciais. Dentre os diversos efeitos oriundos desta terapia locoregional, a osteorradionecrose (ORN) apresenta um papel de destaque devido ao seu impacto físico e psicológico ao paciente oncológico. A abordagem terapêutica da ORN pode variar do tratamento conservador ao tratamento invasivo através da cirurgia. Objetivo coletar na literatura científica informações concisas e atuais acerca dos benefícos do uso dessas terapias na ORN. A presente revisão narrativa de literatura teve a seleção de artigos com base nos títulos que abordaram as terapias empregadas na osteorradionecrose, bem como os sistemas de avaliação adotados. Após análise prévia, foram incluídos 39 artigos relevantes sobre a temática proposta. De acordo com a literatura, várias hipóteses foram estabelecidas para explicar a etiopatogenia da ORN, assim como inúmeros sistemas de avaliação foram desenvolvidos nos últimos anos. Com relação as principais modalidades terapêuticas empregadas, novas terapias menos invasivas têm adquirido espaço, a exemplo da ozonioterapia, laserterapia associada à terapia fotodinâmica e medicamentos antioxidantes, antifibróticos e antireabsortivos. Todavia, apesar dos resultados promissores, novos ensaios clínicos precisam ser realizados, para se descobrir a real eficácia dessas terapias na ORN. Portanto, torna-se uma questão desafiadora para os Cirurgiões dentistas, uma vez que requer o monitoramento constante e a longo prazo desses pacientes, devido ao risco de progressão ou recidiva desta afecção.Palavras-chave: Radioterapia. Osteoradionecrosis. Tratamento Conservador. Ozônio. Fotoquimioterapia.

Primary vs Secondary Endosseous Implantation After Fibular Free Tissue Reconstruction of the Mandible for Osteoradionecrosis

Importance

The clinical and financial implications of the timing of dental rehabilitation after a fibula free tissue transfer (FFTT) for osteoradionecrosis (ORN) and osteonecrosis (ON) of the mandible have yet to be established.

Objective

To compare the outcomes of primary implantation vs secondary implantation after FFTT for ORN and ON of the mandible.

Design, Setting, and Participants

A retrospective review was conducted of 23 patients at a single tertiary academic referral center undergoing primary implantation or secondary implantation after FFTT for ORN and ON from January 1, 2006, to November 10, 2015.

Interventions

All patients underwent FFTT with primary implantation (n = 12) or secondary implantation (n = 11).

Main Outcomes and Measures

Outcomes of FFTT, dental implantation, implant use, diet, speech, and disease-free survival were reviewed. Fixed unit costs were estimated based on the mean cost analysis.

Results

Twenty-three patients (7 women and 16 men; mean [SD] age, 62.4 [8.2] years [range, 24-81 years]) met the inclusion criteria. Of these, 18 had ORN and 5 had ON. Dental implantation was performed at the time of FFTT for 12 patients and was performed secondarily for 11 patients. There were a mean of 5.2 implants per patient performed, for a total of 121 implants. There was 1 complete flap failure in the primary implantation group. Neither flap nor implant complications were affected by the timing of the implantation. Overall, the implant survival rate was 95% (55 of 58) in the primary implantation group and 98% (62 of 63) in the secondary implantation group. Time from FFTT to abutment placement (primary implantation, 19.6 weeks; secondary implantation, 61.0 weeks) was significantly shorter after primary implantation (P < .001). There was no clinical difference in postoperative complications and implant outcomes for ORN vs ON. Improvement in speech and oral competence in the primary implantation group vs the secondary implantation group was not statistically significant, given an experiment-adjusted P = .001 set as significant (normal speech, 9 vs 3; P = .02; and normal oral competence, 9 vs 3; P = .02). Disease-free survival was 91% (20 of 22 patients) overall. Fixed unit (U) costs were 1.0 U for primary implantation and 1.24 U for secondary implantation.

Conclusions and Relevance

Patients undergoing primary implantation after FFTT for ORN and ON had a similar rate of complications compared with those undergoing secondary implantation. However, primary implantation allowed a faster return than secondary implantation to oral nutrition and prosthesis use. The fixed unit cost was reduced for those undergoing primary implantation. Although dental implantation was safe and effective in both groups, the decreased time to use and the decreased overall cost should prompt surgeons to consider primary implantation after FFTT for ORN and ON.

Level of Evidence

3.

Cell therapy stimulates bone neoformation in calvaria defects in rats subjected to local irradiation

BACKGROUND

The purpose of the study was to analyze the effect of cell therapy on the repair process in calvaria defects in rats subjected to irradiation.

METHODS

Bone marrow mesenchymal cells were characterized for osteoblastic phenotype. Calvariae of male Wistar rats were irradiated (20 Gy) and, after 4 weeks, osteoblastic cells were placed in surgically created defects in irradiated (IRC) and control animals (CC), paired with untreated irradiated (IR) and control (C) animals. After 30 days, histological and microtomographic evaluation was performed to establish significant (P < 0.05) differences among the groups.

RESULTS

Higher alkaline phosphatase detection and activity, along with an increase in mineralized nodules, in the IRC, C and CC groups compared to the IR group, confirmed an osteoblastic phenotype. Histology showed impaired bone neoformation following irradiation, affecting bone marrow composition. Cell therapy in the IRC group improved bone neoformation compared to the IR group. Microtomography revealed increased bone volume, bone surface and trabecular number in IRC group compared to the IR group.

CONCLUSION

Cell therapy may improve bone neoformation in defects created after irradiation.

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.

Nonvascularized Bone Graft Reconstruction of the Irradiated Murine Mandible: An Analogue of Clinical Head and Neck Cancer Treatment

Nonvascularized bone grafts (NBGs) represent a practical method of mandibular reconstruction that is precluded in head and neck cancer patients by the destructive effects of radiotherapy. Advances in tissue-engineering may restore NBGs as a viable surgical technique, but expeditious translation demands a small-animal model that approximates clinical practice. This study establishes a murine model of irradiated mandibular reconstruction using a segmental iliac crest NBG for the investigation of imperative bone healing strategies. Twenty-seven male isogenic Lewis rats were divided into 2 groups; control bone graft and irradiated bone graft (XBG). Additional Lewis rats served as graft donors. The XBG group was administered a fractionated dose of 35Gy. All rats underwent reconstruction of a segmental, critical-sized defect of the left hemi-mandible with a 5 mm NBG from the iliac crest, secured by a custom radiolucent plate. Following a 60-day recovery period, hemi-mandibles were evaluated for bony union, bone mineralization, and biomechanical strength (P < 0.05). Bony union rates were significantly reduced in the XBG group (42%) compared with controls (80%). Mandibles in the XBG group further demonstrated substantial radiation injury through significant reductions in all metrics of bone mineralization and biomechanical strength. These observations are consistent with the clinical sequelae of radiotherapy that limit NBGs to nonirradiated patients. This investigation provides a clinically relevant, quantitative model in which innovations in tissue engineering may be evaluated in the setting of radiotherapy to ultimately provide the advantages of NBGs to head and neck cancer patients and reconstructive surgeons.

BMP-2-releasing gelatin microspheres/PLGA scaffolds for bone repairment of X-ray-radiated rabbit radius defects

The purpose of this research is to assess the feasibility of poly(lactic-co-glycolic) acid (PLGA) incorporating gelatin microspheres (PLGA/GMs scaffold) for enhancing osteogenesis in vitro and at a radius defect of rabbits after X-ray radiation in vivo. After incorporating gelatin microspheres, PLGA scaffold demonstrated improved mechanical properties. Moreover, a sustained release property of recombinant human bone morphogenetic protein-2 (BMP-2) was achieved in BMP-2-releasing PLGA/GMs scaffold. BMP-2-releasing PLGA/GMs scaffold also enhanced proliferation and osteogenesis of rabbit bone mesenchymal stem cells (BMSCs) in vitro, indicating the bioactivity of BMP-2. After finishing X-ray radiation of the radius bone, 20-mm radius bone defects were generated, followed by being implanted with BMP-2-releasing PLGA/GMs scaffolds with or without bone marrow. Both PLGA/GMs scaffolds containing bone marrow or BMP-2 showed more obvious enhancement for bone regeneration than the empty scaffolds (control) at the radius defect. In the X-ray radiated groups, however, the bone regeneration was inhibited either with bone marrow or BMP-2. When combined with bone marrow, the BMP-2 showed significantly high osteogenic effect, regardless of X-ray radiation. It is considered that it is a promising way to repair bone defects even after X-ray radiation by a combination of bone marrow with the BMP-2-releasing PLGA/GMs scaffold.

Anterior Skull Base Reconstruction following Ablative Surgery for Osteoradionecrosis: Case Report and Review of Literature

Introduction:

Osteoradionecrosis is one of many potentially severe complications of radiotherapy for nasopharyngeal carcinoma. Osteoradionecrosis of the skull base is life-threatening due to the critical proximity of the pathological process to vital structures, for example, the intracranial cavity, the upper spine, and major blood vessels. Reconstructive options following surgical debridement of the anterior skull base and upper spine osteonecrosis have been scarcely described in the literature.

Case presentation and management:

We present a rare case of osteoradionecrosis of the clivus and cervical vertebrae C1-C2 in a patient previously treated with chemoradiotherapy for nasopharyngeal carcinoma, presenting as severe soft tissue infection of the neck. Aggressive surgical debridement and reconstruction with a two-paddle free anterolateral thigh flap was performed using a combination of transcervical and transnasal endoscopic approaches. A novel endoscopic procedure in the sphenoid sinus enabled flap anchoring in this complex area.

Discussion:

Surgical modalities for osteoradionecrosis of the skull base and upper spine are discussed and review of the literature is presented.

Conclusion:

Reconstruction of the anterior skull base with a well-vascularized free flap following ablative surgery should be considered in management of life-threatening osteoradionecrosis of the area. Endoscopic opening of the sphenoid sinus and creating a funnel-shaped stem is a newly described technique that guarantees precise placement of the flap and is a valuable adjunct to the reconstructive armamentarium.

The development of a nomogram to predict post-radiation necrosis in nasopharyngeal carcinoma patients: a large-scale cohort study

Objective: This study aimed to establish a nomogram to predict the risk of post-radiation necrosis in nasopharyngeal carcinoma (NPC) patients.

Background: This study was performed to identify influencing factors for developing post-radiation necrosis, and to establish an effective nomogram model to predict individual risks in NPC patients.

Methods: 7144 NPC patients receiving radical radiotherapy from 2007 to 2012 were involved in the study, and 207 of them developed nasopharyngeal necrosis (NPN). The clinical characteristics and baseline laboratory results were collected and analyzed. Independent predictive factors were selected using the Cox proportional model and incorporated into the nomogram. The receiver operating characteristic curve and the calibration curve were used to verify discrimination and calibration.

Results: The experience of re-irradiation contributed most to the occurrence of NPN (HR, 15.56, 95% CI 10.84–22.35, p<0.001). Clinical factors including age, pathology type, history of diabetes, and original T stage were independent predictors of NPN. Factors reflecting patients’ baseline nutritional and inflammatory status such as hemoglobin, albumin, and C-reactive protein were also significantly associated with the development of NPN. With all independent predictive factors incorporated, a nomogram was generated, and it showed excellent discrimination and calibration.

Conclusion: This study was the first large-scale cohort study focusing on the development of NPN and established a nomogram to predict its occurrence based on the clinical and laboratory indicators. The nomogram demonstrated good discriminative capacity and satisfactory agreement, which would offer valuable clues for clinicians to distinguish the high-risk NPN population and maintain close surveillance.

Osteoradionecrosis, an increasing indication for microvascular head and neck reconstruction

Better cancer treatment has led to a steadily growing population of cancer survivors suffering from late adverse effects after cancer treatment. The aim of this study was to investigate whether there has been an increase in free flap reconstruction due to osteoradionecrosis (ORN). A retrospective review was conducted to identify all consecutive head and neck free flap reconstructions performed over an 18-year period (1995-2012) at Karolinska University Hospital. A total of 235 free flaps were identified. Cases were divided into two groups: head and neck cancer reconstructions and ORN reconstructions. A comparison between the two groups showed longer survival (P<0.001) and higher rates of late complications (P<0.001) among ORN cases. ORN as an indication for reconstruction increased over time, from 7.0% of the total number of free flaps performed in 1995-2000, to 15.2% during the period 2001-2006, and to 27.3% in 2007-2012 (P<0.001). This, in accordance with the results of other studies, highlights the importance of the appropriate allocation of resources within the healthcare system to treat this patient group within the steadily increasing population of cancer survivors.

Esophageal Stricture Following Radiation, Concurrent Immunochemotherapy, Treated With Hyperbaric Oxygen and Dilation

Low-dose palliative radiation may offer symptomatic relief in patients with spinal metastases from primary renal cell cancer and is unlikely to result in radiation injury. Patients with advanced malignancy requiring palliative radiation are often also receiving chemotherapy. Synergistic adverse effects resulting from combined palliative radiation and novel antiprogrammed cell death-1 (anti-PD 1) and/or multityrosine kinase inhibitors are rare.

We report about a 60-year-old woman with metastatic clear-cell renal cancer, status post-left nephrectomy, with debilitating mid-back pain from metastatic tumor burden and foraminal nerve compression. Her chemotherapeutic regimen was repeatedly altered because of progression of disease until she was maintained on the anti-PD 1 checkpoint inhibitor, nivolumab. She received palliative radiation to her thoracic spine over a 2-week period, and nivolumab was then switched to cabozantinib midway through a course of palliative radiation. The patient rapidly developed severe esophagitis, progressing to esophageal stricture, and required placement of a percutaneous endoscopic gastrostomy tube. She was successfully treated with serial esophageal dilation and hyperbaric oxygen treatments to diminish inflammation and improve tissue vascularity. Concurrent use of anti-PD 1 and/or multityrosine kinase drugs may accelerate development of radiation injury regardless of radiation dosage. Radiation-induced esophageal stricture was managed successfully in this patient with serial esophageal dilation and adjuvant hyperbaric oxygen.

Ability to Propose Optimal Prosthetic Rehabilitation can be Improved by Discussion between the Dentist and Radiation Oncologist Regarding Upstream Dosimetry

Objective Improvement of dental rehabilitation for patients who have undergone radiation therapy requires knowledge of the dose in the maxillary and mandible bones.

Materials and Methods Forty-three patients with head and neck cancers underwent evaluation for dental rehabilitation before radiation treatment dosimetry. The delivered dose to the maxilla and mandible was determined. From the dose data in the literature, three levels of risk of implant failure were defined. According to the delivered doses, the authors calculated the percentage of patients who could be fully rehabilitated with an implant, as proposed by the dentist before radiation planning.

Results Before dosimetry calculation, all of the completely edentulous arches and 94 partially edentulous (PESs) sextants could be optimally rehabilitated. After dose calculation, among the 14 arches of 7 patients who were completely edentulous, according to the mean and maximal delivered doses, 11 arches (78.6%) and 7 arches (50%) could receive an optimal prosthesis, respectively. For the three patients, who were PESs but with one arch that was completely edentulous, according to the mean and maximal delivered doses, one arch for each dose condition could receive an optimal prosthesis. Among the 94 PESs sextants, according to the mean and maximal delivered doses, 41 (43.6%) and 24 (25.5%) sextants could receive an optimal prosthesis, respectively.

Conclusion By determining the sites of implantation before dosimetry, the radiation oncologist could shield specified areas, potentially improving the possibilities for dental rehabilitation. The dialogue between the dentist and the radiation oncologist can improve the possibilities for implants and decrease the risk of unsafe implantation.

Is there a role for pentoxifylline and tocopherol in the management of advanced osteoradionecrosis of the jaws with pathological fractures? Case reports and review of the literature

Osteoradionecrosis (ORN) is an infrequent but serious complication of radiotherapy, especially in the head and neck region. It is a slowly progressive condition, with management in the early stages focused on symptom control, and surgery usually reserved for advanced ORN. However, established ORN is difficult to treat. The role of hyperbaric oxygen therapy has recently been contested. The use of pentoxifylline in the management of ORN was first described by Delanian in 2004, but its benefits have not been replicated in other studies. In cases of advanced ORN with pathological fractures, many centres still advocate surgical resection and reconstruction. However, in this group of patients who often have multiple medical comorbidities, many of whom have previously undergone significant surgery, a resective plan is not always ideal. This paper presents two successful cases of bony union after the use of pentoxifylline and tocopherol to manage grade III ORN of the mandible. Both patients had pathological fractures and orocutaneous fistulas and were deemed unsuitable for surgery. The possible reasons for the success of pentoxifylline and tocopherol are discussed, and a review of the current literature evidence of similar cases is presented. Pentoxifylline and tocopherol should be considered for the management of advanced ORN where surgical management is not appropriate.

Full-Thickness Skin Grafting for Local Defect Coverage Following Scalp Adjacent Tissue Transfer in the Setting of Cranioplasty

INTRODUCTION

Numerous techniques have been described to overcome scalp deficiency and high-tension closure at time of cranioplasty. However, there is an existing controversy, over when and if a free flap is needed during complex skull reconstruction (ie, cranioplasty). As such the authors present here our experience using full-thickness skin grafts (FTSGs) to cover local defects following scalp adjacent tissue transfer in the setting of cranioplasty.

METHODS

By way of an institutional review board-approved database, the authors identified patients treated over a 3-year period spanning January 2015 to December 2017, who underwent scalp reconstruction using the technique presented here. Patient demographics, clinical characteristics, technical details, outcomes, and long-term follow up were statistically analyzed for the purpose of this study.

RESULTS

Thirty-three patients, who underwent combined cranioplasty and scalp reconstruction using an FTSG for local donor site coverage, were identified. Twenty-five (75%) patients were considered to have "high complexity" scalp defects prior to reconstruction. Of them, 12 patients (36%) were large-sized and 20 (60%) medium-sized; 21 (64%) grafts were inset over vascularized muscle or pericranium while the remaining grafts were placed over bare calvarial bone. In total, the authors found 94% (31/33) success for all FTSGs in this cohort. Two of the skin grafts failed due to unsuccessful take. Owing to the high rate of success in this series, none of the patient's risk factors were found to correlate with graft failure. In addition, the success rate did not differ whether the graft was placed over bone verses over vascularized muscle/pericranium.

CONCLUSION

In contrary to previous studies that have reported inconsistent success with full-thickness skin grafting in this setting, the authors present a simple technique with consistent results-as compared to other more complex reconstructive methods-even in the setting of highly complex scalp reconstruction and simultaneous cranioplasty.

Protocol for prospective randomised assessor-blinded pilot study comparing hyperbaric oxygen therapy with PENtoxifylline+TOcopherol± CLOdronate for the management of early osteoradionecrosis of the mandible

INTRODUCTION

Osteoradionecrosis (ORN) of the mandible is a painful and debilitating condition occurring after radiotherapy to the head and neck to treat cancer. For decades, hyperbaric oxygen (HBO) has formed the mainstay of the early management of ORN. Literature about the efficacy of HBO is contentious. Recently, Oral and Maxillofacial surgical units in France and UK have trialled a combination of medications to treat ORN, also known as PENTOCLO (PENtoxifylline+TOcopherol±CLOdronate). This regime has shown promising results to date however randomised controlled trials in the area comparing HBO against PENTOCLO are lacking and there are no current trials registered in Europe, UK, Australia and the USA. The purpose of this pilot study is to generate a hypothesis that can be tested in large multi-centre controlled trials.

METHODS AND ANALYSIS

For this pilot study we will recruit 16 patients who will be randomly allocated to one of either HBO or PENTOCLO. After a 4 week period of uniform 'pre-treatment' medication patients will be commenced on their allocated treatment. Standard follow-up examination, imaging and photographs will be taken and de-identified and then presented to two Oral and Maxillofacial surgeons for allocation of a Notani & Lyons classification score. Data for each patient will be tracked over the 18 months of treatment and follow-up. The results will then be analysed using descriptive statistics and all patients included in an intention to treat analysis.

ETHICS AND DISSEMINATION

Ethical approval for this study has been granted by the South Metropolitan Health Service HREC (PRN RGS0000001193). Data generated by conducting this study will be uploaded to an open access repository in a de-identified form. Results from this study will be disseminated at national and international conferences as well as peer reviewed medical publications.

TRIAL REGISTRATION NUMBER

ACTRN12618001099213; Pre-results.

Retrospective study of osteoradionecrosis in the jaws of patients with head and neck cancer

Objectives

Osteoradionecrosis (ORN) is one of the most severe complications resulting from radiotherapy (RT) in patients with head and neck cancer (HNC). It is characterized by persistent exposed and devitalized bone without proper healing for greater than 6 months after a high dose of radiation in the area. To describe the profile and dental management of ORN in HNC patients undergoing RT in an oncological clinical research center.

Materials and Methods

A retrospective descriptive study was performed to analyze dental records from HNC patients with ORN treated at an oncological clinical research center from 2013 to 2017. A total of 158 dental records for HNC patients were selected from a total of 583 records. Afterwards, this number was distributed to three examiners for manual assessments. Each examiner was responsible for selecting dental records that contained an ORN description, resulting in 20 dental records.

Results

Mean patient age was 60.3 years with males being the most affected sex (80.0%). The most affected area was the posterior region of the mandible (60.0%) followed by the anterior region of the mandible (20.0%) and the posterior region of the maxilla (10.0%). The factors most associated with ORN were dental conditions (70.0%) followed by isolated systemic factors (10.0%) and tumor resection (5.0%). There was total exposed bone closure in 50.0% of cases. The predominant treatment was curettage associated with chlorhexidine 0.12% irrigation (36.0%).

Conclusion

Poor dental conditions were related to ORN occurrence. ORN management through less invasive therapies was effective for the closure of exposed bone areas and avoidance of infection.

Head and Neck Cancer Research and Support Foundations

Ongoing genetic and epigenetic research involving DNA methylation, salivary biomarkers, wild-type p53 tumor suppressor gene proteins, and HPV oncogenes are being directed at identification and treatment of dysplastic and malignant squamous cell mucosal lesions. Research is being conducted to improve immunotherapy drug response rates by increasing the amount of inflammation within the tumor microenvironment. Ongoing research is focused on the application of the antidiabetic drug metformin for the prevention and management of oral squamous cell dysplastic lesions. Professional and nonprofit cancer support organizations are essential for furthering education and research within the area of head and neck cancer.

Intraoperative Fluorescent Angiography Predicts Pharyngocutaneous Fistula After Salvage Laryngectomy

BACKGROUND

Technology to assess tissue perfusion is exciting with translational potential, although data supporting its clinical applications have been lagging. Patients who have undergone radiation are at particular risk of poor tissue perfusion and would benefit from this expanding technology. We designed a prospective clinical trial using intraoperative indocyanine green angiography to evaluate for wound-healing complications in patients undergoing salvage laryngectomy after radiation failure.

PATIENTS AND METHODS

This prospective trial included patients undergoing salvage laryngectomy at a National Cancer Institute-designated tertiary cancer center between 2016 and 2018. After tumor extirpation and prior to reconstruction, 10 mg indocyanine green dye was infused and the fluorescence (F_HYPO) and ingress rate of the pharyngeal mucosa recorded. The primary outcome measure was formation of a pharyngocutaneous fistula (PCF).

RESULTS

Patients who developed a PCF had significantly lower F_HYPO (87 vs 172, p < 0.001) and ingress rates (6.7 vs 15.8, p = 0.043) compared with those who did not develop a fistula. There were no fistulas in patients with F_HYPO > 150 (n = 21) or ingress > 15 (n = 15). There was a 50% fistula rate in patients with F_HYPO ≤ 103 (n = 10) and ingress rate ≤ 6 (n = 6).

CONCLUSIONS

Intraoperative indocyanine green angiography can assess hypoperfusion in patients and predict risk of PCFs after salvage laryngectomy, and can thus intraoperatively risk-stratify patients for postoperative wound-healing complications.

Antiresorptive Agent-Related Osteonecrosis of the Jaw (ARONJ): A Twist of Fate in the Bone

Bisphosphonates (BPs) have been used as antiresorptive agents to treat patients with osteoporosis or metastatic bone cancer, each of which is characterized by bone loss due to the increased bone resorption. However, BPs could cause osteonecrosis of the jaw (ONJ), known as bisphosphonate-related osteonecrosis of the jaw (BRONJ). ONJ is associated with severe pain and deteriorated quality of life. ONJ is also caused by administration of denosumab, a monoclonal antibody against receptor activator of NFκB ligand (RANKL), that functions as a powerful antiresorptive agent. Accordingly, antiresorptive agent-related ONJ (ARONJ) has been advocated, the incidence of which is continuing to increase in Japan as a super-aging society. Importantly, the jawbone is more susceptible to infection compared with bones in other parts of the body, due to the unique anatomical and physiological characteristics; for example, the jawbone with a high remodeling rate is stimulated by teeth during mastication. The risk factors of ARONJ include dental infection, poor occlusal or oral hygiene status, and bone-invasive dental treatment, such as tooth extraction, dental implants, and dentures. Proper collaboration between doctors and dentists is of utmost importance to understand the current status of ARONJ and prevent developing ARONJ. It is also important to ensure that the patients treated with BPs or denosumab can receive appropriate dental treatment. More recently, angiogenesis inhibitors were reported to cause ONJ; thus, medication-related ONJ (MRONJ) has been advocated. This article overviews the concept of MRONJ by focusing on antiresorptive agents and the status of BRONJ in Japan.

Adjunctive hyperbaric oxygen therapy for irradiated rat calvarial defects

Purpose

The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy.

Methods

Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses.

Results

New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2.

Conclusions

HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.

Role of Steroids in Preventing Osteoradionecrosis of the Head and Neck: A Systematic Review

Objective:

The aim of this study was to summarize the effectiveness of steroids in the prevention of osteoradionecrosis of the head and neck.

Data Sources:

PubMED, MEDLINE, Embase, Google Scholar, and Cochrane trial registries.

Methods:

A systematic review of these data sources was performed through September 2018 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included were English-language studies evaluating patients of all age groups diagnosed with head and neck cancer who underwent radiation therapy while receiving peritreatment steroids compared with those who did not receive steroids.

Results:

Two retrospective cohort studies were identified for qualitative review. On the basis of analysis of 25 328 participants (36-82 years of age) with head and neck cancer who underwent radiation therapy, the use of peritreatment steroids was associated with a significantly lower risk for osteoradionecrosis in both studies, with a hazard ratio of 0.74 (95% confidence interval, 0.59-0.94; P = .012) and a relative risk of 0.04 (95% confidence interval, 0.003-0.560; P = .017). Meta-analysis was precluded by clinical and statistical heterogeneity. Overall, the studies were of limited quality with high risk for bias and poor methodology.

Conclusions:

Limited retrospective data suggest that steroids are predictive of a reduced risk for osteoradionecrosis; however, no definitive conclusions can be made given the poor quality of the available literature. Well-designed, comparison-controlled trials are needed to clarify the promising role of steroids in the prevention of osteoradionecrosis of the head and neck.

Fluorescence and Near-Infrared Light Transillumination

This article describes the current applications of various technologies based on either autofluorescence or near-infrared light illumination, tailored to aid practitioners in detecting and quantitatively monitoring oral diseases such as dental caries and oral cancer at the earliest stage of their formation, or in the conservative surgical excision of necrotic bones in diseases such as chronic osteomyelitis, osteoradionecrosis, and medication-related osteonecrosis of the jaw. The data discussed are primarily based on published scientific studies and reviews from case reports, clinical trials, and in vitro and in vivo studies. References have been traced manually, by MEDLINE, or through manufacturer's websites.

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).

Therapeutic Irradiation: Consequences for Bone and Bone Marrow Adipose Tissue

Radiotherapy continues to be one of the most accepted medical treatments for cancer. Localized irradiation is the most common treatment for prostate, pancreatic, rectal, cervical and endometrial malignancies. Conventional localized fractions are total doses of 30-62Gy at 1.8-2Gy per fraction, with administration of ~60Gy often used for tumor ablation. However, even the lowest dose of localized irradiation exposure can result in adverse complications to adjacent organs, tissues, and vessels, which absorb a portion of the treatment. Skeletal complications are common amongst cancer patients undergoing these localized treatments. Irradiation exposure causes deterioration to the overall quantity and quality of bone by interfering with the trabecular architecture through increased osteoclast activity and decreased osteoblast activity. Irradiation-induced bone damage parallels adipocyte infiltration of the bone marrow (BM) resulting in compositional alterations of the microenvironment that may further affect bone quality and disease state. There may also be direct effects of irradiation on the BM adipocyte/pre-adipocyte, although in vitro findings do not always agree and cellular response is dependent on irradiation dosage. Hematopoietic cells also become apoptotic upon irradiation, which causes a range of skeletal effects. Bone loss leaves patients at a greater risk for osteopenia, osteoporosis, osteonecrosis, and skeletal fractures that drastically reduce quality of life. Osteoanabolic agents stimulate bone formation and reduce fracture risk in patients with low bone density; thus, osteoanabolic or anti-resorptive agents may be useful co-treatments with irradiation. This review discusses these topics and proposes further research directions using novel or combination therapies to enhance bone health during irradiation.

Assessment of hyperbaric patients at risk of malnutrition using the Malnutrition Screening Tool - a pilot study

BACKGROUND

Nutritional assessment and support is essential for wound management. The hyperbaric oxygen clinic is a unique outpatient service where chronically unwell patients present daily for hyperbaric oxygen treatment (HBOT) over several weeks, allowing time for effective nutritional intervention. This is the first study to examine the prevalence of those at risk of malnutrition in a cohort of hyperbaric medical patients.

METHODS

A prospective study was undertaken over six months. Following consent, 39 enrolled patients had the Malnutrition Screening Tool and Baseline Characteristic Collection Form completed. Those at risk of malnutrition were given an option to be assessed by a dietitian to complete a Subjective Global Assessment (SGA). At the completion of treatment, the patients completed a questionnaire.

RESULTS

Twelve of the 39 patients screened were at risk of malnutrition using our screening process. Of these, all the patients with available SGA results were diagnosed with moderate to severe malnutrition. Patients receiving HBOT for non-healing wounds and osteoradionecrosis were most at risk of malnutrition.

CONCLUSION

The prevalence of patients being at risk of malnutrition in our hyperbaric medical service was about one in three. Malnutrition screening should be part of routine patient assessment in order to ensure patients receive timely nutritional intervention. This may improve wound healing.

Radiation-induced skin reactions: mechanism and treatment

Radiotherapy (RT) is a major treatment for malignant tumors. The latest data show that >70% of patients with malignant tumors need RT at different periods. Skin changes can be experienced by up to 95% of patients who underwent RT. Inflammation and oxidative stress (OS) have been shown to be generally associated with radiation-induced skin reactions (RISRs). Inflammatory response and OS interact and promote each other during RISRs. Severe skin reactions often have a great impact on the progress of RT. The treatment of RISRs is particularly critical because advanced RT technology can also lead to skin reactions. RISRs are classified into acute and chronic reactions. The treatment methods for acute RISRs include steroid treatment, creams, ointments, and hydrocolloid dressings, depending on the reaction grading. Chronic RISRs includes chronic ulcerations, telangiectasias, and fibrosis of the skin, and advanced treatments such as mesenchymal stem cells, hyperbaric oxygen therapy, superoxide dismutase, and low-intensity laser therapy can be considered. Here, we review and summarize the important mechanisms that cause RISRs as well as the standard and advanced treatments for RISRs.