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

Acute toxicities in proton therapy for head and neck cancer - A matched analysis of the DAHANCA 35 feasibility study

Background and purpose

As preparation for a national randomized study comparing proton radiotherapy to photon radiotherapy, DAHANCA 35, we performed a non-randomized pilot study to investigate patient selection, logistics, planning, and treatment delivery. With the present study, as a comprehensive safety analysis, we want to compare toxicity during and up to two months after therapy to a historically matched group of patients treated with photon radiotherapy.

Materials and methods

62 patients treated with protons were matched to 124 patients who received photon treatment outside a protocol. Available data were retrieved from the DAHANCA database. Patients were matched on treatment centre, concurrent chemotherapy, tumour site, stage, p16 status for oropharynx cancers. Selection of patients for proton therapy was based on comparative treatment plans with a NTCP reduction for dysphagia and xerostomia at six months.

Results

Baseline characteristics between groups were well balanced, except for the type of drug used concurrently; more photon patients received Carboplatin (21.2 % vs 5.8 %, p = 0.01). Proton therapy was associated with significantly less weight loss at the end of treatment, mean weight loss of 3 % for protons and 5 % for photons (p < 0.001). There were more grade 3 skin reactions and grade 3 mucositis after proton treatment compared with photons at the end of treatment, Risk Ratio (RR) 1.9 (95 % CI: 1.01-3.5, p = 0.04) and RR 1.5 (95 % CI: 1.3-1.7, p < 0.001), respectively. All differences resolved at follow up two months after treatment. There were no significant differences between groups on opioid use, use of feeding tubes, or hospitalization during the observation period.

Conclusion

Proton treatment resulted in excess objective mucositis and dermatitis, which was transient and did not seem to negatively influence weight or treatment compliance and intensity. Selection bias was likely especially since NTCP models were used for selection of proton treatment and photon treated patients were matched manually. We are currently including patients in a randomized controlled trial.

Planned Dental Extractions After Radiation Therapy

Importance

Nonrestorable teeth are recommended to be extracted prior to radiation therapy (RT). Occasionally, preradiation extractions introduce unacceptable delays in treatment initiation. Planned dental extractions immediately postradiation presents an alternative strategy, though outcomes are uncertain.

Objective

To evaluate the feasibility and safety of dental extractions immediately postradiation.

Design, Setting, and Participants

A prospective cohort study including patients planned for curative-intent RT but unable or unwilling to proceed with 1 or more extractions recommended pretreatment was carried out. From January 2020 to September 2022, 58 patients were screened and 50 enrolled. The dental care was performed at a single academic department and the cancer care at regional centers. Analysis took place between September 22, 2023, and June 10, 2024.

Exposure

On completion of RT, patients were recommended to complete extractions as soon as feasible, and ideally within 4 months.

Main Outcomes and Measures

The primary end point was the actuarial cumulative incidence of exposed alveolar bone noted by any practitioner at any time after extraction, calculated using Gray method with death as a competing risk. As a pilot study, no formal power calculation was performed; resources allowed for 50 evaluable patients.

Results

Among the 50 participants enrolled, RT was nonoperative for 32 patients (64%) and postoperative for 18 patients (36%). Intensity-modulated RT (IMRT) was delivered in all patients. Of the 50 patients, 20 (40%) declined dental extractions immediately postradiation and the remaining 30 (60%) underwent a median (range) of 8.5 (1-28) extractions at a median (range) of 64.5 (13-152) days after RT. The median (IQR) follow-up for survivors without exposed bone was 26 (17-35) months from the end of RT. The 2-year cumulative incidence of any exposed bone was 27% (95% CI, 14%-40%). The 2-year incidence of exposed bone for those who underwent dental extractions immediately postradiation was 40% (95% CI, 22%-58%) and 7% (95% CI, 0%-22%) for those who did not. Of the 13 who developed exposed bone: 4 resolved, 1 was lost to follow-up, and 8 were confirmed as osteoradionecrosis.

Conclusions and Relevance

This cohort study found that postradiation dental extractions incur considerable risk, even if performed within a 4-month window.

Current Status and Future Directions of Proton Therapy for Head and Neck Carcinoma

The growing interest in proton therapy (PT) in recent decades is justified by the evidence that protons dose distribution allows maximal dose release at the tumor depth followed by sharp distal dose fall-off. But, in the holistic management of head and neck cancer (HNC), limiting the potential of PT to a mere dosimetric advantage appears reductive. Indeed, the precise targeting of PT may help evaluate the effectiveness of de-escalation strategies, especially for patients with human papillomavirus associated-oropharyngeal cancer (OPC) and nasopharyngeal cancer (NPC). Furthermore, PT could have potentially greater immunogenic effects than conventional photon therapy, possibly enhancing both the radiotherapy (RT) capability to activate anti-tumor immune response and the effectiveness of immunotherapy drugs. Based on these premises, the aim of the present paper is to conduct a narrative review reporting the safety and efficacy of PT compared to photon RT focusing on NPC and OPC. We also provide a snapshot of ongoing clinical trials comparing PT with photon RT for these two clinical scenarios. Finally, we discuss new insights that may further develop clinical research on PT for HNC.

Impact of Relative Biologic Effectiveness for Proton Therapy for Head and Neck and Skull-Base Tumors: A Technical and Clinical Review

Proton therapy has emerged as a crucial tool in the treatment of head and neck and skull-base cancers, offering advantages over photon therapy in terms of decreasing integral dose and reducing acute and late toxicities, such as dysgeusia, feeding tube dependence, xerostomia, secondary malignancies, and neurocognitive dysfunction. Despite its benefits in dose distribution and biological effectiveness, the application of proton therapy is challenged by uncertainties in its relative biological effectiveness (RBE). Overcoming the challenges related to RBE is key to fully realizing proton therapy's potential, which extends beyond its physical dosimetric properties when compared with photon-based therapies. In this paper, we discuss the clinical significance of RBE within treatment volumes and adjacent serial organs at risk in the management of head and neck and skull-base tumors. We review proton RBE uncertainties and its modeling and explore clinical outcomes. Additionally, we highlight technological advancements and innovations in plan optimization and treatment delivery, including linear energy transfer/RBE optimizations and the development of spot-scanning proton arc therapy. These advancements show promise in harnessing the full capabilities of proton therapy from an academic standpoint, further technological innovations and clinical outcome studies, however, are needed for their integration into routine clinical practice.

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.

Preoperative Management of the Adult Oncology Patient

Anesthesiologists are experiencing first-hand the aging population, given older patients more frequently presenting for surgery, often with geriatric syndromes influencing their anesthetic management. The overall incidence and health burden of cancer morbidity and mortality are also rapidly increasing worldwide. This growth in the cancer population, along with the associated risk factors and comorbidities often accompanying a cancer diagnosis, underscores the need for anesthesiologists to become well versed in the preoperative evaluation and management of the adult patient with cancer. This article will focus on the unique challenges and opportunities for the anesthesiologist caring for the adult oncology patient presenting for surgery.

Oral Cavity Squamous Cell Carcinoma: Review of Pathology, Diagnosis, and Management

Squamous cell carcinoma of the oral cavity presents a significant global health burden, primarily due to risk factors such as tobacco smoking, smokeless tobacco use, heavy alcohol consumption, and betel quid chewing. Common clinical manifestations of oral cavity cancer include visible lesions and sores, often accompanied by pain in advanced stages. Diagnosis relies on a comprehensive assessment involving detailed history, physical examination, and biopsy. Ancillary imaging studies and functional evaluations aid in accurate staging and facilitate treatment planning. Prognostic information is obtained from histopathological factors, such as tumor grade, depth of invasion, lymphovascular invasion, and perineural invasion. Notably, lymph node metastasis, found in approximately half of the patients, carries significant prognostic implications. Effective management necessitates a multidisciplinary approach to optimize patient outcomes. Surgical resection is the backbone of treatment, aimed at complete tumor removal while preserving functional outcomes. Adjuvant therapies, including radiation and chemotherapy, are tailored according to pathological factors. Further work in risk stratification and treatment is necessary to optimize outcomes in squamous cell carcinoma of the oral cavity.

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.

Oral Surgery and Osteoradionecrosis in Patients Undergoing Head and Neck Radiation Therapy: An Update of the Current Literature

Osteoradionecrosis (ORN) is a serious long-term complication of head and neck radiotherapy (RT), which is often triggered by dental extractions. It results from avascular aseptic necrosis due to irradiated bone damage. ORN is challenging to treat and can lead to severe complications. Furthermore, ORN causes pain and distress, significantly reducing the patient's quality of life. There is currently no established preventive strategy. This narrative review aims to provide an update for the clinicians on the risk of ORN associated with oral surgery in head and neck RT patients, with a focus on the timing suitable for the oral surgery and possible ORN preventive treatments. An electronic search of articles was performed by consulting the PubMed database. Intervention and observational studies were included. A multidisciplinary approach to the patient is highly recommended to mitigate the risk of RT complications. A dental visit before commencing RT is highly advised to minimize the need for future dental extractions after irradiation, and thus the risk of ORN. Post-RT preventive strategies, in case of dento-alveolar surgery, have been proposed and include antibiotics, hyperbaric oxygen (HBO), and the combined use of pentoxifylline and tocopherol ("PENTO protocol"), but currently there is a lack of established standards of care. Some limitations in the use of HBO involve the low availability of HBO facilities, its high costs, and specific clinical contraindications; the PENTO protocol, on the other hand, although promising, lacks clinical trials to support its efficacy. Due to the enduring risk of ORN, removable prostheses are preferable to dental implants in these patients, as there is no consensus on the appropriate timing for their safe placement. Overall, established standards of care and high-quality evidence are lacking concerning both preventive strategies for ORN as well as the timing of the dental surgery. There is an urgent need to improve research for more efficacious clinical decision making.

Patient Navigation for Timely, Guideline-Adherent Adjuvant Therapy for Head and Neck Cancer: A National Landscape Analysis

BACKGROUND

Aligned with the NCCN Clinical Practice Guidelines in Oncology for Head and Neck Cancers, in November 2021 the Commission on Cancer approved initiation of postoperative radiation therapy (PORT) within 6 weeks of surgery for head and neck cancer (HNC) as its first and only HNC quality metric. Unfortunately, >50% of patients do not commence PORT within 6 weeks, and delays disproportionately burden racial and ethnic minority groups. Although patient navigation (PN) is a potential strategy to improve the delivery of timely, equitable, guideline-adherent PORT, the national landscape of PN for this aspect of care is unknown.

MATERIALS AND METHODS

From September through November 2022, we conducted a survey of health care organizations that participate in the American Cancer Society National Navigation Roundtable to understand the scope of PN for delivering timely, guideline-adherent PORT for patients with HNC.

RESULTS

Of the 94 institutions that completed the survey, 89.4% (n=84) reported that at least part of their practice was dedicated to navigating patients with HNC. Sixty-eight percent of the institutions who reported navigating patients with HNC along the continuum (56/83) reported helping them begin PORT. One-third of HNC navigators (32.5%; 27/83) reported tracking the metric for time-to-PORT at their facility. When estimating the timeframe in which the NCCN and Commission on Cancer guidelines recommend commencing PORT, 44.0% (37/84) of HNC navigators correctly stated ≤6 weeks; 71.4% (60/84) reported that they did not know the frequency of delays starting PORT among patients with HNC nationally, and 63.1% (53/84) did not know the frequency of delays at their institution.

CONCLUSIONS

In this national landscape survey, we identified that PN is already widely used in clinical practice to help patients with HNC start timely, guideline-adherent PORT. To enhance and scale PN within this area and improve the quality and equity of HNC care delivery, organizations could focus on providing better education and support for their navigators as well as specialization in HNC.

Oral Complications from Oropharyngeal Cancer Therapy

Post-oropharyngeal cancer treatment complications include a multitude of oral side effects that impact overall survival and quality of life. These include acute and chronic conditions affecting the oral cavity and head and neck, such as mucositis, infection, xerostomia, dysgeusia, radiation caries, osteonecrosis, and trismus. This review will summarize the most common oral complications from oropharyngeal cancer therapy. The authors would like to point out that the literature cited frequently combines oropharyngeal and head and neck cancer results. If recommendations are made strictly related to oropharyngeal cancers, this will be highlighted.

Phase Angle in Head and Neck Cancer: A Sex-Differential Analysis from Biological and Clinical Behavior to Health-Related Quality of Life

Head and neck cancer (H&NC) is a diverse category of tumors related to malignancies in the common aerodigestive pathway, with high metabolic rate, poor nutritional and treatment outcomes, and elevated mortality despite the best standard treatment. Herein, we focus on determining how the phase angle (PA) differs across sex as a predictor of poor prognosis, low quality-of-life (QoL) scores, and mortality in patients with head and neck cancer. This follow-up study presents a sex-differential analysis in a prospective cohort of 139 head and neck cancer patients categorized by sex as male (n = 107) and female (n = 32). Patients were compared in terms of nutritional, biochemical, and quality-of-life indicators between low and normal PA in women (<3.9° (n = 14, 43.75%) and ≥3.9°) and men (<4.5° (n = 62, 57.9%) and ≥4.5°). Our results show that most patients were in locally advanced clinical stages (women: n = 21 (65.7%); men: n = 67 (62.6%)) and that patients with low PA had a lower punctuation in parameters such as handgrip strength, four-meter walking speed, albumin, C-reactive protein (CRP), and CRP/albumin ratio (CAR), as well as the worst QoL scores in functional and symptomatic scales in both the male and female groups. A comparison between sexes revealed significant disparities; malnourishment and tumor cachexia related to an inflammatory state was more evident in the women's group.

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.

Molecular events in the jaw vascular unit: A traditional review of the mechanisms involved in inflammatory jaw bone diseases

Inflammatory jaw bone diseases are common in stomatology, including periodontitis, peri-implantitis, medication-related osteonecrosis of the jaw, radiation osteomyelitis of the jaw, age-related osteoporosis, and other specific infections. These diseases may lead to tooth loss and maxillofacial deformities, severely affecting patients' quality of life. Over the years, the reconstruction of jaw bone deficiency caused by inflammatory diseases has emerged as a medical and socioeconomic challenge. Therefore, exploring the pathogenesis of inflammatory diseases associated with jaw bones is crucial for improving prognosis and developing new targeted therapies. Accumulating evidence indicates that the integrated bone formation and dysfunction arise from complex interactions among a network of multiple cell types, including osteoblast-associated cells, immune cells, blood vessels, and lymphatic vessels. However, the role of these different cells in the inflammatory process and the 'rules' with which they interact are still not fully understood. Although many investigations have focused on specific pathological processes and molecular events in inflammatory jaw diseases, few articles offer a perspective of integration. Here, we review the changes and mechanisms of various cell types in inflammatory jaw diseases, with the hope of providing insights to drive future research in this field.

Review of Osteoradionecrosis of the Jaw: Radiotherapy Modality, Technique, and Dose as Risk Factors

Radiotherapy (RT) or concurrent chemoradiotherapy (CCRT) is the cornerstone of organ-sparing or adjuvant therapy for nearly all head and neck cancers. Unfortunately, aggressive RT or CCRT can result in severe late toxicities, such as osteoradionecrosis of the jaws (ORNJ). The incidence of ORNJ is currently less than 5-6% due to advances in dental preventive care programs, RT planning systems, and RT techniques. Although numerous patient-, tumor-, and treatment-related factors may influence the incidence rates of ORNJ, RT modality (equipment), technique, and dose-volume-related factors are three of the most influential factors. This is mainly because different RT equipment and techniques have different levels of success at delivering the prescribed dose to the focal volume of the treatment while keeping the "organ at risk" safe. ORNJ risk is ultimately determined by mandibular dose, despite the RT technique and method being known predictors. Regardless of the photon delivery method, the radiobiological effects will be identical if the total dose, dose per fraction, and dose distribution within the tissue remain constant. Therefore, contemporary RT procedures mitigate this risk by reducing mandibular dosages rather than altering the ionizing radiation behavior in irradiated tissues. In light of the paucity of studies that have examined the impact of RT modality, technique, and dose-volume-related parameters, as well as their radiobiological bases, the present review aims to provide a comprehensive overview of the published literature on these specific issues to establish a common language among related disciplines and provide a more reliable comparison of research results.