Superimposed infection in mandibular osteoradionecrosis: diagnosis and outcomes

Role of Photodynamic Therapy in Osteonecrosis and Osteoradionecrosis of the Jaws: A Systematic Review

Aim

Photodynamic therapy (PDT) is a minimally invasive treatment modality that has been used clinically for early stage and inoperable cancers. Successful use of this atraumatic therapy in osteoradionecrosis (ORN) and osteonecrosis of the jaws (ONJ) has been documented in the literature. The aim of this review was to systematically evaluate the role of photodynamic therapy in ORN and ONJ.

Methods

Two independent reviewers conducted an elaborate search in PubMed, Google Scholar and Cochrane's CENTRAL database for studies published on PDT as stand-alone or adjuvant therapy in ORN/ONJ until June 2022. The present study was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Demographic data, type and stage of necrosis of the jaws, site, PDT protocol, time to heal and follow-up were evaluated. Eighteen articles were included totally based on the inclusion and exclusion criteria for final analysis.

Results

A total of 94 patients were included in the present review out of which 36 were males and 58 were females. Five studies reported the use of PDT as an adjuvant therapy in ORN. Thirteen studies reported successful outcomes with PDT in ONJ. Complete epithelialization was achieved with PDT ± other adjuvants in 86/94 (91.48%) patients. The time taken for regression of the lesion ranged between 4 days and 12 months with PDT in the present study.

Conclusion

The reviewed studies demonstrate the effectiveness of PDT, as an adjuvant therapy, in managing various stages of ORN and ONJ.

Invasive Fungal Infections of the Head and Neck: A Tertiary Hospital Experience

From the existing millions of fungal species, only a few cause disease. In this study, we investigated invasive fungal infections in the head and neck (H&N) over a 19-year period (2005 to 2024) at a large academic healthcare system. Among the 413 documented fungal H&N infections, 336 were noninvasive, and 77 were invasive. The highest incidence of invasive infections occurred in the sinonasal cavities, with a 15-fold difference compared to other sites. Most infections affected adults over 40 years old. The most common organisms were Mucorales (51%), hyaline molds (29%), and Candida (11%). Risk factors included malignancy, transplant, diabetes, and illicit drug use. Mortality was high in patients with malignancy and/or transplant. Infections affecting the mandible were usually a complication of osteoradionecrosis and were associated with the coinfection of Candida and Actinomyces. At other sites, infections were rare and were usually the result of penetrating injuries or immunosuppression. Treatment typically involved a combination of antifungals and surgical procedures.

Mandibular Osteoradionecrosis: Defining the Microbial Milieu and Antimicrobial Resistance at the Time of Rescue Flap Surgery

OBJECTIVE

To report the microorganisms and their antibiotic sensitivity profile from tissue cultures and stains at the time of anterolateral thigh fascia lata (ALTFL) rescue flap for management of mandibular osteoradionecrosis (ORN).

METHODS

Retrospective chart review of patients who underwent ALTFL rescue flap for native mandibular ORN between 2011 and 2022.

RESULTS

Twenty-six cases comprising 24 patients (mean age 65.4 years, 65.4% male) with mandibular ORN from whom tissue cultures and gram stain were obtained at the time of ALTFL rescue flap. 57.7% grew bacterial species, while 34.6% grew fungal species. Multibacterial speciation was noted in 26.9% of cultures. A combination of bacterial and fungal growth was also seen in 15.4% of cases. All gram-positive cocci (GPC) were pansensitive to antibiotics except for one case of Staphylococcus aureus, which was resistant to levofloxacin. Gram-negative bacilli (GNB) species were isolated in 50.0% of cases. All fungal growth was due to Candida species. No growth was noted in 23.1% of cases. Multidrug resistance was noted in 53.8% of cases when GNB was isolated.

CONCLUSION

We report 76.9% of our cases of mandibular ORN had microbial growth from tissue cultures obtained at the time of the ALTFL rescue flap. Fungal growth was noted in a substantial number of cases and should be obtained as a specimen when pursuing culture-driven antibiotic therapy. Most GPCs were pansensitive to antibiotics, while GNBs were often the harbinger of multidrug resistant mandibular ORN.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:166-169, 2024.

Leuconostoc, a masquerading pathogen in oral cancer patient: A rare case report

Osteoradionecrosis is the most common cause of mandibular osteomyelitis. Here we are reporting a case of osteomyelitis of the mandible caused by Leuconostoc mesenteroides spp cremoris. The frequency of Leuconostoc infections are under reported mainly due to its difficult identification. Non pathogenic organism like leuconostoc can cause infection in the immunocompromised and should warrant proper microbial identification and adequate targeted treatment to manage the patients.

Skull base osteomyelitis in patients with head and neck cancer: Diagnosis, management, and outcomes in a case series of 23 patients

BACKGROUND

Skull base osteomyelitis (SBO) is an infection of the central cranial bones, most commonly resulting from contiguous spread of infection from adjacent head and neck structures. SBO is a well-recognized complication of treatment of head and neck cancer (HNC) that results in significant morbidity.

METHODS

We conducted a retrospective chart review of HNC patients diagnosed with SBO.

RESULTS

SBO was commonly diagnosed with nasal endoscopy showing mucosal breakdown between the naso/oropharynx and skull base and with characteristic changes on CT/MRI. Culture data were often polymicrobial, inclusive of naso/oropharyngeal flora, but half of the patients additionally had antibiotic-resistant or atypical pathogens. The mean duration of antimicrobial therapy was 117 +/- 94 days. Recurrent SBO was found in half of the patients, associated with Pseudomonas aeruginosa and with persistent defects in the mucosa abutting the skull base.

CONCLUSIONS

Diagnosis and management of SBO in HNC patients are challenging. Recommendations to aid in clinical care are proposed.

LEVEL OF EVIDENCE

4, case series.

Imaging of Complications of Chemoradiation

Chemoradiation for head and neck cancer is associated with a variety of early and late complications. Toxicities may affect the aero-digestive tract (mucositis, salivary gland injury), regional osseous and cartilaginous structures (osteoradionecrosis (ORN) and chondronecrosis), vasculature (progressive radiation vasculopathy and carotid blow out syndromes), and neural structures (optic neuritis, myelitis, and brain injury). These may be difficult to distinguish from tumor recurrence on imaging, and may necessitate the use of advanced MRI and molecular imaging techniques to reach the correct diagnosis. Secondary radiation-induced malignancies include thyroid cancer and a variety of sarcomas that may manifest several years after treatment. Checkpoint inhibitors can cause a variety of adverse immune events, including autoimmune hypophysitis and encephalitis.

MRI Dynamic Contrast Imaging of Oral Cavity and Oropharyngeal Tumors

ABSTRACT

In the past decade, dynamic contrast-enhanced magnetic resonance imaging has had an increasing role in assessing the microvascular characteristics of various tumors, including head and neck cancer. Dynamic contrast-enhanced magnetic resonance imaging allows noninvasive assessment of permeability and blood flow, both important parametric features of tumor hypoxia, which is in turn a marker for treatment resistance for head and neck cancer.In this article we will provide a comprehensive review technique in evaluating tumor proliferation and application of its parameters in differentiating between various tumor types of the oral cavity and how its parameters can correlate between epidermal growth factor receptor and human papillomavirus which can have an implication in patient's overall survival rates.We will also review how the parameters of this method can predict local tumor control after treatment and compare its efficacy with other imaging modalities. Lastly, we will review how its parameters can be used prospectively to identify early complications from treatment.

Computed Tomography Radiomics Kinetics as Early Imaging Correlates of Osteoradionecrosis in Oropharyngeal Cancer Patients

Osteoradionecrosis (ORN) is a major side-effect of radiation therapy in oropharyngeal cancer (OPC) patients. In this study, we demonstrate that early prediction of ORN is possible by analyzing the temporal evolution of mandibular subvolumes receiving radiation. For our analysis, we use computed tomography (CT) scans from 21 OPC patients treated with Intensity Modulated Radiation Therapy (IMRT) with subsequent radiographically-proven ≥ grade II ORN, at three different time points: pre-IMRT, 2-months, and 6-months post-IMRT. For each patient, radiomic features were extracted from a mandibular subvolume that developed ORN and a control subvolume that received the same dose but did not develop ORN. We used a Multivariate Functional Principal Component Analysis (MFPCA) approach to characterize the temporal trajectories of these features. The proposed MFPCA model performs the best at classifying ORN vs. Control subvolumes with an area under curve (AUC) = 0.74 [95% confidence interval (C.I.): 0.61–0.90], significantly outperforming existing approaches such as a pre-IMRT features model or a delta model based on changes at intermediate time points, i.e., at 2- and 6-month follow-up. This suggests that temporal trajectories of radiomics features derived from sequential pre- and post-RT CT scans can provide markers that are correlates of RT-induced mandibular injury, and consequently aid in earlier management of ORN.

Quantitative Dynamic Contrast-Enhanced MRI Identifies Radiation-Induced Vascular Damage in Patients With Advanced Osteoradionecrosis: Results of a Prospective Study

PURPOSE

We aim to characterize the quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters associated with advanced mandibular osteoradionecrosis (ORN) compared with the contralateral normal mandible.

METHODS AND MATERIALS

Patients with a diagnosis of advanced ORN after curative-intent radiation treatment of head and neck cancer were prospectively enrolled after institutional review board approval and study-specific informed consent were obtained. Quantitative maps generated with the Tofts and extended Tofts pharmacokinetic models were used for analysis. Manual segmentation of advanced ORN 3-dimensional volume was done using anatomic sequences to create ORN volumes of interest (VOIs). Subsequently, normal mandibular VOIs were segmented on the contralateral healthy mandible of similar volume and anatomic location to create control VOIs. Finally, anatomic sequences were coregistered to DCE sequences, and contours were propagated to the respective parameter maps.

RESULTS

Thirty patients were included. The median time to ORN diagnosis after completion of IMRT was 38 months (range, 6-184 months), whereas median time to ORN progression to advanced grade after initial diagnosis was 5.6 months (range, 0-128 months). There were statistically significant higher K^trans and V_e in ORN-VOIs compared with controls (0.23 vs 0.07 min^-1, and 0.34 vs 0.15; P < .0001 for both). The average relative increase of K^trans in ORN-VOIs was 3.2-fold higher than healthy mandibular control VOIs. Moreover, the corresponding rise of V_e in ORN-VOIs was 2.7-fold higher than in the controls. Using combined K^trans and V_e parameters, 27 patients (90%) had at least a 200% increase of either of the studied parameters in the ORN-VOIs compared with their healthy mandible VOIs.

CONCLUSIONS

Our results confirm that there is a quantitatively significant higher degree of leakiness in the mandibular vasculature as measured using DCE-MRI parameters of areas with advanced ORN versus healthy mandible.

Styloid Process Osteoradionecrosis: Report of 3 Cases

We report the imaging and clinical findings in 3 patients with osteoradionecrosis of the styloid process, an uncommon consequence of radiation therapy for head and neck malignancy.

Disease- and Treatment-related Complication on F-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Oncology Practice: A Pictorial Review

F-18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is routinely performed in oncology patients for various indications including staging, restaging, recurrence detection, and treatment response evaluation. Many disease- and treatment-related complications can be incidentally detected on PET/CT, which may be due to the complication of radiotherapy, chemotherapy, intervention, or primary tumor itself. Some of these complications could be life threatening and need urgent intervention. Therefore, these incidental findings should be recognized on PET/CT and immediately informed to the treating physicians if required urgent intervention.

Nomogram model to predict postoperative infection after mandibular osteoradionecrosis surgery

Osteoradionecrosis of the mandible (ORNM) is one of the most dreaded complications of radiotherapy. The poor healing capacity of soft tissue after radiation may lead to surgical failure. The current study was designed to identify prognostic factors for postoperative infection (PPI) and propose corresponding prophylaxis and intervention protocols. A retrospective study was conducted concerning ORNM patients from 2000 to 2015. A risk-stratification score and nomogram model were established to predict the risk of PPI. A total of 257 patients were analyzed, and the total incidence of PPI was 23.3% (60/257). In multiple logistic regression analysis, radiation dose [Formula: see text]80 Gy (versus <80 Gy, OR = 2.044, P = 0.035, 95% CI: 1.05-3.979), bilateral ORNM (versus unilateral, OR = 4.120, P = 0.006, 95% CI: 1.501-11.307), skin fistula (versus none, OR = 3.078, P = 0.040, 95% CI: 1.05-9.023), and implant utilization (versus none, OR = 2.115, P = 0.020, 95% CI: 1.125-3.976) were significantly associated with PPI. The susceptibility to PPI in patients with risk-stratification scores of 14-22 was 2.833 times that of patients with scores of 7-13, and 7.585 times that of cases defined as scores of 0-6. The discrimination capability of the nomogram model was estimated using a ROC curve with an AUC of 0.708, revealing potentially useful predictive abilities. In conclusion, current risk-stratification scores and nomogram models effectively predicted the risk of PPI in ORNM patients.

Dynamic contrast-enhanced MRI detects acute radiotherapy-induced alterations in mandibular microvasculature: prospective assessment of imaging biomarkers of normal tissue injury

Normal tissue toxicity is an important consideration in the continued development of more effective external beam radiotherapy (EBRT) regimens for head and neck tumors. The ability to detect EBRT-induced changes in mandibular bone vascularity represents a crucial step in decreasing potential toxicity. To date, no imaging modality has been shown to detect changes in bone vascularity in real time during treatment. Based on our institutional experience with multi-parametric MRI, we hypothesized that DCE-MRI can provide in-treatment information regarding EBRT-induced changes in mandibular vascularity. Thirty-two patients undergoing EBRT treatment for head and neck cancer were prospectively imaged prior to, mid-course, and following treatment. DCE-MRI scans were co-registered to dosimetric maps to correlate EBRT dose and change in mandibular bone vascularity as measured by K_trans and V_e. DCE-MRI was able to detect dose-dependent changes in both K_trans and V_e in a subset of patients. One patient who developed ORN during the study period demonstrated decreases in K_trans and V_e following treatment completion. We demonstrate, in a prospective imaging trial, that DCE-MRI can detect dose-dependent alterations in mandibular bone vascularity during chemoradiotherapy, providing biomarkers that are physiological correlates of acute of acute mandibular vascular injury and recovery temporal kinetics.

Osteonecrosis of the Jaws in Dogs in Previously Irradiated Fields: 13 Cases (1989-2014)

The aim of this report was to characterize osteonecrosis of the jaws (ONJ) in previously irradiated fields in dogs that underwent radiotherapy (RT) for oral tumors. Osteoradionecrosis of the jaw (ORNJ) was further defined as osteonecrosis in a previously irradiated field in the absence of a tumor. Thirteen dogs clinically diagnosed with 15 ONJ lesions were included in this retrospective case series. Medical records were reviewed for: breed, sex, weight, and age of the patient, tumor type, location in the oral cavity and size, location of the ONJ, time from RT to ONJ onset, known duration of the ONJ, and tumor presence. Where available, histological assessment of tissues obtained from the primary tumor, and tissues obtained from the ONJ lesion, was performed, and computed tomographic (CT) images and dental radiographs were reviewed. RT and other treatment details were also reviewed. Twelve dogs developed ONJ in the area of the previously irradiated tumor or the jaw closest to the irradiated mucosal tumor. Recurrence of neoplasia was evident at the time of ONJ diagnosis in five dogs. Time from RT start to ONJ onset varied from 2 to 44 months. In three cases, ORNJ developed after dental extractions in the irradiated field. Dental radiographs mostly revealed a moth-eaten pattern of bone loss, CT mostly revealed osteolysis, and histopathology was consistent with osteonecrosis. To conclude, development of ONJ/ORNJ following RT is a rare, but potentially fatal complication. Patients undergoing RT may benefit from a comprehensive oral and dental examination and treatment prior to RT.

CT findings in temporal bone osteoradionecrosis

PURPOSE

The goal of this study was to describe computed tomographic findings in patients with clinically proven temporal bone (TB) osteoradionecrosis (ORN) (TB-ORN).

MATERIALS AND METHODS

Computed tomographic scans of 20 patients were retrospectively evaluated for bony and soft tissue abnormalities. Clinical severity was graded based on level of therapy administered: mild (observation), moderate (antibiotics/hyperbaric oxygen), or severe (surgery).

RESULTS

Radiation dose to the primary tumor ranged from 30 to 75.6 Gy. Time to onset of ORN from completion of radiation therapy was 2 to 22 years (median, 7 years).

CLINICAL FINDINGS

exposed bone, 20 of the 20 patients; otorrhea, 17 of the 20 patients; hearing loss, 11 of the 20 patients; otalgia, 10 of the 20 patients; facial nerve paralysis, 2 of the 20 patients; gait imbalance, 2 of the 20 patients. Computed tomographic findings: external auditory canal erosions, 18 of the 20 patients; mastoid effusion, 18 of the 20 patients; mastoid bony coalescence, 5 of the 20 patients; enhancing soft tissue, 6 of the 20 patients; soft tissue gas, 6 of the 20 patients; temporomandibular joint/condylar erosion, 3 of the 20 patients.Three patients developed an abscess.

CONCLUSION

Mastoid effusion and external auditory canal erosions are commonly seen with TB-ORN. Clinically moderate or severe cases of TB-ORN are more likely to demonstrate enhancing soft tissue (P = 0.002), soft tissue gas (P = 0.002), and temporomandibular joint involvement (P = 0.07).

Osteoradionecrosis after radiation therapy for head and neck cancer: differentiation from recurrent disease with CT and PET/CT imaging

BACKGROUND AND PURPOSE

Our aim was to compare the CT and PET/CT imaging features of osteoradionecrosis with those of recurrent disease after treatment of head and neck malignancy.

MATERIALS AND METHODS

We retrospectively reviewed maxillofacial and neck CT scans obtained for suspected osteoradionecrosis or tumor recurrence for the presence of the following: 1) discrete solid mass, 2) cystic mass, 3) interruption of the bony cortex, 4) bony fragmentation, 5) bony trabecular loss, 6) intraosseous gas, and 7) bony sclerosis. Trabecular bone loss was further categorized as permeative (<75% loss of trabecula) or lucent (>75% loss). PET/CT studies performed for suspected osteoradionecrosis or tumor recurrence were evaluated for mean standard uptake value and maximum standard uptake value.

RESULTS

Ten maxillofacial CT, 53 neck CT, and 23 PET/CT studies were performed in 63 patients. Osteoradionecrosis was diagnosed by pathology or imaging stability in 46 patients, and tumor recurrence, in 17 patients. Bony sclerosis was found to be significantly more prevalent in osteoradionecrosis and was never seen with tumor recurrence (P = .013). Patients with tumor recurrence were more likely to have a solid (P < .001) or cystic mass (P = .025), which was rare in osteoradionecrosis. While patients with tumor recurrence had significantly higher mean standard uptake values and maximum standard uptake values, there was significant overlap in mean standard uptake values and maximum standard uptake values between the 2 groups.

CONCLUSIONS

There is significant overlap of standard uptake values in patients with osteoradionecrosis and tumor recurrence. CT findings provide more reliable diagnostic tools, with a solid or cystic mass strongly associated with tumor recurrence and bony sclerosis seen only with osteoradionecrosis.