Radiation-Induced Fibrosis in Patients with Head and Neck Cancer: A Review of Pathogenesis and Clinical Outcomes

Radiation-Induced Fibrosis in Head and Neck Cancer: Challenges and Future Therapeutic Strategies for Vocal Fold Treatments

Head and neck cancer encompasses a diverse group of malignant neoplasms originating in regions such as the oral cavity, oropharynx, hypopharynx, larynx, sinonasal cavities, and salivary glands. HNC represents a significant public health challenge, and recent reports indicate an increment in the incidence of HNC in young adults. In 2020, approximately 377,700 new HNC cases and 177,800 HNC-related deaths were reported globally. Major risk factors include tobacco smoking, alcohol consumption, and human papillomavirus (HPV) infections. HNC impacts vital functions such as breathing, swallowing, and speech. Treatments for this type of cancer within this complex anatomy include surgery, radiotherapy, and chemotherapy combinations. Radiotherapy is often an essential component of both curative and palliative HNC treatment, balancing tumor control with the preservation of function and appearance. However, its use can damage adjacent normal tissues, causing acute or chronic toxicity. One complication of HNC irradiation is VF fibrosis, which leads to severe voice impairments, significantly affecting patients' quality of life. Fibrosis involves excessive and aberrant deposition of extracellular matrix, driven by factors such as TGF-β1 and inflammatory cytokines, which ultimately impair the flexibility and function of VF. Current radiation-induced fibrosis treatments primarily focus on symptom management and include systemic therapies like corticosteroids, anti-inflammatory drugs, and antioxidants. However, these treatments have limited efficacy. Experimental approaches targeting molecular pathways involved in fibrosis are being explored. Given the limitations of these treatments, advancing research is crucial to develop more effective therapeutic strategies that can significantly improve the quality of life for HNC patients, especially those vulnerable to VF fibrosis.

Long-Term Outcomes After Elective Contralateral Neck Dissection for HPV-Related Oropharyngeal Cancer

OBJECTIVE

Patients with human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC), particularly of the base of tongue, have a high rate of occult nodal disease in the contralateral neck. The risk of failure in the contralateral neck is reduced with elective treatment. The optimal treatment strategy to minimize treatment-related toxicity while preserving regional control in the contralateral neck has not been elucidated.

STUDY DESIGN

Cross-sectional study of patients who underwent elective contralateral neck dissection as part of primary surgical treatment for HPV-related OPSCC between January 2002 and December 2018.

SETTING

Tertiary care center.

METHODS

Patients who underwent elective contralateral neck dissection as part of primary surgical treatment for HPV-related OPSCC between January 2002 and December 2018 were selected for inclusion. Long-term patient-reported functional outcomes were assessed via telephone at the time of data collection.

RESULTS

In total, 64 patients met the criteria for inclusion with a median follow-up of 58.5 months. In total, 56 patients (88%) had a primary cancer within the base of tongue or glossotonsillar sulcus. In total, 12 patients (19%) were found to have occult nodal metastasis in the contralateral neck, of whom 9 received adjuvant contralateral neck radiation. None of the patients who had node-negative contralateral neck dissections went on to receive radiation in the contralateral neck. Two patients (3%) recurred locally, two patients (3%) developed ipsilateral regional recurrence, and four patients (6%) developed distant metastasis. There were no regional recurrences within the contralateral neck. Five-year progression-free survival was 82.0%, whereas 5-year locoregional control was 93.0%. The mean Neck-Dissection Impairment Index was 94.4 with a median interval time of 92 months after surgery.

CONCLUSION

Elective contralateral neck dissection in patients with HPV-related OPSCC provides excellent regional control with minimal long-term functional impairment, and most patients can be spared contralateral neck radiation without compromising oncologic outcomes. This may decrease long-term toxicity related to bilateral neck irradiation.

Radiation-Induced Nasopharyngeal Fibrosis Resulting in a Difficult Airway: A Case Report

Patients with head and neck cancer often experience airway complications. This case highlights a patient with nasopharyngeal cancer post-radiotherapy (RT), who presented with a difficult airway (DA). An 83-year-old woman, scheduled for a partial left lower lobe pneumonectomy, had received RT for nasopharyngeal cancer one year prior. Physical examination revealed trismus, limited neck movement, Mallampati class IV, and grade III on the upper lip bite test. Bronchoscopy showed mucous membrane irregularities in the nasopharynx, along with an edematous epiglottis and vocal cords. After general anesthesia induction, both mask ventilation and McGrath™ intubation (Covidien Inc., Tokyo, Japan) attempts failed. Lifting the patient's tongue manually allowed visualization of the vocal cords via a fiberoptic bronchoscope, enabling successful intubation. Patients who have undergone head and neck radiotherapy (HNRT) are at increased risk of DAs due to radiation-induced fibrosis (RIF) of pharyngeal soft tissues.

Exploring Quantitative MRI Biomarkers of Head and Neck Post-Radiation Lymphedema and Fibrosis: Post Hoc Analysis of a Prospective Trial

BACKGROUND

Quantifying head and neck lymphedema and fibrosis (HN-LEF) is crucial in the investigation and management of treatment sequelae in head and neck cancer (HNC).

METHODS

The T1- and T2-weighted MRI signal intensity (SI) was examined in relation to HN-LEF categories per physical/tactile examination (No-LEF, A-B = edema, C = edema + fibrosis, D = fibrosis), and MRI structural volumes were examined in relation to a novel 10-point HN-LEF score in the intraoral and submental regions.

RESULTS

We identified differences in ranks among HN-LEF categories in relation to the MRI SI (A-B and C are higher than D and No-LEF for T2 SI, and A-B is the highest for T1). Furthermore, six pairs of FOM volumes on MRI demonstrated a strong negative correlation (p < 0.05) with the HN-LEF score at adjacent palpable sites.

CONCLUSION

Both MRI SI and structural volumes can potentially be imaging biomarkers of edematous soft tissue states in HNC patients.

Antiresorptive therapy in combination with radiation results in enhanced risk for necrosis and associated complicatifions

OBJECTIVE

Patients exposed to a combination of antiresorptive medication and radiotherapy of the head and neck area developing necrosis of the jaw in the course of treatment are extremely rare. Therefore, the aim of this study was to identify the outcome and complications in this highly vulnerable patient cohort.

STUDY DESIGN

Seventeen patients who received both antiresorptive treatment and radiotherapy (medication-related osteonecrosis of the jaw/osteoradionecrosis = the [MRONJ/ORN] group) in the head and neck area were enrolled in this study. Included patients were treated in our department between 2005 and 2022. Four hundred twenty-four patients with MRONJ (the MRONJ group) and 138 patients with ORN of the jaw were enrolled as two control groups (the ORN group). Demographic data, lesion localization, date of primary diagnosis, clinical symptoms, type of therapy (surgical or non-surgical), details on antiresorptive treatment, outcome, and complications were recorded.

RESULTS

Pathological fractures, continuity resection, and recurrence appear more often in patients who receive a combination of antiresorptive treatment and radiotherapy in the head and neck area compared with patients undergoing only one of these treatments. There was a statistically significant difference (P < .001) between the MRONJ/ORN group and the MRONJ group and the MRONJ/ORN group and the ORN group considering recurrence, fracture, and continuity resection. Patients with ORN combined with MRONJ have a 4-times higher risk for developing recurrence compared with patients with MRONJ and a 1.5-times higher risk for recurrence compared with patients with ORN. Jaw fracture and continuity resection appear more often in patients with MRONJ/ORN.

CONCLUSIONS

Patients under antiresorptive therapy in combination with radiation therapy in the head and neck area have a higher risk for developing complications in case of osteonecrosis of the jaw. Therefore, a strict follow-up care schedule is highly recommended.

Near-infrared photoimmunotherapy: mechanisms, applications, and future perspectives in cancer research

Photoimmunotherapy (PIT) involves the targeted delivery of a photosensitizer through antibody conjugation, which, upon binding to its cellular target and activation by external irradiation, induces localized toxicity. This approach addresses several limitations of conventional cancer therapies, such as chemo- and radiotherapies, which result in off-target effects that significantly reduce patient quality of life. Furthermore, PIT improves on the challenges encountered with photodynamic therapy (PDT), such as nonspecific localization of the photosensitizer, which often results in unintended toxicities. Although PIT was first proposed in the early 1980s, its clinical applications have been constrained by limitations in antibody engineering, conjugation chemistries, and optical technologies. However, recent advances in antibody-drug conjugate (ADC) research and the emergence of sophisticated laser technologies have greatly benefited the broader applicability of PIT. Notably, the first near-infrared photoimmunotherapy (NIR-PIT) treatment for head and neck cancer has been approved in Japan and is currently in phase III clinical trials in the USA. A significant advantage of PIT over traditional ADCs in cancer management is the agnostic nature of PDT, making it more adaptable to different tumor types. Specifically, PIT can act on cancer stem cells and cancer cells displaying treatment resistance and aggressive phenotypes-a capability beyond the scope of ADCs alone. This review provides an overview of the mechanism of action of NIR-PIT, highlighting its adaptability and application in cancer therapeutics, and concludes by exploring the potential of PIT in advancing cancer treatments.

Vocal Fold Medialization Procedures in Previously Radiated Patients: A Survey of Practice Patterns

BACKGROUND/OBJECTIVES

Head and neck radiation therapy (HNRT) has traditionally been considered a contraindication to vocal fold medialization procedures. Although safety has been demonstrated, we hypothesize that actual management varies. This study evaluates practice patterns of otolaryngologists regarding vocal fold medialization in patients after HNRT.

METHODS

A 25-question survey evaluating respondents' management of patients status post HNRT with vocal fold paresis/paralysis was distributed to 357 otolaryngologists. Practice patterns regarding injection laryngoplasty (IL), medialization thyroplasty (MT), and arytenoid adduction (AA) were queried.

RESULTS

Eight-two clinicians (23%) completed the survey. Ninety-one percent of respondents were laryngologists, 9% head and neck surgeons, 3% comprehensive otolaryngologists, and 3% "other." Eleven (15%) had been in practice <5 years, 19 (25%) for 5-10 years, and 46 (61%) for >10 years. No respondents considered HNRT a contraindication to IL, and 11 (14%) reported complications from the procedure. Hyaluronic acid (58, 75%) was most commonly injected. Twenty percent considered HNRT a contraindication to MT, and 37% considered it a contraindication to AA. Gore-Tex was used most commonly (65%). Twenty-seven percent reported major complications after MT. All complications occurred in the >10-year practice group, and this group was more likely to delay surgery after HNRT (p = 0.022). Respondents with complications were more likely to perform MT in HNRT patients (p = 0.0191).

CONCLUSIONS

Otolaryngologists generally do not consider HNRT to be a contraindication to IL, but some consider it a contraindication to MT/AA. Previous complications do not appear to deter surgeons from performing MT.

LEVEL OF EVIDENCE

NA (Survey Study) Laryngoscope, 135:183-190, 2025.

The Quantification of Radiation Fibrosis Using Clinically Indicated Magnetic Resonance Imaging for Head and Neck Cancer Patients

Currently, no objective method exists to measure the extent of fibrosis in swallowing musculature in head and neck cancer (HNC) patients. We developed and psychometrically tested a method of quantifying fibrosis volume using magnetic resonance imaging (MRI). The overall aim of this study was to determine if clinical MRI is a reliable tool to measure fibrosis of the pharyngeal musculature in patients with HNC managed with RT and to assess its potential to capture changes in fibrosis over time. Eligible participants were adults with HNC treated with radiation therapy (RT) who received minimally two MRIs and videofluoroscopic swallow (VFS) studies from baseline (pre-RT) up to 1-year post-RT. Two neuroradiologists independently contoured fibrosis volume in batches from MRIs using Vitrea™. Sufficient inter-rater reliability was set at Intraclass Correlation Coefficient (ICC) > 0.75. Two speech-language pathologists independently rated VFSs for swallowing impairment using standardized scales, with discrepancies resolved by consensus. MRI and VFS scores were correlated using Spearman's rank coefficient. Participants included 42 adults (male = 33); mean age 59 (SD = 8.8). ICC (95% Confidence Interval) for fibrosis volume was 0.34 (0, 0.76) for batch one and 0.43 (0, 0.82) for batch two. Consensus meetings were held after each batch. Sufficient reliability was reached by batch three (ICC = 0.95 (0.79, 0.99)). Fibrosis volume increased significantly from 3 to 12 months (mean change = 1.28 mL (SD = 5.21), p = 0.006), as did pharyngeal impairment from baseline to 12 months (mean score change = 3.05 (SD = 3.02), p = 0.003). Fibrosis volume moderately correlated with pharyngeal impairment at 3 and 12 months (0.49, p = 0.004 and 0.59, p = 0.005, respectively). We demonstrated a reliable measure of fibrosis volume in swallowing musculature from existing clinical MRIs and identified that larger fibrosis volume was associated with worse swallowing function. The reliable capture of fibrosis volume offers a pragmatic method for early detection of fibrosis and concomitant dysphagia.

Global Immune-Nutrition-Inflammation Index as a novel comprehensive biomarker in predicting the radiation-induced trismus rates in locally advanced nasopharyngeal carcinoma patients

In this study, we aimed to evaluate whether the novel pretreatment Global Immune-Nutrition-Inflammation Index (GINI) can predict radiation-induced trismus (RIT) in locally advanced nasopharyngeal carcinoma (LA-NPC) patients undergoing concurrent chemoradiotherapy (CCRT). Data of LA-NPC patients presenting without RIT were reviewed retrospectively. Any post-CCRT maximum mouth openings (MMO) ≤ 35 mm were considered RIT. The GINI index was calculated using the formula: GINI = (CRP x Monocytes x Platelets x Neutrophils) ÷ (Albumin x Lymphocytes). We used receiver operating characteristic (ROC) curve analysis to examine the potential correlation between pretreatment GINI measures and post-CCRT RIT status. Logistic regression analysis examined the independence of the association between confounding factors and RIT rates. The study comprised 230 participants, and 52 (22.6%) received an RIT diagnosis. The optimal pre-CCRT GINI cutoff that dichotomizes RIT rates was determined to be 1,424 (area under the curve [AUC]: 76%; sensitivity: 75.0%; specificity: 71.7%; J-index: 0.463). RIT incidence was significantly higher in the GINI ≥ 1424 group than in its GINI < 1424 counterpart (43.3% vs. 9.3%; hazard ratio: 4.76; P < 0.001). Multivariate logistic regression analysis revealed that a pre-CCRT GINI ≥ 1424 was an independent predictor of increased RIT rates after definitive CCRT in this patient group (P < 0.001). In conclusion, the present results revealed that elevated pre-CCRT GINI measures (≥ 1424) can efficiently and independently predict elevated RIT rates in LA-NPC patients after CCRT.

Development of Mesenchymal Stem Cell Encoded with Myogenic Gene for Treating Radiation-Induced Muscle Fibrosis

Radiation therapy (RT) is a typical treatment for head and neck cancers. However, prolonged irradiation of the esophagus can cause esophageal fibrosis due to increased reactive oxygen species and proinflammatory cytokines. The objective of this study was to determine whether myogenic gene-transfected mesenchymal stem cells (MSCs) could ameliorate damage to esophageal muscles in a mouse model of radiation-induced esophageal fibrosis. We cloned esophageal myogenic genes (MyoD, MyoG, and Myf6) using plasmid DNA. Afterward, myogenic genes were transfected into Human Mesenchymal Stem Cells (hMSCs) using electroporation. Gene transfer efficiency, stemness, and myogenic gene profile were examined using flow cytometry, quantitative polymerase chain reaction, and RNA sequencing. In vivo efficacy of gene-transfected hMSCs was demonstrated through histological and gene expression analyses using a radiation-induced esophageal fibrosis animal model. We have confirmed that the gene transfer efficiency was high (∼75%). Pluripotency levels in gene-transfected MSCs were significantly decreased compared with those in the control (vector). Particularly, myogenesis-related genes such as OAS2, OAS3, and HSPA1A were overexpressed in the group transfected with three genes. At 4 weeks after injection, it was found that thickness collagen layer and esophageal muscle in MSCs transfected with all three genes were significantly reduced compared to those in the saline group. Muscularis mucosa was observed prominently in the gene combination group. Moreover, expression levels of myogenin, Myf6, calponin, and SM22α known to be specific markers of esophageal muscles tended to increase in the group transfected with three genes. Therefore, using gene-transfected MSCs has the potential as a promising therapy against radiation-induced esophageal fibrosis.

Quantification of Radiation-Induced Fibrosis in Head and Neck Cancer Patients Using Shear Wave Elastography

Background Radiation-induced fibrosis (RIF) is a common side effect in head and neck cancer (HNC) patients treated with radiotherapy. A validated tool to measure RIF does not currently exist. In this study, we evaluate the ability of shear wave elastography (SWE) to measure RIF in HNC survivors. Methods HNC patients treated with surgery and adjuvant radiation between January and September 2022 at a single tertiary medical center were enrolled with age and gender-matched control patients. Median tissue stiffness was recorded with SWE at the sternocleidomastoid (SCM) muscle, overlying subcutaneous tissues (ST), and the base of the tongue (BOT). Results A total of 20 patients were included. Tissue stiffness was significantly higher among HNC patients at the SCM ipsilateral (53.7 kPa vs. 17.5 kPa, p=0.002) and contralateral (44.1 kPa vs. 21.6 kPa, p=0.027) than the side of treatment. Tissue stiffness was not significantly different in ST ipsilateral (6.6 kPa vs. 5.3 kPa, p=0.922) or contralateral (8.0 kPa vs. 6.4 kPa, p=0.426) to treatment. Tissue stiffness at the BOT was not significantly different (19.1 kPa vs. 13.1 kPa, p=0.084). Conclusion SWE is a noninvasive method for measuring tissue fibrosis and is a promising tool for the measurement of RIF in patients with HNC. SWE measurements were taken from the SCM, ST, and BOT in HNC patients at least one year out from treatment with surgery and adjuvant radiation as well as age and gender-matched control patients. HNC patients showed significantly higher levels of tissue stiffness at the SCM both ipsilateral and contralateral to radiotherapy. SWE may be useful for tracking the progression of RIF in HNC patients.

Effects of Head and Neck Cancer Radiotherapy on Cricothyroid Membrane Related Dimensions

Background

Radiation treatment can modify soft tissue dynamics depending on the extent and location of irradiation. We hypothesized that head and neck radiotherapy caused alterations in cricothyroid membrane (CTM) related dimensions.

Objectives

Primary objective was to evaluate changes in the cricothyroid membrane height (CTMH) and skin-to-CTM distance (STCD) in patients who underwent radiation treatment for head and neck cancers.

Methods

Pre- and post-head-and-neck cancer-radiated computed tomography (CT) scans were analyzed retrospectively. The patients' demographics (age, sex, body mass index, cancer location), radiation dose and laterality, time from radiation initiation to CT scan assessments were summarized. CTMH and STCD were measured from pre-and post-radiation CT scans. Pre- and post-radiation comparisons were conducted using a paired t-test, or Wilcoxon signed-rank test if more appropriate. Chi-squared or Fisher's Exact test were used for categorical variables.

Results

Among 231 study patients, who underwent head and neck radiotherapy in our institution 73.2% were males, and the median age of total population was 66 years (31-93). The median BMI was 25.2 kg/m2 (13.8-47.2). The median time from first radiation dose to CT scan assessment was 29.5 months (2-115).The median pre- and post-radiation CTMH were 8.7 mm (3-16.2) and 7.5 mm (3.1-14.3) respectively. The median pre- and post-radiation STCD were 11.7 mm (2.9-71.1) and 10.2 mm (3.9-38) respectively.

Conclusion

In summary our patient population had significant reduction of cricothyroid membrane related dimensions following head-and-neck radiotherapy, which can limit the localization of the cricothyroid membrane.

Level of evidence III

Retrospective cohort study.

The Impact of Radiation Therapy in Patients with Systemic Sclerosis and Head and Neck Cancer

OBJECTIVE

Systemic sclerosis (SSc) is considered a relative, or in some cases, absolute contraindication for radiation therapy for various cancers; however, radiation is the standard of care and the best option for tumor control for locally advanced head and neck (H&N) cancer. We present a case series to document postradiation outcomes in patients with SSc and H&N cancer.

METHODS

Patients with SSc and H&N cancer treated with radiation were identified from the Johns Hopkins Scleroderma Center and the University of Pittsburgh Scleroderma Center research registries. Through chart review, we identified whether patients developed predetermined acute and late side effects or changes in SSc activity from radiation. We further describe therapies used to prevent and treat radiation-induced fibrosis.

RESULTS

Thirteen patients with SSc who received radiation therapy for H&N cancer were included. Five-year survival was 54%. Nine patients (69%) developed local radiation-induced skin thickening, and 7 (54%) developed reduced neck range of motion. Two patients required long-term percutaneous endoscopic gastrostomy use due to radiation therapy complications. No patients required respiratory support related to radiation therapy. Regarding SSc disease activity among the patients with established SSc before radiation therapy, none experienced interstitial lung disease progression in the postradiation period. After radiation, one patient had worsening skin disease outside the radiation field; however, this patient was within the first year of SSc, when progressive skin disease is expected. Treatment strategies to prevent radiation fibrosis included pentoxifylline, amifostine, and vitamin E, while intravenous immunoglobulin (IVIG) was used to treat it.

CONCLUSION

Although some patients with SSc who received radiation for H&N cancer developed localized skin thickening and reduced neck range of motion, systemic flares of SSc were uncommon. This observational study provides evidence to support the use of radiation therapy for H&N cancer in patients with SSc when radiation is the best treatment option.

Single-cell transcriptional analysis of irradiated skin reveals changes in fibroblast subpopulations and variability in caveolin expression

BACKGROUND

Radiation-induced fibrosis (RIF) is an important late complication of radiation therapy, and the resulting damaging effects of RIF can significantly impact reconstructive outcomes. There is currently a paucity of effective treatment options available, likely due to the continuing knowledge gap surrounding the cellular mechanisms involved. In this study, detailed analyses of irradiated and non-irradiated human skin samples were performed incorporating histological and single-cell transcriptional analysis to identify novel features guiding development of skin fibrosis following radiation injury.

METHODS

Paired irradiated and contralateral non-irradiated skin samples were obtained from six female patients undergoing post-oncologic breast reconstruction. Skin samples underwent histological evaluation, immunohistochemistry, and biomechanical testing. Single-cell RNA sequencing was performed using the 10X single cell platform. Cells were separated into clusters using Seurat in R. The SingleR classifier was applied to ascribe cell type identities to each cluster. Differentially expressed genes characteristic to each cluster were then determined using non-parametric testing.

RESULTS

Comparing irradiated and non-irradiated skin, epidermal atrophy, dermal thickening, and evidence of thick, disorganized collagen deposition within the extracellular matrix of irradiated skin were readily appreciated on histology. These histologic features were associated with stiffness that was higher in irradiated skin. Single-cell RNA sequencing revealed six predominant cell types. Focusing on fibroblasts/stromal lineage cells, five distinct transcriptional clusters (Clusters 0-4) were identified. Interestingly, while all clusters were noted to express Cav1, Cluster 2 was the only one to also express Cav2. Immunohistochemistry demonstrated increased expression of Cav2 in irradiated skin, whereas Cav1 was more readily identified in non-irradiated skin, suggesting Cav1 and Cav2 may act antagonistically to modulate fibrotic cellular responses.

CONCLUSION

In response to radiation therapy, specific changes to fibroblast subpopulations and enhanced Cav2 expression may contribute to fibrosis. Altogether, this study introduces a novel pathway of caveolin involvement which may contribute to fibrotic development following radiation injury.

Areca nut-induced oral fibrosis - Reassessing the biology of oral submucous fibrosis

BACKGROUND

Oral submucous fibrosis (OSF) is a pathological condition characterized by excessive tissue healing resulting from physical, chemical, or mechanical trauma. Notably, areca nut consumption significantly contributes to the development of oral fibrosis. The current definition of OSF, recognizing its potential for malignant transformation, necessitates a more comprehensive understanding of its pathophysiology and etiology.

HIGHLIGHTS

Areca nut induces fibrotic pathways by upregulating inflammatory cytokines such as TGF-β and expressing additional cytokines. Moreover, it triggers the conversion of fibroblasts to myofibroblasts, characterized by α-SMA and γSMA expression, resulting in accelerated collagen production. Arecoline, a component of areca nut, has been shown to elevate levels of reactive oxygen species, upregulate the expression of various cytokines, and activate specific signaling pathways (MEK, COX2, PI3K), all contributing to fibrosis. Therefore, we propose redefining OSF as "Areca nut-induced oral fibrosis" (AIOF) to align with current epistemology, emphasizing its distinctive association with areca nut consumption. The refined definition enhances our ability to develop targeted interventions, thus contributing to more effective prevention and treatment strategies for oral submucous fibrosis worldwide.

CONCLUSION

Arecoline plays a crucial role as a mediator in fibrosis development, contributing to extracellular matrix accumulation in OSF. The re-evaluation of OSF as AIOF offers a more accurate representation of the condition. This nuanced perspective is essential for distinguishing AIOF from other forms of oral fibrosis and advancing our understanding of the disease's pathophysiology.

Adipose-Derived Stromal Cell-Based Therapies for Radiation-Induced Fibrosis

Significance: Half of all cancer patients receive radiation therapy as a component of their treatment regimen, and the most common resulting complication is radiation-induced fibrosis (RIF) of the skin and soft tissue. This thickening of the dermis paired with decreased vascularity results in functional limitations and esthetic concerns and poses unique challenges when considering surgical exploration or reconstruction. Existing therapeutic options for RIF of the skin are limited both in scope and efficacy. Cell-based therapies have emerged as a promising means of utilizing regenerative cell populations to improve both functional and esthetic outcomes, and even as prophylaxis for RIF. Recent Advances: As one of the leading areas of cell-based therapy research, adipose-derived stromal cells (ADSCs) demonstrate significant therapeutic potential in the treatment of RIF. The introduction of the ADSC-augmented fat graft has shown clinical utility. Recent research dedicated to characterizing specific ADSC subpopulations points toward further granularity in understanding of the mechanisms driving the well-established clinical outcomes seen with fat grafting therapy. Critical Issues: Various animal models of RIF demonstrated improved clinical outcomes following treatment with cell-based therapies, but the cellular and molecular basis underlying these effects remains poorly understood. Future Directions: Recent literature has focused on improving the efficacy of cell-based therapies, most notably through (1) augmentation of fat grafts with platelet-rich plasma and (2) the modification of expressed RNA through epitranscriptomics. For the latter, new and promising gene targets continue to be identified which have the potential to reverse the effects of fibrosis by increasing angiogenesis, decreasing inflammation, and promoting adipogenesis.

Long-term stability of jaw reconstruction with microvascular bone flaps: A prospective longitudinal study

OBJECTIVES

Microvascular bone flap jaw reconstruction has achieved satisfactory clinical outcomes. However, little is known about the long-term stability of the reconstructed jaw. This prospective longitudinal study aimed to investigate the long-term stability of jaw reconstruction and factors that were associated with it.

METHODS

Patients with successful computer-assisted osseous free-flap jaw reconstruction in the Department of Oral and Maxillofacial Surgery, Queen Mary Hospital, Hong Kong were recruited for this prospective longitudinal study. The three-dimensional jaw models at the pre-operative plan, post-operative 1-month, and 2 years were aligned and compared.

RESULTS

A total of 69 patients were recruited, among which 48 patients were available for the long-term analysis. Compared to 1-month after surgery, further deviation from the pre-operative plan was observed at post-operative 2 years. Lack of accuracy in surgery, segmental mandible resection especially with the involvement of mandible angles, and post-operative radiation therapy were identified as the significant factors affecting the positional stability of the reconstructed jaw (p < 0.05). Stable reconstruction was observed in the subgroup analysis of patients without post-operative radiation therapy.

CONCLUSION

Up to the best of our knowledge, this is the first prospective longitudinal study reporting the long-term stability of jaw reconstruction and its affecting factors. Our data demonstrated that the reconstructed jaw position lacked stability over the postoperative period. How to improve long-term stability of reconstructed jaw thus optimize the functional outcomes warrants further studies.

Exploring predictors of dysphagia in survivors of head and neck cancer: A cross-sectional study

PURPOSE

To evaluate the prevalence of dysphagia in survivors of head and neck cancer (sHNC) and to identify the predictors contributing to the development of dysphagia.

METHODS

We enrolled 62 sHNC in a cross-sectional study to check the prevalence of dysphagia in sHNC and to evaluate which factors were influencing the presence of this side effect. Besides dysphagia, sociodemographic and clinical characteristics, oral symptoms, maximal mouth opening (MMO), sleep quality and physical condition were evaluated, and a linear regression analysis was performed to verify which of these outcomes impact dysphagia.

RESULTS

Among all the sHNC, 85.5% presented dysphagia. The linear regression analysis confirmed that 44.9% of the variance in dysphagia was determined by coughing, MMO and sleep quality, being MMO the most powerful predictor, followed by coughing and sleep quality.

CONCLUSION

Dysphagia affected the great majority of sHNC. Moreover, symptoms as coughing, reduced MMO and sleep disorders may act as predictors contributing to the development of dysphagia. Our results emphasize the importance of an early and proper identification of the symptoms as well as an adequate treatment strategy to address the cluster of symptoms that sHNC undergo.

Exploring the mechanisms behind autologous lipotransfer for radiation-induced fibrosis: A systematic review

AIM

Radiation-induced fibrosis is a recognised consequence of radiotherapy, especially after multiple and prolonged dosing regimens. There is no definitive treatment for late-stage radiation-induced fibrosis, although the use of autologous fat transfer has shown promise. However, the exact mechanisms by which this improves radiation-induced fibrosis remain poorly understood. We aim to explore existing literature on the effects of autologous fat transfer on both in-vitro and in-vivo radiation-induced fibrosis models, and to collate potential mechanisms of action.

METHOD

PubMed, Cochrane reviews and Scopus electronic databases from inception to May 2023 were searched. Our search strategy combined both free-text terms with Boolean operators, derived from synonyms of adipose tissue and radiation-induced fibrosis.

RESULTS

The search strategy produced 2909 articles. Of these, 90 underwent full-text review for eligibility, yielding 31 for final analysis. Nine conducted in-vitro experiments utilising a co-culture model, whilst 25 conducted in-vivo experiments. Interventions under autologous fat transfer included adipose-derived stem cells, stromal vascular function, whole fat and microfat. Notable findings include downregulation of fibroblast proliferation, collagen deposition, epithelial cell apoptosis, and proinflammatory processes. Autologous fat transfer suppressed hypoxia and pro-inflammatory interferon-γ signalling pathways, and tissue treated with adipose-derived stem cells stained strongly for anti-inflammatory M2 macrophages. Although largely proangiogenic initially, studies show varying effects on vascularisation. There is early evidence that adipose-derived stem cell subgroups may have different functional properties.

CONCLUSION

Autologous fat transfer functions through pro-angiogenic, anti-fibrotic, immunomodulatory, and extracellular matrix remodelling properties. By characterising these mechanisms, relevant drug targets can be identified and used to further improve clinical outcomes in radiation-induced fibrosis. Further research should focus on adipose-derived stem cell sub-populations and augmentation techniques such as cell-assisted lipotransfer.

Radiomics and Deep Learning in Nasopharyngeal Carcinoma: A Review

Nasopharyngeal carcinoma is a common head and neck malignancy with distinct clinical management compared to other types of cancer. Precision risk stratification and tailored therapeutic interventions are crucial to improving the survival outcomes. Artificial intelligence, including radiomics and deep learning, has exhibited considerable efficacy in various clinical tasks for nasopharyngeal carcinoma. These techniques leverage medical images and other clinical data to optimize clinical workflow and ultimately benefit patients. In this review, we provide an overview of the technical aspects and basic workflow of radiomics and deep learning in medical image analysis. We then conduct a detailed review of their applications to seven typical tasks in the clinical diagnosis and treatment of nasopharyngeal carcinoma, covering various aspects of image synthesis, lesion segmentation, diagnosis, and prognosis. The innovation and application effects of cutting-edge research are summarized. Recognizing the heterogeneity of the research field and the existing gap between research and clinical translation, potential avenues for improvement are discussed. We propose that these issues can be gradually addressed by establishing standardized large datasets, exploring the biological characteristics of features, and technological upgrades.

Radiation-induced long-term dysphagia in survivors of head and neck cancer and association with dose-volume parameters

BACKGROUND

Although dysphagia is a common side effect after radiotherapy (RT) of head and neck cancer (HNC), data on long-term dysphagia is scarce. We aimed to 1) compare radiation dose parameters in HNC survivors with and without dysphagia, 2) investigate factors associated with long-term dysphagia and its possible impact on health-related quality of life (HRQoL), and 3) investigate how our data agree with existing NTCP models.

METHODS

This cross-sectional study conducted in 2018-2020, included HNC survivors treated in 2007-2013. Participants attended a one-day examination in hospital and filled in patient questionnaires. Dysphagia was measured with the EORTC QLQ-H&N35 swallowing scale. Toxicity was scored with CTCAE v.4. We contoured swallowing organs at risk (SWOAR) on RT plans, calculated dose-volume histograms (DVHs), performed logistic regression analyses and tested our data in established NTCP models.

RESULTS

Of the 239 participants, 75 (31%) reported dysphagia. Compared to survivors without dysphagia, this group had reduced HRQoL and the DVHs for infrahyoid SWOAR were significantly shifted to the right. Long-term dysphagia was associated with age (OR 1.07, 95% CI 1.03-1.10), female sex (OR 2.75, 95% CI 1.45-5.21), and mean dose to middle pharyngeal constrictor muscle (MD-MPCM) (OR 1.06, 95% CI 1.03-1.09). NTCP models overall underestimated the risk of long-term dysphagia.

CONCLUSIONS

Long-term dysphagia was associated with higher age, being female, and high MD-MPCM. Doses to distally located SWOAR seemed to be risk factors. Existing NTCP models do not sufficiently predict long-term dysphagia. Further efforts are needed to reduce the prevalence and consequences of this late effect.

Advances in and applications of imaging and radiomics in head and neck cancer survivorship

PURPOSE OF REVIEW

Radiological imaging is an essential component of head/neck cancer (HNC) care. Advances in imaging modalities (including CT, PET, MRI and ultrasound) and analysis have enhanced our understanding of tumour characteristics and prognosis. However, the application of these methods to evaluate treatment-related toxicities and functional burden is still emerging. This review showcases recent literature applying advanced imaging and radiomics to the assessment and management of sequelae following chemoradiotherapy for HNC.

RECENT FINDINGS

Whilst primarily early-stage/exploratory studies, recent investigations have showcased the feasibility of using radiological imaging, particularly advanced/functional MRI (including diffusion-weighted and dynamic contrast-enhanced MRI), to quantify treatment-induced tissue change in the head/neck musculature, and the clinical manifestation of lymphoedema/fibrosis and dysphagia. Advanced feature analysis and radiomic studies have also begun to give specific focus to the prediction of functional endpoints, including dysphagia, trismus and fibrosis.

SUMMARY

There is demonstrated potential in the use of novel imaging techniques, to help better understand pathophysiology, and improve assessment and treatment of functional deficits following HNC treatment. As larger studies emerge, technologies continue to progress, and pathways to clinical translation are honed, the application of these methods offers an exciting opportunity to transform clinical practices and improve outcomes for HNC survivors.

Associations between patient-reported late effects and systemic cytokines in long-term survivors of head and neck cancer treated with radiotherapy

PURPOSE

Head and neck cancer (HNC) treatment may lead to late effects and impaired health-related quality of life of survivors. Knowledge on long-term late effects after radiotherapy (RT) and potential underlying biological mechanisms is lacking. We assessed the prevalence of xerostomia, dysphagia, and chronic fatigue (CF) in HNC survivors ≥ 5 years post-RT, and examined associations between pro-inflammatory cytokines and late effects.

METHODS

In a cross-sectional study, 263 HNC survivors treated between 2007 and 2013 were enrolled. They completed validated questionnaires assessing xerostomia and dysphagia (the EORTC QLQ-H&N35), and CF (the Fatigue Questionnaire), and underwent blood sampling and clinical examination. Pro-inflammatory cytokines were analyzed in 262 survivors and 100 healthy age- and gender-matched controls.

RESULTS

Median time since treatment was 8.5 years. The proportions of survivors reporting xerostomia, dysphagia, and CF were 58%, 31%, and 33%, respectively, with a preponderance of females. We found no significant associations between IL-6, IL-8, IP-10, TARC, TNF, or ENA-78 and the three late effects. The odds of having elevated levels of IL-6 and IP-10 were significantly higher in the survivors compared to the controls.

CONCLUSIONS

More than one-third of long-term HNC survivors experienced xerostomia, dysphagia, and CF. Persistent inflammation, with elevated systemic cytokines, was not associated with these late effects, although HNC survivors had higher levels of some cytokines than the controls.

IMPLICATIONS FOR CANCER SURVIVORS

This study provides new knowledge on late effects that can serve as grounds for informing patients with HNC about risk of late effects more than 5 years after RT.

Overview of radiotherapy-induced chronic pain in childhood cancer survivors: A narrative review

Radiotherapy is an important aspect of oncological treatment in several childhood cancers. However, radiotherapy is known to have numerous side effects, including detrimental effects on growth, neurocognitive impairment, and the development of secondary malignancies. One less studied long-term side effect of pediatric radiotherapy treatment is chronic pain. While the short-term toxicities of radiotherapy resolve over a few weeks to months, the chronic pain caused by radiotherapy-induced tissue damage can significantly affect children's quality of life. As long-term childhood cancer survivors age into adulthood, they are typically followed up by a wide variety of doctors, not all of whom may be familiar with radiotherapy-induced chronic pain and its management. The aim of this review is to discuss the various common manifestations of radiotherapy-related pain in children, as well as ways to identify and manage these. Common radiotherapy-related side effects leading to chronic pain symptoms include radiation fibrosis, enteritis, dermatitis, lymphedema, neuropathic pain, and effects on bone development. The pathophysiology, evaluation and management of these are briefly summarized in this review. This is followed by an overview of radiotherapy techniques that allow greater sparing of normal tissue, minimizing future painful side effects. Finally, the assessment of pain in children is described, as well as strategies for management, and red flag symptoms that should prompt urgent specialist referral. In conclusion, a good understanding of the long-term side effects of radiotherapy treatment in children is essential for the various medical professionals that follow-up the child in the years after treatment. For young children, the evaluation of pain is in itself a challenge, and effects on growth, development, and learning are crucial. For older children, social and psychological factors become increasingly important. As radiation therapy techniques continue to advance, the spectrum and incidence of chronic pain syndromes may change over time.

Unplanned Readmission After Surgery for Cervical Spine Metastases

OBJECTIVE

Patients undergoing surgery for cervical spine metastases are at risk for unplanned readmission due to comorbidities and chemotherapy/radiation. Our objectives were to: 1) report the incidence of unplanned readmission, 2) identify risk factors associated with unplanned readmission, and 3) determine the impact of an unplanned readmission on long-term outcomes.

METHODS

A single-center, retrospective, case-control study was undertaken of patients undergoing cervical spine surgery for metastatic disease between 02/2010 and 01/2021. The primary outcome of interest was unplanned readmission within 6 months. Survival analysis was performed for overall survival (OS) and local recurrence (LR).

RESULTS

A total of 61 patients underwent cervical spine surgery for metastatic disease with the following approaches: 11 (18.0%) anterior, 28 (45.9%) posterior, and 22 (36.1%) combined. Mean age was 60.9 ± 11.2 years and 38 (62.3%) were males. A total of 9/61 (14.8%) patients had an unplanned readmission, 3 for surgical reasons and 6 for medical reasons. No difference was found in demographics, preoperative Karnofsky Performance Scale (P = 0.992), motor strength (P = 0.477), or comorbidities (P = 0.213) between readmitted patients versus not. Readmitted patients had a higher rate of preoperative radiation (P = 0.009). No statistical differences were found in operative time (P = 0.893), estimated blood loss (P = 0.676), length of stay (P = 0.720), discharge disposition (P = 0.279), and operative approach (P = 0.450). Furthermore, no difference was found regarding complications (P = 0.463), postoperative Karnofsky Performance Scale (P = 0.535), and postoperative Modified McCormick Scale (P = 0.586). Lastly, unplanned readmissions were not associated with OS (log-rank; P = 0.094) or LR (log-rank; P = 0.110).

CONCLUSIONS

In patients undergoing cervical spine metastasis surgery, readmission occurred in 15% of patients, 33% for surgical reasons, and 67% for medical reasons. Preoperative radiotherapy was associated with an increased rate of unplanned readmissions, yet readmission had no association with OS or LR.

Quantitative Evaluation of the Reduced Capacity of Skeletal Muscle Hypertrophy after Total Body Irradiation in Relation to Stem/Progenitor Cells

The effects of total body irradiation (TBI) to the capacity of skeletal muscle hypertrophy were quantified using the compensatory muscle hypertrophy model. We additionally assessed the responses of stem and/or progenitor cells in the muscles. A single TBI of 9.0, 5.0 and 2.5 Gy was delivered to C57BL/6 mice. Bone marrow stromal cells were obtained from GFP-Tg mice, and were injected into the tail vein of the recipient mice (1 × 106 cells/mouse), for bone marrow transplantation (BMT). Five weeks after TBI, the mean GFP-chimerism in the blood was 96 ± 0.8% in the 9 Gy, 83 ± 3.9% in the 5 Gy, and 8.4 ± 3.4% in the 2.5 Gy groups. This implied that the impact of 2.5 Gy is quite low and unavailable as the BMT treatment. Six weeks after the TBI/BMT procedure, muscle hypertrophy was induced in the right plantaris muscle by surgical ablation (SA) of the synergist muscles (gastrocnemius and soleus), and the contralateral left side was preserved as a control. The muscle hypertrophy capacity significantly decreased by 95% in the 9 Gy, 48% in the 5 Gy, and 36% in the 2.5 Gy groups. Furthermore, stem/progenitor cells in the muscle were enzymatically isolated and fractionated into non-sorted bulk cells, CD45-/34-/29+ (Sk-DN), and CD45-/34+ (Sk-34) cells, and myogenic capacity was confirmed by the presence of Pax7+ and MyoD+ cells in culture. Myogenic capacity also declined significantly in the Bulk and Sk-DN cell groups in all three TBI conditions, possibly implying that skeletal muscles are more susceptible to TBI than bone marrow. However, interstitial Sk-34 cells were insusceptible to TBI, retaining their myogenic/proliferative capacity.