An update on radiation therapy in head and neck cancers

Effect of radiotherapy, immediate dentin sealing and irrigation simulating single- or two-visits endodontic treatment on the bond strength to pulp chamber dentin: an in vitro study

This study aimed to evaluate the influence of radiotherapy and different endodontic treatment protocols on the bond strength to pulp chamber dentin. Eighty mandibular molars were randomly divided into two groups (n = 40): non-irradiated and irradiated (60 Gy). The pulp chambers were sectioned, and each group was subdivided (n = 8), according to the endodontic treatment protocol: no treatment (Control); Single-visit; Two-visits; Immediate dentin sealing (IDS) + single-visit; and IDS + two-visits. Each endodontic treatment visit was simulated through irrigation with 2.5% NaOCl, 17% EDTA and distilled water. IDS was performed by actively applying two coats of a universal adhesive to the lateral walls of the pulp chamber. After, the pulp chambers were restored with resin composite and four sticks were obtained for microtensile test. In addition, the dentin of the pulp chamber roof was assessed for surface roughness, chemical composition, and topography after each treatment protocol. Two-way ANOVA, Tukey's post hoc, Mann-Whitney, Kruskal-Wallis and Dunn's post hoc were performed (α = 5%). The treatment protocol affected bond strength (p < 0.05), while the irradiation did not (p > 0.05). The control group presented the highest values (p < 0.05). The single-visit group demonstrated better performance compared to the other groups (p < 0.05), which did not differ from each other (p > 0.05) The use of IDS changed the surface roughness (p < 0.05), chemical composition (p < 0.05) and topography of the dentin. In conclusion, the treatment protocol influenced dentin adhesion, while irradiation did not.

Effect of Radiotherapy and Taper of Root Canal Preparation on the Biomechanical Behavior of Mesial Roots of Mandibular Molars

INTRODUCTION

This study aimed to investigate the effect of radiotherapy and taper of root canal preparation on the biomechanical behavior of mesial roots of mandibular molars.

METHODS

Eighty mandibular molars with 2 canals in the mesial root were randomly allocated into 2 groups (n = 40): one group underwent irradiation (60 Gy), while the other did not. Subsequently, the mesial roots were sectioned and each group was subdivided into 5 subgroups (n = 8), according to the preparation taper: no preparation (control); 25.03; 25.04; 25.06; and 25.08. All groups were considered homogeneous regarding their dimensions, weight, and morphology. The prepared specimens were embedded in cylindrical plastic molds and subjected to a cyclic fatigue test. A failure analysis was performed according to the extension and course of the fractures. Two-way ANOVA, Tukey's post-hoc, Fisher's exact, and Kaplan-Meier tests were conducted to evaluate the obtained data (α = 5%).

RESULTS

Fatigue resistance decreased as the taper of the preparation increased (P < .05). Preparation 25.03 presented significantly higher values only than 25.08 (P < .05), while 25.04, 25.06, and 25.08 were considered similar (P > .05). Irradiation significantly reduced the biomechanical performance (P < .05). Survival analysis corroborated these findings. There were no differences in the distribution of fracture types among the groups (P > .05).

CONCLUSION

The biomechanical behavior of the mesial roots of the mandibular molars decreased significantly in the face of irradiation and as the taper of the preparation increased.

Effect of radiation therapy on fracture resistance of simulated immature teeth submitted to root reinforcement

BACKGROUND

The literature is scanty regarding the effect of radiation therapy (RT) on the mechanical properties of immature permanent teeth.

AIM

To evaluate the effect of RT on the fracture resistance of simulated immature teeth submitted to different types of root reinforcement.

DESIGN

Sixty-four human teeth simulating the Cvek stage 3 of root development were distributed into eight groups (n = 8), according to exposure or not to RT (70 Gy) and the root reinforcement method: Group NR (control)-no reinforcement/no RT; Group NR + RT (control)-no reinforcement/RT; Group PO-tricalcium silicate-based cement (TS) apical plug/canal obturation/no RT; Group PO + RT-TS apical plug/canal obturation/RT; Group TS-canal filling with TS/no RT; Group TS + RT-canal filling with TS/RT; Group FP-TS apical plug/fibreglass post/no RT; and Group FP + RT-TS apical plug/fibreglass post/RT. Fracture resistance was determined using a universal testing machine (0.5 mm/min).

RESULTS

In the intergroup comparison, nonirradiated teeth had higher fracture resistance (p < .05). Groups FP and FP + RT had higher fracture resistance (p < .001).

CONCLUSION

Radiotherapy affected the fracture resistance of simulated immature teeth. Reinforcement with fibreglass posts increased the fracture resistance, regardless of the radiation.

Ayurvedic Drug Triphala in Combination with Providone Iodine Mitigates Radiation-Induced Mucositis in Head and Neck Cancer Patients without Affecting the Tumor Response

Radiation-induced mucositis is a dose-limiting concern in the treatment of head and neck cancers (HNC). This study was conducted to determine the effectiveness of the Ayurvedic drug Triphala in reducing radiation-induced mucositis and influencing tumour control when combined with providone iodine. Data from patient files of HNC patients who received Triphala in conjunction with iodine or iodine alone over the course of curative radiotherapy (> 60 Gy) from May 2013 to February 2015 were extracted for this retrospective chart based study. Data was subjected to statistical analysis, X2 and unpaired t test using the Statistical Package for Social Sciences (SPSS), version 17 (IBM, Chicago, USA). When compared to iodine alone, the group that utilised Triphala gargling was very efficient in delaying mucositis, the extent of weight loss (p = 0.038), the incidence (p = 0.03), and the number (p = 0.02) of treatment breaks. However, it had no influence on the radiation-induced tumour response. According to the observations, Triphala coupled with iodine was more successful in preventing radiation mucositis, and without affecting the killing of tumour cells than iodine gargle alone. According to the authors, this is the first observation to demonstrate the value of combining providone iodine with Triphala in preventing radiation-induced oral mucositis.

PET/CT standardized uptake value and EGFR expression predicts treatment failure in nasopharyngeal carcinoma

OBJECTIVE

This study inventively combines epidermal growth factor receptor (EGFR) expression of the primary lesion and standardized uptake value (SUV) of positron emission tomography and computed tomography (PET/CT) to predict the prognosis of nasopharyngeal carcinoma (NPC). This study aimed to evaluate the predictive efficacy of maximum standard uptake value (SUVmax) and EGFR for treatment failure in patients with NPC.

METHODS

This retrospective study reviewed the results of EGFR expression and pretreatment ¹⁸F-FDG PET/CT of 313 patients with NPC. Time-dependent receiver operator characteristics was used for analyzing results and selecting the optimal cutoff values. Cox regression was used to screen out multiple risk factors. Cumulative survival rate was calculated by Kaplan-Meier.

RESULTS

The selected cutoff value of SUVmax-T was 8.5. The patients were categorized into four groups according to EGFR expression and SUVmax-T. There were significant differences in the 3-year local recurrence-free survival (LRFS) (p = 0.0083), locoregional relapse-free survival (LRRFS) (p = 0.0077), distant metastasis-free survival (DMFS) (p = 0.013), and progression-free survival (PFS) (p = 0.0018) among the four groups. Patients in the EGFR-positive and SUVmax-T > 8.5 group had the worst survival, while patients in the EGFR-negative and SUVmax-T ≤ 8.5 group had the best prognosis. Subsequently, patients with only positive EGFR expression or high SUVmax-T were classified as the middle-risk group. There were also a significant difference in 3-year overall survival among the three risk groups (p = 0.034). SUVmax-T was associated with regional recurrence-free survival and LRRFS in multivariate analysis, whereas EGFR was an independent prognostic factor for LRRFS, DMFS, and PFS.

CONCLUSION

The combination of SUVmax-T and EGFR expression can refine prognosis and indicate clinical therapy.

Current Therapeutic Strategies in Patients with Oropharyngeal Squamous Cell Carcinoma: Impact of the Tumor HPV Status

Simple Summary

Contrary to other head and neck subsites, oropharyngeal squamous cell carcinoma (OPSCC) has shown a considerable increase in incidence over the past 20 years. This growing incidence is largely due to the increasing place of human papillomavirus (HPV)-related tumors. HPV-positive and HPV-negative OPSCC are two distinct entities with considerable differences in terms of treatment response and prognosis. However, there are no specific recommendations yet in the therapeutic management of OPSCC patients according to their tumor HPV-status. The aim of this review is therefore to discuss the therapeutic management of patients with OPSCC and the impact of HPV status on treatment selection.

Abstract

Since there is no published randomized study comparing surgical and non-surgical therapeutic strategies in patients with oropharyngeal squamous cell carcinoma (OPSCC), the therapeutic management of these patients remains highly controversial. While human papillomavirus (HPV)-positive and HPV-negative OPSCC are now recognized as two distinct diseases with different epidemiological, biological, and clinical characteristics, the impact of HPV status on the management of OPSCC patients is still unclear. In this review, we analyze the current therapeutic options in patients with OPSCC, highlighting the most recent advances in surgical and non-surgical therapies, and we discuss the impact of HPV status on the therapeutic strategy.

Time-Course of Salivary Metabolomic Profiles during Radiation Therapy for Head and Neck Cancer

Oral mucositis (OM) is one of the most frequently observed adverse oral events in radiation therapy for patients with head and neck cancer. Thus, objective evaluation of OM severity is needed for early and timely intervention. Here, we analyzed the time-course of salivary metabolomic profiles during the radiation therapy. The severity of OM (National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events v3.0) of nine patients with head and neck cancer was evaluated. Partial least squares regression-discriminant analysis, using samples collected before radiation therapy, showed that histidine and tyrosine highly discriminated high-grade OM from low-grade OM before the start of radiation therapy (significant difference, p = 0.048 for both metabolites). Further, the pretreatment concentrations of gamma-aminobutyric acid and 2-aminobutyric acids were higher in the high-grade OM group. Although further validations are still necessary, this study showed potentially associated metabolites with worse radiotherapy-related OM among patients with head and neck cancer.

Targeted Treatment of Head and Neck (Pre)Cancer: Preclinical Target Identification and Development of Novel Therapeutic Applications

Head and neck squamous cell carcinomas (HNSCC) develop in the mucosal lining of the upper-aerodigestive tract. In carcinogen-induced HNSCC, tumors emerge from premalignant mucosal changes characterized by tumor-associated genetic alterations, also coined as 'fields' that are occasionally visible as leukoplakia or erythroplakia lesions but are mostly invisible. Consequently, HNSCC is generally diagnosed de novo at more advanced stages in about 70% of new diagnosis. Despite intense multimodality treatment protocols, the overall 5-years survival rate is 50-60% for patients with advanced stage of disease and seems to have reached a plateau. Of notable concern is the lack of further improvement in prognosis despite advances in treatment. This can be attributed to the late clinical presentation, failure of advanced HNSCC to respond to treatment, the deficit of effective targeted therapies to eradicate tumors and precancerous changes, and the lack of suitable markers for screening and personalized therapy. The molecular landscape of head and neck cancer has been elucidated in great detail, but the absence of oncogenic mutations hampers the identification of druggable targets for therapy to improve outcome of HNSCC. Currently, functional genomic approaches are being explored to identify potential therapeutic targets. Identification and validation of essential genes for both HNSCC and oral premalignancies, accompanied with biomarkers for therapy response, are being investigated. Attentive diagnosis and targeted therapy of the preceding oral premalignant (preHNSCC) changes may prevent the development of tumors. As classic oncogene addiction through activating mutations is not a realistic concept for treatment of HNSCC, synthetic lethality and collateral lethality need to be exploited, next to immune therapies. In recent studies it was shown that cell cycle regulation and DNA damage response pathways become significantly altered in HNSCC causing replication stress, which is an avenue that deserves further exploitation as an HNSCC vulnerability for treatment. The focus of this review is to summarize the current literature on the preclinical identification of potential druggable targets for therapy of (pre)HNSCC, emerging from the variety of gene knockdown and knockout strategies, and the testing of targeted inhibitors. We will conclude with a future perspective on targeted therapy of HNSCC and premalignant changes.

Effectiveness and cost-effectiveness analysis of nimotuzumab for the radiotherapy of locoregionally advanced nasopharyngeal carcinoma

BACKGROUND

This study aimed to assess the effectiveness and cost-effectiveness of nimotuzumab in patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC).

METHODS

LA-NPC patients treated between October 2013 and December 2016 were retrospectively reviewed. A well-balanced cohort of patients who received nimotuzumab in addition to standard treatment (n = 50) and patients who did not receive nimotuzumab (n = 100) was selected using propensity score-matching method (1:2 ratio) for the cost-effectiveness analysis.

RESULTS

Compared with concurrent chemoradiotherapy (CCRT) alone, addition of nimotuzumab to CCRT significantly improved the 3-year overall survival (OS) (98.00% vs. 91.00%, P = 0.032). On multivariate analysis, nimotuzumab (hazard ratio = 0.124, 95% confidence interval: 0.017-0.902, P = 0.039) showed prognostic significance for OS. No serious treatment-related adverse events were observed in the nimotuzumab group (P > 0.05). Cost-effectiveness analysis revealed that addition of nimotuzumab increased the average treatment costs by $14,364.63. The additional cost for every one percent increase in OS rate was $ 2,052.09.

CONCLUSION

Addition of nimotuzumab to CCRT for LA-NPC confers significant survival benefits; however, it is not cost-effective.

Radiation-Induced Oral Mucositis in Head and Neck Cancer Patients. Five Years Literature Review

Backround: Radiation-induced oral mucositis consists of a series of relatively frequent side effects after head and neck cancer radiotherapy and has an adverse impact on both regular treatment process and the quality of life of patients.

OBJECTIVE

The purpose of the present review is to optimize the current management of radiation-induced oral mucositis in head and neck cancer patients.

METHODS

PubMed database research was performed on articles published since 2015 that demonstrated efficacy in the management of radiation-induced oral mucositis in head and neck cancer patients. The study selection included observational, prospective, comparative, randomized, double- blind, placebo-controlled or uncontrolled, and retrospective studies, as well as systematic reviews and metanalyses.

RESULTS

From the 931 citations obtained from the search, only 94 articles met the inclusion criteria, including mucosal protectants, anti-inflammatory agents, growth factors, and various miscellaneous and natural agents. Several methods, including both pharmacological and natural agents, have been proposed for the management of oral mucositis. In addition to the already known interventions with strong evidence, according to the Multinational Association of Supportive Care in Cancer and he International Society of Oral Oncology guidelines, further agents have been used. However, a great number of them lack clear evidence, which surely requires the design of more controlled clinical trials for a better assessment of the ideal methods.

CONCLUSION

The management of oral mucositis constitutes an active area of research. In light of these results, it is aimed to illustrate those treatment strategies that are most effective regarding the treatment approach of oral mucositis.

Honey Against Radiation-induced Oral Mucositis in Head and Neck Cancer Patients. An Umbrella Review of Systematic Reviews and Meta- Analyses of the Literature

Backround: Oral mucositis (OM) consists of a major side effect of radiotherapy (RT) in head and neck (H-N) cancer patients and natural honey is gaining more and more scientific interest due to its beneficial effects in tissue repair.

OBJECTIVE

The aim of this review is to better clarify the preventive/therapeutic role of honey in the management of OM in patients with H-N cancer undergoing RT with or without chemotherapy (CT).

METHODS

We used the PubMed database to retrieve journal articles and the inclusion criteria were only reviews and meta-analyses that illustrated the effective use of honey for either the prevention or treatment of OM in H-N cancer patients receiving either RT alone or in combination with CT.

RESULTS

Our search resulted in 92 citations, of which 12 eventually fulfilled the inclusion criteria of our study. Decreased incidence and severity of OM, extended time of occurrence of mucositis, less weight loss and less treatment interruptions were occasionally documented with conventional honey use in the included reviews and meta-analyses. In contrast to conventional honey, manuka honey proved to be weak in improving OM management in the small number of included reviews in our search.

CONCLUSION

Conventional honey might constitute a highly promising natural product against OM attracting much scientific interest due to its easy accessibility and low financial cost. Hence, the lack of studies with high evidence requires further advanced research to enhance the existing knowledge about the potential value of honey in radiation-induced OM in H-N cancer patients.

Can neoadjuvant chemotherapy improve survival in stage T3-4N1 nasopharyngeal carcinoma? A propensity matched analysis

Background

To estimate the efficacy of neoadjuvant chemotherapy (NCT) in stage T3-4N1 nasopharyngeal carcinoma (NPC).

Methods

Data on stage T3-4N1 NPC patients treated with concurrent chemoradiotherapy (CCRT) with or without NCT at the Sun Yat-sen University Cancer Center between January 2006 and December 2013 were retrospectively reviewed. Propensity score matching (PSM) was carried out to balance prognostic factors in NCT followed by CCRT (NCT + CCRT) group and CCRT group in a 1:1 ratio. Survival outcomes of matched patients in the two groups were compared, and prognostic factors were identified using Cox regression model.

Results

A total of 282 patients were involved in this study, with 136 of NCT + CCRT group and 146 of CCRT group. After PSM, 85 pairs of patients were selected. There were no significant differences in 5-year overall survival (OS), locoregional recurrence-free survival (LRFS), distant recurrence-free survival (DRFS), and recurrence-free survival (RFS) between NCT + CCRT group and CCRT group (81.0% vs. 77.5%, P = 0.750; 85.8% vs. 88.1%, P = 0.495; 92.5% vs. 93.9%, P = 0.759; 81.0% vs.77.5%, P = 0.919, respectively). Multivariate analysis found that smoking history (P = 0.044) and T classification (P = 0.027) were independent prognostic factors for OS, lymph node diameter (P = 0.032) was independent prognostic factor for LRFS, positive pretreatment lymph node condition (PLNC), which was defined as the lymph node necrosis or confluent, was independent prognostic factor for DRFS (P = 0.007), and RFS (P = 0.009). Lower 5-year OS (82.7% vs. 94.1%, P = 0.014), DRFS (79.3% vs. 96.2%, P = 0.003), and RFS (62.4% vs. 86.8%, P = 0.001) were found in positive PLNC group compared with negative PLNC group. In terms of toxicities, the incidences of acute hematological Grade 3–4 adverse events (AEs) were higher in NCT + CCRT group compared with CCRT group (P < 0.05), while no significant difference was observed in the rates of non-hematological Grade 3–4 AEs between these two groups (P > 0.05).

Conclusions

Additional NCT is not associated with improved survival outcomes for patients with stage T3-4N1 NPC, but bring increased hematological Grade 3–4 AEs. PLNC is independent prognostic factor in stage T3-4N1 NPC, with positive PLNC correlating with poor survival outcomes.

Effect of different solutions in reversing the damage caused by radiotherapy in dentin structure

Background

Previous studies have shown that radiotherapy of the head and neck region can cause direct changes in dental structure. This study evaluated the effect of different solutions on the dentin chemical composition and collagen structure of irradiated dentin.

Material and Methods

Sixty maxillary canines were distributed in 2 groups (n=30): non-irradiated and irradiated (radiotherapy: X-rays of 6 MV in 30 cycles of 2 Gy to 60 Gy). The teeth were sectioned, sanded, and polished to obtain 3x3x2 mm fragments, which were redistributed in 3 subgroups (n=10) according to the treatment employed: chlorhexidine 2% (CL), chitosan 0.2% (QT), and 0.5 M carbodiimide (EDC). The samples were analyzed in FTIR at time zero (T0-control) and after 1 (T1), 3 (T3), and 5 (T5) minutes of immersion in the tested solutions. The data for the areas of the carbonate (C), amide I (AI) bands, and the ratio between the areas of the amide III/proline and hydroxyproline (AIII/PH) bands were analyzed using ANOVA and Tukey test (α=5%).

Results

QT showed lower C values at T1, T3, and T5 (P<0.0001), presenting lower values when compared to CL and EDC subgroups (P<0.05). AI values at T3 and T5 were higher than T0-control and T1, independently of the radiotherapy and dentin treatment factors (P<0.05). At T0-control, the AIII/PH ratio was lower in the irradiated group (P<0.05), whereas the EDC treatment at T1, T3, and T5 and QT at T3 and T5 increased these values (P<0.05), making them similar to non-irradiated subgroups (P>0.05).

Conclusions

Radiotherapy changes the secondary structure of collagen, and EDC was able to restore collagen integrity after 1 minute of immersion, without changing dentin inorganic composition.

Key words:Radiotherapy, collagen, dentin, FTIR, chemical composition.

Nimotuzumab for Patients With Inoperable Cancer of the Head and Neck

EGFR activation induces cell proliferation, neoformation of blood vessels, survival, and metastasis of the cancer cells. Nimotuzumab is an engineered, intermediate affinity anti-EGFR antibody, that apart from other drugs in its class, is very safe and does not cause hypomagnesemia or grade 3–4 cutaneous rash. The antibody inhibits cell proliferation and angiogenesis, activates natural killer cells, stimulates dendritic cell maturation, and induces cytotoxic T cells. Nimotuzumab restores MHC-I expression on tumor cells, hindering one of the EGFR immune-escape ways. The antibody has been extensively studied in 7 clinical trials, concurrently with irradiation or irradiation plus chemotherapy in subjects with inoperable head and neck tumors. Nimotuzumab was safe and efficacious in unfit patients receiving irradiation alone and in subjects treated with cisplatin and radiotherapy. In patients with locally advanced squamous cell carcinomas of the head and neck, nimotuzumab in combination with low dose cisplatin and radiotherapy was superior to cisplatin and radiotherapy in progression free survival, disease free survival, and locoregional tumor control.

Hypofractionated palliative volumetric modulated arc radiotherapy with the Radiation Oncology Study Group 8502 "QUAD shot" regimen for incurable head and neck cancer

BACKGROUND

To review a single institutional experience of the Radiation Therapy Oncology Group (RTOG) 8502 "QUAD shot" regimen using volumetric modulated arc radiotherapy (VMAT) for incurable head and neck cancer (HNC).

METHODS

Thirty-four consecutive patients with HNC were treated with at least one cycle of the RTOG 8502 regimen. Treatment plans included the use of VMAT with 6 MV photons generated by a linear accelerator. Two daily fractions of 3.7 Gy were delivered with an interval of at least 6 h for 2 consecutive days, totaling 14.8 Gy over 4 fractions. This was repeated every 3-4 weeks for a total of three cycles. No concurrent systemic therapy was performed.

RESULTS

The number of completed cycles was 1 in 6 (18%) patients, 2 in 5 (15%), and 3 in 23 (68%). Tumor response was achieved in 29 (85%) patients and symptom relief in 20 (77%) of 26 patients. Overall response (tumor response or symptom relief) was achieved in 32 (94%) patients. All patients who received 2 or more treatment cycles achieved overall response. Median overall survival (OS) was 5.7 months. Multivariate analysis revealed that completion of all three treatment cycles was significantly associated with better OS (P = 0.002). Grade 2 toxicity was observed in four (12%) patients, but no acute Grade ≥ 3 or late toxicity was observed.

CONCLUSIONS

The RTOG 8502 "QUAD shot" regimen using VMAT is effective for incurable HNC with highly reduced toxicity. Treatment with multiple cycles is recommended for better treatment response and/or survival.

Effect of carbodiimide and chlorhexidine on the bond strength longevity of resin cement to root dentine after radiation therapy

AIM

To evaluate the effect of carbodiimide (EDC) and chlorhexidine (CHX) on the bond strength (BS) of resin cement to root dentine of teeth submitted to radiotherapy.

METHODOLOGY

One hundred and twenty extracted maxillary canines were selected and assigned to 2 groups (n = 60): nonirradiated and irradiated (30 cycles of 2 Gy, total 60 Gy). Roots lengths were standardized, and canals were prepared and filled. Post spaces were then prepared, and the samples were redistributed according to dentine treatment (n = 20): saline solution (SF); CHX 2%; or EDC 0.5M. After drying the post space, fibreglass posts were cemented. Cross-sectioned slices were obtained, and in half of the specimens of each subgroup (n = 10), the analysis was performed immediately; the others (n = 10) were stored for 10 months before analyses. The most cervical slice of each third was subjected to a push-out test and failure pattern analysis (n = 10), and the most apical slice submitted to the analysis of the adhesive interface by SEM (n = 5). The bond strength data were submitted to anova and Tukey tests, the adhesive interface adaptation was submitted to Kruskal-Wallis and Dunn's tests, and the Chi-square test was used to evaluate the type of failure.

RESULTS

The irradiated specimens had significantly lower bond strength (13.8 ± 4.3) than the nonirradiated (18.1 ± 3.1; P < 0.001). For the irradiated teeth, the bond strengths were significantly lower in the SF and CHX groups (P < 0.001). Also, the bond strengths reduced significantly after 10 months in the SF and CHX groups (P < 0.001). Cohesive failures occurred in dentine for irradiated specimens. Poorer interface adaptation, dentine fractures and microfractures were observed in irradiated specimens, and better adaptation was observed for specimens after EDC treatment.

CONCLUSIONS

Radiotherapy was associated with lower bond strength and worse interface adaptation. Dentine treatment with EDC contributed to adhesive interface longevity during the cementation of glass fibre posts in nonirradiated and irradiated teeth.

A comparison of clinical outcomes between simultaneous integrated boost (SIB) versus sequential boost (SEQ) intensity modulated radiation therapy (IMRT) for head and neck cancer: A meta-analysis

BACKGROUND

The optimal intensity modulated radiation therapy (IMRT) technique for head and neck cancer (HNC) has not been determined yet. The present study aimed to compare the clinical outcomes of the simultaneous integrated boost (SIB)-IMRT versus the sequential boost (SEQ)-IMRT in HNC.

METHODS

A meta-analysis of 7 studies involving a total of 1049 patients was carried out to compare the treatment outcomes together with severe acute adverse effects of the SIB-IMRT versus the SEQ-IMRT in HNC patients.

RESULTS

Comparison of the SIB-IMRT and SEQ-IMRT showed no significant difference in the measurement of overall survival (OS) (hazard ratio [HR] 0.94; 95% confidence inerval [CI], 0.70-1.27; P = .71), progression free survival (PFS) (HR 1.03; 95% CI, 0.82-1.30; P = .79), locoregional recurrence free survival (LRFS) (HR 0.98; 95% CI, 0.65-1.47; P = .91), and distance metastasis free survival (DMFS) (HR 0.87; 95% CI, 0.50-1.53; P = .63). Moreover, there were no significant differences in adverse effect occurrence between the SIB-IMRT and SEQ-IMRT groups.

CONCLUSION

SIB-IMRT and SEQ-IMRT can provide comparable outcomes in the treatment of patients afflicted by HNC. Both IMRT techniques were found to carry a similar risk of severe acute adverse effect. SIB-IMRT may have advantages due to its convenience and short-course of treatment; however, the optimum fractionation and prescribed dose remained unclear. Furthermore, both IMRT techniques can be advocated as the technique of choice for HNC. Treatment plan should be individualized for patients.

Prophylactic NS-21 maintains the skin moisture but does not reduce the severity of radiation dermatitis in patients with head and neck cancer: a randomized control trial

Background

To evaluate the practicality of NS-21 cream with regard to its skin-related toxicity in patients with head and neck cancer (HNC) who are undergoing concurrent chemoradiation therapy (CCRT) or radiotherapy (RT).

Methods

Between July 2015 and November 2017, 30 HNC patients who underwent RT or CCRT were randomly allocated to receive either NS-21 or control treatment on their irradiated skin three times per day, starting at the initiation of RT or CCRT and ending 2 weeks after the completion of RT or until the appearance of grade 3 acute radiation dermatitis (ARD). Dermatitis was recorded weekly according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Skin humidity was monitored by a digital moisture meter. The generalized estimating equation (GEE) and logit link function method were used for statistical analysis.

Results

No serious adverse events were observed in either group. Itching dermatitis occurred on the right lower neck in one patient of the NS-21 group during the 3rd week of CCRT, but the severity was mild. The median skin moisture value at the time of the final treatment was significantly different between the study and control groups (30.6 vs. 27.3, p = 0.013). Additionally, there was an inverse relationship between skin moisture and ARD grade (B = -0.04, p = 0.005). The incidence of ARD at the time of the last treatment was not significantly different between the study and control groups (6.7% vs 26.7%, p = 0.165). The risk of grade 3 ARD for skin that had received an irradiation dose of 47–70 Gy was higher than that of skin that had received an irradiation dose ≤46 Gy (OR = 31.06, 95% CI =5.95–162.21, p < 0.001). Nevertheless, the risk of ARD was not significantly different between the groups (OR = 0.38, 95% CI = 0.08–1.74, p = 0.212).

Conclusions

NS-21 was well tolerated and effective for the maintenance of skin moisture; however, there was no statistically significant reduction in the risk of ARD in HNC patients undergoing RT or CCRT when compared with HNC patients in the control group.

Trial registration

The study was approved by the Institutional Review Board of Far Eastern Memorial Hospital (FEMH-IRB, 104048-F), Registered 1st June 2015,