Mandibular conservation in oral cancer

Clinical, Radiological, and Pathological Correlation of Mandibular Invasion in Carcinoma Bucco-alveolar Complex

A prospective cross-sectional study was conducted to correlate clinically, radiologically, and pathologically the mandibular invasion in carcinoma bucco-alveolar complex. All biopsy-proven oral cavity cancer cases (64 patients) were assessed clinically and radiologically for involvement of the mandible. Preoperative clinicoradiological findings were compared with postoperative histopathological findings. In our study, oral cancer was 4 times more prevalent in males as compared to females and clinical evaluation was found to be highly sensitive in predicting mandibular invasion. Orthopantomogram showed sensitivity of 66.6% and specificity of 100%. CT scan showed sensitivity of 100% and specificity of 46% whereas MRI showed sensitivity of 54.5% and a specificity of 96%. MRI correlates well with final histopathology in predicting size of tumor. Prevalence of bony invasion in carcinoma oral cavity was 18%. We noted an inverse relation with tumor differentiation and mandibular invasion, and none of the verrucous carcinoma lesions showed mandibular invasion. Association of clinical T and N staging with postoperative histopathology was found to be statistically significant. Despite recent advances in molecular biology, radiological techniques, and newer modalities like visual surgical planning, exact measurement of bone invasion is still challenging. At present, CT scan and MRI along with clinical evaluation are widely used to evaluate mandibular invasion in carcinoma oral cavity, and all these are complementary to each other. The recent progress in tissue engineering technologies and stem cell biology has significantly promoted the development of regenerative reconstruction of jawbone defects.

Effect of segmental versus marginal mandibular resection on local and lymph node recurrences in oral squamous cell carcinoma: is tumorous bone infiltration or location and resulting soft tissue recurrences a long-term problem?

PURPOSE

Oral squamous cell carcinomas (OSCCs) adjacent to the mandible or with clinically suspected bone infiltration are surgically treated either with marginal or segmental resections. This retrospective study compared both resections regarding local recurrence and lymph node recurrence or secondary lymph node metastases.

METHODS

All consecutive primary OSCC cases between January 2007 and December 2015 that underwent mandibular marginal or segmental resection were included. Rates of local and lymph node recurrences or secondary metastases and possible risk factors such as tumor localization according to Urken's classification were recorded.

RESULTS

In total, 180 patients with 85 marginal (group I) and 95 segmental (group II) mandibular resections were analyzed. The local recurrence rates were comparable between the groups (28.2% vs. 27.4%; p = 0.897). Lymph node recurrences or secondary metastases were higher in group I (9.4% (n = 8) vs. 6.2% (n = 6); p = 0.001). Tumor localization appears to affect the outcomes. Significantly fewer local and lymph node recurrences/metastases were found for Urken's classification SB and S calculated by two-proportion z-test (p = 0.014 and 0.056, respectively). Local recurrences mostly emerged from soft tissues, which should be resected more radically than the bones.

CONCLUSION

While bone infiltration appears technically well controllable from an oncologic point of view, local recurrences and lymph node recurrences/metastases remain an issue. Regular clinical aftercare with imaging is crucial to detect recurrences.

Endoscopically Assisted Marginal Mandibulectomy Using an Intraoral Approach Alone for Squamous Cell Carcinoma of the Posterior Mandibular Gingiva: A Technical Note

Study Design

Technical note.

Objective

Marginal mandibulectomy is a surgical procedure for treatment of mandibular gingival tumors. The intraoral approach to the posterior region of the mandible for marginal mandibulectomy is difficult due to limited access and operating field visibility; the conventional surgical procedure may require some skin incisions. This report discusses the effectiveness of endoscopic assistance in marginal mandibulectomy.

Methods

This article describes endoscopically assisted marginal mandibulectomy using an intraoral approach alone for squamous cell carcinoma of the posterior mandibular gingiva.

Results

The advantages of this surgical method are twofold: (1) superior visibility to the lower edge of the mandible without any skin incision; and (2) safe surgical confirmation of important anatomy on the buccolingual side (e.g., mental foramen, lingual nerve, mandibular foramen, and neurovascular bundle). This minimally invasive approach without any skin incision, as well as the superior visibility of the operating field, are important advantages of endoscopically assisted marginal mandibulectomy that cannot be obtained by other surgical methods.

Conclusions

Endoscopically assisted marginal mandibulectomy using an intraoral approach alone may be useful because it avoids damage to facial skin and improves safety by employing an enlarged bright field.

Accuracy of cone-beam computed tomography for the evaluation of mandible invasion by oral squamous cell carcinoma

BACKGROUND

For patients with oral squamous cell carcinoma (OSCC), accurate evaluation of mandible invasion and resection with appropriate boundaries are important for preserving the structure and function of the mandible and preventing local recurrence. Although cone-beam computed tomography (CBCT), which has high spatial resolution, is now widely used in the diagnosis of oral and maxillofacial bone lesions, no studies have systematically evaluated the accuracy of CBCT for evaluating the presence of bone invasion, the boundaries of bone invasion and the presence of nerve invasion. Therefore, this study aimed to systemically explore the accuracy of CBCT in the preoperative assessment of mandibular invasion by OSCC.

METHODS

Thirty mandibular specimens from OSCC patients were collected in this study. The samples were marked and subjected to CBCT examination. Hematoxylin-eosin staining was used for histopathological assessment sed as the gold standard. The evaluation included the presence of bone invasion, the boundaries of bone invasion and the presence of nerve invasion. The CBCT and histopathological boundaries of bone invasion were delineated and merged to compare and calculate the deviation of CBCT in boundary evaluation.

RESULTS

The accuracy of CBCT in evaluating the presence of mandible invasion was 100%, and the accuracy of CBCT in evaluating the presence of nerve invasion was 69.2%. A mean deviation of 2.97 mm was found for assessment of the boundary of bone invasion using CBCT compared with the histopathological standard. The interexaminer agreement and intraexaminer agreement were perfect for the detection of bone invasion and nerve invasion (κ > 0.8). The intraclass correlation coefficient was 0.923 for the consistency test of boundary delineation on CBCT images.

CONCLUSION

CBCT is quite reliable in determining the presence or absence of mandible invasion but not as reliable for nerve invasion. The deviation in bone invasion boundary estimation should be considered in osteotomy for OSCC.

Proton Therapy for Mandibula Plate Phantom

Purpose: In this study, the required dose rates for optimal treatment of tumoral tissues when using proton therapy in the treatment of defective tumours seen in mandibles has been calculated. We aimed to protect the surrounding soft and hard tissues from unnecessary radiation as well as to prevent complications of radiation. Bragg curves of therapeutic energized protons for two different mandible (molar and premolar) plate phantoms were computed and compared with similar calculations in the literature. The results were found to be within acceptable deviation values. Methods: In this study, mandibular tooth plate phantoms were modelled for the molar and premolar areas and then a Monte Carlo simulation was used to calculate the Bragg curve, lateral straggle/range and recoil values of protons remaining in the therapeutic energy ranges. The mass and atomic densities of all the jawbone layers were selected and the effect of layer type and thickness on the Bragg curve, lateral straggle/range and the recoil were investigated. As protons move through different layers of density, lateral straggle and increases in the range were observed. A range of energies was used for the treatment of tumours at different depths in the mandible phantom. Results: Simulations revealed that as the cortical bone thickness increased, Bragg peak position decreased between 0.47–3.3%. An increase in the number of layers results in a decrease in the Bragg peak position. Finally, as the proton energy increased, the amplitude of the second peak and its effect on Bragg peak position decreased. Conclusion: These findings should guide the selection of appropriate energy levels in the treatment of tumour structures without damaging surrounding tissues.

Oral squamous carcinoma: Aggressive tumor pattern of invasion predicts direct mandible invasion

BACKGROUND

Aggressive histologic worst pattern of invasion (WPOI) in surrounding soft tissue has been shown to be predictive of higher local recurrence and poorer survival in oral cavity squamous cell carcinoma (OCSCC) patients. This study investigates whether aggressive WPOI can predict the mandibular invasion phenotype.

METHODS

Patients consecutively diagnosed with OCSCC undergoing a mandibulectomy (marginal or segmental) between 2013 and 2018 were reviewed. Senior physicians re-reviewed radiologic scans and pathologic slides of 44 cases.

RESULTS

Aggressive WPOI (WPOI-4, 5) is significantly associated with infiltrative bone invasion. Non-aggressive WPOI (WPOI-1, 2, 3) is significantly associated with the absence of bone invasion.

CONCLUSIONS

WPOI has become a useful tool that further characterizes the biologic behavior of OCSCC. Potentially, planned surgery may escalate from a marginal to segmental mandibulectomy based on aggressive WPOI for patients with radiographically uncertain cortical status. Further studies are needed to validate the relationship between OCSCC WPOI and mandible status.

Mandible handling in the surgical treatment of oral squamous cell carcinoma: lessons from clinical results after marginal and segmental mandibulectomy

OBJECTIVE

The aim of this retrospective, single-center study was to analyze long-term results after marginal and segmental mandibulectomies in patients with oral squamous cell carcinoma (OSCC).

STUDY DESIGN

The study included 259 patients treated for OSCC with mandibulectomy between 1996 and 2010. Data acquisition consisted of analysis of operation reports, re-evaluation of histologic bone specimens, and collection of clinical follow-up data.

RESULTS

Of the included patients, 86.5% had received segmental and 13.5% marginal mandibulectomies. Patients who received segmental mandibulectomy generally displayed a higher TNM (tumor-node-metastasis) stage; 47% of patients who received segmental mandibulectomy and 14% of those receiving marginal mandibulectomy showed bone infiltration (pT4 a). Of all patients with bone infiltration, 49% showed an invasive histologic infiltration pattern, and 35% showed an erosive histologic infiltration pattern. We found healthy residual crestal bone height in 43% of all segmental mandibulectomies. Only 8% of all patients were prosthodontically rehabilitated. With regard to prognostic parameters, there was no significant difference between patients receiving marginal mandibulectomy and those receiving segmental mandibulectomy.

CONCLUSIONS

Because healthy residual crestal bone height was found in 43% of all patients who had received segmental mandibulectomies, it is conceivable that a significant number of patients would profit from marginal mandibulectomy, at least in cases of absent or erosive bone infiltration pattern, because the residual crestal bone is functionally stable.

Cheek-splitting technique for marginal mandibulectomy: A novel approach

When performing marginal mandibulectomy, ensuring complete tumor removal and preventing postoperative iatrogenic mandibular fracture are essential. Pathological fracture can result due to stress concentration at the site requiring acute angle resection. To perform marginal mandibulectomy without making acute angles in patients with a lesion in the molar or more posterior region, a submandibular or transbuccal approach is necessary. Compared to the submandibular approach, the transbuccal approach is considered useful as it reduces operative time and prevents injury to the facial and mental nerves. Additionally, this approach does not leave a scar in the surgical field, which is beneficial in subsequent neck dissection for late neck metastasis. Here, we report 2 cases of lower gingival carcinoma in which satisfactory aesthetic outcomes were achieved with an improved cheek-splitting technique for marginal mandibulectomy using a transbuccal approach, taking into consideration the angle of the mouth, design of the triangular flap, and modiolus.

Key words:Mandibular gingival carcinoma, cheek-splitting technique, transbuccal approach, marginal mandibulectomy.

Oncologic outcome of marginal mandibulectomy in squamous cell carcinoma of the lower gingiva

Background

There is a large amount of controversy about the best management of the mandible in oral squamous cell carcinoma (SCC), mainly owing to the inability to acquire accurate bone invasion status. Therefore, our goal was to analyse the oncologic safety in patients undergoing marginal mandibulectomy (MM) for cT1-2 N0 SCC of the lower gingiva.

Methods

Patients undergoing MM for untreated cT1-2 N0 SCC of the lower gingiva were retrospectively enrolled. The main endpoints of interest were locoregional control (LRC) and disease-specific survival (DSS).

Results

A total of 142 patients were included in the analysis, and a pathologic positive node was noted in 27 patients. Cortical invasion was reported in 23 patients, and medullary invasion was reported in 9 patients. The 5-year LRC and DSS rates were 85 and 88%, respectively. Patients with bone invasion had a significantly higher risk for recurrence than patients without bone invasion. However, the DSS was similar in patients with versus without bone invasion. Patients with a high neutrophil lymphocyte ratio had a higher risk for worse prognosis.

Conclusions

The oncologic outcome in patients undergoing MM for cT1-2 N0 SCC of the lower gingiva was favourable; bone invasion was not uncommon, but it significantly decreased the prognosis in patients undergoing MM.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

Evaluation of bone resection margins of segmental mandibulectomy for oral squamous cell carcinoma

Resection margins are frequently studied in patients with oral squamous cell carcinoma and are accepted as a constant prognostic factor. While most evidence is based on soft tissue margins, reported data for bone resection margins are scarce. The aim of this retrospective study was to evaluate and determine the utility of surgical margins in bone resections for oral cavity squamous cell carcinoma (OCSCC). The status of bone resection margins and their impact on survival was investigated in patients who had undergone segmental mandibulectomy for OCSCC. Medical records were retrieved for the years 2000-2012; 127 patients were identified and included in the study. Tumour-positive bone resection margins were found in 21% of the patients. The 5-year overall survival was significantly lower in this group (P<0.005). Therefore, there is a need for intraoperative feedback on the status of bone resection margins to enable immediate additional resection where necessary. Although the lack of intraoperative methods for the evaluation of bone tissue has been addressed by many authors, there is still no reliable method for widespread use. Future research should focus on an objective, accurate, and rapid method of intraoperative assessment for the entire bone resection margin to optimize patient outcomes.

Computed Tomography Versus Magnetic Resonance in Head and Neck Cancer: When to Use What and Image Optimization Strategies

This article provides a practical overview of head and neck cancers, outlining an approach to evaluating these lesions and optimizing imaging strategies. Recognition of key anatomic landmarks as suggested by American Joint Committee on Cancer (AJCC) tumor, node, metastasis (TNM) criteria is emphasized. Further, the recently updated eighth edition of the AJCC staging manual has introduced some modifications that influence the TNM staging. These modifications are discussed throughout the article to provide an updated review on head and neck cancer.

Magnetic resonance imaging for diagnosis of mandibular involvement from head and neck cancers: a systematic review and meta-analysis

Background

Diagnosis of mandibular involvement caused by head and neck cancers is critical for treatment. We performed a meta-analysis to determine the diagnostic efficacy of MR for distinguishing mandibular involvement caused by head and neck cancers.

Methods

Thirteen databases were searched electronically and hand-searching was also done. Two reviewers conducted study inclusion, data extractions, and quality assessment of the studies independently. Meta-disc 1.4 and STATA 11.0 were used to conduct the meta-analysis.

Results

16 studies involving a total of 490 participants underwent MR examinations and were accounted for in this meta-analysis. Among the included studies, 2 had high risk of bias, while the rest had unclear risk of bias. Meta-regression showed that the slight clinical and methodological heterogeneities did not influence the outcome (P>0.05). Meta-analysis indicated that the MR for the diagnosis of mandibular involvement had a pooled sensitivity (SEN) of 78%, specificity (SPE) of 83%, positive likelihood ratio (+LR) of 3.80, negative likelihood ratio (-LR) of 0.28, diagnostic odds ratio (DOR) of 28.94, area under curve (AUC) of 0.9110, and Q* of 0.8432. Two studies detected the diagnostic efficacy of MR for the mandibular medullar invasion, and only one study reported the inferior alveolar canal invasion, which made it impossible to include it in our meta-analysis. In comparing to CT, MR had a higher SEN without statistical significance (P = 0.08), but a significantly lower SPE (P = 0.04). The synthesized diagnostic efficacy (AUC and Q*) on mandibular involvement was similar between the two modalities (P>0.05).

Conclusions

Present clinical evidence showed that MR had an acceptable diagnostic value in detecting mandibular involvement caused by head and neck cancers. MR exceeded CT in diagnosing patients with mandibular invasion (higher sensitivity than CT) but was less efficacious to exclude patients without the mandibular invasion (lower specificity than CT).

Biomaterial scaffolds for treating osteoporotic bone

Healing fractures resulting from osteoporosis or cancer remains a significant clinical challenge. In these populations, healing is often impaired not only due to age and disease, but also by other therapeutic interventions such as radiation, steroids, and chemotherapy. Despite substantial improvements in the treatment of osteoporosis over the last few decades, osteoporotic fractures are still a major clinical challenge in the elderly population due to impaired healing. Similar fractures with impaired healing are also prevalent in cancer patients, especially those with tumor growing in bone. Treatment options for cancer patients are further complicated by the fact that bone anabolic therapies are contraindicated in patients with tumors. Therefore, many patients undergo surgery to repair the fracture, and bone grafts are often used to stabilize orthopedic implants and provide a scaffold for ingrowth of new bone. Both synthetic and naturally occurring biomaterials have been investigated as bone grafts for repair of osteoporotic fractures, including calcium phosphate bone cements, resorbable polymers, and allograft or autograft bone. In order to re-establish normal bone repair, bone grafts have been augmented with anabolic agents, such as mesenchymal stem cells or recombinant human bone morphogenetic protein-2. These developing approaches to bone grafting are anticipated to improve the clinical management of osteoporotic and cancer-induced fractures.

Surgical errors and risks - the head and neck cancer patient

Head and neck surgery is one of the basic principles of head and neck cancer therapy. Surgical errors and malpractice can have fatal consequences for the treated patients. It can lead to functional impairment and has impact in future chances for disease related survival. There are many risks for head and neck surgeons that can cause errors and malpractice.

To avoid surgical mistakes, thorough preoperative management of patients is mandatory. As there are ensuring operability, cautious evaluation of preoperative diagnostics and operative planning. Moreover knowledge of anatomical structures of the head and neck, of the medical studies and data as well as qualification in modern surgical techniques and the surgeons ability for critical self assessment are basic and important prerequisites for head and neck surgeons in order to make out risks and to prevent from mistakes. Additionally it is important to have profound knowledge in nutrition management of cancer patients, wound healing and to realize and to be able to deal with complications, when they occur.

Despite all precaution and surgical care, errors and mistakes cannot always be avoided. For that it is important to be able to deal with mistakes and to establish an appropriate and clear communication and management for such events. The manuscript comments on recognition and prevention of risks and mistakes in the preoperative, operative and postoperative phase of head and neck cancer surgery.

Radiation therapy with concurrent retrograde superselective intra-arterial chemotherapy for gingival carcinoma

PURPOSE

The aim of this study was to review the efficacy and toxicity of radiation therapy with concurrent retrograde superselective intra-arterial chemotherapy in the treatment of gingival carcinoma.

METHODS AND MATERIALS

In all, 34 patients (21 men and 13 women) with squamous cell carcinoma of the gingiva underwent radiation therapy with concurrent retrograde superselective intra-arterial chemotherapy. Treatment consisted of daily external irradiation and concurrent retrograde superselective intra-arterial infusion with cisplatin and docetaxel. A median total dose of 60 Gy in 30 fractions was delivered to tumors.

RESULTS

Of the 34 patients, 29 (85 %) achieved a complete response (CR) and 5 had residual tumors. Of the 29 patients with a CR, 2 had local recurrences and 1 had distant metastasis 1-15 months after treatment. Twenty-six of the 36 patients had survived at a median follow-up time of 36 months (range 12-79 months); 4 died of cancer and 4 died of non-cancer-related causes. At both 3 and 5 years after treatment, the overall survival rates were 79 % and the cause-specific survival rates were 85 %. Osteoradionecrosis of the mandibular bone only developed in 1 patient after treatment.

CONCLUSION

Radiation therapy with concurrent retrograde superselective intra-arterial chemotherapy was effective and safe in the treatment of gingival carcinoma. This treatment may be a promising curative and organ-preserving treatment option for gingival carcinoma.