Computer-aided 3-D 99mTc-DPD-SPECT reconstruction to assess mandibular invasion by intraoral squamous cell carcinoma: diagnostic improvement or not?

Diagnostic efficacy of PET-CT, CT, and MRI in preoperative assessment of mandibular invasion caused by head and neck cancer: A systematic review and meta-analysis

OBJECTIVE

This study aims to conduct a systematic review and meta-analysis of the performance of PET-CT, CT, and MRI in diagnosing mandible invasion induced by head and neck cancer (HNC).

MATERIALS AND METHODS

The MEDLINE, Embase, Science Direct, CNKI and CQVIP databases were searched from inception until August 1, 2020. Then, a meta-analysis was conducted to calculate the combined diagnostic values with the corresponding 95% CIs. Two independent researchers completed the full text screening, data abstraction, and risk assessment.

RESULTS

This meta-analysis included 53 studies (N = 2 946 participants). For the pooled sensitivity (SEN), MRI (SEN: 0.88, 95% CI: 0.81-0.93) was found to have a significantly higher SEN (P = 0.0045), when compared to CT (SEN: 0.77, 95% CI: 0.71-0.82), while compared with PET-CT (SEN: 0.88, 95% CI: 0.64-0.97), the SEN was approximately equal (P > 0.05). The analysis revealed that the combined specificity (SPE) of MRI (SPE: 0.83, 95% CI: 0.74-0.89) and PET-CT (SPE: 0.81, 95% CI: 0.57-0.93) was lower than that of CT (SPE: 0.87, 95% CI: 0.83-0.90), but there was no statistical significance among these (P > 0.05). The comparison of the area under curve (AUC) reflected that PET-CT, CT and MRI have approximately equal summary diagnostic power in detecting mandibular invasion (P > 0.05).

CONCLUSION

The findings suggest that compared with CT, MRI is significantly superior for higher SEN in diagnosing mandibular invasion. The SEN of MRI and PET-CT were approximately equal. For the summary of diagnostic power, more prospective clinical trials that directly compare these three methods are needed in the future.

Facial Reconstruction: A Systematic Review of Current Image Acquisition and Processing Techniques

Introduction: Plastic and reconstructive surgery is based on a culmination of technological advances, diverse techniques, creative adaptations and strategic planning. 3D imaging is a modality that encompasses several of these criteria while encouraging the others. Imaging techniques used in facial imaging come in many different modalities and sub-modalities which is imperative for such a complex area of the body; there is a clear clinical need for hyper-specialized practice. However, with this complexity comes variability and thus there will always be an element of bias in the choices made for imaging techniques. Aims and Objectives: The aim of this review is to systematically analyse the imaging techniques used in facial reconstruction and produce a comprehensive summary and comparison of imaging techniques currently available, including both traditional and novel methods. Methods: The systematic search was performed on EMBASE, PubMed, Scopus, Web of Science and Cochrane reviews using keywords such as "image technique/acquisition/processing," "3-Dimensional," "Facial," and "Reconstruction." The PRISMA guidelines were used to carry out the systematic review. Studies were then subsequently collected and collated; followed by a screening and exclusion process with a final full-text review for further clarification in regard to the selection criteria. A risk of bias assessment was also carried out on each study systematically using the respective tool in relation to the study in question. Results: From the initial 6,147 studies, 75 were deemed to fulfill all selection criteria and selected for meta-analysis. The majority of papers involved the use of computer tomography, though the use of magnetic resonance and handheld scanners using sonography have become more common in the field. The studies ranged in patient population, clinical indication. Seminal papers were highlighted within the group of papers for further analysis. Conclusions: There are clearly many factors that affect the choice of image acquisition techniques and their potential at being ideal for a given role. Ultimately the surgical team's choice will guide much of the decision, but it is crucial to be aware of not just the diagnostic ability of such modalities, but their treatment possibilities as well.

Performance of different imaging techniques in the diagnosis of head and neck cancer mandibular invasion: A systematic review and meta-analysis

BACKGROUND

To assess diagnostic efficacy of imaging techniques for mandibular invasion by head and neck cancer.

METHODS

Thirteen databases were searched. Study inclusion, data-extraction and quality assessment were performed independently. STATA 14.0 were mainly used for meta-analysis.

RESULTS

Forty-nine studies were included. For mandibular invasion (cortex and marrow), CBCT, SPECT, CT, MRI, orthopantomography, PET-CT and bone-scintigraphy showed pooled sensitivities of 90%, 97%, 73%, 88%, 75%, 90%, 92%, specificities of 85%, 69% 91%, 90%, 83%, 89%, 79%, AUC of 0.9461, 0.9434, 0.8995, 0.9296, 0.8761, 0.9290, 0.9207, respectively. The combined SROC curves indicated CBCT and SPECT were superior to other techniques. For mandibular medullary invasion (marrow), CT and MRI showed pooled sensitivities of 85% and 93%, specificities of 86% and 84%.

CONCLUSIONS

CBCT was top-priority choice for bone invasion diagnosis. SPECT was recommended for exclusion, CT and MRI were suitable for conformation. Further investigations are needed for mandibular medullary involvement.

[Single-photon emission computed tomography for the diagnosis of mandibular invasion caused by oral cancers: a systematic review and Meta-analysis]

Objective This review aimed at assessing the diagnostic efficacy of contrast-enhanced single-photon emission computed tomography (SPECT) in the diagnosis of mandibular invasion by oral cancers. Methods Five databases were searched electronically on August 5, 2016. The reference lists of included studies were hand searched. Quality assessment was performed by two reviewers in duplicate with tools suggested by Cochrane's handbook. Furthermore, the data extraction of included studies was delivered. Meta-analysis was performed using STATA 11.0. Results Ten studies with 460 participants were included. One study had a low risk of bias, and two studies had a high risk of bias. The remaining seven studies had an unclear risk of bias. Meta-analysis results showed that SPECT had a pooled sensitivity of 0.99 [95% confidence interval=0.87-
1.00]. Sensitivity was 0.99 on Q* point. The specificity of 0.61 and the area under summary receiver operating characteristic curve (SROC) were 0.93 [95% confidence interval=0.90-
0.95]. The pooled positive likelihood ratio was 2.555. The negative likelihood ratio was 0.015. The diagnostic odd ratio was 5.115. Conclusion SPECT had high sensitivity, which became suitable for excluding bone invasion by oral cancers. However, its specificity was relatively low, indicating its limited capability in confirming diagnosis. Therefore, surgeons should perform this method under certain conditions.

Contemporary Diagnostic Imaging of Oral Squamous Cell Carcinoma - A Review of Literature

Oral squamous cell carcinoma (OSCC) is the most common cancer of the oral cavity and constitutes 95% of all cancers of this area. Men are affected twice as commonly as women, primarily if they are over 50 years of age. Forty percent of the lesions are localized in the tongue and 30% in the floor of the oral cavity. OSCC often affects upper and lower gingiva, buccal mucous membrane, the retromolar triangle and the palate. The prognosis is poor and the five-year survival rate ranges from 20% (OSCC in the floor of the mouth) to 60% (OSCC in the alveolar part of the mandible). Treatment is difficult, because of the localization and the invasiveness of the available methods. The diagnosis is made based on a histopathological examination of a biopsy sample.

The low detection rate of early oral SCC is a considerable clinical issue. Although the oral cavity can be easily examined, in the majority of cases oral SCC is diagnosed in its late stages. It is difficult to diagnose metastases in local lymph nodes and distant organs, which is important for planning the scope of resection and further treatment, graft implantation, and differentiation between reactive and metastatic lymph nodes as well as between disease recurrence and scars or adverse reactions after surgery or radiation therapy.

Imaging studies are performed as part of the routine work-up in oral SCC. However, it is difficult to interpret the results at the early stages of the disease. The following imaging methods are used – dental radiographs, panoramic radiographs, magnetic resonance imaging with diffusion-weighted and dynamic sequences, perfusion computed tomography, cone beam computed tomography, single-photon emission computed tomography, hybrid methods (PET/CT, PET/MRI, SPECT/CT) and ultrasound. Some important clinical problems can be resolved with the use of novel modalities such as MRI with ADC sequences and PET.

The aim of this article is to describe oral squamous cell carcinoma as it appears in different imaging methods considering both their advantages and limitations.

Mandibular conservation in oral cancer

Surgery is one of the established modes of initial definitive treatment for a majority of oral cancers. Invasion of bony or cartilaginous structures by advanced upper aero-digestive tract cancer has been considered an indication for primary surgery on the basis of historic experience of poor responsiveness to radiation therapy [1]. The mandible is a key structure both in the pathology of intra-oral tumours and their surgical management. It bars easy surgical access to the oral cavity, yet maintaining its integrity is vital for function and cosmesis. Management of tumours that involve or abut the mandible requires specific understanding of the pattern of spread and routes of tumour invasion into the mandible. This facilitates the employment of mandibular sparing approaches like marginal mandibulectomy and mandibulotomy, as opposed to segmental or hemimandibulectomy which causes severe functional problems, as the mandibular continuity is lost. Accurate preoperative assessment that combines clinical examination and imaging along with the understanding of the pattern of spread and routes of invasion is essential in deciding the appropriate level and extent of mandibular resection in oral squamous cell carcinoma. Studies have shown that local control rates achieved with marginal mandibulectomy are comparable with that of segmental mandibulectomy. In carefully selected patients, marginal mandibulectomy is an oncologically safe procedure to achieve good local control and provides a better quality of life. This article aims to review the mechanism of spread, evaluation and prognosis of mandibular invasion, various techniques and role of mandibular conservation in oral squamous cell carcinoma.

Bildfusion von SPECT und CT als präzisierende Diagnostik von malignen Tumoren im Mund-Kiefer-Gesichtsbereich

OBJECTIVE

The aim of this study was to evaluate the benefit of image fusion of CT (computertomography) and bone SPECT (single photon emission computed tomography) in diagnosis of head and neck cancer.

METHODS AND PATIENTS

Computer based image fusion has been applied in 39 patients with suspected cancer in the oromaxillofacial region following CT and SPECT without any further hazard for the patients. Afterwards image fusion was set in comparision to simultaneously evaluation of CT and SPECT and histological findings.

RESULTS

In 5 out of 39 patients SPECT/CT image fusion obtained more precise anatomical findings in tumour expansion than simultaneously evaluation of CT and SPECT.

CONCLUSION

For planning of surgical and radiation therapy of oral and maxillofacial cancer, image fusion of CT/SPECT provides efficient and plastical diagnostic imaging. Particularly in complex anatomical regions like maxilla or base of the skull image fusion could be an additional device, if simultaneous evaluation of CT and SPECT is not clear.

Bone SPECT reduces the number of unnecessary mandibular resections in patients with squamous cell carcinoma

High percentages (35-78%) of resected mandibles without bone invasion have been reported in squamous cell carcinoma (SCC), adjacent or fixed to the mandible, stressing the need for accurate imaging methods. The aim of this study is to determine the value of bone single photon emission computed tomography (SPECT) for the evaluation of mandibular invasion by SCC. Seventy-nine patients with SCC, adjacent or fixed to the mandible, were included. The results of bone SPECT were compared to the histology of the resection specimens. Bone SPECT was positive in all 50 patients with mandibular invasion and negative in 17 of 29 patients without mandibular invasion. In conclusion, a negative bone SPECT rules out mandibular invasion. Important clinical implications are then that further imaging is not necessary and that the resection can be kept limited. Inclusion of SPECT in the preoperative assessment of these patients will lead to a considerable reduction of unnecessary mandibular resections.

A new guide to mandibular resection for oral squamous cell carcinoma based on the Cawood and Howell classification of the mandible

A new guide for mandibular resection in the management of oral squamous cell carcinoma based on the Cawood and Howell classification of the jaws is suggested. This was a retrospective review of case records and pre-operative orthopantomograms (OPG), bone scintigraphy and magnetic resonance imaging (MRI). The classification of the mandible was based on the residual bone height as measured in the molar region of the OPG to be equivalent to the Cawood and Howell classification of the mandible (Class I-II dentate or immediate post-extraction), Class III-IV >20mm well-rounded or knife-edge ridge, and Class V-VI <20mm (flat or depressed ridge form). Of the 77 patients, 58% (22/38) of Class I-II, 43% (9/23) of Class III-IV and 6% (1/16) of Class V-VI were treated with a marginal (rim) resection of the mandible. The predictability of the pre-operative investigations was more accurate in the edentulous mandible (Class III-VI). A simple guide is suggested for mandibular resection taking into account the pre-operative investigations, the estimation of invasion clinically, and the Cawood and Howell classification of ridge resorption.

[On the indications for and morbidity of segmental resection of the mandible for squamous cell carcinoma in the lower oral cavity]

BACKGROUND

Segmental resection of the mandibula in oral cancer surgery leads to both functional and aesthetic problems. The decision to preserve or resect the mandible depends on the vicinity of the lesion to the bone. Consequently, based on the rules of safety margins to all planes that are recommended for soft tissues, each lesion that is closer than 10 mm to the mandible needs resection of the bone.

PATIENTS AND METHODS

To establish data-based treatment modalities, a retrospective study was initiated and the results from all preoperative staging investigations of 152 patients with intraoral squamous cell carcinoma who underwent continuity or marginal resection of the mandible were evaluated. The histological outcome of the resected bone was compared to the staging results. Functional rehabilitation and long-term follow-up including survival rates were evaluated. The study reports on typical complications following segmental resection such as fracture of the reconstruction plate and demonstrates experiences with secondary microsurgical reconstructive surgery.

RESULTS

Mainly in cases of stage T1 and T2 carcinomas which are closer than 10 mm to the bone and clinically do not show any infiltration to the mandible, a marginal resection seems to be adequate. The decision about the extension of mandibular resection can be based on intraoperative cross sectional investigation of the periosteum. The survival rate of patients with intraoral carcinomas close to the mandible who underwent marginal mandibulectomy seems to be the same as in cases of continuity resection. A more conservative management of mandibular resection seems to be adequate and a data-based concept to standardize therapy of mandibular resection is presented.

Complex head and neck specimens and neck dissections. How to handle them

Dissecting surgical specimens from the upper aerodigestive tract is often difficult because of their complicated anatomy. The local environment dictates the routes of tumour spread and surgical margins at risk, and these features differ for various subsites within this part of the body. The examination of surgical specimens of the upper aerodigestive tract should disclose whether postoperative adjuvant treatment is needed and allow the evaluation of preoperatively performed diagnostic imaging. The aim of this article is to provide a concise guideline for the dissection of specimens from this part of the body.

Mechanisms of cancer invasion of the mandible

There is little evidence that the tumor enters the mandible preferentially through the occlusal surface, the periodontal membrane, or named foramina. Tumor enters the mandible at the point of contact, which is often at the junction of the attached and reflected mucosa, which lies below the crest of the ridge in all but grossly resorbed mandibles. Angulation of the bone cut in rim or marginal resection of the mandible is advised. The erosive pattern of disease is associated with shallow mandibular invasion and smaller tumors in the soft tissue. This finding supports the principle of marginal resection in such cases. There is little evidence to support the principle that the tumor spreads preferentially along the inferior alveolar nerve or the bone marrow. The inclusion of the neurovascular bundle in marginal resections of the mandible is not necessary. Preoperative assessment should include plain radiography combined with a sensitive scan (bone scintigraphy, single photon emission computerized tomography, or MRI) and inspection of the bone surface after periosteal stripping at the time of the resection.

Biomedical technology revolution: opportunities and challenges for oral and maxillofacial surgeons

During this 45-minute presentation, I have tried to describe my vision of the exciting future that awaits us. I have tried to impart my enthusiasm for the opportunities provided to us as surgeons by the advances in molecular biology and genetics, imaging, surgical technology and bioinformatics. Most of all, I hope I have transmitted my optimism for the future to our younger members. I think the following statement or observation by the great educator Margaret Mead accurately summarizes our current situation regarding the application of all this new knowledge that will become available to us as surgeons: 'We are now at the point where we must educate people (surgeons) in what nobody knew yesterday, and prepare in our schools (training programs) for what no one knows yet but what some people must know tomorrow.'