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

[On the relevance of histopathology results in oropharyngeal cancer with mandibular involvement and the necessary imaging]

BACKGROUND

Planning of surgical procedures in patients suffering from oropharyngeal cancer requires appropriate imaging, particularly in consideration of the spatial relationship to the mandible. Resection of portions of the mandible (box, marginal, or segmental resection) is often necessary, while simultaneously avoiding overtreatment. Typically, a computed tomography (CT) scan is initially performed. However, the question arises of whether CT alone is adequate for reliable assessment of mandibular involvement.

MATERIALS AND METHODS

A patient cohort of 25 individuals aged 44-79 years (mean 62 years) undergoing partial oropharyngeal resection with segmental mandibular resection was examined. The indication for segmental resection was based on the close relationship of the tumor to the mandible observed in imaging. Reconstruction was consistently carried out with a reconstruction plate and free or pedicled flaps. Preoperative radiological findings were compared with histopathology results after decalcification of the mandibular bone.

RESULTS

Cortical tumor infiltration was observed in the mandible in 9 patients (36%). Preoperatively, clear bone infiltration had been identified in CT in only 2 of these 9 patients; in the remaining 7, only direct tumor contact with the mandible was evident. Magnetic resonance imaging (MRI) revealed bone infiltration in 1 of these 7 patients.

DISCUSSION

Adhering to safety margins requires a radical surgical approach and reliable intraoperative frozen section analysis. However, at the bone level, intraoperative frozen section analysis is technically impractical due to the required decalcification. Only after decalcification can the entire specimen be assessed for tumor infiltration. In our cohort, a significant discrepancy in terms of bone infiltration was noted between preoperative imaging assessments and postoperative histopathology. CT preoperatively identified bone infiltration in only 8% of our patients. In two thirds of the specimens, no bone infiltration was evident after decalcification and histopathological processing, retrospectively indicating overtreatment by segmental resection; box or marginal resections may have been sufficient in these cases. Therefore, when tumors are adjacent to the bone in CT, MRI should also be performed preoperatively to more reliably detect bone infiltration.

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.

Impact of Planning Method (Conventional versus Virtual) on Time to Therapy Initiation and Resection Margins: A Retrospective Analysis of 104 Immediate Jaw Reconstructions

Simple Summary

Computer-aided design and manufacturing of osseous reconstructions are currently widely used in jaw reconstructive surgery, providing an improved surgical outcome and decreased procedural stumbling block. However, data on the influence of planning time on the time-to-surgery initiation and resection margin are missing in the literature. This retrospective, monocentric study compares process times from the first patient contact in hospital, time of in-house or out-of-house biopsy for tumor diagnosis and surgical therapy of tumor resection, and immediate reconstruction of the jaw with free fibula flaps (FFF). Two techniques for reconstruction are used: Virtual surgical planning (VSP) and non-VSP. A total of 104 patients who underwent FFF surgery for immediate jaw reconstruction from 2002 to 2020 are included. The study findings fill the gaps in the literature and obtain clear insights based on the investigated study subjects.

Abstract

Virtual surgical planning (VSP) and patient-specific implants are currently increasing for immediate jaw reconstruction after ablative oncologic surgery. This technique contributes to more accurate and efficient preoperative planning and shorter operation time. The present retrospective, single-center study analyzes the influence of time delay caused by VSP vs. conventional (non-VSP) reconstruction planning on the soft and hard tissue resection margins for necessary oncologic safety. A total number of 104 cases of immediate jaw reconstruction with free fibula flap are included in the present study. The selected method of reconstruction (conventionally, non-VSP: n = 63; digitally, VSP: n = 41) are analyzed in detail. The study reveals a statistically significant (p = 0.008) prolonged time to therapy initiation with a median of 42 days when the VSP method compared with non-VSP (31.0 days) is used. VSP did not significantly affect bony or soft tissue resection margin status. Apart from this observation, no significant differences concerning local tumor recurrence, lymph node, and distant metastases rates are found according to the reconstruction method, and affect soft or bone tissue resection margins. Thus, we conclude that VSP for immediate jaw reconstruction is safe for oncological purposes.

Partial mandibulectomy without bony reconstruction in patients with oropharyngeal or mouth cancer

Aim of the study

Resection of tumours of the oral cavity has significant consequences relating to function and aesthetic properties. Advancements in surgical techniques and microvascular surgery have enabled reconstructive outcomes to reach those of pre-surgery levels with good functional and aesthetic results. However, reconstructive options are not without complications.

Material and methods

We report the outcome of 23 patients with large tumours of the oral cavity or floor of the mouth, who underwent resection of the tumour and parts of the mandible without bony reconstruction. The patient population consisted of 19 oropharyngeal carcinomas and four floor of the mouth cancers, all of which had stage cT4 (six female and 17 male patients), and with an average patient age of 59.8 years. The pre- and postoperative ability to open the mouth, level of pain while masticating, mastication function pre and post-surgery, and the aesthetic outcome post-surgery were measured.

Results

The results obtained were deemed pleasantly acceptable by the patients, from aesthetic, functional, and analgesic points of view.

Discussion

A thorough preoperative work up is required and discussion with a multidisciplinary team is a necessity. This treatment option is more acceptable to the patient than would be expected and provides a satisfactory functional and aesthetic outcome. Therefore, we believe that partial mandibulectomy without bony reconstruction is an acceptable management option for a carefully selected group of patients who may not be suitable for the extensive surgery involved with bony reconstruction.

The diagnosis and treatment of oral cavity cancer

BACKGROUND

About 10,000 persons are diagnosed as having carcinoma of the oral cavity or the throat in Germany every year. Squamous-cell carcinoma accounts for 95% of cases.

METHODS

We systematically reviewed the pertinent literature on predefined key questions about these tumors (which were agreed upon by a consensus of the investigators), concerning imaging, the removal of cervical lymph nodes, and resection of the primary tumor.

RESULTS

246 clinical trials were selected for review on the basis of 3014 abstracts. There was only one randomized, controlled trial (evidence level 1-); the remaining trials reached evidence levels 2++ to 3. Patients with mucosal changes of an unclear nature persisting for more than two weeks should be examined by a specialist without delay. The diagnosis is made by computed tomography or magnetic resonance imaging along with biopsy and a standardized histopathological examination. Occult metastases are present in 20% to 40% of cases. Advanced disease (stages T3 and T4) should be treated by surgery followed by radiotherapy, with or without chemotherapy. 20% of the patients overall go on to have a recurrence, usually within 2 to 3 years of the initial treatment. The 5-year survival rate is somewhat above 50%. Depending on the radicality of surgery and radiotherapy, there may be functional deficits, osteoradionecrosis, and xerostomia. The rate of loss of implants in irradiated bone is about 10% in 3 years.

CONCLUSION

The interdisciplinary planning and implementation of treatment, based on the patient's individual constellation of findings and personal wishes, are prerequisites for therapeutic success. Reconstructive measures, particularly microsurgical ones, have proven their usefulness and are an established component of surgical treatment.