Summary of Japanese clinical practice guidelines for head and neck cancer - 2022 update edited by the Japan society for head and neck cancer.

The aim of the "Japanese Clinical Practice Guidelines for Head and Neck Cancer - 2022 Update" is to review the latest evidence regarding head and neck cancer and to present the current standard approaches for diagnosis and treatment. These evidence-based recommendations were created with the consensus of the Guideline Committee, which is composed of otorhinolaryngologists and head and neck surgeons, together with radiologists, radiation oncologists, medical oncologists, plastic surgeons, dentists, palliative care physicians, and rehabilitation physicians. These guidelines were created by the Clinical Practice Guideline Committee of the Japan Society for Head and Neck Cancer based on the "Head and Neck Cancer Treatment Guidelines 2018 Edition," and the revised draft was compiled after evaluation by the Assessment Committee and public comments. The 'Clinical questions and recommendations' section consists of 13 categories, and 59 clinical questions are described in total. Here we describe 6 clinical questions specific to other sets of guidelines with recommendations and comments.

Risk factors for osteoradionecrosis of the jaw in patients with head and neck squamous cell carcinoma.

BACKGROUND: To evaluate factors associated with osteoradionecrosis of the jaw (ORNJ) in patients with head and neck squamous cell carcinoma (HNSCC), focusing on jaw-related dose-volume histogram (DVH) parameters. METHODS: We retrospectively reviewed the medical records of 616 patients with HNSCC treated with curative-intent or postoperative radiation therapy (RT) during 2008-2018. Patient-related (age, sex, history of smoking or alcohol use, diabetes mellitus, performance status, pre-RT dental evaluation, pre- or post-RT tooth extraction), tumor-related (primary tumor site, T-stage, nodal status), and treatment-related (pre-RT surgery, pre-RT mandible surgery, induction or concurrent chemotherapy, RT technique) variables and DVH parameters (relative volumes of the jaw exposed to doses of 10 Gy-70 Gy [V10-70]) were investigated and compared between patients with and without ORNJ. The Mann-Whitney U test was used to compare RT dose parameters. Univariate and multivariate Cox regression analyses were used to assess factors associated with ORNJ development. Kaplan-Meier analyses were performed for cumulative ORNJ incidence estimation. RESULTS: Forty-six patients (7.5%) developed ORNJ. The median follow-up duration was 40 (range 3-145) months. The median time to ORNJ development was 27 (range 2-127) months. DVH analysis revealed that V30-V70 values were significantly higher in patients with than in those without ORNJ. In univariate analyses, primary tumor site, pre-RT mandible surgery, post-RT tooth extraction, and V60 > 14% were identified as important factors. In multivariate analyses, V60 > 14% (p = 0.0065) and primary tumor site (p = 0.0059) remained significant. The 3-year cumulative ORNJ incidence rates were 2.5% and 8.6% in patients with V60 ≤ 14% and > 14%, respectively (p < 0.0001), and 9.3% and 1.4% in patients with oropharyngeal or oral cancer and other cancers, respectively (p < 0.0001). CONCLUSIONS: V60 > 14% and oropharyngeal or oral cancer were found to be independent risk factors for ORNJ. These findings might be useful to minimize ORNJ incidence in HNSCC treated with curative RT.

Keratocystoma of the parotid gland.

An 18-year-old man had a painless, elastic, firm mass in his left parotid area that gradually increased in size over a period of 6 months. At the time of examination, the parotid mass was poorly mobile and 46 mm in size. Although fine needle aspiration cytology revealed no malignant findings, we suspected a malignancy because the movement of his left mouth angle was slightly impaired; facial nerve paralysis as a result of tumor invasion was suspected. A superficial parotidectomy was performed. The tumor had a strong adhesion to the subcutaneous tissue and facial nerve. Histologically, multiple, randomly distributed cystic structures containing keratinized lamellae were present. The cystic spaces were lined with stratified squamous epithelium lacking a granular layer, and no skin appendage was observed. We diagnosed this case as a keratocystoma. Keratocystoma of the parotid gland is a rare benign tumor with only 6 cases reported worldwide. This case is the first to describe facial nerve palsy in association with a keratocystoma.

Dental intervention against osteoradionecrosis of the jaws in irradiated patients with head and neck malignancy: a single-arm prospective study.

BACKGROUND: The purpose of this study was to investigate the effectiveness of dental intervention before and after radiation therapy (RT) for head and neck malignancy on prevention of osteoradionecrosis (ORN) of the jaws. METHODS: This is a single-arm prospective study according to intervention protocol of prophylactic dental extraction before RT and routine follow-up after RT. The primary endpoint was the occurrence of jawbone exposure during the first 2 years after RT. RESULTS: Sixty-seven patients were assessed. Before RT, 144 teeth among 39 patients (58%) were prophylactically extracted. The occurrence of transient jawbone exposure during the first 2 years after RT was 7%. Because those jawbone exposures healed with intervention after RT, no jawbone exposure was found at 2 years after RT. CONCLUSIONS: Dental intervention both before and after RT seemed to be important to prevent ORN development. Further studies in larger cohorts are necessary.

Modified partial maxillary swing approach for myxofibrosarcoma in pterygopalatine fossa.

BACKGROUND: Extirpation of tumors arising in the pterygopalatine fossa is challenging because of its anatomic complexity. METHODS AND RESULTS: A 67-year-old man was referred to our department with a diagnosis of a tumor in his left pterygoid fossa. An incisional biopsy through the canine fossa was diagnosed as myxofibrosarcoma. The upper part of the maxilla was swung laterally to remove the tumor while the hard plate was preserved. The defect was reconstructed using rectus abdominis musculocutaneous free and ipsilateral temporal. The postoperative course was uneventful, without facial palsy or mastication disorders. CONCLUSION: Our experience with this case suggests that the modified partial maxillary swing approach with preservation of the hard palate and orbital floor in combination with infratemporal and cervical approaches is useful for lesions in the pterygoid process without causing severe complications. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2519-E2522, 2016.

Cause and occurrence timing of osteoradionecrosis of the jaw: a retrospective study focusing on prophylactic tooth extraction.

PURPOSE: This retrospective study aimed to analyze the relationship between tooth extraction and osteoradionecrosis (ORN) occurrence. The irradiation field, dose, and time interval between radiotherapy (RT) and ORN were reviewed. We also discuss appropriate guidelines for prophylactic tooth extraction. METHODS: A total of 33 patients treated for grade ≥2 (clinical) ORN in our department from 2002 to 2014 were enrolled. The following epidemiological data were retrospectively gathered: age, sex, histological diagnosis, primary tumor sites, radiation dose, chemotherapy, site of ORN, relationship between tooth extraction and ORN occurrence, and time interval between tooth extraction and the initiation or end of RT. RESULTS: Twenty-one percent of ORN cases resulted from tooth extraction. The most common site of ORN (82 %) was the mandibular molar region. About half of ORN cases (49 %) occurred within 2 years after RT. All patients who received tooth extraction after RT developed ORN (100 %) independently of time interval between tooth extraction and the end of RT (median interval, 37.5 months; range, 27-120 months). In contrast, only 50 % of patients who received tooth extraction before RT developed ORN. There may have been an association between the irradiation field and the site of ORN development CONCLUSIONS: ORN occurrence due to tooth extraction was 21 %. Occurrence timing of ORN did not depend on time interval between tooth extraction and the end of RT. The irradiation field is certainly related to the site of ORN; therefore, prophylactic tooth extraction should be performed in consideration of the proposed radiation field and dose.

FDG-PET findings of Ameloblastoma: a case report.

INTRODUCTION: Ameloblastoma is a benign odontogenic neoplasm of the jaw, rarely presenting as a malignant tumor. Although it is very important to discriminate ameloblastoma from ameloblastic carcinoma in order to decide the appropriate operative procedure, this is difficult using conventional CT and MRI. CASE DESCRIPTIONS: We report a case of maxillar ameloblastoma in a 78-year-old man where FDG-PET/CT was useful for making this discrimination. CT demonstrated a 31 × 43 × 46-mm mass in the left posterior maxillary sinus with destruction of its posterior and lateral wall and alveolar bone. MRI demonstrated a hypo- to isointense heterogeneous pattern on T1WI, heterogeneous hyperintensity with a prominent high-signal spot on T2WI, high signal intensity on DWI reflecting restricted diffusion, and strong heterogeneous enhancement. Because FDG-PET/CT showed mild FDG uptake (SUVmax 2.40) by the mass, ameloblastoma, rather than ameloblastic carcinoma, was considered to be the correct diagnosis. DISCUSSION AND EVALUATION: It appears that ameloblastic carcinoma shows intense FDG uptake, whereas ameloblastoma shows mild or moderate FDG uptake, and only rarely intense FDG uptake. Our experience suggests that FDG-PET/CT may be effective for discriminating ameloblastoma from ameloblastic carcinoma. Especially, in cases showing mild FDG uptake, benign ameloblastoma would seem the most likely diagnosis. CONCLUSIONS: FDG-PET/CT may be useful as an adjunctive modality for diagnosis, treatment planning and surveillance of ameloblastoma and ameloblastic carcinoma.

Oral candidiasis mimicking tongue cancer.

Candida species inhabit the mucosal surfaces of healthy individuals. Major forms of oral candidiasis are pseudomembranous and atrophic form, but chronic hyperplastic candidiasis (CHC) is rarely seen. We encountered a nodule caused by candidal infection on a forearm flap in the oral cavity mimicking a recurrent tongue cancer, which revealed as CHC by histopathological examination. Like other forms of oral candidiasis, the nodule well responded to the treatment of antifungal agents and eventually disappeared. When an intraoral nodule is observed, the possibility of CHC should be taken into consideration.

Curious complication after oroesophageal reconstruction with free jejunal flap: intussusception-like deformity of transferred jejunum.

Regions of oropharyngeal cancer, hypopharyngeal cancer, and cervical esophageal cancer in a 70-year-old man were surgically resected and reconstructed with a free jejunal flap. Postoperatively the patient showed severe dysphagia and a chimneylike protrusion in the oral cavity. In a second operation, a dorsal, longitudinal incision for phimosis was made to release the stenosis; however, the dysphagia persisted, and peristalis seemed to interfere with deglutition. Here, we discuss the cause of the dysphagia, a complication of total reconstruction of oroesophageal defects with a single free jejunal flap, and the procedures of reconstruction.

Simple reconstruction with titanium mesh and radial forearm flap after globe-sparing total maxillectomy: a 5-year follow-up study.

BACKGROUND: Reconstruction of eye globe-sparing total maxillectomy defects is one of the major challenges to reconstructive surgeons. In 1994, the authors developed an uncomplicated and easy reconstructive method, where a titanium mesh is applied for the support of orbital contents, a radial forearm free flap for covering the mesh and the cheek lining, and an obturator prosthesis for palatal and dental rehabilitation. METHODS: Five patients who underwent primary reconstruction with the authors' method after globe-sparing maxillectomy with loss of the orbital floor from 1994 to 1999 and who were followed up for more than 5 years were retrospectively reviewed for (1) the presence of diplopia, (2) the shape of the reconstructed orbital floor assessed by coronal section magnetic resonance imaging, and (3) the presence of infection/exposure of the titanium mesh. RESULTS: Only one of the five patients developed slight diplopia. Coronal magnetic resonance imaging showed that the orbital floor restored with titanium mesh had in all cases maintained a proper shape and position for more than 5 years. No infection or exposure of the titanium mesh had developed in any of the cases, despite exposure to irradiation of not less than 30 Gy. All the patients had well-retentive obturator prostheses. CONCLUSION: This long-term follow-up study demonstrated that the authors' method attained a long-lasting successful outcome functionally and is the method of choice for reconstruction after globe-sparing total maxillectomy.

Indications for vascularized free rectus abdominis musculocutaneous flap in oromandibular region in terms of efficiency of anterior rectus sheath.

The anterior rectus sheath, efficacious in reconstructive surgery, is used in oromandibular reconstruction with the free rectus abdominis musculocutaneous flap. This study describes reconstruction with this sheath in 20 patients: to preserve only the swallowing function in 10 patients (formation of the bulge of the reconstructed oral floor and prevention of its sinking); to preserve both swallowing and articulation in 5 patients (formation of the bulge of the reconstructed tongue and prevention of its sinking, concurrent with a money-pouch-like reconstruction of the tongue, laryngeal suspension, and neuroanastomosis); and to prevent exposure of the reconstruction plate, replacing the resected mandibular continuity in 5 patients. The purpose of reconstruction was achieved in all patients. The vascularized free rectus abdominis musculocutaneous flap with a firm anterior rectus sheath may be the first choice for these types of reconstruction.