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.

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.