Hyperbaric oxygen treatment of mandibular osteoradionecrosis: Combined data from the two randomized clinical trials DAHANCA-21 and NWHHT2009-1.

PURPOSE: Osteoradionecrosis (ORN) of the mandible is a serious complication of head and neck radiotherapy. This study aims to investigate the effect of hyperbaric oxygen (HBO) treatment on ORN in two randomized, controlled multicentre trials. METHODS AND MATERIALS: Patients with ORN with indication for surgical treatment were randomised to either group 1: surgical removal of necrotic mandibular bone supplemented by 30 pre- and 10 postoperative HBO exposures at 243 kPa for 90 min each, or group 2: surgical removal of necrotic bone only. Primary outcome was healing of ORN one year after surgery evaluated by a clinically adjusted version of the Common Toxicity Criteria of Adverse Events (CTCAE) v 3.0. Secondary outcomes included xerostomia, unstimulated and stimulated whole salivation rates, trismus, dysphagia, pain, Activities of Daily Living (ADL) and quality of life according to EORTC. Data were combined from two separate trials. Ninety-seven were enrolled and 65 were eligible for the intent-to-treat analysis. The 33% drop-out was equally distributed between groups. RESULTS: In group 1, 70% (21/30) healed compared to 51% (18/35) in group 2. HBO was associated with an increased chance of healing independent of baseline ORN grade or smoking status as well as improved xerostomia, unstimulated whole salivary flow rate, and dysphagia. Due to insufficient recruitment, none of the endpoints reached a statistically significant difference between groups. ADL data could only be obtained from 50 patients. CONCLUSION: Hyperbaric oxygen did not significantly improve the healing outcome of osteoradionecrosis after surgical removal of necrotic bone as compared to standard care (70% vs. 51%). This effect is not statistically significant due to the fact that the study was underpowered and is therefore prone to type II error.

External validation of deep learning-based contouring of head and neck organs at risk.

BACKGROUND AND PURPOSE: Head and neck (HN) radiotherapy can benefit from automatic delineation of tumor and surrounding organs because of the complex anatomy and the regular need for adaptation. The aim of this study was to assess the performance of a commercially available deep learning contouring (DLC) model on an external validation set. MATERIALS AND METHODS: The CT-based DLC model, trained at the University Medical Center Groningen (UMCG), was applied to an independent set of 58 patients from the Radboud University Medical Center (RUMC). DLC results were compared to the RUMC manual reference using the Dice similarity coefficient (DSC) and 95th percentile of Hausdorff distance (HD95). Craniocaudal spatial information was added by calculating binned measures. In addition, a qualitative evaluation compared the acceptance of manual and DLC contours in both groups of observers. RESULTS: Good correspondence was shown for the mandible (DSC 0.90; HD95 3.6 mm). Performance was reasonable for the glandular OARs, brainstem and oral cavity (DSC 0.78-0.85, HD95 3.7-7.3 mm). The other aerodigestive tract OARs showed only moderate agreement (DSC 0.53-0.65, HD95 around 9 mm). The binned measures displayed the largest deviations caudally and/or cranially. CONCLUSIONS: This study demonstrates that the DLC model can provide a reasonable starting point for delineation when applied to an independent patient cohort. The qualitative evaluation did not reveal large differences in the interpretation of contouring guidelines between RUMC and UMCG observers.

External beam radiotherapy with endocavitary boost for nasopharyngeal cancer: treatment results and late toxicity after extended follow-up.

PURPOSE: To evaluate the long-term outcome after treatment of nasopharyngeal carcinoma and assess late toxicity in a multidisciplinary clinic. METHODS AND MATERIALS: A retrospective analysis of 117 patients treated for nasopharyngeal cancer in a single institute between 1985 and 2002 was performed. Fifty-one long-term survivors were evaluated for late toxicity by a multidisciplinary team comprising a radiation oncologist, otolaryngologist, neurologist, and oral and maxillofacial surgeon. RESULTS: The 5-year local control rate for T1 to T2 and T3 to T4 tumors was 97% and 76%, respectively. Five-year disease-free survival and overall survival were 82% and 88% for Stage I to IIb disease and 46% and 52% for Stage III to IVb, respectively. Late morbidity evaluation revealed Radiation Therapy Oncology Group (RTOG) Grade III to IV toxicity in 71% of patients. A high incidence of cranial nerve palsies (47%) and mandibular osteolysis (82%) was found, although these complications had limited clinical impact. CONCLUSIONS: The multidisciplinary late morbidity clinic revealed an unexpected high incidence of cranial nerve palsies and mandibular osteolysis and overall an RTOG Grade III to IV toxicity in 71% of patients treated for nasopharyngeal cancer. External beam radiotherapy with endocavitary brachytherapy produces excellent rates of local control for T1 to T2 tumors, but the high incidence of late toxicity suggests an overtreatment.

Ipsilateral irradiation for oral and oropharyngeal carcinoma treated with primary surgery and postoperative radiotherapy.

PURPOSE: The purpose was to evaluate the contralateral nodal control (CLNC) in postoperative patients with oral and oropharyngeal cancer treated with ipsilateral irradiation of the neck and primary site. Late radiation-induced morbidity was also evaluated. METHODS AND MATERIALS: The study included 123 patients with well-lateralized squamous cell carcinomas treated with surgery and unilateral postoperative irradiation. Most patients had tumors of the gingiva (41%) or buccal mucosa (21%). The majority of patients underwent surgery of the ipsilateral neck (n = 102 [83%]). The N classification was N0 in 73 cases (59%), N1 or N2a in 23 (19%), and N2b in 27 cases (22%). RESULTS: Contralateral metastases developed in 7 patients (6%). The 5-year actuarial CLNC was 92%. The number of lymph node metastases was the only significant prognostic factor with regard to CLNC. The 5-year CLNC was 99% in N0 cases, 88% in N1 or N2a cases, and 73% in N2b cases (p = 0.008). Borderline significance (p = 0.06) was found for extranodal spread. Successful salvage could be performed in 71% of patients with contralateral metastases. The prevalence of Grade 2 or higher xerostomia was 2.6% at 5 years. CONCLUSIONS: Selected patients with oral or oropharyngeal carcinoma treated with primary surgery and postoperative ipsilateral radiotherapy have a very high CLNC with a high probability of successful salvage in case of contralateral metastases. However, bilateral irradiation should be applied in case of multiple lymph node metastases in the ipsilateral neck, particularly in the presence of extranodal spread. The incidence of radiation-induced morbidity is considerably lower as observed after bilateral irradiation.