Surgical site complications of isolated salvage neck dissection post-radiotherapy and post-chemoradiotherapy - A cohort analysis (1997-2017).

INTRODUCTION: This study aims to quantify surgical site complications (SSC) after isolated salvage neck dissection (ND) compared with primary ND. PATIENTS AND METHODS: Between 1997 and 2017 in the Netherlands Cancer Institute - Antoni van Leeuwenhoek, a total of 323 isolated NDs were performed in 308 patients: primary ND (n = 144), post-radiotherapy (RT) ND (n = 53) and post-chemoradiotherapy (CRT) ND (n = 126). Patient, tumor and therapy characteristics were recorded. SSCs were scored according to the Clavien-Dindo Classification (CDC). RESULTS: 101 NDs (31%) were complicated by at least one SSC. In total, 189 different SSCs occurred. Translated to CDC, 45 complications were grade 2, 25 grade 3a and 31 grade 3b. No significant difference in occurrence of SSC (CDC >1) was found between all groups. However, post-CRT, selective (SND) and modified radical ND and radical ND (MRND/RND) (p = 0.005), resection of sternocleidomastoid muscle (SCM) (p = 0.039) and duration of super selective ND surgery (p = 0.048) were significantly associated with more SSC. SCM muscle removal was associated with more surgical site infection (p = 0.045) and necrosis (p = 0.036). From week 10 post-RT/CRT, no difference in complication frequency with primary ND was seen. CONCLUSION: Post-CRT SND, MRND/RND and SCM muscle resection were associated with an increased incidence of SSCs. If oncologically possible, limit the extent of ND and when an MRND is inevitable, preserve the SCM muscle for optimal prevention of SSC. Concerning SSC, optimal timing of salvage ND is minimal 10 weeks after RT/CRT.

Malignant transformation of salivary gland pleomorphic adenoma: proof of principle.

Supposed risk of malignant transformation of salivary gland pleomorphic adenoma (SGPA) is an important reason for aggressive retreatment in recurrent pleomorphic adenoma (RPA). However, although the diagnostic category 'carcinoma ex-pleomorphic adenoma' suggests that malignant transformation of a pleomorphic adenoma is a regular event, this has to date not been shown to occur in sequential lesions of one patient. Here, we show the molecular events in transformation to malignancy of a pleomorphic adenoma of the parotid gland. Detailed molecular analysis revealed an LIFR/PLAG1 translocation characteristic for pleomorphic adenoma and, next to this, a PIK3R1 frameshift mutation and several allelic imbalances. In subsequent malignant recurrences, the same LIFR/PLAG1 translocation, PIK3R1 frameshift mutation, and allelic imbalances were present in addition to TP53 mutations. Thus, this case not only shows malignant transformation of SGPA, but also demonstrates that molecular analysis can be of help in recognising malignancy in the rare instance of RPA.

Surgical site complications of post-chemoradiotherapy neck dissection: Urgent need for standard registration.

Nowadays, a substantial number of head and neck cancer patients are treated by organ-preserving chemoradiation (CRT), with a possible increased risk of complications after planned or salvage neck dissections. We try to determine the risk pattern of surgical site complications (SSC) post-CRT.