COMPARATIVE STUDY BETWEEN SELECTIVE NECK DISSECTION AND RADIOTHERAPY IN THE MANAGEMENT OF CLINICALLY NODE NEGATIVE NECK IN CASES OF HEAD AND NECK CANCERS

Background: The management of clinically node negative neck (cN0) remains a matter of controversy. The used methods of treatment are observation and follow up and treating the neck when clinical metastasis developed, prophylactic radiotherapy, or elective neck dissection. Many surgeons prefer the elective surgical intervention because of the increasing incidence of clinically node negative neck having occult metastatic lymph nodes. Objective: The aim of this study was to compare between the efficacy of both elective neck dissection and elective neck irradiation in the management of clinically node negative neck (cN0) of patients with squamous cell carcinoma of head and neck, and to determine which type of treatment improves the 2- year survival, disease-free survival and loco-regional control rates. Patients and Methods: During the period from 2012-2015, this prospective study was done at Al- Azhar University hospitals (Otorhinolaryngology Department, and Surgical Oncology Unit) on 50 patients diagnosed to have clinically node negative neck (cN0) of squamous cell carcinoma of head and neck randomized into two groups, 25 of them managed by selective neck dissection (Group I) and 25 managed by elective radiotherapy (Group II). They were followed up for a period ranged from 6 months to 24 months with a mean period of 15months. All patients were subjected for full history taking, general and local examination, (assessment of the primary site and state of nodes of the neck), neck ultrasound, computed tomography (CT) and chest X-ray. Patients of Group (I) were evaluated postoperatively for surgical complications. Patients of Group II received 50 Gy using conventional fractionation (2 Gy per fraction with 2 days rest) to a total duration of 5 weeks. The incidences of local and regional recurrences were recorded. Survival times were calculated starting from the date of the surgery. Results: Nineteen female (38%) and 31 male patients (62%) were included in this study. 38% of patients have their primary lesion in the tongue and 30% of patients with primary laryngeal lesion. The check, lower lip, hypopharynx, alveolar margin, and nasopharynx were affected by primary lesion in 14%, 6%, 4%, 2% and 4% respectively. Moderately differentiated tumors (G2) were the most prevalent grade among the study groups. 26% of patients were presented with T1 lesion. T2, T3 and T4 were diagnosed in 50%, 14% and 12% of the studied patients respectively. Pathologically, positive nodes were observed in 4 cases of the dissected specimens ranging from 1-2 LN with the mean positive LN 1.3 nodes. Extra capsular extension was present in 3 patients (12%); positive LN without extra capsular spread was present in one patient (4%). Nine patients (18%) had a recurrence. In group I, 4 patients had recurrence, (2 local recurrences and 2 regional recurrences). In group II, 5 patients had a recurrence, (3 local recurrences, 1 regional recurrence and 1 loco-regional recurrence). The loco-regional control rate (LRC) for group I was 84% and for group II was 80%. Two years disease free survival rate in group (I) was 64% while that for group (II) was 56%. The overall survival rate (OSR) for group (I) was 80%, while that of group II was 76%. The differences between study groups as regard recurrence, loco-regional control rate, disease free survival rate, and survival time were statistically insignificant. Conclusion: Patients with clinically node negative neck of cases of squamus cell carcinoma of head and neck, elective neck dissection and elective radiotherapy were both suitable in terms of survival and locoregional control rates. Patients receiving both modalities of therapy can get nearly the same outcome. They were nearly equally effective in controlling the cN0 neck. The choice of the type of treatment modality depended mainly on the surgical experience of the treating oncologist, how the primary site is managed, the surgeon and patient choices.