Abstract】 Objective To explore the options and rules of personalized treatment modalities for multiple types of parotid tumors. In order to achieve the purpose of functional and precise surgery. Methods Retrospectively, we analyzed 115 cases of parotid tumor treatment modalities, divided the parotid masses into upper parotid masses and lower parotid masses, and adopted corresponding surgical modalities for different parts of the tumor, with postoperative radiation therapy for malignant tumors. Postoperative follow-up was 0.5 to 10 years. The treatment effect and postoperative complications were evaluated. Results There were 95 cases of benign parotid tumors, 17 cases of postoperative temporary facial nerve palsy, which recovered after 1 to 3 months; 3 cases of Frey’s syndrome; no recurrence, salivary fistula and obvious facial depression. In 20 cases of malignant tumors, total parotidectomy or supraglottic cervical lymph node dissection was used. 15 cases of temporary facial nerve palsy and 5 cases of permanent facial palsy occurred after surgery, of which 2 cases had both preoperatively. 18 cases were treated with postoperative radiation therapy and no recurrence occurred after surgery, and 2 cases did not have radiation therapy and recurred 2 years after surgery. Conclusion Individualized treatment of benign parotid tumors is the ideal choice, and selective supraglottic cervical lymph node dissection of malignant tumors based on total parotidectomy according to the guidelines of the National Comprehensive Cancer Network (NCCN) requires postoperative radiation therapy. Parotid tumors are common oral and maxillofacial tumors, and tumor types often require pathological examination to be determined. Treatment is mainly surgical, and the choice of surgical approach is generally based on the site and nature of the tumor, and treatment modalities for benign and malignant tumors vary greatly. Prognosis is directly related to the choice of treatment modality, and postoperative complications, especially the appearance of facial nerve palsy, are something that we try to avoid during parotid surgery (1). We tried to evaluate the treatment outcome by the choice of different treatment modalities for different types of parotid tumors. 1 .Clinical Material 1.1 General: 115 patients with parotid tumors who were hospitalized and treated surgically at the 306th Hospital of the PLA in Beijing from 2002.1 to 2011.12. The main complaint was a preauricular or subauricular swelling, the shortest being 7 days and the longest 20 years. Among them, 57 cases were male and 58 cases were female. The ages ranged from 11 to 87 years, with a median age of 49 years. The smallest mass diameter was 0.5 cm and the largest was 8 cm. 95 cases were benign tumors and 20 cases were malignant tumors (Table 1). Frozen sections were performed in 56 cases, with 100% tumor characterization and 94% diagnostic compliance rate. The follow-up was from 6 months to 10 years. 1.2 Methods: 1.2.1 Excision of the lower parotid region: The incision was made from the earlobe backward down to 2 cm below the mastoid process and then obliquely forward down to 2 cm below the angle of the mandible, and the skin, subcutaneous tissue, broad cervical muscle and parotid chewing muscle fascia were incised. The lower part of the parotid gland is exposed, and the mandibular border branch of the facial nerve is searched for to isolate the cervical-facial trunk and determine the location of parotid gland excision, and the parotid tissue is excised at 0.5-1 cm outside the border of the swelling and sent for frozen section. The deep lobe of the parotid gland was removed or left intact as appropriate. The ducts and the upper part of the superficial lobe of the parotid gland are preserved. 1.2.2 Parotid mass excision: The incision site is determined according to the location of the mass, the parotid gland and its mass are exposed, and the tumor is removed by separation on the surface of the mass. 1.2.3 Total parotidectomy and supraglottic cervical lymph node dissection: A conventional “S” incision is made, and the parotid chewing muscle fascia is preserved or removed as appropriate. The parotid gland is exposed, and the facial nerve is dissected and the parotid gland and its mass are excised. If the tumor is malignant, the involved facial nerve is excised or preserved as appropriate. Carotid triangle and submandibular lymph node dissection is performed if necessary. 1.2.4 Excision of the upper parotid region: A longitudinal incision is made in front of the ear screen, and if necessary, the incision is extended upward to reveal the parotid gland after deep fascial separation, and the parotid gland is amputated 0.5-1 cm outside the mass. The indications are limited because the parotid ducts may be removed, and it is only used when the mass is close to the zygomatic arch and the tumor is less than 1.5 cm. 1.3 Individualized management of benign parotid tumors: 1.3.1 Subdivision of the parotid gland: The parotid gland is divided into two parts according to the anatomical and physiological characteristics of the parotid gland, with the boundary being the line from the earlobe to the corner of the mouth. The upper part of the parotid gland is defined as the upper part of the parotid gland, which contains the parotid ducts. The following is the lower part of the parotid gland. 1.3.2 For benign tumors located in the lower part of the parotid gland, a total of 43 cases were selected for partial parotidectomy, including 25 cases of mixed tumors, 13 cases of adenolymphoma, and 5 cases of other benign parotid tumors; for those located in the upper part of the parotid gland, a total of 34 cases were selected for total parotidectomy or partial parotidectomy, including 24 cases of mixed tumors, 3 cases of adenolymphoma, and 7 cases of other benign tumors. Among the 18 cases, there were 12 cases of adenolymphoma and 6 cases of other benign tumors. 1.4 Individualized management of malignant tumors of the parotid gland: 2 of the 20 cases had postoperative patients who refused radiation therapy. 1.4.1 Mucinous epidermoid carcinoma in 8 cases, including 1 patient with bilateral, total parotidectomy with preservation of the facial nerve or excision of the involved facial nerve in 6 cases, postoperative radiation therapy, including 1 case plus supraglottic cervical lymph node dissection; 2 cases with regional excision of the lower parotid gland. 1.4.2 Three cases of malignant lymphoma were treated with total parotidectomy and preservation of the facial nerve. Postoperative radiation therapy was performed. 1.4.3 Two cases of adenoid cystic carcinoma were treated with total parotidectomy with preservation of facial nerve and postoperative radiation therapy. 1.4.4 Seven cases of other malignant tumors, including four cases of total parotidectomy and three cases of total parotidectomy with supraglottic cervical lymph node dissection. 2, Results: 95 cases of benign tumors were followed up for 0.5-9 years. 17 cases (17.5%) had temporary facial nerve palsy, which returned to normal after 1 to 3 months; 3 cases of Frey’s syndrome were not treated. There was no recurrence and salivary fistula in all cases, and there was no significant facial depression. There were 20 cases of malignant tumor, 15 cases of temporary facial nerve palsy, which generally recovered after 3 months, and 5 cases of permanent facial nerve palsy, of which 2 cases had pre-operative facial nerve palsy; 1 case of recurrence, which was not treated with radiation after surgery; 2 cases of obvious depression in the parotid area; and 1 case of death due to cardiovascular disease. Frey’s syndrome and parotid fistula were not observed. According to the anatomical and physiological characteristics of the parotid gland, the parotid gland was divided into two parts, with the intention of preserving the parotid duct and part of the gland during surgery, so that the parotid gland could retain part of its function, which is in line with the modern surgical trend. The parotid ducts begin as two branching ducts in the anterior part of the parotid gland, with the dominant duct at the midpoint of the posterior margin of the ascending mandibular branch. The ducts are collected from the upper parotid and the lower parotid branches (2). Tumors in the lower parotid gland can be resected in the lower parotid region to preserve some parotid function in the upper parotid gland, which results in less surgical damage and less chance of facial nerve injury. The section of the parotid gland should be trimmed and sutured during surgery to avoid salivary fistula. Among benign tumors of the parotid gland, mixed tumors are generally considered to be the most common, followed by adenolymphomas, as shown in our data. The treatment of mixed tumors has traditionally used superficial parotidectomy with dissection of the facial nerve, whereas in recent years findings have shown that it is feasible to use regional resection, the key to regional resection is to perform it outside a safe enough border, both 0.5 to 1 cm or more outside the tumor border, which ensures that the mixed tumor does not recur (3). We have taken individualized treatment for different regions of mixed tumors, and the extent of resection follows the principle of outside the safety boundary, so the damage is small, facial nerve palsy is reduced, and the prognosis obtained after surgery is ideal, and no recurrence cases have occurred. Secondly, we have done intraoperative frozen section examination in some cases, and if it is a mixed tumor, it is performed strictly according to the surgical boundary. For adenolymphoma it is possible to take lumpectomy and regional resection, both of which differ in the length of surgery, but the prognosis is not affected. Malignant tumors of the parotid gland are common malignant tumors of the oral and maxillofacial region. The tissue origin is mainly from the adenoepithelium and a few from the mesodermal tissue, with diverse pathological features, varying degrees of malignancy, infiltrative growth, and invasion of the facial nerve. The diagnosis is mainly based on history, clinical examination, CT and pathological examination. Needle aspiration cytology and frozen section examination are more commonly used clinically to determine the nature of the lesion for surgical planning, and postoperative pathology is instructive for further management and prognosis. Excisional pathology is generally not advocated (4). In our 20 cases of parotid malignancies, frozen section examination was performed intraoperatively, and in some cases of early mucous epidermoid carcinoma of the lower parotid gland, regional resection of the parotid gland was taken, and no recurrence occurred in the postoperative follow-up with good prognosis. This may be related to the adherence to the anaplastic principle, the degree of cell differentiation and postoperative radiation therapy. In the case of malignant lymphoma we preserved the facial nerve intraoperatively, and postoperative conventional radiotherapy was used without recurrence. In contrast, two patients who refused radiation therapy developed recurrence after surgery, illustrating the importance of postoperative adjuvant radiation therapy in 20 of our patients. In some cases, supraglottic cervical lymph node dissection was performed according to the National Comprehensive Cancer Network (NCCN) guidelines. Postoperative complications: The postoperative complications of parotid tumors include facial nerve palsy, Frey’s syndrome, salivary fistula and recurrence, etc. Facial nerve palsy is a serious complication of parotid surgery, the cause of which is related to the nature of the tumor and surgery. Frey’s syndrome is generally considered to be related to the cross-anastomosis of sympathetic and parasympathetic nerves, especially the surgical operation of the upper parotid gland, attention should be paid to preserve the parotid chewing muscle fascia as much as possible, which may reduce the occurrence of this complication; salivary fistula is caused by the residual glandular secretion that cannot be discharged into the oral cavity (5), in more than 100 of our patients, there was no case of salivary fistula after 7-14 days of postoperative compression; benign tumors of parotid gland, especially mixed tumors, have more recurrences. The reason is that the biological behavior of mixed tumor is special and the border of resection is not enough, but taking sufficient border of parotid area resection can avoid recurrence of mixed tumor. It is feasible to take parotidectomy for parotid malignant tumor T1-T2N0M0, and postoperative radiation therapy can be practiced as a routine to prevent tumor recurrence. Advantages and disadvantages of this study: personalized treatment of parotid tumors can be aligned with modern popular treatment trends, especially with modern surgical robots. The treatment outcome is good and can reduce postoperative complications. However further refined studies are pending to bring benefits to patients.