Radiotherapy for parotid cancer: 10 years of experience in a single center.

<b><br>Introduction:</b> We report our experience in the treatment of parotid cancers by radiotherapy delivered with curative intent over a period of 10 years.</br> <b><br>Aim:</b> The aim of this study was to evaluate the therapeutic results and prognostic factors.</br> <b><br>Materials and methods:</b> This is a retrospective study of patients with parotid cancer treated with radiotherapy between 2008 and 2017 at the National Institute of Oncology in Rabat. Patients who received adjuvant or exclusive radiotherapy were included in this study. We performed a multivariate analysis for the factors related to locoregional control and overall survival.</br> <b><br>Results:</b> Initially, 74 patients (45 men and 29 women), at a median age of 57 years. were identified. At the time of diagnosis, 10 (13.6%), 36 (48.6%), and 28 (37.8%) patients were in stage II, III, and IVab, respectively. Sixty patients received adjuvant radiotherapy after parotidectomy and 14 patients received exclusive radiotherapy for an unresectable tumor. At 5 years, the rate of locoregional control and overall survival were 68.2% and 53.7%, respectively. Surgical resection and negative margins were significantly correlated with locoregional control. Lymph node involvement, unresectable tumors, high-grade histological types, and cystic adenoid carcinoma were significantly correlated with poor overall survival.</br> <b><br>Conclusions:</b> Acceptable long-term results are obtained with surgery combined with radiotherapy. Surgical resection remains essential for parotid cancer, given the disappointing results of treatment with radiotherapy alone.</br>.

Long-Term Outcome of Photobiomodulation Therapy for Refractory Diabetic Wound After Secretory Carcinoma of the Parotid Gland Surgery: A Case Report.

Objective: To evaluate the efficacy and safety of photobiomodulation therapy (PBMT) in the treatment of diabetic patients with refractory wound. Background: Refractory wound is one of the most challenging clinical complications of diabetes mellitus. Studies have shown that PBMT can promote wound healing in many ways. Methods: We reported a 55-year-old male patient with refractory diabetic wound after secretory carcinoma of the parotid gland surgery responding to 810 nm laser. Results: After PBMT, the refractory diabetic wound healed gradually without adverse events. During follow-up 5-years, the healed wound remained stable and showed no signs of recurrence. Conclusions: PBMT can be potentially considered as a therapeutic method in diabetic patients with refractory diabetic wound.

[Radiation-induced parotid leiomyosarcoma]. / Léiomyosarcome parotidien en territoire irradié.

INTRODUCTION: First case of radiation-induced parotid leiomyosarcoma. ANATOMO-CLINICAL OBSERVATION: A 50-year-old woman with a history of cervical irradiation for Hodgkin's lymphoma presented with a right parotid tumefaction. Examination noted a deep adherent pretragal mass with peripheral facial palsy. A total parotidectomy with intra-operative examination and cervical curage was performed. Histopathological analysis concluded to a grade 3 parotid leiomyosarcoma according to the National Federation of Cancer Centers. Adjuvant radiotherapy was performed. After 24 months of follow-up, the patient presented bone and liver metastases without local recurrence. DISCUSSION: This is the first case of radiation-induced leiomyosarcoma and the 12th case of parotid leiomyosarcoma described in the literature. The management associates surgery with adjuvant radiotherapy. Follow-up is by clinical examination, parotid MRI, and annual thoracoabdominal CT scan to search for metastases. Recurrences occur during the first year in 40 to 64% of cases, and distant metastases in 40 to 60% of cases. The 5-year survival rate is between 10 and 30%.

Perimesencephalic subarachnoid hemorrhage as a rare delayed complication of radiation therapy in a patient with parotid basaloid squamous cell carcinoma.

In this case report, we address a rare entity of parotid cancer: basaloid squamous cell carcinoma, which was surgically unresectable and had thus far only been treated with radiation therapy. Following twenty years of continuous remission, our patient presented with an acute perimesencephalic subarachnoid hemorrhage. The cause of the acute perimesencephalic subarachnoid hemorrhage was a delayed complication of radiation therapy.

Disease and toxicity outcomes for a modern cohort of patients with squamous cell carcinoma of cutaneous origin involving the parotid gland: Comparison of volumetric modulated arc therapy and pencil beam scanning proton therapy.

OBJECTIVES: We sought to describe outcomes for locally advanced cutaneous squamous cell carcinoma (SCC) involving the parotid treated with volumetric modulated arc therapy (VMAT) versus pencil beam scanning proton beam therapy (PBT). MATERIALS AND METHODS: Patients were gathered from 2016 to 2022 from 5 sites of a large academic RT department; included patients were treated with RT and had parotid involvement by: direct extension of a cutaneous primary, parotid regional spread from a previously or contemporaneously resected but geographically separate cutaneous primary, or else primary parotid SCC (with a cutaneous primary ostensibly occult). Acute toxicities were provider-reported (CTCAE v5.0) and graded at each on treatment visit. Statistical analyses were conducted. RESULTS: Median follow-up was 12.9 months (1.3 - 72.8); 67 patients were included. Positive margins/extranodal extension were present in 34 cases; gross disease in 17. RT types: 39 (58.2 %) VMAT and 28 (41.8 %) PBT. Concurrent systemic therapy was delivered in 10 (14.9 %) patients. There were 17 treatment failures (25.4 %), median time of 168 days. Pathologically positive neck nodes were associated with locoregional recurrence (p = 0.015). Oral cavity, pharyngeal constrictor, and contralateral parotid doses were all significantly lower for PBT. Median weight change was -3.8 kg (-14.1 - 5.1) for VMAT and -3 kg (-16.8 - 3) for PBT (p = 0.013). Lower rates of ≥ grade 1 xerostomia (p = 0.002) and ≥ grade 1 dysguesia (p < 0.001) were demonstrated with PBT. CONCLUSIONS: Cutaneous SCC involving the parotid can be an aggressive clinical entity despite modern multimodal therapy. PBT offers significantly lower dose to organs at risk compared to VMAT, which seemingly yields diminished acute toxicities.

Dosimetric investigation of radiation-induced trigeminal nerve toxicity in parotid tumor patients.

PURPOSE: We aimed to describe the association between trigeminal nerve (TN) dose and toxicity and determine a threshold value that leads to TN toxicity in patients with parotid tumors treated with adjuvant conventional fractionated radiation therapy. METHODS AND MATERIALS: Eighteen patients who underwent adjuvant radiotherapy (RT) between 2013 and 2018 were included in this retrospective study. TN and its branches were outlined subsequently on the planning CT scans. The doses received by TN were obtained based on the dose-volume histogram. The dose and toxicity relationship was investigated over the total prescribed dose. RT-related toxicity was graded according to Common Terminology Criteria for Adverse Events V4.0 (CTCAEv4.0). RESULTS: The median follow-up was 29.5 months. After RT, 61% of patients had Grade I-II late TN toxicity divided into Grade I in 4 (22%) and Grade II in 7 (39%) patients. TN injury symptoms were as follows: loss of sensation in the chin area in 3, difficulty in jaw movements in 3, and paresthesia in 5 patients. The total RT dose (p = 0.001), Dmax (p = 0.001), PTV-TN Dmax (p = 0.001), D1cc (p = 0.004), D0.5cc (p = 0.001), and D0.1cc (p = 0.01) had a significant effect on TN toxicity. Cut-off values leading to toxicity were determined as 66, 65.5, 65.25, 63.6, and 62.7 Gy for Dmax, PTV-TN Dmax, D0.1cc, D 0.5cc, and D1cc, respectively. CONCLUSIONS: Radiation-induced TN injury in head and neck cancer patients may further be investigated in clinically prospective trials by virtue of high toxicity rates with current RT doses in our retrospectively designed dosimetric study in parotid tumors.

Survival in Patients with Primary Parotid Gland Carcinoma after Surgery-Results of a Single-Centre Study.

This study aims to analyse a single-centre cohort series of patients who underwent parotidectomy for primary malignant parotid tumours. A retrospective chart review of 64 consecutive patients treated from November 2010 to March 2022 was performed. Outcomes were analysed by Kaplan-Meier curves. Sixty-four patients with a primary parotid malignancy were included in the study, with one bilateral case in this cohort. Patients were classified as stage I-II in 39 cases and stage III-IV in 26 cases. The five-year overall survival (OS), disease-specific survival (DSS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) rates were 78.4%, 89%, 92.5%, and 87.1%, respectively. Univariate analysis showed that high-risk histology, stage IV disease, lymphovascular invasion, perineural invasion, node metastasis, skin involvement, facial nerve involvement, and positive or close margins were risk factors associated with poorer outcomes. At present, the best evidence suggests that radical surgery should be the standard approach, and adjuvant therapy, in terms of radiotherapy/chemoradiotherapy, is recommended in patients with risk factors.

Adjuvant radiotherapy in node-negative salivary malignancies of the parotid gland: A multi-institutional analysis.

BACKGROUND AND PURPOSE: To determine the role of adjuvant radiotherapy (ART) in parotid gland cancer without nodal metastasis, we evaluated the survival outcomes, prognostic factors, and dose-response relationships in patients with node-negative parotid gland cancer patients. MATERIALS AND METHODS: Patients who underwent curative parotidectomy and were pathologically diagnosed with parotid gland cancer without regional or distant metastases between 2004 and 2019 were reviewed. The benefit of ART in terms of locoregional control (LRC) and progression-free survival (PFS) were evaluated. RESULTS: In total, 261 patients were included in the analysis. Of them, 45.2 % received ART. The median follow-up period was 66.8 months. Multivariate analysis revealed that histological grade and ART were independent prognostic factors for LRC and PFS (all p <.05). For patients with high-grade histology, ART was associated with a significant improvement in 5-year LRC (p =.005) and PFS (p =.009). Among patients with high-grade histology who completed RT, higher biologic effective dose (≥77 Gy10) significantly increased PFS (adjusted hazard ratio [HR], 0.10 per 1-Gy increase; 95 % confidence interval [CI], 0.02-0.58; p =.010). ART significantly improved LRC (p =.039) in patients with low-to-intermediate histological grade as well per multivariate analysis, and subgroup analyses revealed patients with T3-4 stage and close/positive resection margins (<1 mm) would benefit from ART. CONCLUSION: ART should be strongly recommended for patients with node-negative parotid gland cancer with high-grade histology in terms of disease control and survival. In patients with low-to-intermediate-grade disease, those with high T stage and incomplete resection margin benefit with ART.

Presentation and outcomes of patients with clinically T1-2, N0 parotid mucoepidermoid carcinoma: The roles of elective neck dissection and adjuvant radiotherapy.

OBJECTIVES: Examine the role of elective neck dissection (END) and adjuvant radiotherapy (RT) in early-stage clinically N0 parotid mucoepidermoid carcinoma (MEC). METHODS: The study is a retrospective analysis of the National Cancer Database, 2004-2016. The study population included adult patients with MEC who underwent parotidectomy. RESULTS: A total of 1233 patients were included. Histopathology demonstrated well, moderately, and poorly differentiated MEC 47.12%, 39.98%, and 12.90% of the time, respectively. END was performed in 78.67% of patients, resulting in nodal upstaging in 4.43% and identification of extracapsular extension (ECE) in 0.72%. RT was utilized in 67.33% of patients with advanced pathological features. Neither END nor RT improved overall survival separately (p < 0.05) or combined (adjusted HR: 1.19, 95%CI: 0.52, 2.70, p = 0.68). CONCLUSION: This study provides an epidemiological perspective regarding patients with clinically T1-2, N0 MEC. There was no observed survival advantage with END and RT.

Assessment of radiation-induced otitis media in patients with parotid gland malignancy.

BACKGROUND: Otitis media with effusion (OME) is a known side effect of radiation therapy in patients with head and neck cancer. AIMS/OBJECTIVES: To investigate the incidence rate and clinical course of radiation-induced OME, we have reported on the long-term characteristics of OME in patients with parotid gland malignancy. MATERIAL AND METHODS: This cohort study assessed 200 patients who underwent post-parotidectomy radiation therapy from January 2010 to December 2019 in a tertiary referral center. Postoperative radiation therapy was performed at 6 weeks post-surgery. Serial magnetic resonance images were collected to detect otitis media. Two blinded otologists individually assessed data from radiation therapy initiation to 36 months of post-radiation therapy. RESULTS: A total of 121 patients were enrolled (male, 61 [50.4%]; mean age, 46.98 ± 15.69 years), of which 14 developed otitis media (11.6%) within 6 months after radiation therapy. Spontaneous remission occurred without intervention within 1 year, excluding one patient who sustained otitis media for 2 years. CONCLUSIONS AND SIGNIFICANCE: Radiation-induced OME occurred in 11.6% of patients and it remitted within 1 year without intervention. Therefore, cooperation between otolaryngologists and radiation oncologists is required and invasive intervention should be considered with careful risk-benefit evaluation.

Surgery combined with 125I brachytherapy for treatment of carcinoma ex pleomorphic adenoma of the parotid gland.

OBJECTIVE: The aim of this study was to investigate the effectiveness and safety of surgery combined with 125I seed brachytherapy for treatment of carcinoma ex pleomorphic adenoma (CXPA) of the parotid gland and to identify the factors associated with prognosis. STUDY DESIGN: We conducted a retrospective analysis of data of patients with CXPA of the parotid gland treated with surgery plus 125I seed brachytherapy at the Peking University School of Stomatology Hospital between December 2003 and July 2018. RESULTS: Fifty-five patients (median age, 51 years) were included in the study. Median follow-up was 50.5 months. The 3-, 5-, and 10-year overall survival rates were 91.1%, 91.1%, and 81.5%, respectively. The 3-, 5-, and 10-year local control rates were all 85.2%. Grades 1-3 adverse effects occurred in 22 patients; no grade 4 reactions occurred. T stage, N stage, tumor invasiveness, perineural invasion, and surgical margins significantly affected local control rates. Lymph node metastasis and perineural invasion were independent predictors of poor local control. Lymph node metastasis was an independent predictor of poor survival. CONCLUSIONS: Surgery plus 125I seed brachytherapy appears to be an effective and safe treatment for CXPA of the parotid gland. T stage, N stage, tumor invasiveness, and perineural invasion are factors influencing prognosis.

Epithelial-myoepithelial carcinoma of the parotid gland with primary lung cancer: A rare case report.

INTRODUCTION: Epithelial-myoepithelial carcinoma (EMC) is a rare, low-grade malignancy that occurs primarily in the parotid gland and is most common in women aged 60 to 70 years. Cases of parotid EMC have been reported previously. Furthermore, some studies have suggested an increased risk of salivary gland tumors with secondary primary malignancies. There have been few reports of parotid EMC with other primary tumors. PATIENT CONCERNS: A 62-year-old Chinese man visited the hospital with a complaint of a mass on his left cheek that had persisted for 20 years. Routine pulmonary computed tomography showed a local ground glass shadow in the lower lobe of the right lung. DIAGNOSIS: The pathological diagnosis of lung was right lower lobe lung adenocarcinoma (pT1N0). Immunohistochemistry analysis showed that cytokeratin (CK)-7, NapsinA, and thyroid transcription factor-1 tested positive, while CK5/6, P40, and ALKD5F3 tested negative. The pathological diagnosis of left parotid gland: EMC. On immunohistochemistry staining, the outer cells expressed myoepithelial markers, such as CK5/6, P63, smooth muscle actin, while the inner cells expressed glandular epithelial markers, such as low-molecular-weight CK7 and CK8. INTERVENTIONS: The patient underwent resection of the lung and parotid tumors, and received preventive radiotherapy in the parotid gland area. OUTCOMES: The patient is in good condition. No symptom recurrence, distant metastatic spread or significant toxicity occurred during or after the treatment. The patient remains under regular surveillance. CONCLUSION: We report a rare case of parotid EMC with a second primary lung adenocarcinoma. This case is the third case of primary lung cancer associated with parotid EMC reported to date and the first to be reported in nearly 30 years.

The impact of clinicopathological factors on clinical outcomes in patients with salivary gland adenoid cystic carcinoma: a multi-institutional analysis in Japan.

BACKGROUND: Owing to the low incidence of adenoid cystic carcinoma (AdCC), reliable survival estimates and prognostic factors remained unclarified. METHODS: In this multi-institutional retrospective analysis, we collected 192 AdCC cases, and investigated the impact of clinicopathological factors on clinical outcomes of the patients. All AdCC cases were of salivary gland origin and were surgically treated with curative intent. Diagnoses of AdCC were validated by a central pathology review by expert pathologists. RESULTS: The 5-year overall survival (OS) and disease-free survival (DFS) rates were 92.5 and 50.0%, respectively. Treatment failure occurred in 89 patients (46%) with the distant failures in 65 (34%). Multivariate analysis indicated that pN2 and a pathologically positive surgical margin were independent prognostic factors for both OS and DFS. Histological grade III was an independent prognostic factor for OS. A primary site in the submandibular gland, pT3/4, pN1, and histological grade II were independent prognostic factors for DFS. Postoperative radiation therapy (PORT) improved the locoregional control (LRC) rate. Prophylactic neck dissection was not associated with a better OS or better LRC among patients with cN0. Facial nerve dissection did not improve clinical outcomes in parotid AdCC cases without facial nerve palsy. CONCLUSIONS: A higher TN classification, a pathologically positive surgical margin, and a higher histological grade were associated with a lower OS. PORT improved LRC rates but neck dissection failed to improve clinical outcomes in patients with cN0. As the distant metastasis was frequent, effective systemic therapy is imperative to improve the survival of AdCC patients.

Surgical extent and role of adjuvant radiotherapy of surgically resectable, low-grade parotid cancer.

BACKGROUND: Due to the rarity of low-grade parotid gland cancer and the diversity of histologic subtype, its optimal treatment modalities and prognostic factors have not been established yet. In this study, we aimed to identify the prognostic factors and adequate treatment modalities for patients with low-grade parotid gland cancer. METHODS: We retrospectively analyzed clinico-pathologic data from 287 patients with low-grade parotid gland cancer from 1999 to 2018. RESULTS: Recurrence-free survival, disease-specific survival, and overall survival rates at 10 years were 80.6%, 93.9%, and 84.4%, respectively. Among all patients, 56.1% received surgery alone, and the remaining 43.9% received surgery with adjuvant radiotherapy. Resection margin status and TNM stage were significant unfavorable prognostic factors. In patients with T1-2 tumor, surgical extent (total vs. less-than-total) did not show any significant effect on disease recurrence and patients' survival, and the disease was controlled well if a negative surgical margin was obtained after surgery, even with microscopic clear margin of<1 mm. In patients with adverse pathologic features (positive margin, lymphovascular invasion, perineural invasion, extracapsular nodal spread, T3-4, and N1-3), adjuvant radiotherapy significantly decreased loco-regional recurrence. CONCLUSIONS: Oncological outcomes were good in patients with low-grade parotid gland cancer with surgery and radiotherapy. In patients with T1-2 low-grade parotid gland cancer, surgery alone showed good local control rate regardless of the extent of surgery, if a negative surgical margin was obtained after surgery. Adjuvant radiotherapy played a significant role in controlling loco-regional recurrence in patients with adverse pathologic features.

Pure abscopal effect of radiotherapy in a salivary gland carcinoma: Case report, literature review, and a search for new approaches.

We report the case of an 84-year-old woman with poorly differentiated non-small cell carcinoma of the right parotid who presented with headache, was found to have a primary right parotid gland cancer as well as metastatic disease, and underwent palliative radiotherapy to the primary site. The patient received no chemotherapy or immunotherapy, but both the primary site and several non-irradiated foci in the lungs regressed or completely resolved. The patient remained free of disease for about one year before progression. The case is a rare instance of abscopal regression of metastatic disease in the absence of pharmacologic immunomodulation. A literature review surveys the history of the abscopal effect of radiation therapy, attempts to understand the mechanisms of its successes and failures, and points to new approaches that can inform and improve the outcomes of radioimmunotherapy.

Review of treatment modalities and outcomes of patients with basal cell adenocarcinoma.

PURPOSE: This study summarizes the treatment modalities of basal cell adenocarcinoma (BCAC) of the parotid gland and subsequent outcome at a single institution to better define the treatment of this rare tumor. MATERIAL AND METHODS: A retrospective review of patients treated for BCAC of the parotid gland from 1/01/1996 to 08/1/2018 was performed. Patients were identified using our institution's Cancer Registry. RESULTS: A total of thirteen patients (46% female, median age of 56) treated for BCAC of the parotid gland were identified. Eight patients (57%) were staged as T1, four were staged as T2 (29%), and two were stage T4a (14%) due to tumor involvement of the facial nerve. None of the patients had nodal involvement or distant metastases. Three patients (21%) underwent radiation therapy ranging from 60-70Gy for positive margin or facial nerve involvement by tumor. Five patients (36%) underwent a neck dissection (ND) ranging from just a level IIb dissection up to levels IIa, IIb, and III with none of the nodes being positive for disease. The remainder of patients did not undergo a neck dissection. Follow-up was 8.1 ± 6.2 (mean ± SD) years with no local or regional recurrence at time of last follow-up in any patient cohort. CONCLUSIONS: Our review suggests that elective neck dissections are not necessary following resection of T1/T2N0M0 basal cell adenocarcinoma for the prevention of local or regional recurrence. No longer performing neck dissections for T1/T2N0M0 BCAC would reduce the morbidity associated with the treatment of this rare parotid tumor.