ABSTRACT
BACKGROUND: The aim of the present study is to assess efficacy and efficiency of Volumetric-modulated arc therapy (VMAT) technique in treatment of nasopharyngeal cancer in our institution and to report toxicity related to this technique. METHODS: Between June 2013 and January 2015, thirty-two patients with non metastatic nasopharyngeal cancer were curatively treated using VMAT Rapidarc. Dose prescription was performed using two different schedules, it consisted of either simultaneous integrated boost or simultaneous modulated accelerated radiation therapy delivering 70 Gy in 35 fractions and 69.96 in 33 fractions respectively. The choice was leaved at the discretion of the treating physician. The optimization process was performed by Eclipse software version 10.0 (Varian Medical Systems), using PRO algorithm (Progressive resolutive optimisation) version 3. Data was collected from dose-volume histograms for both planning target volumes (PTV) and organs at risk (OAR). We calculated the homogeneity index and the conformity index as well as the number of monitor units MU and the treatment delivery time. We also reported acute and late toxicity related to radiation therapy. RESULTS: For the PTV high risk (HR), intermediate risk (PTV IR) and low risk (LR) the D95% was 97.21 ± 1.5, 97.5 ± 3.3 and 97.10 ± 6.86 respectively. Whereas, The D5% was 104.6 ± 2.16, 103.8 ± 2.1 and 100.89 ± 7.26. The CI for PTV HR was 0.98 ± 0.02 and the HI was 0.08 ± 0.02. The mean treatment delivery time was 2.3 ± 0.2, and the mean MU number was 527.6 ± 131.4. Grade 4 toxicity was not reported in any case. Grade 3 xerostomia was observed in only 3(9.4%) patients and no patients developed grade 3 hearing loss. CONCLUSION: Our results confirmed the abilities of VMAT to provide excellent coverage of target volumes while sparing OAR especially the nervous structures and salivary glands.
Subject(s)
Nasopharyngeal Neoplasms/radiotherapy , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Intensity-Modulated/methods , Adult , Dermatitis/etiology , Female , Hearing Loss/etiology , Hospitals, Military , Hospitals, Teaching , Humans , Male , Middle Aged , Morocco , Mucositis/etiology , Radiometry/methods , Radiotherapy Dosage , Radiotherapy, Intensity-Modulated/adverse effects , Retrospective Studies , Treatment Outcome , Xerostomia/etiologyABSTRACT
BACKGROUND: Sebaceous carcinoma is a rare malignancy primarily with aggressive growth affecting the cutaneous tissues of the periocular region. Sebaceous carcinoma of the parotid gland is exceedingly rare, with only 32 cases reported in the literature. Our case brings this total to 33. CASE PRESENTATION: We present a case of a 57-year-old Moroccan woman with a firm, painless, slowly enlarging swelling at her left parotid area, with normal overlying skin and no palpable neck nodes. Parotidectomy with facial nerve preservation was performed, and microscopic examination showed sebaceous carcinoma. Then, she underwent adjuvant radiotherapy. With a follow up of 20 months, head and neck computed tomography revealed no recurrence. CONCLUSIONS: The optimal treatment is unclear. With more cases reported, clinicopathological characteristics and histogenesis are increasingly understood. Therefore the treatment for this rare tumor continues to evolve.
