Radiation-Induced Olfactory Neuroblastoma Following Treatment for NK/T-cell Lymphoma, Nasal Type.

Radiation-induced olfactory neuroblastoma (ONB) is an uncommon neoplasm that is generally associated with a poor prognosis. We experienced an unusual case of ONB in a patient who had received previous radiation therapy for extranodal NK/T-cell lymphoma 15 years previously. To our knowledge, this is the first report of a patient with radiation-induced ONB obtaining a complete response (CR) with radical re-irradiation alone. The purpose of this report is to discuss therapeutic strategies for radiation-induced ONB. We report an unusual case of ONB suspected to be a radiation-induced neoplasm in a 33-year-old female who had received 30 Gy of irradiation for extranodal NK/T-cell lymphoma, nasal type (NTCL) 15 years earlier. In this case, the patient presented with nasal obstruction and frequent epistaxis. The patient was diagnosed with ONB based on left nasal biopsy findings. The surrounding normal tissues tolerance of nasal ONB radiation had to be limited, because the previously radiated NTCL was located adjacent to critical organs. We performed intensity modulated radiation therapy (IMRT), which could offer precise irradiation (60 Gy in 2 Gy daily fractions) while sparing critical tissues. The present case was treated with radiation therapy alone, whereas previously reported cases were treated with a combination of chemotherapy and radiation therapy. We treated radiation-induced OBN successfully with radical re-irradiation using IMRT alone and the patient has had no recurrence for 3 years.

Comparison of a Hybrid IMRT/VMAT technique with non-coplanar VMAT and non-coplanar IMRT for unresectable olfactory neuroblastoma using the RayStation treatment planning system-EUD, NTCP and planning study.

The purpose of this study was to compare hybrid intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (Hybrid IMRT/VMAT), with non-coplanar (nc) IMRT and nc-VMAT treatment plans for unresectable olfactory neuroblastoma (ONB). Hybrid IMRT/VMAT, nc-IMRT and nc-VMAT plans were optimized for 12 patients with modified Kadish C stage ONB. Dose prescription was 65 Gy in 26 fractions. Dose-volume histogram parameters, conformation number (CN), homogeneity index (HI), integral dose and monitor units (MUs) delivered per fraction were assessed. Equivalent uniform dose (EUD) and normal tissue complication probability (NTCP) based on the EUD model (NTCPLogit) and the Lyman-Kutcher-Burman model (NTCPLKB) were also evaluated. We found that the Hybrid IMRT/VMAT plan significantly improved the CN for clinical target volume (CTV) and planning treatment volume (PTV) compared with the nc-VMAT plan. In general, sparing of organs at risk (OARs) is similar with the three techniques, although the Hybrid IMRT/VMAT plan resulted in a significantly reduced Dmax to contralateral (C/L) optic nerve compared with the nc-IMRT plan. The Hybrid IMRT/VMAT plan significantly reduce EUD to the ipsilateral (I/L) and C/L optic nerve in comparison with the nc-IMRT plan and nc-VMAT plan, but the difference in NTCP between the three technique was <1%. We concluded that the Hybrid IMRT/VMAT technique can offer improvement in terms of target conformity and EUD for optic nerves, while achieving equal or better OAR sparing compared with nc-IMRT and nc-VMAT, and can be a viable radiation technique for treating unresectable ONB. However, the clinical benefit of these small differences in dosimetric data, EUD and NTCP of optic nerves may be minimal.

Interventional radiotherapy (brachytherapy) for squamous cell carcinoma of the nasal vestibule: a multidisciplinary systematic review.

Surgery is the first-line therapy for treatment of cutaneous squamous cell carcinoma (cSCC), and interventional radiotherapy is recommended when surgery is not feasible, contraindicated, or refused by the patient. To provide a multidisciplinary systematic review of the role of interventional radiotherapy for the treatment of cSCC of the nasal vestibule. A systematic search was performed; primary outcomes were tumour local control and overall survival. Acute toxicity, late toxicity, and functional cosmetic results, regardless of the scoring systems used, were secondary outcomes. After full-text review of the 92 papers initially identified, we included only 10 papers in the review; no randomized controlled trials or prospective studies were identified. Five studies reported five-year local control, with rates ranging between 69% and 97%. A high level of heterogeneity was observed regarding the methods used to assess treatment-related toxicity. Interventional radiotherapy may be considered for lesions specifically arising from the area of the nasal vestibule. A multidisciplinary approach might help to select cases that are potential candidates for conservative treatment according to the tumour and the patient's features.

Radiotherapy for recurrent central Giant cell granuloma: a case report.

BACKGROUND: Central giant cell granuloma (CGCG) is a rare, non-neoplastic, benign lesion that exhibits expansive and osteolytic biological behavior. CGCG treatment and management is challenging for clinicians. CASE PRESENTATION: This report presents the treatment and management of recurrent, aggressive CGCG after surgical resection. After informed consent was obtained, the patient underwent radiotherapy. The lesion size was reduced significantly, with no evidence of recurrence or malignant transformation. CONCLUSIONS: This treatment experience indicates that radiotherapy can be used as a rescue treatment for complicated CGCG involving vital neurovascular structures of the cranial base.

Management of orbital invasion in esthesioneuroblastoma: 14 years' experience.

BACKGROUND: There is a scarcity of data about the prognostic value of orbital invasion in esthesioneuroblastoma (ENB), as well as about its management strategies. Indications for the preservation of orbital contents remain controversial, and the evaluation of orbital invasion has been ill defined. METHODS: This retrospective analysis contained 60 ENB patients with orbital invasion who underwent radiotherapy with or without surgery over the past 14 years. Orbital invasion was classified into three grades. RESULTS: There were 52 patients at stage C and 8 at stage D, according to Foote classifications. Grade I, grade II and grade III orbital invasion was detected in 12, 23, and 25 patients, respectively. The median follow-up was 57 months (IQR 32-95 months). Fourteen patients received radical radiotherapy, with a 5-year overall survival (OS) of 63.5%; 46 received surgery plus radiation, with a 5-year OS of 70.7%; and the difference was not statistically significant (p = 0.847). Orbital preservation was feasible in 100% of cases, including 18 cases that extended to extraocular muscles or the eye globe. Five-year locoregional relapse-free survival was 100% in patients with prophylactic elective neck irradiation (PENI) and 58.1% in patients without PENI (p = 0.004). Univariate analysis showed that grade II/III orbital invasion was associated with poorer OS and progression-free survival. Neck metastasis (with a Foote stage of D) was independently associated with shorter OS and distant metastasis-free survival in multivariate analysis. CONCLUSIONS: Our data suggested that primary radiotherapy achieved comparable survival to surgery plus radiotherapy in advanced ENB. Invasion of either the extraocular muscles or the eye globe is not a contraindication for eye-sparing surgery. Orbital invasion in grade II/III was significantly associated with adverse survival outcomes. Prophylactic radiotherapy to the neck with N0 significantly reduces the risk of regional recurrence.

Image Guided Brachytherapy for Cancer of the Nasal Vestibule: Local Control and Cosmesis.

PURPOSE: To evaluate the efficacy of modern image guided brachytherapy for squamous cell carcinoma of the nasal vestibule, to explore tumor volume as a prognostic factor for local and regional recurrence, and to assess patient satisfaction with nasal function and appearance after treatment. METHODS AND MATERIALS: In a retrospective analysis, we reviewed the medical records of 102 patients with Wang T1-T2 nasal vestibule cancer treated at a single institution with brachytherapy as the sole treatment. Median follow-up time was 42 months (range, 3-210 months). A patient satisfaction study using the validated Nasal Appearance and Function Evaluation Questionnaire was conducted among 42 patients more than 1 year after treatment. A statistically significant cutoff point for tumor volume as a prognostic factor of local control was established using Youden's index method. RESULTS: Seventy-seven of 102 patients were treated with interstitial implants, and 25 patients were treated by an intracavitary mould technique. The 5-year control rates were 95%, 91%, and 83% for local, regional, and locoregional control, respectively. Tumor volume ≥2.3 cm3 resulted in worse 3-year regional control compared to tumor volume <2.3 cm3 (62% vs 96%; P = .01). Ultimate regional control after salvage treatment was 96%, with no significant difference observed between subgroups by tumor volume (92% for ≥2.3 cm3 vs 96% for <2.3 cm3; P = .57). Three patients with regional failure developed distant metastases. Five-year disease-specific survival and overall survival were 94% and 74%, respectively. Patient-assessed cosmetic and functional satisfaction were both rated high (mean 3.7 and 4.0 of 5, respectively). CONCLUSION: We report the largest cohort to date treated with brachytherapy as the sole treatment for nasal vestibule carcinoma. Brachytherapy offers excellent local control for Wang T1-T2 tumors with high patient satisfaction. Tumor volume is an adequate predictive factor for patients at risk of regional recurrence, but ultimate control rates after salvage treatment are high. Therefore, we do not recommend elective treatment of the neck.

In-vivo and numerical analysis of the eigenmodes produced by a multi-level Tic-Tac-Toe head transmit array for 7 Tesla MRI.

Radio-frequency (RF) field inhomogeneities and higher levels of specific absorption rate (SAR) still present great challenges in ultrahigh-field (UHF) MRI. In this study, an in-depth analysis of the eigenmodes of a 20-channel transmit Tic-Tac-Toe (TTT) RF array for 7T neuro MRI is presented. The eigenmodes were calculated for five different Z levels (along the static magnetic field direction) of the coil. Four eigenmodes were obtained for each Z level (composed of 4 excitation ports), and they were named based on the characteristics of their field distributions: quadrature, opposite-phase, anti-quadrature, and zero-phase. Corresponding finite-difference time-domain (FDTD) simulations were performed and experimental B1+ field maps were acquired using a homogeneous spherical phantom and human head (in-vivo). The quadrature mode is the most efficient and it excites the central brain regions; the opposite-phase mode excites the brain peripheral regions; anti-quadrature mode excites the head periphery; and the zero-phase mode excites cerebellum and temporal lobes. Using this RF array, up to five eigenmodes (from five different Z levels) can be simultaneously excited. The superposition of these modes has the potential to produce homogeneous excitation with full brain coverage and low levels of SAR at 7T MRI.

Patient characteristics of olfactory neuroblastoma: experience from a tertiary cancer centre 2000-2016 covering Eastern Denmark.

The aim of this study was to report incidence and patient characteristics of olfactory neuroblastoma (ONB) at a tertiary cancer institution during a 16-year period. A retrospective review was conducted on patients with ONB treated at Rigshospitalet, Copenhagen from 2000 to 2016 covering Eastern Denmark. Patient demographics, symptoms, stage, pathology-reports, treatment, and outcome were extracted from the patient records and the Danish pathology register. The tumours were graded both histologically and clinically using Hyam's and Kadish classifications, respectively. We identified a total of 14 patients (ten males, four females, median age 57 years, range 17-81 years). Four patients were in Kadish stage A, one stage B, and seven stage C. According to Hyam's classification, two tumours were grade I, nine grade II, and three grade III. All patients were treated with surgery, eight in combination with radiotherapy, where one received proton therapy, and one a combination with chemotherapy. At a median follow-up time of 58 months, the 5-year overall survival was 90% (95% CI 61; 99). ONB is a rare disease; complete radical surgery alone or combined with radiotherapy offered good oncologic control and outcome. Long-term follow-up of ONB should be mandatory.

A Retrospective Multicenter Study of Carbon Ion Radiotherapy for Locally Advanced Olfactory Neuroblastomas.

The purpose was to evaluate efficacy and safety of carbon ion radiotherapy (C-ion RT) in patients with locally advanced olfactory neuroblastomas (ONBs). This study was a sub-analysis of the Japan Carbon-Ion Radiation Oncology Study Group Study (1402 HN, UMIN000024473). Clinical data of T4 ONBs treated with C-ion RT at four Institutions between November 2003 and December 2014 were retrospectively reviewed. Twenty-one patients underwent C-ion RT. Seven patients had T4a and 14 had T4b tumours without cervical node metastases. The median follow-up period was 39 (range=5-111) months. The 3-year overall survival and local control rates were 88.4% and 83.0%, respectively. Grade 4 late toxicity was observed in three patients, including ipsilateral optic nerve disorder (n=2) and ipsilateral retinopathy (n=1). C-Ion RT is effective and can be a curative modality for T4 ONBs. Prospective multicenter studies are warranted to confirm these findings.

DEVELOPMENT OF A NEW DETECTOR SYSTEM TO EVALUATE POSITION AND ACTIVITY OF PLUTONIUM PARTICLES IN NASAL CAVITIES.

Plutonium dioxide (PuO2) is used to fabricate a mixed oxide fuel for fast breeder reactors. When a glove box containing PuO2 fails, such as by rupture of a glove or a vinyl bag, airborne contamination of plutonium (Pu) can occur. If a worker inhales PuO2 particles, they will be continually irradiating their lung tissue with alpha particles, and this could cause lung cancer. The nasal smear and nose blow methods are useful for checking workers for PuO2 intake in the field. However, neither method can evaluate the quantitative activity of Pu. No alpha-particle detector that can be used for direct measurements in the nasal cavity has been developed. For direct and quantitative measurement, it is required that a shape of the detector should be a fine bar which inserts itself in the nose to measure the accurate activity of Pu. Therefore, we developed a nasal monitor capable of directly measuring the activity of Pu in the nasal cavity to estimate the internal exposure dose of a worker. Prismatic-shaped 2 × 2 acrylic light guides were used to compose a detector block, and a ZnS(Ag) scintillator was adhered to the surface of these light guides. Silicon photomultiplier (SiPM) arrays with 8 × 8 channels were used as a photodetector. Actual PuO2 particles were measured using the nasal monitor. The nasal monitor could be directly inserted in the nasal cavities, and the activity distribution of Pu was obtained by the nasal monitor. The average efficiencies in 4-pi were 11.4 and 11.6% for the left and right nasal cavities, respectively. The influence of gamma and beta rays from Cesium-137 (137Cs) Strontium-90 (90Sr) on the detection of the alpha particles of Pu was negligible. The difference in the measured Pu activity between the ZnS(Ag) scintillation counter and the nasal monitor was within 4.0%. Therefore, it was considered that the developed nasal monitor could be used in direct Pu determination to estimate the internal exposure dose of workers.

Anatomical robust optimization to account for nasal cavity filling variation during intensity-modulated proton therapy: a comparison with conventional and adaptive planning strategies.

The aim of this study is to develop an anatomical robust optimization method for intensity-modulated proton therapy (IMPT) that accounts for interfraction variations in nasal cavity filling, and to compare it with conventional single-field uniform dose (SFUD) optimization and online plan adaptation. We included CT data of five patients with tumors in the sinonasal region. Using the planning CT, we generated for each patient 25 'synthetic' CTs with varying nasal cavity filling. The robust optimization method available in our treatment planning system 'Erasmus-iCycle' was extended to also account for anatomical uncertainties by including (synthetic) CTs with varying patient anatomy as error scenarios in the inverse optimization. For each patient, we generated treatment plans using anatomical robust optimization and, for benchmarking, using SFUD optimization and online plan adaptation. Clinical target volume (CTV) and organ-at-risk (OAR) doses were assessed by recalculating the treatment plans on the synthetic CTs, evaluating dose distributions individually and accumulated over an entire fractionated 50 GyRBE treatment, assuming each synthetic CT to correspond to a 2 GyRBE fraction. Treatment plans were also evaluated using actual repeat CTs. Anatomical robust optimization resulted in adequate CTV doses (V95% ⩾ 98% and V107% ⩽ 2%) if at least three synthetic CTs were included in addition to the planning CT. These CTV requirements were also fulfilled for online plan adaptation, but not for the SFUD approach, even when applying a margin of 5 mm. Compared with anatomical robust optimization, OAR dose parameters for the accumulated dose distributions were on average 5.9 GyRBE (20%) higher when using SFUD optimization and on average 3.6 GyRBE (18%) lower for online plan adaptation. In conclusion, anatomical robust optimization effectively accounted for changes in nasal cavity filling during IMPT, providing substantially improved CTV and OAR doses compared with conventional SFUD optimization. OAR doses can be further reduced by using online plan adaptation.

The Role of Radiation Therapy in the Management of Sinonasal and Ventral Skull Base Malignancies.

Sinonasal and ventral skull base malignancies are rare tumors that arise in a complex anatomic location juxtaposed with critically important normal tissues. The standard treatment paradigm for most histologies has been surgery followed by postoperative radiation therapy. Because of their propensity to present at an advanced stage and the presence of nearby critical structures, patients are at risk for severe radiation-induced long-term toxicity. Recent advances in radiotherapy technique have improved the therapeutic ratio between tumor control and normal tissue toxicity. This article reviews issues pertinent to the use of radiotherapy in the management of these tumors.

Long-Term Prognostic Analysis after Endoscopic Endonasal Surgery for Olfactory Neuroblastoma: A Retrospective Study of 13 Cases.

OBJECTIVES: To summarize the characteristics and long-term outcomes of olfactory neuroblastoma through the analysis of 13 cases in single institution, with the assessment of treatment modality, prognostic factors. METHOD: A retrospective study of thirteen cases diagnosed as olfactory neuroblastoma and underwent combined treatments during the period 2000-2010. Statistical analysis was performed to search for prognostic factors and compared different treatment modalities. RESULTS: 13 patients were enrolled in this study, including 8 male and 5 female, ranging from 15 to 69 (median 43) years old. One patient at stage A was only treated with endoscopic endonasal surgery (EES). Seven patients were treated with preoperative radiotherapy and EES, two with EES and postoperative radiotherapy, and the other three with combined radiotherapy and chemotherapy. The range of follow-up time varied from 23 to 116 months (median 65 months). The 5-year overall survival rate was 46.2% (6/13). To date, these thirteen patients have not suffered local recurrences while two patients had lymph node recurrences and one had distant metastasis in the bone marrow. In 13 patients, 61.5% were diagnosed as late T stage (T3/4), 69.2% late Kadish stage (C/D) and 53.8% were high Hyams grade (I/ II), which indicated poor prognosis. Related prognostic factors were the TNM stage (T stage P = 0.028, N stage P = 0.000, M stage P = 0.007), Kadish stage (P = 0.025) and treatment modality (P = 0.015). CONCLUSION: Late stage of TNM and Kadish staging system indicated a poor prognosis. Combined treatment modality, including endoscopic endonasal surgery, achieved a better outcome than non-surgical approach.

Pre-operative chemoradiation for sinonasal undifferentiated carcinoma of the anterior nasal cavity resected through a lateral nasal flap approach.

INTRODUCTION: Sinonasal undifferentiated carcinoma (SNUC) is an exceedingly rare and aggressive tumor that carries a poor prognosis due to its non-specific presentation and advanced stage at time of diagnosis. Early detection and treatment are vital, with chemotherapy, radiation, and surgery all being viable options. The literature is sparse and there is no consensus for optimal treatment. In surgical candidates, the otolaryngologist must have a vast skill set in order to resect the tumor with wide margins and reconstruct the defect in hopes of returning the patient to their pre-morbid state. METHODS: A 74-year-old female presented with a growing left nasal mass which was biopsied and found to be a sinonasal undifferentiated carcinoma originating from the anterior nasal cavity between the septum and upper lateral cartilage. The patient was treated with neo-adjuvant carboplatin with concurrent radiation, followed by resection through a lateral nasal flap. The defect was reconstructed with a contralateral septal hinge flap and septal cartilage graft with primary closure of the lateral nasal flap. RESULTS: Intraoperatively, no skin or cartilage invasion was noted and as such, nasal skin was spared and utilized for primary closure. At a follow-up of 3 months, the patient had no evidence of recurrence and had a well healing repair site with satisfactory cosmesis. CONCLUSIONS: Despite the aggressive nature of SNUC tumors, neo-adjuvant chemo-radiation and surgical intervention with functionally and aesthetically minded reconstruction can provide patients with improved outcomes and decreased morbidity.

Oncocytic Schneiderian Papilloma of the Sinonasal Tract Treated With Radiotherapy.

A 66-year-old man visited the ophthalmology department due to epiphora and was subsequently diagnosed with oncocytic schneiderian papilloma. Surgical removal was recommended to the patient; however, he refused this option. Therefore, a radiation of 64 gray (Gy) was administered in 32 daily doses (2 Gy daily) over 45 days using intensity-modulated radiotherapy. Four months after radiotherapy, the tumor had disappeared. Two years postradiotherapy, the patient was healthy, without tumor recurrence or the development of orbital complications. The authors suggest that radiotherapy could be an adjuvant or definite treatment modality for patients of oncocytic schneiderian papilloma unsuitable for complete surgical removal, or those associated with a high risk of surgery-related complications.

Radiotherapy combined with chemotherapy versus radiotherapy alone for early stage nasal natural killer/T-cell lymphoma: a meta-analysis.

OBJECTIVE: To compare the efficacy of radiotherapy (RT) plus chemotherapy (CMT) versus RT alone for early stage nasal natural killer (NK)/T-cell lymphoma. METHODS: All the eligible studies were searched by PubMed, Medline, Embase and the Cochrane Library. The meta-analysis was performed to compare odds ratios (ORs) for overall survival (OS), disease-free survival (DFS) and progression-free survival (PFS). RESULTS: Eight studies were included in the meta-analysis. Chemotherapy group did not significantly differ from RT group. The pooled OR and 95% confidence interval (CI) for 1-year, 3-year, 5-year and 10-year OS was 1.25 [0.84, 1.87], 1.10 [0.76, 1.58], 0.83 [0.59, 1.17] and 1.05 [0.70, 1.56]. In addition, the combined OR and 95% CI for 5-year DFS and PFS were 0.96 [0.53, 1.73] and 0.71 [0.45, 1.12]. CONCLUSIONS: The current evidence suggests that CMT was not superior to RT alone. Radiotherapy may be still the main method in the treatment of early stage nasal NK/T-cell lymphoma.

Radiation treatment for the right naris in a pediatric anesthesia patient using an adaptive oral airway technique.

Radiation therapy for pediatric patients often includes the use of intravenous anesthesia with supplemental oxygen delivered via the nasal cannula. Here, we describe the use of an adaptive anesthesia technique for electron irradiation of the right naris in a preschool-aged patient treated under anesthesia. The need for an intranasal bolus plug precluded the use of standard oxygen supplementation. This novel technique required the multidisciplinary expertise of anesthesiologists, radiation therapists, medical dosimetrists, medical physicists, and radiation oncologists to ensure a safe and reproducible treatment course.

Outcome and toxicity profile after brachytherapy for squamous cell carcinoma of the nasal vestibule.

BACKGROUND: The purpose of this study was to evaluate outcome and toxicity profile after primary brachytherapy for squamous cell carcinoma of the nasal vestibule. METHODS: A retrospective study was conducted for patients with Wang classification T1 to 2 cN0 squamous cell carcinoma of the nasal vestibule who received primary treatment with brachytherapy between 1992 and 2010. Tumor control, acute skin, mucosal, and late cartilage toxicity were scored. RESULTS: Of 60 patients (T1, 50; T2, 10), 38 were treated with an interstitial implant and 22 by a mold technique. The 3-year local, regional, and locoregional control rates were 91%, 93%, and 84%, respectively. Tumor diameter <1.5 cm resulted in a better local (p = .02) and regional (p = .05) control. The cumulative incidence of moist skin desquamation and confluent mucositis was 64% and 82%, respectively. The actuarial incidence of chondritis and/or chondronecrosis was 19%. CONCLUSION: Primary brachytherapy for Wang T1 to 2 squamous cell carcinoma of the nasal vestibule offers excellent tumor control rates with acceptable toxicity and preservation of anatomy.

A dosimetric comparison of volumetric modulated arc therapy (VMAT) and non-coplanar intensity modulated radiotherapy (IMRT) for nasal cavity and paranasal sinus cancer.

BACKGROUND: To compare dosimetric parameters of volumetric modulated arc therapy (VMAT) and non-coplanar intensity modulated radiotherapy (IMRT) for nasal cavity and paranasal sinus cancer with regard to the coverage of planning target volume (PTV) and the sparing of organs at risk (OAR). METHODS: Ten patients with nasal cavity or paranasal sinus cancer were re-planned by VMAT (two-arc) plan and non-coplanar IMRT (7-, 11-, and 15-beam) plans. Planning objectives were to deliver 60 Gy in 30 fractions to 95% of PTV, with maximum doses (D(max)) of <50 Gy to the optic nerves, optic chiasm, and brainstem, <40 Gy to the eyes and <10 Gy to the lenses. The target mean dose (D(mean)) to the parotid glands was <25 Gy, and no constraints were applied to the lacrimal glands. Planning was optimized to minimized doses to OAR without compromising coverage of the PTV. VMAT and three non-coplanar IMRT (7-, 11-, and 15-beam) plans were compared using the heterogeneity and conformity indices (HI and CI) of the PTV, D(max) and D(mean) of the OAR, treatment delivery time, and monitor units (MUs). RESULTS: The HI and CI of VMAT plan were superior to those of the 7-, 11-, and 15-beam non-coplanar IMRT. VMAT and non-coplanar IMRT (7-, 11-, and 15-beam) showed equivalent sparing effects for the optic nerves, optic chiasm, brainstem, and parotid glands. For the eyes and lenses, VMAT achieved equivalent or better sparing effects when compared with the non-coplanar IMRT plans. VMAT showed lower MUs and reduced treatment delivery time when compared with non-coplanar IMRT. CONCLUSIONS: In 10 patients with nasal cavity or paranasal sinus cancer, a VMAT plan provided better homogeneity and conformity for PTV than non-coplanar IMRT plans, with a shorter treatment delivery time, while achieving equal or better OAR-sparing effects and using fewer MUs.

Successful reconstruction of irradiated anterior skull base defect using the dual flap technique involving local pericranial flap and radial forearm free flap.

Skull base reconstruction presents a challenging therapeutic problem requiring a multispecialty surgical approach and close cooperation between the neurosurgeon, head and neck surgeon, as well as plastic and reconstructive surgeon during all stages of treatment. The principal goal of skull base reconstruction is to separate the intracranial space from the nasopharyngeal and oropharyngeal cavities, creating support for the brain and providing a water-tight barrier against cerebrospinal fluid leakage and ascending infection. We present a case involving a 58-year-old man with anterior skull base defects (2.5 cm × 3 cm) secondary to the removal of olfactory neuroblastoma. The patient received conventional radiation therapy at 6000 cGy in 30 fractions approximately a month before tumor removal. The patient had radiation therapy before surgery and was planned to have postoperative radiation therapy, which would lead to a higher complication rate of reconstruction. Artificial dura was used for the packing of the dural defect, which was also suspected to increase the complication rate of reconstruction. For these reasons, we chose to apply the dual flap technique, which uses both local pericranial flap and de-epithelized radial forearm free flap for anterior skull base defect to promote wound healing. During 28 months of follow-up after coverage of the anterior skull base defect, the dual flap survived completely, as confirmed through follow-up magnetic resonance imaging. The patient was free of cerebrospinal fluid leakage, meningitis, and abscess, and there was minimal donor-site morbidity of the radial forearm free flap. Reconstruction of anterior skull base defects using the dual flap technique is safe, reliable, and associated with low morbidity, and it is ideal for irradiated wounds and low-volume defects.