The impact of multidisciplinary approaches on the outcomes of olfactory neuroblastoma treated with postoperative radiotherapy.

BACKGROUND: We investigated the outcomes of postoperative radiation therapy for olfactory neuroblastoma (ONB) and our cross-departmental collaboration to enhance the effectiveness of cancer treatment. METHODS: We retrospectively evaluated 22 patients with ONB who underwent postoperative radiotherapy after tumor resection. En bloc resection was performed; pathology specimens were prepared in coronal sections; and irradiation fields were determined after discussion with radiation oncologists, head and neck surgeons, and pathologists. RESULTS: The overall survival and local control rates were 95.5% and 100%, respectively, at a median 37-month follow-up. The 3- and 5-year disease-free survival (DFS) rates were 64.4% and 56.3%, respectively. Of the 22 patients, 9 (8 Kadish C and 1 Kadish B) had disease recurrence. Of the nine patients, five had positive margins and two had closed margins; cervical lymph node recurrence occurred in six, and distant metastasis with or without cervical lymph node recurrence occurred in three. DFS analysis of risk factors showed no statistically significant differences, but positive margins were a significant recurrence factor in multivariate analysis. CONCLUSIONS: The local control rate of ONB treated with postoperative radiation therapy was 100%. This may be attributed to cross-departmental cooperation between head and neck surgeons, pathologists, and radiation oncologists, which resulted in accurate matching of CT images for treatment planning with the location of the tumor and positive margins. Longer follow-up periods are required to evaluate the effectiveness of our strategy.

Outcomes following proton therapy for pediatric esthesioneuroblastoma.

BACKGROUND: Pediatric esthesioneuroblastoma (EN) can infiltrate skull base anatomy, presenting challenges due to high radiation doses and pediatric tissue sensitivity. This study reports outcomes of pediatric EN treated with proton radiotherapy (PT). PROCEDURE: Using an IRB-approved prospective outcomes registry, we evaluated patient, tumor, and treatment-related variables impacting disease control and toxicity in pediatric nonmetastatic EN treated with modern multimodality therapy, including PT. RESULTS: Fifteen consecutive patients (median age 16) comprising Kadish stage B (n = 2), C (n = 9), and D (n = 4) tumors were assessed, including six with intracranial involvement, four with cranial nerve deficits, and four with cervical lymphadenopathy. Before radiation, two had subtotal and 13 had gross total resections (endoscopic or craniofacial). Two underwent neck dissection. Eleven received chemotherapy before radiation (n = 5), concurrent with radiation (n = 4), or both (n = 2). Median total radiation dose (primary site) was 66 Gy/CGE for gross disease and 54 Gy/CGE (cobalt Gray equivalent) for microscopic disease. Median follow-up was 4.8 years. No patients were lost to follow-up. Five-year disease-free and overall survival rates were 86% (no local or regional recurrences). Two patients developed vertebral metastases and died. Two required a temporary feeding tube for oral mucositis/dysphagia. Late toxicities included symptomatic retinopathy, major reconstructive surgery, cataracts, chronic otitis media, chronic keratoconjunctivitis, hypothyroidism, and in-field basal cell skin cancer. CONCLUSIONS: A multimodality approach for pediatric EN results in excellent local control. Despite the moderate-dose PT, serious radiation toxicity was observed; further dose and target volume reductions may benefit select patients. Longer follow-up and comparative data from modern photon series are necessary to fully characterize any relative PT advantage.

Peptide Receptor Radionuclide Therapy for Recurrent Olfactory Neuroblastoma After Cranioplasty for Surgical Infection: A Case Report.

BACKGROUND: Peputide receptor radionuclide therapy with 177Lu for midgut neuroendocrine metastasis has been clinically approved as a safe treatment. Unresectable metastases of olfactory neuroblastoma have shorter survival due to insufficient effective systemic treatment. CASE REPORT: Herein, we report a patient treated with peputide receptor radionuclide therapy for unresectable recurrent olfactory neusroblastoma following a rare cranial metastasectomy infection. A 50-year-old female patient with olfactory neuroblastoma of Kadish C was initially treated by skull base surgery plus postoperative radiotherapy following chemotherapy. Recurrent disease with neck and intracranial metastases was treated by four salvage surgeries. Surgical site infection following intracranial metastasectomy was treated with debridement and delayed cranioplasty. Peputide receptor radionuclide therapy was performed for unresectable multiple metastases after cranioplasty. Successful therapy using four cycles of peputide receptor radionuclide had neither grade 3 nor grade 4 adverse events. The patient was followed at an outpatient clinic. CONCLUSION: Further case accrual of peputide receptor radionuclide therapy is required to develop a treatment for unresectable olfactory neuroblastoma.

Stereotactic radiosurgery for distant brain metastases secondary to esthesioneuroblastoma: a single-institution series.

OBJECTIVE: Esthesioneuroblastoma (ENB), also known as olfactory neuroblastoma, is a rare, malignant tumor of neuroectodermal origin that arises from the olfactory neuroepithelium. In this study the authors present the first series in the literature on distant brain metastases (BMs) secondary to ENB that were treated with stereotactic radiosurgery (SRS), to evaluate the safety and effectiveness of SRS for this indication. METHODS: A retrospective analysis of clinical and radiological outcomes of patients with ENB who underwent CyberKnife (CK) SRS at a single center was conducted. The clinical and radiological outcomes of patients, including progression-free survival, overall survival, and local tumor control (LTC) were reported. RESULTS: Between 2003 and 2022, 32 distant BMs in 8 patients were treated with CK SRS at Stanford University. The median patient age at BM diagnosis was 62 years (range 47-75 years). Among 32 lesions, 2 (6%) had previously been treated with surgery, whereas for all other lesions (30 [94%]), CK SRS was used as their primary treatment modality. The median target volume was 1.5 cm3 (range 0.09-21.54 cm3). CK SRS was delivered by a median marginal dose of 23 Gy (range 15-30 Gy) and a median of 3 fractions (range 1-5 fractions) to a median isodose line of 77% (range 70%-88%). The median biologically effective dose was 48 Gy (range 21-99.9 Gy) and the median follow-up was 30 months (range 3-95 months). The LTC at 1-, 2-, and 3-year follow-up was 86%, 65%, and 50%, respectively. The median progression-free survival and overall survival were 29 months (range 11-79 months) and 51 months (range 15-79 months), respectively. None of the patients presented adverse radiation effects. CONCLUSIONS: In the authors' experience, SRS provided excellent LTC without any adverse radiation effects for BMs secondary to ENB.

Survival impact of postoperative radiotherapy in patients with olfactory neuroblastoma: 513 cases from the SEER database.

PUPOSE: To evaluate the impact of postoperative radiotherapy (PORT) on survival in olfactory neuroblastoma (ONB) patients with different tumor staging. MATERIAL AND METHODS: Patients with ONB were selected in the Surveillance, Epidemiology and End Results (SEER) database from 2004-2016. Survival analyses were performed using Kaplan-Meier (K-M) method, Cox regression analysis, and competing risk model. RESULTS: A total of 513 patients were included in the study. Univariate and multivariate analysis results demonstrated that PORT was not an independent prognostic factor for overall survival (OS) of modified Kadish stage A and B patients (P=0.699 and P=0.248, respectively). Kadish stage C and D patients who underwent PORT had significantly better OS than those who did not undergo PORT (P=0.03 and P<0.0001). K-M curves revealed that the 5- and 10-year OS rates of patients who underwent PORT vs. non-PORT were 85.3% vs. 70.4% and 68.2% vs. 56.8% in stage C patients, respectively. For stage D patients, the 5-year OS rates were 70.7% and 42.6%, and 10-year OS rates were 53.4% and 29.5% in the PORT and non-PORT groups, respectively. The competitive risk model revealed that the 5-year cancer-specific cumulative mortality incidence decreased by 26.6% while the 10-year mortality incidence decreased by 41.4% in Kadish stage C patients who were treated using PORT; meanwhile, for Kadish stage D patients who were treated with PORT, the 5- and 10-year mortality incidences were reduced by 35.3% and 42.6%, respectively. Furthermore, we found that chemotherapy was not related to the prognosis of ONB patients (all P>0.05). CONCLUSION: Our results indicate that PORT improved survival outcomes of modified Kadish stage C and D ONB patients. However, PORT may not affect survival for modified Kadish stage A and B individuals. Chemotherapy was not recommended for ONB; therefore, further studies are warranted to determine its therapeutic significance.

Psychophysical assessments of olfaction after endoscopic unilateral resection with post-operative radiotherapy in olfactory neuroblastomas.

Endoscopic resection with post-operative radiotherapy has been included in the standard therapeutic options for olfactory neuroblastomas (ONBs). Recent publications have indicated the feasibility of olfactory preservation after endoscopic unilateral resection of ONBs. This study validated residual olfaction using the psychophysical assessment, T & T olfactometer, in patients who underwent endoscopic unilateral resection with post-operative radiotherapy. A single-institutional retrospective review was performed to identify patients who underwent endoscopic unilateral resection of ONBs with olfaction monitoring using T & T olfactometer between 2009 and 2020. T & T olfactometry was performed before surgery, after surgery, before radiotherapy, and after completion of radiotherapy. Four patients (one female and three males) were identified. The mean observation period was 41.9 months, and all patients showed no evidence of disease. Three patients exhibited residual olfactory function with two patients having normal or pre-operative level olfaction, although T & T olfactometer results showed a temporary increase in recognition thresholds after surgery. As consequence, endoscopic unilateral resection can achieve satisfactory olfactory preservation in patients with early-stage ONBs.

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.

Radiotherapy of sinonasal cancers.

We present the update of the recommendations of the French society of radiotherapy and oncology on the indications and the technical methods of carrying out radiotherapy of sinonasal cancers. Sinonasal cancers (nasal fossae and sinus) account for 3 to 5% of all cancers of the head and neck. They include carcinomas, mucosal melanomas, sarcomas and lymphomas. The management of sinonasal cancers is multidisciplinary but less standardized than that of squamous cell carcinomas of the upper aerodigestive tract. As such, patients with sinonasal tumors can benefit from the expertise of the French expertise network for rare ENT cancers (Refcor). Knowledge of sinonasal tumour characteristics (histology, grade, risk of lymph node involvement, molecular characterization, type of surgery) is critical to the determination of target volumes. An update of multidisciplinary indications and recommendations for radiotherapy in terms of techniques, target volumes and radiotherapy fractionation of the French society of radiotherapy and oncology (SFRO) was reported in this manuscript.

Absence of Survival Improvement for Patients with Esthesioneuroblastoma Over the Past 2 Decades: A Population-Based Study.

OBJECTIVE: Esthesioneuroblastoma (ENB) is a rare malignancy of the sinonasal tract and its infrequency has confounded efforts at clearly describing the survival trends associated with this neoplasm over the years. In this study, we reviewed survival trends in ENB and investigated the impact of treatment extent and modality on patient outcomes. METHODS: We accessed the Surveillance, Epidemiology, and End Result (SEER) program to identify ENB cases from 1998 to 2016. A χ2 test was used to compare the categorical covariates and a t test or Mann-Whitney U test was utilized for continuous variables. The impact of prognostic factors on survival was computed using a Kaplan-Meier analysis and multivariate Cox proportional hazards model. We divided ENB patients into 4 periods including 1998-2002, 2003-2007, 2008-2012, and 2013-2016, and investigated survival trends using the Kaplan-Meier curve and log-rank test. RESULTS: ENB patients who underwent biopsy alone were associated with older age, larger tumor diameter, increased rates of tumor extension, nodal/distant metastases, and advanced stages as compared with patients undergoing tumor resection. Our results also demonstrated that surgical resection and adjuvant radiotherapy could confer survival advantages, whereas chemotherapy was associated with reduced survival in patients with ENB. Over the past 2 decades, surprisingly, there has been no change in survival rates for patient with ENB (P = 0.793). CONCLUSIONS: Despite advanced diagnostic studies and modernized treatment approaches, ENB survival has remained unchanged over the years, calling for improved efforts to develop appropriate individualized interventions for this rare tumor entity. Our results also confirmed that surgery and adjuvant radiotherapy is associated with improved patient survival whereas the use of chemotherapy should be considered carefully.

Excisional biopsy and radiotherapy for management of an olfactory neuroblastoma in an axolotl (Ambystoma mexicanum).

CASE DESCRIPTION: A 4-year-old sexually intact male leucistic axolotl (Ambystoma mexicanum) was presented with a 2-week history of dysrexia and difficulty swallowing. CLINICAL FINDINGS: Physical examination revealed a 1-cm-diameter intraoral mass on the rostral aspect of the palate and swelling of the left nasal fossa. Local invasion into the left nasal fossa was suspected during oral examination. The lesion was marginally excised, and an incompletely excised olfactory neuroblastoma was diagnosed histologically. Five weeks later, physical examination revealed persistent erythema, delayed healing of the rostral portion of the palate, and a mild facial deformity associated with a white mass in the nasal cavity. TREATMENT AND OUTCOME: 6 weeks after excision, adjuvant electron (6-MeV) beam radiotherapy was initiated for treatment of the incompletely excised olfactory neuroblastoma and likely presence of a recurrent mass. The protocol consisted of 4 weekly fractions of 8 Gy each (total, 32 Gy) with the axolotl under anesthesia. No acute adverse radiation effects were noted following radiotherapy. The oral erythema resolved after the third session. No recurrence was observed 2 months after treatment, and the owners reported no abnormal signs at home. The axolotl died 3.5 months after radiotherapy was completed (8 months after marginal excision of the tumor) secondary to an environmental management failure. Postmortem histologic evaluation showed no evidence of neoplasia. CLINICAL RELEVANCE: In axolotls, olfactory neuroblastoma should be considered in the differential diagnosis of intraoral palatal masses. This report describes the first application of radiotherapy for treatment of an olfactory neuroblastoma in an axolotl.

Elective neck irradiation in the management of esthesioneuroblastoma: a systematic review and meta-analysis.

BACKGROUND: There is no consensus about the optimal management of the neck in clinically node negative esthesioneuroblastoma (ENB). The aim of this study is to assess the impact of elective neck irradiation (ENI) in terms of regional disease control and survival. METHODS: The study was performed according to the PRISMA guidelines searching on Scopus, PubMed/MEDLINE, and Google Scholar databases. The primary outcome was the regional recurrence rate (RRR), that was reported as odds ratio (OR) and 95% confidence interval (CI). Secondary outcomes were the overall survival (OS), and the distant-metastases free survival (DMFS), that were reported as logarithm of the hazard ratios (logHRs) and 95% confidence intervals (CIs). RESULTS: A total of 489 clinically node negative patients were included from 9 retrospective studies. ENI significantly reduced the risk of regional recurrence compared to no treatment. No difference was measured between ENI and observation, according to both OS and DMFS. No stratified analysis could be performed based on Kadish stage and Hyams grade. CONCLUSIONS: ENI should be recommended to improve the regional disease control. No advantage was measured in terms of survival or distant metastases with a low quality of evidence. Further prospective studies should be designed to understand if ENI could be avoided in early stage and low-grade tumors.

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.

Radiation-induced intracranial osteosarcoma of the anterior skull base after treatment of esthesioneuroblastoma.

Esthesioneuroblastoma (ENB) is an uncommon sinonasal cancer of the olfactory neuroepithelium that is typically treated with surgical resection followed by radiation therapy. Radiation-induced intracranial osteosarcoma of the skull base is a rare but devastating long-term complication of radiation therapy in this region. Here, we present a case of an 82-year-old patient who developed radiation-induced osteosarcoma of the anterior skull base and paranasal sinuses 10 years after radiation therapy following resection of an ENB. Older patients may be at risk of developing this complication earlier and with a worse prognosis relative to younger patients. Treating physicians/surgeons should be aware of this devastating complication. Patients who are treated with high-dose radiation therapy in this region should be followed for many years.

[Analysis of the effect of endoscopic surgery combined with conventional surgery in Neuroblastoma].

Objective:The aim of this study is to evaluate the efficacy of endoscopic surgery and conventional surgery combined with radiotherapy in the treatment of Neuroblastoma. Method:Forty-three patients with olfactory neuroblastoma undergoing surgery combined with radiotherapy were retrospectively analyzed. The patients were divided into endoscopic surgery and conventional surgery. All patients received postoperative radiotherapy at a dose of 60-70 Gy, the 5-year survival rate and local recurrence time of the two groups were compared, and the therapeutic effects of endoscopic surgery and traditional surgery were compared. Result:Through survival analysis, the 5-year overall survival rates of the traditional surgery group and the endoscopic surgery group were 50% and 58% （P=0.560）, the local recurrence rates were 44% and 48% （P=0.288）, and the mean recurrence time was 5.6 months and 12.5 months （P=0.032）. Conclusion:There was no difference between endoscopic surgery and conventional surgery combined with radiotherapy in the treatment of Neuroblastoma, and the time of local recurrence was significantly prolonged. In early Neuroblastoma, endoscopic sinus surgery may be superior to open surgery in terms of efficacy and patient survival.

Efficacy of Peptide Receptor Radionuclide Therapy for Esthesioneuroblastoma.

Esthesioneuroblastoma is rare, with limited therapeutic options when unresectable or metastatic; however, expression of somatostatin receptors qualifies it for peptide receptor radionuclide therapy (PRRT). We report outcomes of PRRT in esthesioneuroblastoma from 2 referral centers. Methods: Using PRRT databases at 2 European Neuroendocrine Tumor Society Centers of Excellence, cases were sought between 2004 and 2018 of patients who had PRRT with recurrent or metastatic esthesioneuroblastoma deemed unsuitable for further conventional therapies. Evaluations of survival and of response using a composite reference standard were performed. Results: Of 7 patients, 4 had partial response, 2 had disease stabilization, and one had early progression. Possible side effects include worsening cerebrospinal fluid leaks. Median progression-free survival was 17 mo (range, 0-30 mo), and median overall survival was 32 mo (range, 4-53 mo). Conclusion: PRRT shows promising efficacy and moderate survival duration in unresectable locally advanced or metastatic esthesioneuroblastoma warranting larger cohort studies incorporating measures of quality of life.

Isolated primary maxillary sinus esthesioneuroblastoma presenting as idiopathic syndrome of inappropriate antidiuretic hormone.

Esthesioneuroblastoma is an uncommon tumour, and isolated primary involvement of the maxillary sinus is exceedingly rare. Esthesioneuroblastoma has infrequently been reported as a source of paraneoplastic ectopic hormone production. We report a case of isolated primary maxillary esthesioneuroblastoma, presenting as idiopathic syndrome of inappropriate antidiuretic hormone (SIADH). A 17-year-old girl presented with symptoms consistent with SIADH and no sino-nasal symptoms. MRI to exclude pituitary tumour revealed an isolated lesion of the right maxillary sinus. Biopsy demonstrated esthesioneuroblastoma. The lesion was removed endoscopically as a single en bloc specimen. Following resection, the sodium level returned to normal. This is only the third report in the literature of a primary maxillary esthesioneuroblastoma presenting as SIADH.

Definitive Carbon-Ion Radiation Therapy for Locally Advanced Sinonasal Malignant Tumors: Subgroup Analysis of a Multicenter Study by the Japan Carbon-Ion Radiation Oncology Study Group (J-CROS).

PURPOSE: To evaluate the safety and efficacy of carbon-ion radiation therapy (C-ion RT) for locally advanced sinonasal malignant tumors in a multicenter retrospective study (J-CROS 1402 HN). METHODS AND MATERIALS: Clinical data were collected for patients who had sinonasal malignant tumors of stage N0-1M0 and received C-ion RT at 4 institutions in Japan between November 2003 and December 2014. Of the 458 patients, 393 had naïve tumors and 65 had recurrent tumors. The tumors were located in the nasal cavity (n = 263), maxillary sinus (n = 109), ethmoid sinus (n = 71), and other locations (n = 15). The histologic types were mucosal melanoma (n = 221, 48%), adenoid cystic carcinoma (n = 122, 27%), squamous cell carcinoma (n = 31, 7%), olfactory neuroblastoma (n = 30, 7%), adenocarcinoma (n = 21, 5%), and other types (n = 33, 7%). Of the 458 patients, 300 (66%) had T4 tumors. All patients received definitive C-ion RT. RESULTS: The median follow-up period was 25.2 months for all patients (range, 1.4-132.3 months). The 2-year overall survival and local control rates were 79.6% and 84.1%, respectively. As analyzed according to histology, the 2-year overall survival rate was 68.0% for mucosal melanoma, 96.8% for adenoid cystic carcinoma, 70.0% for squamous cell carcinoma, 96.7% for olfactory neuroblastoma, and 89.7% for adenocarcinoma. Regarding late toxicities, 17% of patients developed grade 3 and 4 toxicities, of which visual impairment was the most common. CONCLUSION: The results of our multicenter study have demonstrated that C-ion RT can provide excellent clinical outcomes with acceptable late toxicities in patients who have locally advanced sinonasal malignant tumors.

Neuroradiological and Neuropathological Changes After 177Lu-Octreotate Peptide Receptor Radionuclide Therapy of Refractory Esthesioneuroblastoma.

BACKGROUND AND IMPORTANCE: Olfactory neuroblastoma, also known as esthesioneuroblastoma (ENB), is a malignant neoplasm with an unpredictable behavior. Currently, the widely accepted treatment is inductive chemotherapy, with or without surgery, followed by radiotherapy. Since data on genetics and molecular alterations of ENB are lacking, there is no standard molecularly targeted therapy. However, ENB commonly expresses the somatostatin receptor (SSTR) that is also expressed by neuroendocrine tumors. Peptide receptor radionuclide therapy (PRRT) using radiolabeled somatostatin analogues, such as 177Lu-octreotate, is an effective treatment for the latter. We present the complex neuroradiological and neuropathological changes associated with 177Lu-octreotate treatment of a patient with a highly treatment-resistant ENB. CLINICAL PRESENTATION: A 60-yr-old male presented with an ENB that recurred after chemotherapy, surgery, stereotactic radiosurgery, and immunotherapy. Pathology revealed a Hyams grade 3 ENB and the tumor had metastasized to lymph nodes. Tumor SSTR expression was seen on 68Ga-octreotate positron emission tomography (PET)/computed tomography (CT), suggesting that PRRT may be an option. He received 4 cycles of 177Lu-octreotate over 6 mo, with a partial response of all lesions and symptomatic improvement. Four months after the last PRRT cycle, 2 of the lesions rapidly relapsed and were successfully resected. Three months later, 68Ga-octreotate PET/CT and magnetic resonance imaging indicate no progression of the disease. CONCLUSION: We describe imaging changes associated with 177Lu-octreotate PRRT of relapsing ENB. To our knowledge, this is the first report describing neuropathological changes associated with this treatment. PRRT is a promising therapeutic option to improve the disease control, and potentially, the survival of patients with refractory ENB.

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.

Definitive re-irradiation using intensity-modulated radiation therapy in cancers of the head and neck, focusing on rare tumors.

PURPOSE: To analyze the outcomes following re-irradiation for local recurrence of rare head and neck tumors. MATERIAL AND METHODS: We retrospectively analyzed 11 patients who had received intensity-modulated radiation therapy (IMRT) for recurrent tumors in the head and neck except for laryngopharynx. RESULTS: Primary tumor sites included the maxillary sinus, nasal cavity, and external ear canal in six, three, and two patients, respectively. The median follow-up times were 13 (range, 3-54) months. The median survival time was 17 months with 1- and 2-year survival rates of 63.64 and 39.77%, respectively. Among 11 patients, five experienced local failure in the follow-up period. The 1- and 2-year local control rates were 58 and 47%, respectively. Patients who had received a radiation dose of ≥3 Gy per fraction showed significantly better local control than those receiving less (p = .0419). One patient experienced Grade 3 facial pain as acute toxicity. Late toxicities included radiographic findings of partial central nervous system necrosis in three patients and Grade 3 osteonecrosis and Grade 3 facial nerve disorder in one patient. CONCLUSIONS: Re-irradiation of rare head and neck tumors using IMRT for loco-regional recurrence may be an acceptable treatment option.