Single-energy metal artefact reduction with CT for carbon-ion radiation therapy treatment planning.

One approach to improving image quality of CT is to use metal artefact reduction image processing, such as single-energy metal artefact reduction (SEMAR). To quantify the impact of image correction on the quality of carbon-ion dose distribution, treatment planning using SEMAR was evaluated

Long-term outcomes after carbon-ion radiotherapy for oral mucosal malignant melanoma.

Oral mucosal malignant melanoma (OMM) is extremely rare and has a poor prognosis. Owing to its rarity, it has not yet been possible to establish an optimal treatment modality. The objective of this study was to evaluate the long-term efficacy of carbon-ion radiotherapy (C-ion RT) for OMM. Between 1997 and 2013, 19 patients with OMM were treated with C-ion RT alone. Patient ages ranged from 44 to 84 years (median, 69 years). Nine men and 10 women were included. OMMs were restaged in accordance with the seventh edition of the tumour/node/metastasis (TNM) Staging System of the International Union Against Cancer. Before treatment, 14 patients had T3 disease and 5 had T4a disease. Three patients were classified as having N1 disease. All patients were classified as having M0. The hard palate was the most frequently involved oral subsite. All patients were treated with 57.6 Gy (relative biological effectiveness) in 16 fractions. The median follow-up period was 61 months (range, 8-190 months). The 5-year local control, overall survival and progression-free survival rates were 89.5%, 57.4% and 51.6%, respectively. For local control and overall survival, T classification was found to be a significant prognostic factor. Grade 2 and 3 osteoradionecrosis was observed in three and four patients, respectively. The presence of teeth within the planning target volume was a significant risk factor for developing osteoradionecrosis. C-ion RT was an effective treatment option with acceptable toxicity for OMM

Estimation of normal tissue complication probability parameters for temporal lobes in carbon ion therapy for skull base tumors

Purpose: The aim of this study was to estimate normal tissue complication probability (NTCP) parameters after carbon ion radiation therapy (C-ion RT) for skull base tumor on late temporal lobes complications.Methods: A total of 39 patients were used to derive NTCP parameters. These patients included were treated with dose ranging from 48 Gy (RBE) up to 60.8 Gy (RBE) including dose escalation trial at the National Institute of Radiological Sciences (NIRS). The Lyman-Kutcher-Burman (LKB) model with DVH as a function of equivalent uniform dose (EUD) was used as a NTCP model. The end points for the analysis were Grade ≥1 and Grade ≥2 toxicity for the temporal lobes.Results: The resulting NTCP parameters were the volume effect parameter; n = 0.15 (95% CI: 0.13-0.17), the steepness of NTCP curve; m = 0.13 (0.081-0.22), the tolerance dose associated with 50% probability of complication; TD50 = 34.8 Gy (RBE) (32.9-36.8 Gy (RBE)) for Grade ≥1, n = 0.22 (0.19-0.26), m = 0.21 (0.13-0.34), TD50 = 33.2 Gy (RBE) (30.6-36.3 Gy (RBE)) for Grade ≥2.Conclusion: A new set of NTCP parameters for temporal lobes in C-ion RT was determined. The n and m values of C-ion RT are almost the same as that of photon therapy. TD50 parameters were almost unchanged with respect to each end point considered, the grade of late temporal lobes complication is not strongly dependent on dose. The new derived parameter values facilitate estimation of NTCP for temporal lobes in C-ion RT.55th Particle Therapy Co-Operative Grou

Definitive carbon-ion radiotherapy for locally advanced parotid gland carcinomas.

BackgroundThe purpose of this study was to present our evaluation of the safety and efficacy of carbon-ion radiotherapy (C-ion RT) for locally advanced parotid gland carcinomas.MethodsClinicopathological features and outcomes were evaluated in 46 patients receiving C-ion RT for parotid gland carcinomas.ResultsSixteen patients had adenoid cystic carcinoma; 8 had adenocarcinoma, 8 had mucoepidermoid carcinoma, and 14 had other carcinomas. T2, T3, T4a, and T4b diseases were diagnosed in 3, 18, 8, and 17 patients, respectively. C-ion RT was provided to 25 patients as the primary treatment, to 20 patients for local recurrences after surgery, and to 1 patient for residual tumor after surgery. During follow-up (median duration, 62 months), 5-year local control and overall survival (OS) rates were 74.5% and 70.1%, respectively. Of the 30 patients without facial nerve palsy before C-ion RT, 25 showed no radiation-induced facial nerve palsy

Evaluation of the safety and efficacy of carbon ion radiotherapy for locally advanced adenoid cystic carcinoma of the tongue base.

Most cases of adenoid cystic carcinoma (ACC) of the tongue base are radioresistant, and are diagnosed in the advanced stage. Therefore, we evaluated the safety and efficacy of carbon ion radiotherapy (C-ion RT) for locally advanced ACC of the tongue base