The Efficacy of a Custom-Made Mouthpiece With Spacer to Reduce Osteoradionecrosis in Carbon-Ion Radiation Therapy for Tongue-Base Tumor

Ikawa, Hiroaki; Koto, Masashi; Ebner, Daniel K.; Hayashi, Kazuhiko; Takagi, Ryo; Tonogi, Morio; Nomura, Takeshi; Tsuji, Hiroshi; Kamada, Tadashi

doi:10.1016/j.adro.2018.08.016

Cited by 13 publications

(23 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…30 Moreover, a custommade mouthpiece and spacer might reduce the volume of the jawbone that would be exposed to high-dose irradiation. 31 In this study, T4 classification was found to be the significant risk factor for local control in multivariate analysis. Although the prescribed dose was not a significant risk factor of local control, a dose less than 64 Gy in 16 fractions (EQD2 α/β 10 = 74.7 Gy [RBE]) was used in 4 cases of 7 cases who developed local recurrence.…”

Section: Factorsmentioning

confidence: 59%

See 1 more Smart Citation

Multicenter study of carbon‐ion radiation therapy for nonsquamous cell carcinomas of the oral cavity

et al. 2019

Self Cite

View full text Add to dashboard Cite

Background The aim of this study was to evaluate the efficacy and safety of carbon‐ion radiation therapy for nonsquamous cell carcinomas of the oral cavity in a multicenter study. Methods Retrospective analysis of the clinicopathological features and outcomes of 76 patients with oral nonsquamous cell carcinomas with N0‐1 M0 status and were treated with carbon‐ion radiation therapy at four institutions in Japan between November 2003 and December 2014 was performed. Results Salivary gland carcinoma, mucosal melanoma, and three other carcinomas were found in 46, 27, and 3 patients, respectively. T1‐3, T4a, and T4b disease was diagnosed in 27, 18, and 31 patients, respectively. Median follow‐up period was 31.1 months (range, 3‐118 months). Three‐year local control, progression‐free survival, and overall survival of all patients were 86.8%, 63.1%, and 78.4%, respectively. Multivariate analysis showed T classification (T4) to be a significant independent poor prognostic factor for local control. Acute grade 3 mucositis was observed in 38 patients. Grades 3 and 4 late morbidities were observed in 9 and 4 patients, respectively. No grade 5 late toxicity was observed. Conclusions Oral nonsquamous cell carcinomas could be treated effectively, with acceptable toxicity, by carbon‐ion radiation therapy.

show abstract

Section: Factorsmentioning

confidence: 59%

“…To reduce the risk of ORN, in case of a questionable prognosis within the PTV, total tooth extraction before starting RT was recommended . Moreover, a custom‐made mouthpiece and spacer might reduce the volume of the jawbone that would be exposed to high‐dose irradiation …”

Section: Discussionmentioning

confidence: 99%

Multicenter study of carbon‐ion radiation therapy for nonsquamous cell carcinomas of the oral cavity

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the photon and charged-particle therapy for head and neck cancer, the effectiveness of the mouthpiece as a spacer to reduce the dose to normal tissues has been reported [3][4][5][6][7][8][9][10]12]. In charged-particle therapy, the beam may unavoidably pass through the mouthpiece or be stopped on the mouthpiece to spare surround normal tissue.…”

Section: Discussionmentioning

confidence: 99%

Stopping-power ratio of mouthpiece materials for charged-particle therapy in head and neck cancer

Ikawa¹,

Inaniwa²,

Koto³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Background: In charged-particle therapy treatment planning, CT numbers of a patient’s body are converted into stopping power ratios (SPRs) using a CT-number-to-SPR conversion table constructed for standard human tissues. Since artificial devices used in treatments of head and neck cancer, such as mouthpieces, do not fit into the CT-number-to-SPR conversion table, they may deteriorate treatment accuracy. In this study, the SPRs of five mouthpiece materials were measured, and the error in predicted SPRs based on the conversion table was investigated.Methods: SPRs of five mouthpiece materials were predicted from their CT numbers using a calibrated conversion table. Independently, the SPRs of the materials were measured by the Bragg-peak shift of a carbon-ion beam passing through the materials. The errors in SPR of the materials were determined as the difference between the predicted and measured SPRs.Results: The SPRs (error) of the ethylene-vinyl acetate copolymers (EVAs), Nipoflex 710TM and BioplastTM, were 0.997 (0.023) and 0.982 (0.007), respectively. The SPRs (error) of the vinyl silicon impression material (Exafine putty typeTM), the light curable resin (Clear Photoreactive Resin for Formlabs 3D printersTM), and the bis-acrylic resin (TempsmartTM) were 1.517 (0.134), 1.161 (0.068), and 1.26 (0.101), respectively. Conclusions: The EVA BioplastTM had the minimum SPR error among the five tested materials, indicating the highest human-tissue equivalency. If other artificial materials such as Exafine putty typeTM are used as mouthpieces, it is recommended that their SPRs be overwritten by the correct values in treatment planning processes.

show abstract

“…Therefore, to reduce the risk of ORN, we routinely perform preemptive extraction of teeth with poor prognoses that are near the irradiation field. Moreover, we use a custom‐made mouthpiece with a spacer to reduce the area of the jawbone that is exposed to high‐dose irradiation …”

Section: Discussionmentioning

confidence: 99%

“…Moreover, we use a custom-made mouthpiece with a spacer to reduce the area of the jawbone that is exposed to high-dose irradiation. 25 The standard treatment for intraoral minor SGC is surgery, which provides 5-year rates of 73.8%-83.1% for local control and 71.8%-73% for survival. [26][27][28] However, in locally advanced cases, surgical resection may be limited by 4 In the present study, the 5-year rates of local control and OS were 75.2% and 65.7%, respectively, among 43 patients with gross tumors, which indicates that C-ion RT is a potentially definitive treatment for locally advanced intraoral SGC.…”

Section: Discussionmentioning

confidence: 99%

Feasibility of carbon‐ion radiotherapy for oral non‐squamous cell carcinomas

et al. 2019

Self Cite

View full text Add to dashboard Cite

Background This study evaluated carbon‐ion radiotherapy (C‐ion RT) for oral non‐squamous cell carcinomas (non‐SCC). Methods We retrospectively obtained data from 74 patients who underwent C‐ion RT for oral malignancies between April 1997 and March 2016. The C‐ion RT was administered in 16 fractions at a total dose of 57.6 or 64.0 Gy (relative biological effectiveness). Results Forty‐three patients had salivary gland carcinomas, 29 patients had mucosal melanoma, and 2 patients had other types of pathologies. The tumors were classified as T1‐T3 (24 cases), T4a (21 cases), or T4b (29 cases). The median follow‐up was 49 months. The 5‐year rates were 78.8% for local control, 36.2% for progression‐free survival, and 58.3% for overall survival. Although 10 patients developed grade 3 osteoradionecrosis after C‐ion RT, all patients maintained their mastication and deglutition functions after sequestrectomy and prosthesis placement. Conclusion C‐ion RT was effective for oral non‐SCC and had acceptable toxicities.

show abstract

The Efficacy of a Custom-Made Mouthpiece With Spacer to Reduce Osteoradionecrosis in Carbon-Ion Radiation Therapy for Tongue-Base Tumor

Cited by 13 publications

References 14 publications

Multicenter study of carbon‐ion radiation therapy for nonsquamous cell carcinomas of the oral cavity

Multicenter study of carbon‐ion radiation therapy for nonsquamous cell carcinomas of the oral cavity

Stopping-power ratio of mouthpiece materials for charged-particle therapy in head and neck cancer

Feasibility of carbon‐ion radiotherapy for oral non‐squamous cell carcinomas

Contact Info

Product

Resources

About