ASTRO Poster Library

Forecast Accuracy of Mucositis Using an Oral Mucosal Dose Model in Intensity Modulated Radiation Therapy for Head and Neck
ASTRO Poster Library. Musha A. 09/24/17; 191948; 2855 Topic: Head and Neck Cancer
Atsushi Musha
Atsushi Musha
All contributions
Login now to access Regular content available to all registered users.
Abstract
Rate & Comment (0)
A. Musha1, K. Shirai2, J. I. Saitoh3, T. Abe4, S. Yokoo5, K. Chikamatsu5, T. Ohno2, and T. Nakano2; 1Gunma University Heavy Ion Medical Center, Gunma, Japan, 2Gunma University Heavy Ion Medical Center, Maebashi, Japan, 3Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Japan, 4Department of Radiation Oncology, Gunma University Graduate School of Medicine., Maebashi, Japan, 5Gunma University Graduate School of Medicine, Maebashi, Japan

Purpose/Objective(s): Acute radiation mucositis (ARM) is the most common acute adverse effect of radiotherapy for the head and neck tumors. It degrades quality of life and disease-fighting ability. Incidence of ARM among radiotherapy for head and neck tumor is 85-100 %. Intensity modulated radiation therapy (IMRT) provides highly conformal target dose while sparing the Organs at risk (OAR). Since IMRT results in a steep dose gradient around the target, it potentially minimizes high dose volumes to the mucosa that may cause high-grade ARM. However, the relationship between radiation dose and detailed severity of ARM in IMRT is unclear. The Oral mucosal dose model (OMDM) was useful for predicting the location and severity of ARM in Carbon-ion radiotherapy (C-ion RT). The maximum point dose in this model correlated well with grade 2–3 ARM. However, applicability of the OMDM to IMRT is unclear. Hence, we applied an OMDM using three-dimensional (3D) treatment planning data for IMRT in the same way as in C-ion RT. The purpose of the present study was to determine whether the maximum and mean dose, dose-volume histogram (DVH) parameters obtained in the OMDM correlate with the severity of ARM, and whether the model is a useful tool for predicting ARM in patients with head and neck tumors treated with IMRT.

Materials/Methods: Between 2015 and 2016, thirty-six patients receiving IMRT for head and neck tumor were evaluated for ARM (once per week for 6 weeks) according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0, and the Radiation Therapy Oncology Group (RTOG) scoring system. 31 patients received 66.0 Gy in 33 fractions, five patients received 70.0 Gy in 35 fractions. A maximum point dose of tongue was evaluated in each patient by using OMDM based on the MIM software. We assessed a time change of the ARM and made the temporal pattern of ARM. In addition, location of the high dose area was compared to pictures of ARM taken weekly during and after IMRT.

Results: The location of the ARM coincided with the high-dose area in the OMDM. There was a clear dose-response relationship between maximum point dose and ARM grade assessed using the RTOG criteria and the CTCAE. The threshold maximum point doses for grade 2–3 ARM in the RTOG and CTCAE were 70.3 Gy and 71.4 Gy, respectively. The threshold mean doses for grade 2–3 ARM in the RTOG and CTCAE were 37.7 Gy and 47.9 Gy, respectively. The ARM recovery period did not differ significantly based on IMRT dose. When the ARM healed, dietary intake was restored.

Conclusion: The OMDM was useful for predicting the location and severity of ARM. Maximum point doses in the model correlated well with grade 2–3 ARM. We recommend that patients and a medical team share information about the onset area and severity of ARM using the OMDM to facilitate early intervention for oral care. There is the case that tongue is included in the irradiation fields. However, we should optimize the radiation treatment plan based on this model.



AuthorDisclosure: A. Musha: None. K. Shirai: None. J. Saitoh: None. T. Abe: None. S. Yokoo: None. K. Chikamatsu: None. T. Ohno: None. T. Nakano: None.
A. Musha1, K. Shirai2, J. I. Saitoh3, T. Abe4, S. Yokoo5, K. Chikamatsu5, T. Ohno2, and T. Nakano2; 1Gunma University Heavy Ion Medical Center, Gunma, Japan, 2Gunma University Heavy Ion Medical Center, Maebashi, Japan, 3Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, Japan, 4Department of Radiation Oncology, Gunma University Graduate School of Medicine., Maebashi, Japan, 5Gunma University Graduate School of Medicine, Maebashi, Japan

Purpose/Objective(s): Acute radiation mucositis (ARM) is the most common acute adverse effect of radiotherapy for the head and neck tumors. It degrades quality of life and disease-fighting ability. Incidence of ARM among radiotherapy for head and neck tumor is 85-100 %. Intensity modulated radiation therapy (IMRT) provides highly conformal target dose while sparing the Organs at risk (OAR). Since IMRT results in a steep dose gradient around the target, it potentially minimizes high dose volumes to the mucosa that may cause high-grade ARM. However, the relationship between radiation dose and detailed severity of ARM in IMRT is unclear. The Oral mucosal dose model (OMDM) was useful for predicting the location and severity of ARM in Carbon-ion radiotherapy (C-ion RT). The maximum point dose in this model correlated well with grade 2–3 ARM. However, applicability of the OMDM to IMRT is unclear. Hence, we applied an OMDM using three-dimensional (3D) treatment planning data for IMRT in the same way as in C-ion RT. The purpose of the present study was to determine whether the maximum and mean dose, dose-volume histogram (DVH) parameters obtained in the OMDM correlate with the severity of ARM, and whether the model is a useful tool for predicting ARM in patients with head and neck tumors treated with IMRT.

Materials/Methods: Between 2015 and 2016, thirty-six patients receiving IMRT for head and neck tumor were evaluated for ARM (once per week for 6 weeks) according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0, and the Radiation Therapy Oncology Group (RTOG) scoring system. 31 patients received 66.0 Gy in 33 fractions, five patients received 70.0 Gy in 35 fractions. A maximum point dose of tongue was evaluated in each patient by using OMDM based on the MIM software. We assessed a time change of the ARM and made the temporal pattern of ARM. In addition, location of the high dose area was compared to pictures of ARM taken weekly during and after IMRT.

Results: The location of the ARM coincided with the high-dose area in the OMDM. There was a clear dose-response relationship between maximum point dose and ARM grade assessed using the RTOG criteria and the CTCAE. The threshold maximum point doses for grade 2–3 ARM in the RTOG and CTCAE were 70.3 Gy and 71.4 Gy, respectively. The threshold mean doses for grade 2–3 ARM in the RTOG and CTCAE were 37.7 Gy and 47.9 Gy, respectively. The ARM recovery period did not differ significantly based on IMRT dose. When the ARM healed, dietary intake was restored.

Conclusion: The OMDM was useful for predicting the location and severity of ARM. Maximum point doses in the model correlated well with grade 2–3 ARM. We recommend that patients and a medical team share information about the onset area and severity of ARM using the OMDM to facilitate early intervention for oral care. There is the case that tongue is included in the irradiation fields. However, we should optimize the radiation treatment plan based on this model.



AuthorDisclosure: A. Musha: None. K. Shirai: None. J. Saitoh: None. T. Abe: None. S. Yokoo: None. K. Chikamatsu: None. T. Ohno: None. T. Nakano: None.
Code of conduct/disclaimer available in General Terms & Conditions
2025 ©
American Society for Radiation Oncology
USER TERMS AND CONDITIONS / PRIVACY POLICY
(Amended according to GDPR)

By clicking “Accept Terms & all Cookies” or by continuing to browse, you agree to the storing of third-party cookies on your device to enhance your user experience and agree to the user terms and conditions of this learning management system (LMS).

Cookie Settings
Accept Terms & all Cookies