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Radiation Oncology Journal > Volume 42(1); 2024 > Article
Lee, Oh, Ahn, Pyo, Yang, and Noh: Comparison of radiotherapy techniques in patients with thymic epithelial tumor who underwent postoperative radiotherapy



This retrospective study aimed to compare clinical outcomes and dosimetric parameters between radiation therapy (RT) techniques in patients with thymic epithelial tumor (TET).

Materials and Methods

From January 2016 to December 2020, 101 patients with TET received adjuvant RT (median, 52.8 Gy; range, 48.4 to 66.0). Three different RT techniques were compared: three-dimensional conformal RT (3D-CRT; n = 59, 58.4%), intensity-modulated RT (IMRT; n = 23, 22.8%), and proton beam therapy (PBT; n = 19, 18.8%).


The median age of the patients and the follow-up period were 55 years (range, 28 to 79) and 43.4 months (range, 7.7 to 77.2). Patients in the PBT group were of the youngest age (mean age, 45.4 years), while those in IMRT group had the largest clinical target volume (mean volume, 149.6 mL). Patients in the PBT group had a lower mean lung dose (4.4 Gy vs. 7.6 Gy vs. 10.9 Gy, respectively; p < 0.001), lower mean heart dose (5.4 Gy vs. 10.0 Gy vs. 13.1 Gy, respectively; p = 0.003), and lower mean esophageal dose than patients in the 3D-CRT and IMRT groups (6.3 Gy vs. 9.8 Gy vs. 13.5 Gy, respectively; p = 0.011). Twenty patients (19.8%) showed disease recurrence, and seven patients (6.9%) died. The differences in the survival rates between RT groups were not statistically significant.


In patients with TET who underwent adjuvant RT, PBT resulted in a lower dose of exposure to adjacent organs at risk. Survival outcomes for patients in PBT group were not significantly different from those in other groups.


Thymic epithelial tumor (TET), which originates from the anterior mediastinum, includes thymoma, thymic carcinoma, and thymic neuroendocrine tumors [1,2]. Although TET is the most common tumor of the anterior mediastinum, it is a rare disease with an age-standardized incidence rate of 0.50 per 100,000 individuals in the Republic of Korea [1-3]. However, the incidence of TET shows increasing trends in Korea [1]. According to the National Comprehensive Cancer Network guidelines [4], the standard treatment for resectable TET is upfront surgery. Patients with TET who have close surgical margins or those at an advanced stage are treated with postoperative radiotherapy (PORT) to eradicate microscopic cancer cells [5-12].
While PORT reduces locoregional recurrence and increases overall survival (OS) in patients with TET [5-12], mediastinal irradiation can cause several acute and late complications in adjacent normal organs, such as the lungs, esophagus, and heart [13-17]. Various complications including radiation pneumonitis, esophagitis, pericarditis, myocardial infarction, and congestive heart failure have been reported in patients with different malignancies who received chest radiation therapy (RT) [13-17]. In addition, considering the relatively younger age of onset of TET compared to that of other cancers [3], radiation-related secondary malignancies should be considered for long-term observation.
Proton beam therapy (PBT), due to its characteristic “Bragg peak” phenomenon, is expected to show decreased radiation exposure to nearby normal tissues [18]. Some studies have already analyzed dosimetric parameters and clinical outcomes of PBT in patients with TET [19-23]. However, only a few studies have compared PBT against other RT techniques, such as three-dimensional conformal RT (3D-CRT) and intensity-modulated RT (IMRT) [23]. Therefore, the purpose of the present study was to compare dose profiles and clinical outcomes between RT techniques in patients with TET.

Materials and Methods

1. Patients

We retrospectively reviewed the medical records of 101 patients with TET who underwent PORT from January 2016 to December 2020 at our institution. This study was approved by the Institutional Review Board of Samsung Medical Center (No. 2022-11-020), and the requirement for informed consent was waived due to the retrospective nature of the study. Three different RT techniques were compared: 3D-CRT, IMRT, and PBT. All patients with TET were classified according to the World Health Organization (WHO) classification [24], Masaoka-Koga staging classification [25,26], and the 8th edition of the TNM staging system, based on their histopathological reports. PORT was delivered 4–6 weeks after surgery, and the target volume included the tumor bed and involved area, according to our institution’s policy [27].

2. Endpoints

The endpoint of this study was to compare OS, disease-free survival (DFS) rates and dosimetric parameters between RT techniques. Dosimetric parameters were analyzed with dose-volume histograms. The duration of OS was calculated from the date of surgery until the date of the last follow-up or death, and the duration of DFS was calculated from the date of surgery until the date of the last follow-up, death, or recurrence. Toxicities and patterns of failure were also analyzed. Treatment complications were graded according to Common Terminology Criteria for Adverse Events version 5.0, and failure patterns were categorized according to International Thymic Malignancy Interest Group (ITMIG) guidelines [28,29].

3. Statistical analysis

For comparison between three RT groups, one-way analysis of variance or the Kruskal–Wallis test was used for assessing continuous variables, while the chi-squared test or Fisher exact test was performed for categorical variables. Survival rates were calculated and compared using the Kaplan–Meier method and the log-rank test. All data were considered as statistically significant when p < 0.05. Statistical analysis was conducted with the IBM SPSS Statistical Software version 27.0 (IBM Inc., Armonk, NY, USA).


1. Patients' characteristics

The median age of all patients was 55 years (range, 28 to 79 years), and 57 patients (56.4%) were men. The baseline characteristics of the 101 patients are shown in Table 1. The majority of patients were Masaoka-Koga stage II (n = 54, 53.5%) or III (n = 34, 33.7%). In terms of WHO classification, WHO B type (n = 45, 44.5%) was the most common histological finding, followed by WHO C type (n = 37, 36.6%).
Of the total number of patients, the 3D-CRT, IMRT, and PBT groups included 59 patients (58.4%), 23 (22.8%), and 19 (18.8%), respectively. The patients' characteristics according to RT technique are summarized in Table 2. The PBT group included patients of the youngest age (mean age, 45.4 ± 11.8 years) compared to those in the 3D-CRT (56.0 ± 10.9 years) and IMRT groups (58.4 ± 10.7 years; p < 0.001). In the 3D-CRT and PBT group, the most common histological types were Masaoka-Koga stage II and WHO B type, while in IMRT group, Masaoka-Koga stage III and WHO C type were the most frequent histological types.

2. Dosimetric parameters

The median radiation dose was 52.8 Gy (range, 48.4 to 66.0 Gy), and the median fraction dose was 2.2 Gy (range, 2.0 to 3.0 Gy). The median clinical target volume (CTV) was 60.3 mL (range, 6.9 to 439.3 mL). The median mean lung dose, mean heart dose, and mean esophageal dose were 7.6 Gy, 8.1 Gy, and 8.3 Gy, respectively. The dosimetric parameters of patients according to RT technique are shown in Table 3. The IMRT group had the largest CTV (mean, 149.6 ± 95.6 mL) compared to the PBT (90.1 ± 105.7 mL) and 3D-CRT groups (56.5 ± 42.6 mL; p < 0.001). The PBT group had a lower mean lung dose (4.4 Gy vs. 7.6 Gy vs. 10.9 Gy, respectively; p < 0.001), lower mean heart dose (5.4 Gy vs. 10.0 Gy vs. 13.1 Gy, respectively; p = 0.003), and lower mean esophageal dose than the 3D-CRT and IMRT groups (6.3 Gy vs. 9.8 Gy vs. 13.5 Gy, respectively; p = 0.011). In addition, there was positive correlation between CTV and dosimetric parameters. The coefficients of correlation with CTV were 0.396 for mean lung dose (p < 0.001), 0.367 for mean heart dose (p < 0.001), and 0.625 for mean esophageal dose (p < 0.001).

3. Clinical outcome

The median follow-up duration was 43.4 months (range, 7.7 to 77.2 months). During that period, 20 patients (19.8%) showed recurrence, and seven patients (6.9%) died. Among the patients with recurrence, local, regional, and distant recurrence were detected in 2 patients (2.0%), 13 (12.9%), and 10 (9.9%), respectively. The most common regional and distant recurrence site was the pleura (n = 12), followed by the lungs (n = 4), and the supraclavicular lymph nodes (n = 3). In terms of PORT target volume, all recurrences (n = 20) included out-field failure. Sixteen patients experienced only out-field failure. In-field and marginal recurrences occurred in two patients each, which were accompanied with out-field failure. The failure patterns according to ITMIG guidelines are summarized in Table 4.
The 3-year OS and 3-year DFS rates for all patients were 95.7% and 80.9%, respectively (Fig. 1). When comparing survival outcomes, there was no statistically significant difference between RT techniques. The 3-year OS rates for the 3D-CRT, IMRT, and PBT groups were 98.1%, 90.6%, and 94.4%, respectively (p = 0.255). The 3-year DFS rates for the 3D-CRT, IMRT, and PBT groups were 85.9%, 67.0%, and 82.5%, respectively (p = 0.147) (Fig. 2).

4. Toxicity

Toxic events were developed in 78 patients (77.2%). Radiation-related complications for all patients and subgroups are summarized in Table 5. Most toxicities were grade 1 or 2, except for one patient who received PBT and experienced grade 3 dermatitis. More than half of the patients (n = 59, 58.4%) showed radiation dermatitis, which was mostly a grade 1 (n = 54, 53.5%) toxicity. Radiation pneumonitis and radiation esophagitis were observed in 18 patients (17.8%) and 35 (34.7%), respectively. The IMRT group showed a higher incidence rate for grade ≥2 pneumonitis (13.0%) and grade ≥2 esophagitis (34.8%) in comparison to the rates shown by the 3D-CRT (5.1% and 18.6%, respectively) and PBT groups (5.3% and 10.5%, respectively).

Discussion and Conclusion

The current study analyzed dose profiles and clinical outcomes of three different RT techniques in patients with TET from a single tertiary institution. As reported in earlier studies [19-23], nearby organs were exposed to lower radiation dose during PBT than during other RT techniques. However, the survival outcome was not statistically different between the three groups.
Based on the number of patients who underwent each RT technique, 3D-CRT may be primarily considered in treatment planning for patients with TET. As patients in the PBT group were younger than those in other groups, PBT may be chosen for young patients, because of the lower possibility to develop short- and long-term toxicities due to excellent dose distribution. PBT provided a significantly lower mean lung dose, lung V20 (the percentage of normal lung receiving at least 20 Gy), mean heart dose, mean/maximum esophagus dose, and maximum spinal cord dose than other RT techniques in the current study.
Compared to other groups, the IMRT group showed the largest CTV and the highest dose exposure to organs at risk. Patients in the IMRT group also showed lower survival rates (although not statistically significant) and tended to experience more radiation-related toxicities than patients in other groups. Masaoka-Koga stage III and WHO type C were the most common histological types in patients in the IMRT group. On the other hand, Masaoka-Koga stage II and WHO type B were the most frequent histological types in patients in the 3D-CRT and PBT groups. According to Masaoka-Koga staging system, stage III suggests macroscopic invasion into adjacent organs, compared to a mere microscopic invasion in stage II. WHO classification C type, also known as thymic carcinoma, has more aggressive features and poorer prognosis than other subtypes of TET [30]. Therefore, the IMRT group consisted of patients with more advanced stage of TET, who required extensive target volume and were expected to have dismal prognosis. These factors may account for the relatively unfavorable dose distribution, survival rates, and toxicities observed in this group.
Although both 3-year OS and 3-year DFS rates were highest in the 3D-CRT group and lowest in IMRT group, the differences between the three groups were not statistically significant. This could be due to several reasons. First, it is possible that the effect of different RT techniques on patients’ survival may be limited because of the relatively high survival rate of patients with TET. Second, since patients were not randomly assigned to each RT technique, but by the physician’s decision, the 3D-CRT group included relatively low-risk patients, while the IMRT group included high-risk patients. Third, due to the low number of patients in PBT group, the survival outcomes in this group may have been underestimated.
Although approximately 80% of patients experienced treatment-related toxicities, complications were limited to grade 1 or 2, except for one PBT-treated patient who underwent grade 3 radiation dermatitis. PBT, due to its high entrance dose, might cause more radiation dermatitis than 3D-CRT or IMRT. The other toxic events observed in the present study were comparable with those observed in other studies [6,20]. Due to the above-mentioned selection bias between RT groups, patients in the IMRT group tended to experience more toxicities compared to those in the other groups. Additionally, as the PBT group comprised patients who were relatively younger, with more favorable dose profiles, fewer long-term complications, such as cardiac events and secondary malignancy, may be expected in this group than in other groups. Some studies predicted a lower risk of radiation-induced malignant neoplasms in patients with TET treated using PBT than in patients using other RT techniques [31-33]. All patients with recurrence (n = 20, 19.8%) experienced out-field failures. The pattern of recurrence in the present study was similar to that in another study that reviewed failure patterns of thymic carcinoma in our institution [27].
This study has some limitations. First, the selection bias, owing to the retrospective nature of the study, interfered with proper statistical analysis. Second, the insufficient number of patients in the PBT group, due to the inherent weakness of a single-center study, may have distorted the clinical outcomes of the PBT group. Multivariate analyses to find out independent prognostic factors for survival outcomes were tried but not feasible due to the limited numbers of patients and events. Additionally, the follow-up duration was not sufficient to compare survival outcomes and long-term toxicities. Further study with larger sample size and longer follow-up might be helpful to overcome the limitation of the current study.
In conclusion, in comparison to other treatments, PBT resulted in a lower dose of exposure to adjacent organs at risk. This lower exposure may be related with fewer long-term radiation-related complications and quality of life in the PBT group. When deciding which RT technique is more appropriate for patients with TET, individual factors, such as age and disease status, should be considered for proper treatment selection. Moreover, prospective studies with long-term follow-up comparing PBT with other RT techniques are required to further examine the clinical outcomes of PBT-treated patients with TET.


Statement of Ethics

This study was approved by the Institutional Review Board of Samsung Medical Center (No. 2022-11-020).

Conflict of Interest

No potential conflict of interest relevant to this article was reported.



Author Contributions

Conceptualization, Noh JM. Investigation and methodology, Lee H, Noh JM. Project administration, Lee H, Noh JM. Resources, all authors. Supervision, Noh JM. Writing of the original draft, Lee H. Writing of the review and editing, Noh JM. Software, Lee H, Noh JM. Validation, Lee H, Noh JM. Formal analysis, Lee H, Noh JM. Data curation, Lee H, Noh JM. Visualization, Lee H, Noh JM. All the authors have proofread the final version.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Fig. 1.
Kaplan-Meier survival curve of all patients: (A) overall survival and (B) disease-free survival.
Fig. 2.
Comparison of survival outcomes according to radiotherapy technique: (A) overall survival and (B) disease-free survival. PBT, proton beam therapy; 3D-CRT, three-dimensional conformal radiation therapy; IMRT, intensity-modulated radiation therapy.
Table 1.
Baseline patient characteristics (n = 101)
Characteristic Value
Age (yr) 55 (28–79)
 Male 57 (56.4)
 Female 44 (43.6)
pT stage (AJCC 8th edition)
 pT1 60 (59.4)
 pT2 7 (6.9)
 pT3 32 (31.7)
 pT4 2 (2.0)
pN stage (AJCC 8th edition)
 pN0 91 (90.1)
 pN1 6 (5.9)
 pN2 4 (4.0)
pM stage (AJCC 8th edition)
 pM0 95 (94.1)
 pM1 6 (5.9)
Masaoka-Koga stage
 I 6 (5.9)
 II 54 (53.5)
 III 34 (33.7)
 IV 7 (6.9)
WHO classification
 A, AB 13 (12.9)
 B1–B3 45 (44.5)
 C (thymic carcinoma) 37 (36.6)
 Others 6 (6.0)
Surgical margin status
 R0 resection 82 (81.2)
 R1 resection 11 (10.9)
 R2 resection 8 (7.9)
 Neoadjuvant 7 (6.9)
 Adjuvant 26 (25.8)
 No 68 (67.3)

Values are presented as median (range) or number (%).

AJCC, American Joint Committee on Cancer; WHO, World Health Organization.

Table 2.
Patients’ characteristics according to RT techniques
Characteristic 3D-CRT (n = 59) IMRT (n = 23) PBT (n = 19) p-value
Age (yr) 56.0 ± 10.9 58.4 ± 10.7 45.4 ± 11.8 <0.001
Sex 0.321
 Male 37 (62.7) 11 (47.8) 9 (47.4)
 Female 22 (37.3) 12 (52.2) 10 (52.6)
Masaoka-Koga stage 0.012
 I 2 (3.4) 3 (13.0) 1 (5.3)
 II 36 (61.0) 5 (21.7) 13 (68.4)
 III 16 (27.1) 13 (56.5) 5 (26.3)
 IV 5 (8.5) 2 (8.7) 0 (0)
WHO classification 0.142
 A, AB 8 (13.6) 1 (4.3) 4 (21.1)
 B1–B3 28 (47.5) 7 (30.4) 10 (52.6)
 C 21 (35.6) 12 (52.2) 4 (21.1)
 Others 2 (3.4) 3 (13.0) 1 (5.3)
RT dose (Gy) 53.8 ± 2.0 56.2 ± 4.8 53.6 ± 2.7 0.075
Surgical margin status 0.095
 R0 resection 51 (86.4) 15 (65.2) 16 (84.2)
 R1 resection 6 (10.2) 3 (13.0) 2 (10.5)
 R2 resection 2 (3.4) 5 (21.7) 1 (5.3)

Values are presented as mean ± standard deviation or number (%).

RT, radiation therapy; 3D-CRT, three-dimensional conformal radiation therapy; IMRT, intensity-modulated radiation therapy; PBT, proton beam therapy; WHO, World Health Organization.

Table 3.
Dosimetric parameters
Parameter 3D-CRT IMRT PBT p-value
Clinical target volume (mL) 56.5 ± 42.6 149.6 ± 95.6 90.1 ± 105.7 <0.001
Mean lung dose (Gy) 7.6 ± 3.5 10.9 ± 3.4 4.4 ± 2.9 <0.001
Lung V20 (%) 10.0 ± 7.1 19.6 ± 10.4 7.5 ± 5.5 <0.001
Mean heart dose (Gy) 10.0 ± 7.6 13.1 ± 6.8 5.4 ± 6.1 0.003
Mean esophageal dose (Gy) 9.8 ± 6.5 13.5 ± 6.8 6.3 ± 10.9 0.011
Max esophageal dose (Gy) 33.2 ± 14.5 41.9 ± 16.8 26.6 ± 24.2 0.017
Max spinal cord dose (Gy) 16.2 ± 9.3 22.3 ± 9.9 2.1 ± 3.7 <0.001

Values are presented as mean±standard deviation.

3D-CRT, three-dimensional conformal radiation therapy; IMRT, intensity-modulated radiation therapy; PBT, proton beam therapy; V20, volume receiving more than 20 Gy.

Table 4.
. Failure patterns according to International Thymic Malignancy Interest Group guidelines
Local + regional Regional Regional + distant Distant Total
 Only - 8 (7.9) 2 (2.0) 6 (5.9) 16 (15.8)
 With marginal - - 1 (1.0) 1 (1.0) 2 (2.0)
 With in-field 2 (2.0) - - - 2 (2.0)
Total 2 (2.0) 8 (7.9) 3 (3.0) 7 (6.9) 20 (19.8)

Values are presented as number (%).

Table 5.
Radiation-related toxicities
Complications Overall 3D-CRT IMRT PBT
Dermatitis 59 (58.4) 33 (55.9) 11 (47.8) 15 (78.9)
 Grade 1 54 (53.5) 32 (54.2) 9 (39.1) 13 (68.4)
 Grade 2 4 (4.0) 1 (1.7) 2 (8.7) 1 (5.3)
 Grade 3 1 (1.0) 0 (0) 0 (0) 1 (5.3)
Esophagitis 35 (34.7) 17 (28.8) 14 (60.9) 4 (21.1)
 Grade 1 14 (13.9) 6 (10.2) 6 (26.1) 2 (10.5)
 Grade 2 21 (20.8) 11 (18.6) 8 (34.8) 2 (10.5)
Pneumonitis 18 (17.8) 8 (13.6) 7 (30.4) 3 (15.8)
 Grade 1 11 (10.9) 5 (8.5) 4 (17.4) 2 (10.5)
 Grade 2 7 (6.9) 3 (5.1) 3 (13.0) 1 (5.3)
Pericarditis 3 (3.0) 2 (3.4) 0 (0) 1 (5.3)
 Grade 2 3 (3.0) 2 (3.4) 0 (0) 1 (5.3)
Lung fibrosis 7 (6.9) 2 (3.4) 3 (13.0) 2 (10.5)
 Grade 1 7 (6.9) 2 (3.4) 3 (13.0) 2 (10.5)

Values are presented as number (%).

3D-CRT, three-dimensional conformal radiation therapy; IMRT, intensity-modulated radiation therapy; PBT, proton beam therapy.


1. Shin DW, Cho JH, Ha J, Jung KW. Trends in incidence and survival of patients with thymic epithelial tumor in a high-incidence Asian country: analysis of the Korean Central Cancer Registry 1999 to 2017. J Thorac Oncol 2022;17:827–37.
crossref pmid
2. Detterbeck FC. Evaluation and treatment of stage I and II thymoma. J Thorac Oncol 2010;5(10 Suppl 4):S318–22.
crossref pmid
3. Engels EA. Epidemiology of thymoma and associated malignancies. J Thorac Oncol 2010;5(10 Suppl 4):S260–5.
crossref pmid pmc
4. National Comprehensive Cancer Center Network. Thymomas and thymic carcinoma, version 2023 [Internet]. Plymouth Meeting, PA: National Comprehensive Cancer Network; 2023 [cited 2023 Nov 5]. Available form: https://www.nccn.org/professionals/physician_gls/pdf/thymic.pdf.

5. Ogawa K, Uno T, Toita T, et al. Postoperative radiotherapy for patients with completely resected thymoma: a multi-institutional, retrospective review of 103 patients. Cancer 2002;94:1405–13.
crossref pmid
6. Oh D, Ahn YC, Kim K, Kim J, Shim YM, Han J. Is there a role of postoperative radiation therapy in completely resected stage I/II thymic epithelial tumor? Cancer Res Treat 2012;44:166–72.
crossref pmid pmc
7. Lim YJ, Kim E, Kim HJ, et al. Survival impact of adjuvant radiation therapy in Masaoka stage II to IV thymomas: a systematic review and meta-analysis. Int J Radiat Oncol Biol Phys 2016;94:1129–36.
crossref pmid
8. Fuller CD, Ramahi EH, Aherne N, Eng TY, Thomas CR Jr. Radiotherapy for thymic neoplasms. J Thorac Oncol 2010;5(10 Suppl 4):S327–35.
crossref pmid pmc
9. Jackson MW, Palma DA, Camidge DR, et al. The impact of postoperative radiotherapy for thymoma and thymic carcinoma. J Thorac Oncol 2017;12:734–44.
crossref pmid
10. Lim YJ, Kim HJ, Wu HG. Role of postoperative radiotherapy in nonlocalized thymoma: propensity-matched analysis of surveillance, epidemiology, and end results database. J Thorac Oncol 2015;10:1357–63.
crossref pmid
11. Rimner A, Yao X, Huang J, et al. Postoperative radiation therapy is associated with longer overall survival in completely resected stage II and III thymoma: an analysis of the International Thymic Malignancies Interest Group Retrospective Database. J Thorac Oncol 2016;11:1785–92.
crossref pmid pmc
12. Komaki R, Gomez DR. Radiotherapy for thymic carcinoma: adjuvant, inductive, and definitive. Front Oncol 2014;3:330.
crossref pmid pmc
13. Chargari C, Riet F, Mazevet M, Morel E, Lepechoux C, Deutsch E. Complications of thoracic radiotherapy. Presse Med 2013;42(9 Pt 2):e342–51.
crossref pmid
14. Benveniste MF, Gomez D, Carter BW, et al. Recognizing radiation therapy-related complications in the chest. Radiographics 2019;39:344–66.
crossref pmid
15. Dess RT, Sun Y, Matuszak MM, et al. Cardiac events after radiation therapy: combined analysis of prospective multicenter trials for locally advanced non-small-cell lung cancer. J Clin Oncol 2017;35:1395–402.
crossref pmid pmc
16. Ratosa I, Ivanetic Pantar M. Cardiotoxicity of mediastinal radiotherapy. Rep Pract Oncol Radiother 2019;24:629–43.
crossref pmid pmc
17. Tomita N, Okuda K, Ogawa Y, et al. Relationship between radiation doses to heart substructures and radiation pneumonitis in patients with thymic epithelial tumors. Sci Rep 2020;10:11191.
crossref pmid pmc pdf
18. Patyal B. Dosimetry aspects of proton therapy. Technol Cancer Res Treat 2007;6(4 Suppl):17–23.
crossref pdf
19. Parikh RR, Rhome R, Hug E, et al. Adjuvant proton beam therapy in the management of thymoma: a dosimetric comparison and acute toxicities. Clin Lung Cancer 2016;17:362–6.
crossref pmid
20. Vogel J, Berman AT, Lin L, et al. Prospective study of proton beam radiation therapy for adjuvant and definitive treatment of thymoma and thymic carcinoma: early response and toxicity assessment. Radiother Oncol 2016;118:504–9.
crossref pmid
21. Mercado CE, Hartsell WF, Simone CB 2nd, et al. Proton therapy for thymic malignancies: multi-institutional patterns-of-care and early clinical outcomes from the proton collaborative group and the university of Florida prospective registries. Acta Oncol 2019;58:1036–40.
crossref pmid
22. Zhu HJ, Hoppe BS, Flampouri S, et al. Rationale and early outcomes for the management of thymoma with proton therapy. Transl Lung Cancer Res 2018;7:106–13.
crossref pmid pmc
23. Haefner MF, Verma V, Bougatf N, et al. Dosimetric comparison of advanced radiotherapy approaches using photon techniques and particle therapy in the postoperative management of thymoma. Acta Oncol 2018;57:1713–20.
crossref pmid
24. Marx A, Strobel P, Badve SS, et al. ITMIG consensus statement on the use of the WHO histological classification of thymoma and thymic carcinoma: refined definitions, histological criteria, and reporting. J Thorac Oncol 2014;9:596–611.
crossref pmid
25. Masaoka A, Monden Y, Nakahara K, Tanioka T. Follow-up study of thymomas with special reference to their clinical stages. Cancer 1981;48:2485–92.
crossref pmid
26. Koga K, Matsuno Y, Noguchi M, et al. A review of 79 thymomas: modification of staging system and reappraisal of conventional division into invasive and non-invasive thymoma. Pathol Int 1994;44:359–67.
crossref pmid
27. Lee KH, Noh JM, Ahn YC, et al. Patterns of failure following postoperative radiation therapy based on “tumor bed with margin” for stage II to IV type C thymic epithelial tumor. Int J Radiat Oncol Biol Phys 2018;102:1505–13.
crossref pmid
28. Huang J, Detterbeck FC, Wang Z, Loehrer PJ Sr. Standard outcome measures for thymic malignancies. J Thorac Oncol 2010;5:2017–23.
crossref pmid
29. Gomez D, Komaki R, Yu J, Ikushima H, Bezjak A. Radiation therapy definitions and reporting guidelines for thymic malignancies. J Thorac Oncol 2011;6(7 Suppl 3):S1743–8.
crossref pmid
30. Eng TY, Fuller CD, Jagirdar J, Bains Y, Thomas CR Jr. Thymic carcinoma: state of the art review. Int J Radiat Oncol Biol Phys 2004;59:654–64.
crossref pmid
31. Lidestahl A, Johansson G, Siegbahn A, Lind PA. Estimated risk of radiation-induced cancer after thymoma treatments with proton- or X-ray beams. Cancers (Basel) 2021;13:5153.
crossref pmid pmc
32. Vogel J, Lin L, Litzky LA, Berman AT, Simone CB 2nd. Predicted rate of secondary malignancies following adjuvant proton versus photon radiation therapy for thymoma. Int J Radiat Oncol Biol Phys 2017;99:427–33.
crossref pmid
33. Konig L, Horner-Rieber J, Forsthoefel M, et al. Secondary malignancy risk following proton vs. X-ray radiotherapy of thymic epithelial tumors: a comparative modeling study of thoracic organ-specific cancer risk. Cancers (Basel) 2022;14:2409.
crossref pmid pmc
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