CARDIAC TOXICITY AFTER RADIATION THERAPY FOR 52 PATIENTS WITH MALIGNANT THYMIC TUMORS

Objective: To analyze the influencing factors for radiation-induced heart disease (RIHD) in a panel of cases with malignant thymic tumors treated by radiotherapy. Methods: 52 consecutive patients were treated by radiotherapy for malignant thymic tumor (14 at Masaoka stage II, 23 at stage III and 15 at stage IV). Treatment included radical (in 20), postoperative (in 14), preoperative (in 2) and palliative (in 16) radiotherapy. The conventional two-dimension (2D) radiation therapy was performed in forty-seven patients and three-dimension (3D) conformal radiation therapy has been used in 5 patients since October 2000. The total tumor dose ranged from 10 Gy to 84.5 Gy (median of 55 Gy). Chemotherapy was given in twenty-five patients before or after radiotherapy. The results of following-up could be obtained from the database and updated where appropriated. The dose volume histogram (DVH) of heart in radiotherapy for all patients was analyzed for the effective volume dose of heart. Result: The median following-up was 14 months (ranged from 0.6 to 111.3 months) in the study. RIHD was observed in seven patients. Cardiac toxicity of these seven patients were evaluated as SOMA grade 1-3. The median two-third effective volume dose of heart was 47.2 Gy (ranged from 8.3 Gy to 70.1 Gy) for conventional 2D radiotherapy, which correlated with thymic tumor dose (P<0.0001). The median two-third effective volume dose of heart was 35.3 Gy (ranged from 13 Gy to 38.7 Gy) for 3D conformal radiotherapy. The effective volume doses of heart were decreased by using 3D conformal radiotherapy (P=0.048). A significant association between cardiac toxicity and effective volume dose of heart was found in this study (P<0.0001). Cardiac toxicity accounted for 10.4% and 4.1% of patients receiving and not receiving adjuvant chemotherapy, respectively, and occurred earlier in radiochemotherapy group (P=0.0528). Multivariate analysis suggested that cardiac toxicity was significantly influenced by the effective volume dose of heart and chemotherapy. Conclusion: the results indicate that decreasing the effective volume dose of heart and carefully using chemotherapy drugs that have significant cardiotoxicity may reduce the probability of radiation-induced heart disease.

Value of metabolic parameters in distinguishing primary mediastinal lymphomas from thymic epithelial tumors

Objective:A high rate of unnecessary thymectomies has been reported.This study aimed to distinguish primary mediastinal lymphomas(PMLs)from thymic epithelial tumors(TETs)by evaluating volumetric and metabolic parameters with l8F-FDG PET/CT.Methods:A total of 136 patients who were pathologically diagnosed with TETs or PMLs were enrolled,and 18F-FDG PET/CT was performed before therapy.Volumetric parameters,including the mean SUV(SUVmean),metabolic tumor volume(MTV),total lesion glycolysis(TLG),and SUVmax,were determined and compared between the 2 subtypes.The diagnostic performance of these parameters was evaluated with receiver operating characteristic(ROC)curve analysis.Results:All parameters significantly differed between patients with PMLs and TETs.Patients with lymphomas were younger and had higher SUVmean,SUVmax,TLG,and MTV values than patients with TETs.The MTV and TLG values had similar diagnostic performance.ROC analysis indicated that the areas under the curves of the SUVmean and SUVmax values performed similarly(approximately 0.76)in differentiating patients with PMLs from TETs,and both values were better than the MTV and TLG values.When age was included with the SUVmax in differentiating TETs from PMLs,the AUC was 0.91,and the sensitivity and specificity increased to 80%and 93%,respectively.Conclusions:The SUVmax and volumetric parameters of 18F-FDG PET/CT can be used to distinguish patients with PMLs versus TETs,and thus may aid in preventing unnecessary thymectomies or other invasive operations.

Thymic lipofibroadenomas:Three case reports

BACKGROUND Thymic lipofibroadenomas are extremely rare.In this study,we investigated the clinicopathological characteristics of thymic lipofibroadenomas.CASE SUMMARY This study included three patients with thymic lipofibroadenomas.We retrospectively analyzed the patient data to determine the clinicopathological characteristics of thymic lipofibroadenomas.The study included one man and two women[mean age,43(33–59)years].All patients were non-smokers and presented with well-defined anterior mediastinal tumors.The cut surfaces of the tumors were solid,with a mixture of yellow and white areas.Microscopic evaluation of resected specimens showed scattered cord-like structures of epithelial cells embedded within abundant fibrotic and hyaline stroma admixed with variable quantities of adipose tissue.One patient showed hyperplastic thymic tissue in a part of the tumor.CONCLUSION Thymic lipofibroadenomas are an extremely rare type of benign thymic tumor.Surgical removal of lipofibroadenomas is usually curative.

GOECP/SEOR radiotherapy guidelines for thymic epithelial tumours

Thymic epithelial tumours(TET)are rare,heterogeneous neoplasms that range from resectable indolent tumours to aggressive thymic carcinomas with a strong tendency to metastasize.The pathological diagnosis is complex,in part due to the management of TETs is scant and mainly based on non-randomised studies and retrospective series.Consequently,the clinical management of TETs tends to be highly heterogenous,which makes it difficult to improve the evidence level.The role of technological advances in the field of radiotherapy and new systemic therapies in the treatment of TETs has received little attention to date.In the present clinical guidelines,developed by the GOECP/SEOR,we review recent developments in the diagnosis and classification of TETs.We also present a consensus-based therapeutic strategy for each disease stage that takes into consideration the best available evidence.These guidelines focus primarily on the role of radiotherapy,including recent advances,in the management of TETs.The main aim of this document is to promote the standardisation of clinical practice and lay the foundations for future studies to clarify the main unresolved questions related to the optimal management of TET.

Postoperative radiotherapy for thymus salivary gland carcinoma:A case report

BACKGROUND Salivary gland cancer is a rare disease in which cancer cells form in the tissues of the salivary glands.It mostly occurs in the glands that have secretion functions,such as the parotid gland,sublingual gland and submandibular gland.This is very rare when it occurs in other nonsecreting glands.Here,we report one case of salivary gland carcinoma occurring in the thymus and discuss related diagnoses and treatment progress.CASE SUMMARY One 33-year-old middle-aged man presented with a thymus mass without any clinical symptoms when he underwent regular physical examination.Later,the patient was admitted to the hospital for further examination.Computed tomography(CT)showed that there was a mass of 3 cm×2.8 cm×1.5 cm in the thymus area.The patient had no symptom of discomfort or tumor-related medical history before.After completing the preoperative examinations,it was confirmed that the patient had indications for surgery.The surgeon performed a transthoracoscope"thymectomy+pleural mucostomy"for him.During the operation,the tumor tissue was quickly frozen,and the symptomatic section showed a malignant tumor.The final pathological result suggested thymus salivary gland carcinoma-mucoepidermoid carcinoma(MEC).In the second month after surgery,we performed local area radiotherapy for the patient,with a total radiation dose of 50.4 Gy/28Fx.After 12 mo of surgery,the patient underwent positron emission tomography-CT examination,which indicated that there was no sign of tumor recurrence or metastasis.After 16 mo of operation,CT scan re-examination showed that there was no sign of tumor recurrence or metastasis.As of the time of publication,the patient was followed up for one and a half years.He had no sign of tumor recurrence and continued to survive.CONCLUSION The incidence of MEC in the thymus is low,and its diagnosis needs to be combined with clinical features and imaging methods.Histopathological analysis plays a key role in the diagnosis of the disease.Patients with early-stage disease have a good prognosis and long survival period.In contrast,patients with advanced-stage disease have a poor prognosis and short survival period.Combining radiotherapy and chemotherapy in inoperable patients may prolong survival.