Treatment Of Mediastinal Lymphoma Research Articles

Consolidative active scanning proton therapy for mediastinal lymphoma: selection criteria, treatment implementation and clinical feasibility.

Proton therapy (PT) represents an advanced form of radiotherapy with unique physical properties which could be of great advantage in reducing long-term radiation morbidity for cancer survivors. Here, we aim to describe the whole process leading to the clinical implementation of consolidative active scanning proton therapy treatment (PT) for mediastinal lymphoma. The process included administrative, technical and clinical issues. Authorization of PT is required in all cases as mediastinal lymphoma is currently not on the list of diseases reimbursable by the Italian National Health Service. Technically, active scanning PT treatment for mediastinal lymphoma is complex, due to the interaction between actively scanned protons and the usually irregular and large volumes to be irradiated, the nearby healthy tissues and the target motion caused by breathing. Aroad map to implement the technical procedures was prepared. The clinical selection of patients was of utmost importance and took into account both patient and tumor characteristics. The first mediastinal lymphoma was treated at our PT center in 2018, four years after the start of the clinical activities. The treatment technique implementation included mechanical deep inspiration breath-hold simulation computed tomography (CT), clinical target volume (CTV)-based multifield optimization planning and plan robustness analysis. The ultimate authorization rate was 93%. In 4cases aproton-photon plan comparison was required. Between May 2018 and February, 2021, 14patients were treated with consolidative PT. The main clinical reasons for choosing PT over photons was abulky disease in 8patients (57%), patient's age in 11patients (78%) and the proximity of the lymphoma to cardiac structures in 10patients (71%). With amedian follow-up of 15months (range, 1-33months) all patients but one(out-of-field relapse) are without evidence of disease, all are alive and no late toxicities were observed during the follow-up period. The clinical implementation of consolidative active scanning PT for mediastinal lymphoma required specific technical procedures and aprolonged experience with PT treatments. An accurate selection of patients for which PT could be of advantage in comparison with photons is mandatory.

RETROSPECTIVE STUDY OF THE RADIOLOGICAL FINDINGS OF THE MEDIASTINUM AFTER END-OF-TREATMENT FOR A MEDIASTINAL LYMPHOMATOUS MASS IN PEDIATRIC ONCOLOGY

Abstract BACKGROUND Reactive thymic hyperplasia, or rebound thymus, is a well-known phenomenon following chemotherapy. While rebound thymus has been described after treatment for many different malignancy, it has been more often noted after treatment for lymphomas. In children and adolescents in which the primary lymphoma was located in the mediastinum, a mediastinal mass, such as a reactive thymic hyperplasia, can be misdiagnosed as a tumor relapse. It can be difficult for the clinician to differentiate between a tumor relapse and a reactive thymic hyperplasia, which may cause unnecessary additional imaging and invasive diagnostic procedures as well as anxiety for the patient and his family. OBJECTIVES The main objective was to measure the incidence of reactive thymic hyperplasia following treatment for a paediatric mediastinal lymphoma. The secondary objectives were to describe the radiologic findings which may help differentiate thymic hyperplasia and tumor relapse and to analyse if the finding of a mediastinal mass changed the clinical management. DESIGN/METHODS We conducted a retrospective cohort study. The consent for reviewing medical files was obtained from the institutional ethics board. We obtained data from the archives at the Centre mère-enfant Soleil, CHU de Québec. The medical and radiologic files of 72 paediatric patients which completed two years of follow-up after the treatment for mediastinal lymphoma were reviewed. The radiologic imaging reports were analysed and the patients were classified depending if they developed a mediastinal mass during follow-up or not. If a mass was developed, its characteristics were described to differentiate between a tumor relapse and a thymic hyperplasia. Statistical analyses were performed using SAS 9.4 Statistical Software (Institute SAS, Cary, NC, USA). Descriptive analysis includes mean ± standard deviation, range and median, interquartile range for continuous variables, and frequency and percentage for categorical. Bivariate tests were used to compare the rebound thymic hyperplasia group with the group without this problem. RESULTS The patients were followed for a mean of 27.7 ± 28.0 months (95% CI 21.1–34.2) and a median of 12.6 months. Of seventy-two patients reviewed, thirty-nine (54.2%) developed a mediastinal mass at follow-up. Of them, three had a mediastinal relapse of their tumor. One patient had a lymphoma relapse located elsewhere than the mediastinum and a benign rebound mediastinal mass. Thirty-five out of the 72 patients (48.6%, 95% CI 37.3%-60%) developed a benign mediastinal mass and were diagnosed with having rebound thymic hyperplasia. Of those thirty-five patients, twelve were investigated with additional imaging, and one had a mediastinal biopsy showing true thymic hyperplasia. The other twenty-three were followed-up according to the clinician, with no modification to their follow-up because of the mediastinal mass. These results are shown in Table 2. The majority of the rebound thymic hyperplasia were a mass of triangular shape, with well-defined margins and homogenous density. It remained unchanged or minimized at follow-up, but it was noted that three patients had an augmentation of the hyperplasia at follow-up, while remaining disease-free. The age <14 years old was a risk factor in our population (Hazard Ratio (HR) 1.95, p=.0491). CONCLUSION Reactive thymic hyperplasia is a common phenomenon showed in half of our cohort of patients. Some radiological findings, including triangular shape, well defined margins and mild homogenous enhancement, oriented towards a rebound thymic hyperplasia. Additional imaging study should be limited to patients whose rebound mass or symptoms make the clinician suspect a tumor relapse. A prospective cohort study with standardized care should be conducted to better characterize the rebound thymic hyperplasia and help the clinician approach a mediastinal mass at follow-up.

Deep-Inspiration Breath-Hold Intensity Modulated Radiation Therapy to the Mediastinum for Lymphoma Patients: Setup Uncertainties and Margins

Patient setup for treating large target volumes can be challenging. In the present study, we measured the local uncertainties in the treatment of mediastinal lymphoma and investigated the need for region-specific planning target volume (PTV) margins. The data from 30 patients who had undergone radiation therapy for mediastinal lymphoma were retrospectively analyzed. A computed tomography (CT)-on-rails (CTOR) system in the treatment room was used for daily image guidance. The total PTV was split into 6 regions: neck, supraclavicular fossa, axilla, mediastinum, upper heart, and lower heart. The total PTV and the 6 local regions were separately aligned to the planning CT scan using automatic rigid registration. The residual local errors using 3 setup strategies were investigated: no image guidance, CTOR setup to total PTV, and simulated cone beam CT setup to the mediastinum. Errors were recorded in the anteroposterior, superoinferior, and right-left directions separately. Using the residual error calculations, the margins required to cover 95% of the clinical target volume for 90% of the patients was estimated. For each patient, 12 to 21 days of daily CTOR data were available for analysis. The residual errors for the total PTV and mediastinum setups were both smaller than those with no image guidance. The lower heart region had more uncertainty with all 3 setup strategies. Margin analysis revealed that the magnitude of the margin is dependent on the imaging strategy, direction, and local region inside the PTV. Margins >7 mm are necessary to account for uncertainty in the neck, lower heart, and axilla regions even under daily CT guidance. Setup uncertainties in the mediastinum are not uniform and are dependent on target location and imaging strategy. However, with the appropriate margin, we can target regions that might not be visualized with the available on-board imager system.

Comparing Breath Hold and Free Breathing during Intensity-Modulated Radiation Therapy and Proton Therapy in Patients with Mediastinal Hodgkin Lymphoma.

In the treatment of mediastinal lymphoma, there has been increased interest over the last 5 years in utilizing proton therapy techniques as well as breath-hold techniques with 3-dimensional conformal radiation therapy (RT) or intensity-modulated RT in an effort to reduce the radiation dose to the organs at risk [1–6]. Combining both breath-hold techniques and proton therapy has been less common owing to concerns about the reproducibility of breath hold, the impact of poor reproducibility when using proton therapy, and the lack of volumetric image-guided RT and real-time diaphragm monitoring of the breath hold. Additionally, the length of treatment may be of concern, especially when matching fields are required due to large treatment volumes. Yet newer RT treatment centers with faster delivery systems and more advanced image-guided RT equipment make the combination of proton therapy and breath hold a more realistic possibility. In the present report, we investigate the impact of using the breath-hold technique with 3 female patients treated for bulky mediastinal stage II Hodgkin lymphoma with proton therapy, and compare our findings with the free-breathing technique.

Comparison of Coronary Artery Calcification in Patients Who Received Proton Versus Photon Radiation for Treatment of Mediastinal Lymphoma

Comparison of Coronary Artery Calcification in Patients Who Received Proton Versus Photon Radiation for Treatment of Mediastinal Lymphoma

Evolution of radiation techniques in the treatment of mediastinal lymphoma: from 3D conformal radiotherapy (3DCRT) to intensity-modulated RT (IMRT) using helical tomotherapy (HT): a single-centre experience and review of the literature.

To evaluate radiation techniques and their toxicity in the treatment of Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL) with mediastinal disease over a 10-year period. Between 2003 and 2015, 173 patients with Stage I-III nodal lymphoma were treated in our institution: some of these patients were irradiated for HL or NHL with mediastinal disease. Some of the patients were treated by three-dimensional conformal radiotherapy (3DCRT), others by intensity-modulated radiotherapy (IMRT). We studied 26 males and 43 females with a median age of 26 years. The median follow-up was 43 months. 49 patients were treated by 3DCRT and 20 patients by IMRT. The median dose received by patients treated for NHL was 40 Gy (range: 36-44 Gy), and the median dose received by patients with HL was 30 Gy (range: 30-36 Gy). Between 2003 and 2006, 16 patients were treated by 3DCRT vs 0 patients by IMRT. Between 2007 and 2009, 16 patients received 3DCRT and one patient received IMRT. Between 2010 and 2015, 19 patients received IMRT, and no patients received 3DCRT. 11 of the 20 (55%) patients treated by IMRT and 35 of the 49 (71.4%) patients treated by 3DCRT experienced acute toxicity. Among the patients treated by 3DCRT, one patient experienced Grade 1 radiation pneumonitis and two patients experienced Grade 1 acute mucositis. No late toxicity was observed in patients treated by IMRT. Improvement of radiation techniques for HL and NHL appears to have improved acute and late clinical safety. Longer follow-up is necessary to evaluate very late toxicity. Improvement of radiation techniques for HL and NHL appears to improve the tolerance.