1. VMAT-technique (volumetric modulated arc therapy), IMRT-technique (intensity modulated radiotherapy) and 3D-conformal radiation for Lymphomas in Radiation Oncology Department in Banc of Cyprus Oncology Center.
Marilena Theodorou, MD 1, , Andriana Peratikou, MSc, DABR, 2 , Stefani Stefanou MSc,CSI, MIPEM, 2, , Lora Ioannou, MSc, CSI, MIPEM, 2,, Efthymiou Themos MSc, 2, Erato Stylianou MSc, 2,,Ali Vehbi Artikan MSc, DABR, Aristotelis Giannos MSc 2, Demetrios Andreopoulos, MD,PhD 1
1 Radiation Oncology Department, Bank of Cyprus Oncology Center, 2 Medical Physics Department, Bank of Cyprus Oncology Center,
Contact:
Radiation Oncology and Radiodiagnostics, Banc of Cyprus Oncology Center, Nicosia, Cyprus ,
Introduction
From October 2015 to May 2017, 40 patients were radiated in the Radiation Oncology Department in Banc of Cyprus Oncology Center due to Hodgkin (HL) or Non-Hodgkin Lymphoma (NHL). The Classification followed the Ann Arbor Classification system for Lymphomas. All the patients had the FDG-PET-scan either for the Staging or for Restaging after completion the chemotherapy. During chemotherapy a Restaging with CT scan to estimate the response to chemotherapy was occurred. Most of the patient have partial response after the 4th cycle of chemotherapy and complete response after the 6th cycle of chemotherapy. The first line chemotherapy for NHL was 6 cycles R-CHOP and for HL 4-6 cycles ABVD. The 40 patients with Lymphoma were in different Stages (I-IV) and have different anatomical location such as cervical, mediastinal, axilla, para-aortal, inguinal, and some of them were diagnosed with bulky disease. . B
Methods
The patients are referred to us 4-6 weeks after the completion of chemotherapy with Restaging (CT, FDG-PET) for the Involved Field Radiation or they are referred for the primary Radiation if they were in Stage I NHL. Every patient has a Planning-CT, for the cervical/mediastinal Lymphomas a thermoplastic mask was used for the fixation. The Contouring for the Clinical Target Definition (GTV, CTV, and PTV) and the Risk organs (OAR) followed in Oncentra Master Plan and the Treatment Planning in Monaco Treatment Plan System. For an exact clinical target definition we fused the pre-Chemotherapy-CT, post-Chemotherapy-CT, FDG-PET and MRI, if available, with the Planning-CT. We used VMAT and 3D-conformal technique in Linear Accelerator equipped with Cone-Beam-CT for all the 40 patients. The GTV (gross tumor volume) included the macroscopic rest Lymphoma in the post-Chemotherapy-CT-scan. The CTV (clinical tumor volume) included the involved lymphnodes stations in the pre-Chemotherapy-CT-scan and the PTV included the GTV+CTV adapted in anatomical structures.
Example 1: 1st plan abdominal lymphoma in 3D conformal plan, 2nd plan VMAT with partial arc to avoid kidneys , DVH showes the dose of the risk organs from both techniques
Example 2: 1st plan: mediastinal Lymphoma in VMAT plan with partial arc, 2nd plan: 3D conformal plan, DVH showes the dose at organ at risk from both techniques
Results
The IMRT and VMAT plans delivered high coverage to the targets and very good safety for the risk organs compared with the 3D-plans. The risk organs received less dose with the VMAT plan compared with 3D conformal plan. The toleration is good without significant side effects or complications. Some acute side effects such as skin erythema, mild dyscataposia, mild esophagitis, were mentioned. No late side effects were mentioned in the further FU
All the patients have weekly FU during Radiation and the 1st FU after completion of the Radiation is in 6 weeks. The next FUs are every 3 months for the first year after treatment and by second year every 6 months. The FUs after the radiation gave no significant late side effects of all the patients.
Conclusion and summary
The VMAT / IMRT technique has more benefits due to lower dose to the risk organs and better coverage. In the VMAT technique a partial rapid arc technique was used in order to avoid radiation of breast by young female patients for example, or to avoid kidneys.
In conclusion, VMAT or IMRT for Lymphomas Radiation is suggested due to high coverage of the PTV and the good safety of the risk organs especially for young patients.
DEGRO 2017, Berlin