Radiation-induced second malignancies after involved-node radiotherapy with deep-inspiration breath-hold technique for early stage Hodgkin Lymphoma: a dosimetric study

Abstract

BackgroundTo estimate the risk of radiation induced second cancers after radiotherapy using deep-inspiration breath-hold (DI) technique with three-dimensional conformal (3DCRT) and volumetric arc therapy (VMAT) for patients with Hodgkin’s lymphoma (HL).MethodsEarly-stage HL with mediastinal and supraclavicular involvement was studied using an Alderson phantom. A whole body CT was performed and all tissues were delineated. The clinical target volumes and planning target volumes (PTV) were determined according to the German Hodgkin study group guidelines. Free-breathing (FB) technique and DI technique were simulated by different safety margins for the PTV definition. In both cases, 30 Gy in 15 fractions was prescribed. Second cancer risk was estimated for various tissues with a second cancer model including fractionation.ResultsWhen compared with FB-3DCRT, estimated relative life time attributable risk (LAR) of cancer induction after DI-3DCRT was 0.86, 0.76, 0.94 and 0.92 for breast, lung, esophagus and stomach, respectively. With DI-VMAT, the corresponding values were 2.05, 1.29, 1.01, 0.93, respectively. For breast cancer, the LAR observed with DI-VMAT was not substantially distinguishable from the LAR computed for mantle RT with an administered dose of 40 Gy.ConclusionsThis study suggests that DI may reduce the LAR of secondary cancers of all OARs and may be a valuable technique when using 3DCRT. Conversely, VMAT may increase substantially the LAR and should be cautiously implemented in clinical practice.

Optimized Volumetric Modulated Arc Therapy Versus 3D-CRT for Early Stage Mediastinal Hodgkin Lymphoma Without Axillary Involvement: A Comparison of Second Cancers and Heart Disease Risk

“…These preliminary findings were in contrast with those obtained by a pioneering study with a comparable design (14) but pursuing different planning solutions (3D-CRT vs IMRT vs RapidArc). Likewise, in later reports, VMAT appeared to be associated with higher estimates of second cancer risk (15,16).…”

“…From OED we then estimated the lifetime attributable risk (LAR). Individual LAR values were calculated according to Schneider et al (15) by using the equation originally described by Kellerer et al (22). According to this method, OED is first converted to excess absolute risk (EAR) for a western population for each organ, and then the resulting LAR for a patient from the specific RT treatment is (15) suggested using a follow-up time interval instead of the life expectancy (estimated from the general population of the same age), and we used a 30-year time interval from radiation treatment.…”

Second cancer risk assessments after involved-site radiotherapy for mediastinal Hodgkin lymphoma

“…All plans consisted of two isocentric anteroposterior (AP) and posteroanterior (PA) fields with gantry angles of 0° and 180° giving a total dose of 30 Gy to the PTV. This irradiation technique has been extensively used for three‐dimensional conformal radiotherapy (3D CRT) for mediastinal HL . The XiO software was employed for the three‐dimensional treatment planning procedure (CMS Inc., St Louis, MO, USA).…”

“…This irradiation technique has been extensively used for three-dimensional conformal radiotherapy (3D CRT) for mediastinal HL. [13][14][15] The XiO software was employed for the three-dimensional treatment planning procedure (CMS Inc., St Louis, MO, USA). The IFRT and ISRT plans were designed for use on a linear accelerator with multileaf collimators producing 6 MV photon beams (Primus, Siemens, Germany).…”

Dosimetric comparison of non-coplanar three-dimensional conformal radiation therapy (nc3DCRT) planning and radio biologically optimized partial arc volumetric modulated arc therapy (VMAT) planning of unilateral brain tumours � a retrospective study

“…For our study, all these patients were again planned with partial arc VMAT in Monaco TPS with radiobiological based optimization with 6 MV (FF) partial arc, as partial arc provides better contra lateral organ sparing [8]. Target objectives were defined as Equivalent Uniform Dose (EUD) and for critical structures with serial and parallel radiobiological constraints, physical constraints such as quadratic overdose, conformity and maximum dose were also used to control maximum dose inside the target and to reduce dose sharply outside the target volumes in IMRT constraint tab.…”