title: 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.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the risks of second cancers and cardiovascular diseases associated with an optimized volumetric modulated arc therapy (VMAT) planning solution in a selected cohort of stage I/II Hodgkin lymphoma (HL) patients treated with either involved-node or involved-site radiation therapy in comparison with 3-dimensional conformal radiation therapy (3D-CRT).
  
  
  METHODS
  Thirty-eight patients (13 males and 25 females) were included. Disease extent was mediastinum alone (n=8, 21.1%); mediastinum plus unilateral neck (n=19, 50%); mediastinum plus bilateral neck (n=11, 29.9%). Prescription dose was 30 Gy in 2-Gy fractions. Only 5 patients had mediastinal bulky disease at diagnosis (13.1%). Anteroposterior 3D-CRT was compared with a multiarc optimized VMAT solution. Lung, breast, and thyroid cancer risks were estimated by calculating a lifetime attributable risk (LAR), with a LAR ratio (LAR(VMAT)-to-LAR(3D-CRT)) as a comparative measure. Cardiac toxicity risks were estimated by calculating absolute excess risk (AER).
  
  
  RESULTS
  The LAR ratio favored 3D-CRT for lung cancer induction risk in mediastinal alone (P=.004) and mediastinal plus unilateral neck (P=.02) presentations. LAR ratio for breast cancer was lower for VMAT in mediastinal plus bilateral neck presentations (P=.02), without differences for other sites. For thyroid cancer, no significant differences were observed, regardless of anatomical presentation. A significantly lower AER of cardiac (P=.038) and valvular diseases (P<.0001) was observed for VMAT regardless of disease extent.
  
  
  CONCLUSIONS
  In a cohort of patients with favorable characteristics in terms of disease extent at diagnosis (large prevalence of nonbulky presentations without axillary involvement), optimized VMAT reduced heart disease risk with comparable risks of thyroid and breast cancer, with an increase in lung cancer induction probability. The results are however strongly influenced by the different anatomical presentations, supporting an individualized approach.
authors: Department of Oncology, Radiation Oncology, University of Torino, Torino, Italy. Electronic address: andreariccardo.filippi@unito.it.
authors: Andrea Riccardo
authors: AR
authors: Filippi
authors: Department of Oncology, Radiation Oncology, University of Torino, Torino, Italy.
authors: Riccardo
authors: R
authors: Ragona
authors: Department of Oncology, Radiation Oncology, University of Torino, Torino, Italy.
authors: Cristina
authors: C
authors: Piva
authors: Department of Oncology, Radiation Oncology, University of Torino, Torino, Italy.
authors: Davide
authors: D
authors: Scafa
authors: Department of Oncology, Radiation Oncology, University of Torino, Torino, Italy.
authors: Christian
authors: C
authors: Fiandra
authors: Medical Physics, AOU Città della Salute e della Scienza Hospital, Torino, Italy.
authors: Marco
authors: M
authors: Fusella
authors: Medical Physics, AOU Città della Salute e della Scienza Hospital, Torino, Italy.
authors: Francesca Romana
authors: FR
authors: Giglioli
authors: Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany.
authors: Frank
authors: F
authors: Lohr
authors: Department of Oncology, Radiation Oncology, University of Torino, Torino, Italy.
authors: Umberto
authors: U
authors: Ricardi
mesh_terms: D000293:Adolescent; D000328:Adult; D001940:Breast / Q000528:radiation effects; D001943:Breast Neoplasms / Q000209:etiology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000528:radiation effects*; D006331:Heart Diseases / Q000209:etiology; D006689:Hodgkin Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000528:radiation effects; D008175:Lung Neoplasms / Q000209:etiology; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D009381:Neoplasms, Radiation-Induced; D016609:Neoplasms, Second Primary; D058958:Organs at Risk / Q000000981:diagnostic imaging / Q000528:radiation effects*; D011859:Radiography; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects* / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects* / Q000379:methods; D018570:Risk Assessment; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000528:radiation effects; D013964:Thyroid Neoplasms / Q000209:etiology; D055815:Young Adult