Predicted risk of radiation-induced cancers after involved field and involved node radiotherapy with or without intensity modulation for early-stage hodgkin lymphoma in female patients.
OBJECTIVE
To assess the excess relative risk (ERR) of radiation-induced cancers (RIC) in female patients with Hodgkin lymphoma (HL) female patients treated with conformal (3DCRT), intensity modulated (IMRT), or volumetric modulated arc (RA) radiation therapy.


METHODS
Plans for 10 early-stage HL female patients were computed for 3DCRT, IMRT, and RA with involved field RT (IFRT) and involvednode RT (INRT) radiation fields. Organs at risk dose--volume histograms were computed and inter-compared for IFRT vs. INRT and 3DCRT vs. IMRT/RA, respectively. The ERR for cancer induction in breasts, lungs, and thyroid was estimated using both linear and nonlinear models.


RESULTS
The mean estimated ERR for breast, lung, and thyroid were significantly lower (p < 0.01) with INRT than with IFRT planning, regardless of the radiation delivery technique used, assuming a linear dose-risk relationship. We found that using the nonlinear model, the mean ERR values were significantly (p < 0.01) increased with IMRT or RA compared to those with 3DCRT planning for the breast, lung, and thyroid, using an IFRT paradigm. After INRT planning, IMRT or RA increased the risk of RIC for lung and thyroid only.


CONCLUSIONS
In this comparative planning study, using a nonlinear dose--risk model, IMRT or RA increased the estimated risk of RIC for breast, lung, and thyroid for HL female patients. This study also suggests that INRT planning, compared to IFRT planning, may reduce the ERR of RIC when risk is predicted using a linear model. Observing the opposite effect, with a nonlinear model, however, questions the validity of these biologically parameterized models.
Weber
Damien C
DC
Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland. damien.weber@unige.ch
Johanson
Safora
S
Peguret
Nicolas
N
Cozzi
Luca
L
Olsen
Dag R
DR
D000328:Adult; D001943:Breast Neoplasms / Q000209:etiology*; D005260:Female; D006689:Hodgkin Disease / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D016014:Linear Models; D008175:Lung Neoplasms / Q000209:etiology*; D015182:Lymphatic Irradiation / Q000009:adverse effects*; D009367:Neoplasm Staging; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D058958:Organs at Risk / Q000528:radiation effects; D020266:Radiotherapy, Conformal / Q000009:adverse effects* / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods; D012306:Risk; D013964:Thyroid Neoplasms / Q000209:etiology*