Estimation of second cancer risk after radiotherapy for rectal cancer: comparison of 3D conformal radiotherapy and volumetric modulated arc therapy using different high dose fractionation schemes.

ABSTRACT:

Purpose

To investigate second cancer risk (SCR) comparing volumetric modulated arc therapy (VMAT) and 3D conformal radiotherapy (3DCRT) with different high dose fractionation schemes.

Methods

VMAT and 3DCRT virtual treatment plans for 25 patients previously treated with radiotherapy for rectal cancer were evaluated retrospectively. Doses prescribed were 25 × 1.8 Gy and 5 × 5 Gy, respectively. SCR was estimated using a carcinogenesis model and epidemiological data for carcinoma and sarcoma induction. SCR was determined by lifetime attributable risk (LAR).

Results

Mean excess LAR was highest for organs adjacent to the PTV. Total LAR for VMAT and 3DCRT was 2.3-3.0 and 2.0-2.7 %, respectively. For 5 × 5 Gy, LAR was 1.4-1.9 % for VMAT and 1.2-1.6 % for 3DCRT. Organ-specifi

SUBMITTER: Zwahlen DR 

PROVIDER: S-EPMC5103599 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature