Comparison of Radiation-Induced Secondary Malignancy Risk Between Sequential and Simultaneous Integrated Boost for the Treatment of Nasopharyngeal Carcinoma: Intensity-Modulated Radiotherapy versus Volumetric-Modulated Arc Therapy

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Hacıislamoğlu E., Cinar Y., Eren M., Canyılmaz E., Gürcan F., Serdar L., ...More

CANCER MANAGEMENT AND RESEARCH, vol.12, pp.2513-2521, 2020 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 12
  • Publication Date: 2020
  • Doi Number: 10.2147/cmar.s244901
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, Directory of Open Access Journals
  • Page Numbers: pp.2513-2521
  • Karadeniz Technical University Affiliated: Yes


Purpose: This study aimed to compare the secondary cancer risk (SCR) between the
sequential boost (SEQ) technique and simultaneous integrated boost (SIB) technique in
intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT)
in patients with nasopharyngeal carcinoma (NPC) using the concepts of organ equivalent
dose (OED) and excess absolute risk (EAR).
Patients and Methods: IMRT-SEQ, VMAT-SEQ, IMRT-SIB, and VMAT-SIB plans were
created with identical objective functions for five patients with early-stage NPC. Three
different planning tumor volumes (PTVs; PTV1, PTV2, and PTV3) were delineated for
each patient, and the prescribed doses were 50 Gy, 60 Gy, and 70 Gy (2 Gy/fraction),
respectively, for the SEQ technique and 52.8 Gy, 59.4 Gy, and 69.3 Gy (33 fractions),
respectively, for the SIB technique.
Results: All plans were clinically acceptable. There was no difference in most OED-based
SCRs between IMRT and VMAT when the same fractionation scheme was used. Compared
with the SEQ technique, the SIB technique in IMRT and VMAT was associated with the
lowest OEDs for the oral cavity, pharynx, parotids, and submandibular glands, resulting in
SCR reduction. SCR for the parotids was much lower than that for the other assessed organs
when the SIB technique was used.
Conclusion: Our findings suggest that OED-based SCRs are lower with the SIB technique
than with the SEQ technique in IMRT and VMAT in most organs for which SCR was
calculated; furthermore, SCR for the parotids is much lower than that for other organs when
the SIB technique is used in patients with NPC.
Keywords: excess absolute risk, intensity-modulated radiotherapy, organ equivalent dose,
secondary cancer risk, volumetric-modulated arc therapy