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Clinical Trial
. 2015 May;56(3):539-45.
doi: 10.1093/jrr/rrv004. Epub 2015 Feb 26.

A comparative planning study of step-and-shoot IMRT versus helical tomotherapy for whole-pelvis irradiation in cervical cancer

Imjai Chitapanarux  1 , Ekkasit Tharavichitkul  2 , Wannapa Nobnop  2 , Somsak Wanwilairat  2 , Roy Vongtama  3 , Patrinee Traisathit  4
Affiliations
Clinical Trial

A comparative planning study of step-and-shoot IMRT versus helical tomotherapy for whole-pelvis irradiation in cervical cancer

Imjai Chitapanarux et al. J Radiat Res. 2015 May.

Abstract

The aim of this study was to compare the dosimetric parameters of whole-pelvis radiotherapy (WPRT) for cervical cancer between step-and-shoot IMRT (SaS-IMRT) and Helical Tomotherapy™ (HT). Retrospective analysis was performed on 20 cervical cancer patients who received WPRT in our center between January 2011 and January 2014. SaS-IMRT and HT treatment plans were generated for each patient. The dosimetric values for target coverage and organ-at-risk (OAR) sparing were compared according to the criteria of the International Commission on Radiation Units and Measurements 83 (ICRU 83) guidelines. Differences in beam-on time (BOT) were also compared. All the PTV dosimetric parameters (D5%, D50% and D95%) for the HT plan were (statistically significantly) of better quality than those for the SaS-IMRT plan (P-value < 0.001 in all respects). HT was also significantly more accurate than SaS-IMRT with respect to the D98% and Dmean of the CTV (P-values of 0.008 and <0.001, respectively). The median Conformity Index (CI) did not differ between the two plans (P-value = 0.057). However, the Uniformity Index for HT was significantly better than that for SaS-IMRT (P-value < 0.001). The median of D50% for the bladder, rectum and small bowel were significantly lower in HT planning than SaS-IMRT (P-value < 0.001). For D2%, we found that HT provided better sparing to the rectum and bladder (P-value < 0.001). However, the median of D2% for the small bowel was comparable for both plans. The median of Dmax of the head of the left femur was significantly lower in the HT plan, but this did not apply for the head of the right femur. BOT for HT was significantly shorter than for SaS-IMRT (P-value < 0.001). HT provided highly accurate plans, with more homogeneous PTV coverage and superior sparing of OARs than SaS-IMRT. In addition, HT enabled a shorter delivery time than SaS-IMRT.

Keywords: IMRT; cervical cancer; step-and-shoot; tomotherapy.

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Figures

Fig. 1.
Fig. 1.
Dose distribution for SAS-IMRT (left) and HT (right) plan.
See this image and copyright information in PMC

References

    1. Ferlay J, Shin H, Bray F, et al. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. Int J Cancer 2010;127:2893–917. - PubMed
    1. Rose PG, Bundy BN, Watkins EB, et al. Concurrent cisplatin-based radiotherapy and chemotherapy for locally advanced cervical cancer. N Engl J Med 1999;340:1144–53. - PubMed
    1. Whitney CW, Sause W, Bundy BN, et al. Randomized comparison of fluorouracil plus cisplatin versus hydroxyurea as an adjunct to radiation therapy in stage IIB–IVA carcinoma of the cervix with negative para-aortic lymph nodes: a Gynecologic Oncology Group and Southwest Oncology Group study. J Clin Oncol 1999;17:1339–48. - PubMed
    1. John M, Flam M, Caplan R, et al. Final results of a phase II chemoradiation protocol for locally advanced cervical cancer: RTOG 85–15. Gynecol Oncol 1996;61:221–6. - PubMed
    1. Tan LT, Zahra M. Long-term survival and late toxicity after chemoradiotherapy for cervical cancer—the Addenbrooke's experience. Clin Oncol 2008;20:358–64. - PubMed

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