Impact of treatment time and dose escalation on local control in locally advanced cervical cancer treated by chemoradiation and image-guided pulsed-dose rate adaptive brachytherapy

Radiother Oncol. 2015 Feb;114(2):257-63. doi: 10.1016/j.radonc.2014.11.045. Epub 2014 Dec 10.


Purpose: To report the prognostic factors for local control in patients treated for locally advanced cervical cancer with image guided pulsed-dose rate brachytherapy.

Materials/methods: Patients treated with curative intent by a combination of external beam radiotherapy and pulsed-dose rate brachytherapy were selected. Local failure was defined as any relapse in the cervix, vagina, parametria, or uterus during follow-up. Prognostic factors were selected based on log rank tests and then analyzed with a Cox model. Dose/effect correlations were performed using the probit model.

Results: Two hundred and twenty-five patients treated from 2006 to 2011 were included. According to the FIGO classification, 29% were stage IB, 58% stage II, 10% stage III, and 3% stage IVA; 95% received concomitant chemotherapy. Thirty patients were considered having incomplete response or local failure. Among the selected parameters, D90 for HR-CTV, D90 for IR-CTV, the overall treatment time, the TRAK, and the HR-CTV volume appeared significantly correlated with local control in univariate analysis. In multivariate analysis, overall treatment time >55days and HR-CTV volume >30cm(3) appeared as independent. The probit analysis showed significant correlations between the D90 for both CTVs, and the probability of achieving local control (p=0.008 and 0.024). The thresholds to reach to warrant a probability of 90% of local control were 85Gy to the D90 of the HR-CTV and 75Gy to 90% of the IR-CTV (in 2Gy equivalent, α/β=10). To warrant the same local control rate, the D90 HR-CTV should be significantly increased in stage III-IV tumors, in case of HR-CTV >30cm(3), excessive treatment time, or tumor width at diagnosis >5cm (97, 92, 105, and 92Gy respectively).

Conclusions: Overall treatment time and HR-CTV volume were independent prognostic factors for local control. The D90 for HR and IR CTV were significantly correlated with local control, and D90 HR-CTV should be adapted to clinical criteria.

Keywords: Cervical cancer; D90; Dose–effect correlation; Image-guided adaptive brachytherapy; Local control; Treatment time.

MeSH terms

  • Brachytherapy / methods*
  • Carboplatin / therapeutic use*
  • Chemoradiotherapy
  • Cisplatin / therapeutic use*
  • Dose-Response Relationship, Radiation
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Middle Aged
  • Neoplasm Recurrence, Local / drug therapy
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Recurrence, Local / radiotherapy
  • Proportional Hazards Models
  • Radiotherapy Dosage
  • Retrospective Studies
  • Tomography, X-Ray Computed
  • Treatment Outcome
  • Uterine Cervical Neoplasms / drug therapy*
  • Uterine Cervical Neoplasms / pathology
  • Uterine Cervical Neoplasms / radiotherapy*


  • Carboplatin
  • Cisplatin