Challenges in Standardizing Stereotactic Ablative Radiation Therapy for Recurrent Ovarian Cancer

Strategic Insights -

A recent study published in the BMC Cancer journal has highlighted the complexities in standardizing stereotactic ablative radiation therapy (SABR) for recurrent ovarian cancer. The research, funded by the Ministry of Health and Welfare, aimed to assess treatment planning consistency and protocol adherence in a prospective, randomized, multicenter phase III trial. The study found that overall agreement in target delineation was low, with mean Dice similarity coefficients of 0.278 and 0.255 for gross tumor volume and planning target volume, respectively. Treatment plans generally adhered to protocol dose prescriptions, but deviations from organ-at-risk constraints frequently occurred.

Key Takeaways:

  • The study, titled "Radiotherapy quality assurance program of ongoing clinical trial using stereotactic ablative radiation therapy for recurrent ovarian cancer (SABR-ROC): a dummy run study of a prospective, randomized, multicenter phase III trial (KGOG 3064/KROG 2204)," aimed to evaluate the variability in target delineation and treatment planning among 10 centers participating in the SABR-ROC trial.
  • The researchers examined four representative cases, each presenting with different anatomical sites and treatment challenges, to assess target volume consistency and treatment planning adherence.
  • The study found that consistency was higher for cases involving lymph node and lung metastases but significantly lower for intraperitoneal and liver seeding metastases.
  • Treatment plans generally adhered to protocol dose prescriptions, but deviations from organ-at-risk constraints frequently occurred, particularly in cases involving small bowel proximity.
  • The study highlights the challenges in standardizing SABR for recurrent ovarian cancer, particularly in achieving a consensus on target delineation and balancing treatment efficacy with organ-at-risk safety.
  • Clinician discretion remains essential in complex cases, and the insights from this study will guide the development of standardized protocols to improve outcomes and reduce adverse effects in patients with recurrent ovarian cancer.

Statistics:

  • 10 centers participated in the SABR-ROC trial.
  • 4 representative cases were selected for evaluation.
  • The mean Dice similarity coefficients for gross tumor volume and planning target volume were 0.278 and 0.255, respectively.
  • 80% of treatment plans adhered to protocol dose prescriptions.
  • 60% of treatment plans deviated from organ-at-risk constraints.

Sources:

  • NewsRx LLC. Researchers at Yonsei University College of Medicine Describe Findings in Ovarian Cancer [Radiotherapy quality assurance program of ongoing clinical trial using stereotactic ablative radiation therapy for recurrent ovarian cancer (SABR-ROC): a ...]. OBGYN & Reproduction Week. September 1, 2025; p 728.
  • Kim H, Park S, Wee CW, et al. Radiotherapy quality assurance program of ongoing clinical trial using stereotactic ablative radiation therapy for recurrent ovarian cancer (SABR-ROC): a dummy run study of a prospective, randomized, multicenter phase III trial (KGOG 3064/KROG 2204). BMC Cancer. 2025;25(1):1336.