Revolutionizing Postoperative Cancer Care: A New Dawn in Radiation Therapy
Study Overview
The study titled: "Evaluation of PTV margins with daily iterative online adaptive radiotherapy for postoperative treatment of endometrial and cervical cancer: a prospective single-arm phase 2 study" was prospective, single-arm, and non-randomized, undertaken as a phase 2 trial (1). It focused on postoperative patients with endometrial and cervical cancer, specifically investigating the use of daily iterative cone-beam computed tomography (iCBCT)-guided online adaptive radiotherapy (oART) for these conditions.
The population under investigation included 15 postoperative patients with endometrial and cervical cancer. The intervention in question was daily iCBCT-guided oART, aimed at evaluating optimal planning target volume (PTV) margins for sufficient coverage by this method in the postoperative treatment of endometrial and cervical cancer.
The study did not explicitly mention a control group, as it was a single-arm trial. A total of 15 patients were included, with the intervention applied across 381 fractions. However, three fractions were excluded from the PTV margin analysis due to the loss of posttreatment iCBCT.
The results showed that a uniform PTV margin of 5 mm could encompass nodal clinical target volume (CTVpost) in 100% of the fractions (175/175) and vaginal CTVpost in 98% of the fractions (172/175). Further reduction to 4 mm was possible if ≥95% CTV coverage was predicted to be achieved. The study also found significant improvements in pelvic organ-at-risk dosimetry with the adapted plan using a 5 mm margin compared to the conventional margin plan. Grade 3 toxicities were observed in only one patient, and no patients experienced acute urinary toxicity.
Overall, the study concludes that in postoperative treatment of endometrial and cervical cancer, oART could reduce PTV margins to 5 mm, which significantly decreases the dose to critical organs at risk and potentially leads to a lower incidence of acute toxicity.
Standard Treatment
The standard treatment for postoperative endometrial and cervical cancer typically involves a combination of surgery, radiation therapy, and chemotherapy, depending on the stage and specific characteristics of the cancer. Surgery is often the initial step, involving the removal of the uterus (hysterectomy) and possibly other affected tissues. Postoperative radiation therapy, which may include external beam radiation or brachytherapy, is used to eliminate any remaining cancer cells and reduce the risk of recurrence. In some cases, chemotherapy may be administered either before or after surgery to treat advanced stages of the disease. The treatment plan is tailored to the individual patient based on various factors such as the cancer's stage, type, and the patient's overall health.
Clinical Impact Potential
The clinical impact potential of this trial can be considered medium. This assessment is based on the trial's focus on refining radiation therapy techniques for postoperative endometrial and cervical cancer. The use of daily iterative cone-beam computed tomography (iCBCT)-guided online adaptive radiotherapy (oART) represents an advancement in precision and customization of treatment. While the results suggest potential benefits in reducing toxicity and improving organ-at-risk dosimetry, the study's single-arm design and small sample size limit its immediate applicability. Further research with larger, randomized trials is necessary to fully understand its impact and establish new standards of care.
Reference
Wang G, Wang Z, Guo Y, Zhang Y, Qiu J, Hu K, Li J, Yan J, Zhang F. Evaluation of PTV margins with daily iterative online adaptive radiotherapy for postoperative treatment of endometrial and cervical cancer: a prospective single-arm phase 2 study. Radiat Oncol. 2024 Jan 4;19(1):2. doi: 10.1186/s13014-023-02394-2. PMID: 38178254; PMCID: PMC10768299.