This randomized clinical trial will evaluate whether adding spatially fractionated radiation therapy (SFRT) to definitive chemoradiotherapy improves outcomes in patients with locally advanced cervical cancer. Adult patients with FIGO 2018 stage IIB to IVA cervical cancer who are planned to receive definitive chemoradiotherapy will be randomly assigned in a 1:1 ratio to an SFRT group or a control group. Both groups will receive external-beam radiation therapy, concurrent chemotherapy, and brachytherapy. Patients with pelvic wall, rectal, or bladder invasion may also receive immunotherapy as specified in the study protocol. In the experimental group, external-beam radiation therapy will begin with three fractions of SFRT, using a peak dose of 8 Gy per fraction and keeping the valley dose as low as reasonably achievable, generally no more than 3 Gy per fraction. Conventional fractionated external-beam radiation therapy will then begin within 1 to 3 days. Participants in the control group will receive conventional fractionated external-beam radiation therapy without SFRT. The primary objective is to determine whether SFRT improves 3-year progression-free survival. Secondary objectives include objective response rate, treatment safety, overall survival, and the occurrence of an abscopal effect. Exploratory translational studies will evaluate tumor and peripheral blood immune characteristics when biospecimens are available and participants provide consent.
This is an investigator-initiated, randomized, parallel-group clinical trial evaluating spatially fractionated radiation therapy in patients with locally advanced cervical cancer. A total of 126 participants with histologically confirmed FIGO 2018 stage IIB to IVA cervical cancer will be enrolled and randomly assigned in a 1:1 ratio to the experimental SFRT group or the control group. Participants in both groups will receive definitive treatment consisting of external-beam radiation therapy, concurrent chemotherapy, and brachytherapy. Patients with pelvic wall, rectal, or bladder invasion will additionally receive immunotherapy as specified by the protocol. Target-volume coverage and normal-tissue dose constraints will follow the same standards in both treatment groups. In the experimental group, external-beam radiation therapy will begin with three fractions of spatially fractionated radiation therapy. The peak dose will be 8 Gy per fraction. The valley-to-peak dose ratio will be kept as low as reasonably achievable, with the valley dose generally approximately one-third of the peak dose and usually no more than 3 Gy per fraction. Conventional fractionated external-beam radiation therapy will begin 1 to 3 days after SFRT. The higher radiation dose within selected intratumoral regions constitutes the main difference between the experimental and control groups. The primary endpoint is 3-year progression-free survival. Secondary endpoints include objective response rate according to RECIST version 1.1, acute and late treatment-related toxicity, overall survival, and abscopal effect rate. Optional translational analyses will investigate changes in tumor PD-L1 expression, tumor and peripheral blood immune-cell subsets, and transcriptomic characteristics.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
126
Spatially fractionated external-beam radiation therapy will be delivered in three fractions before conventional fractionated radiation therapy. The prescribed peak dose is 8 Gy per fraction. The valley-to-peak dose ratio will be minimized, with the valley dose generally approximately one-third of the peak dose and usually no more than 3 Gy per fraction. Conventional fractionated external-beam radiation therapy will begin within 1 to 3 days after completion of SFRT.
Participants in the control arm will undergo conventional concurrent chemoradiotherapy followed by brachytherapy. Participants in the SFRT arm will first receive SFRT, then receive the same chemoradiotherapy and brachytherapy regimen. For both arms, the decision to add concurrent and consolidation immunotherapy to the backbone treatment will be made according to the latest clinical guidelines and standard practice at the time of treatment.
The University of Hong Kong - Shenzhen Hospital,
Shenzhen, Guangdong, China
3-Year Progression-Free Survival (PFS) Rate
The percentage of participants who are alive without disease progression at 3 years after randomization. Progression-free survival is defined as the time from randomization to the first documented recurrence or progression at any site or death from any cause, whichever occurs first.
Time frame: From randomization to 3 years after randomization
Objective Response Rate (ORR) at 3 Months After Radiotherapy
Objective response rate is defined as the percentage of evaluable participants who achieve a complete response (CR) or partial response (PR) according to Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1), based on post-treatment imaging assessment.
Time frame: 3 months after completion of radiotherapy
Incidence of Acute Adverse Events
The number and percentage of participants experiencing adverse events from the first day of study treatment through 90 days after completion of radiotherapy. Acute adverse events will be graded according to the Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0).
Time frame: From the first day of treatment through 90 days after completion of radiotherapy
Incidence of Late Radiation Toxicity
The number and percentage of participants experiencing late radiation-related toxicities by grade. Late toxicity is defined as toxicity occurring more than 90 days after completion of radiotherapy and will be assessed using the Radiation Therapy Oncology Group late radiation morbidity scoring criteria.
Time frame: From more than 90 days after completion of radiotherapy through 5 years after randomization
Overall Survival (OS)
Overall survival is defined as the time from randomization to death from any cause. Participants who are alive at the last follow-up will be censored at the date of their last known follow-up.
Time frame: From randomization to death from any cause, assessed up to 5 years
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.