Editor’s note: As China’s population ages and public awareness of cancer screening increases, the clinical demand for managing urologic malignancies continues to rise. Radiotherapy, a cornerstone of cancer treatment, has undergone rapid evolution—from conventional techniques to intensity-modulated radiotherapy (IMRT), and from standard fractionation to stereotactic radiotherapy. Precision radiotherapy is becoming a central pillar in the treatment of urologic cancers. Professor Ningning Lu of the National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, has long specialized in precision radiotherapy for urologic tumors, accumulating extensive clinical and research experience. UroStream invited Professor Lu to provide an in-depth interpretation of the clinical applications of precision radiotherapy in urologic malignancies, offering guidance for clinical practice.
01 UroStream: Radiotherapy plays an increasingly important role in the multidisciplinary management of urologic cancers. From a clinical standpoint, how is precision radiotherapy reflected in treatment, and what is its significance?
Professor Ningning Lu: Precision radiotherapy is the core approach to improving local control and quality of life in urologic tumors, and its principles apply across the entire radiotherapy workflow.
In target delineation, accurate contouring based on multimodal imaging forms the foundation of effective treatment. It is essential to precisely define tumor boundaries, subclinical disease, and adjacent organs at risk. This directly influences tumor control and the risk of complications. Patient positioning stability and reproducibility during simulation and treatment are also critical.
In treatment planning, precision is achieved through advanced dose-calculation algorithms and optimization techniques that create highly conformal dose distributions. This ensures adequate and uniform tumor coverage while minimizing dose to nearby organs at risk such as the rectum and bladder, thereby maximizing therapeutic benefit.
In treatment delivery, accurate positioning verification and dose administration are crucial. For prostate cancer, for example, the prostate, seminal vesicles, bladder, and rectum exhibit considerable interfraction motion and shape change. Daily variations in bladder filling and rectal content pose significant challenges. Image-guided radiotherapy is therefore indispensable. A Dutch randomized study comparing different CBCT frequencies showed that daily imaging significantly improved biochemical failure–free survival and reduced toxicity compared with weekly imaging, underscoring the value of precise image guidance.
More recently, MR-guided adaptive radiotherapy has entered clinical application, elevating precision to a new level. MR-Linac systems combine high-field MRI with a linear accelerator, allowing high-resolution soft tissue imaging immediately before each treatment. Based on daily anatomy, target volumes and treatment plans can be adapted online, shifting from a “fixed plan” to a “customized per-fraction” model. Its key advantage is real-time adaptation to organ motion, enabling tighter tumor dose conformality while protecting surrounding structures—an ideal approach for urologic tumors.
02 UroStream: Compared with conventional precision radiotherapy, what advantages and value does MR-guided adaptive radiotherapy offer in urologic cancers?
Professor Ningning Lu: For localized prostate cancer, radiotherapy is a critical curative option. With stereotactic radiotherapy now a standard choice, the increased dose per fraction heightens the demand for precision. At the same time, as clinicians, we recognize the importance of preserving quality of life—particularly urinary, bowel, and sexual function.
MR-guided adaptive radiotherapy adjusts for daily anatomical changes of the prostate and nearby organs at risk, achieving personalized precision for each session. This improves target coverage and significantly reduces dose to the rectum, bladder, and neurovascular bundles.
Our clinical experience shows that using shape-adaptive workflows in hypofractionated radiotherapy not only maintains tumor control but also reduces acute and late toxicities in the urinary and gastrointestinal systems. Particularly noteworthy is the trend toward improved preservation of sexual function. Among early-stage low- and intermediate-risk patients, sexual function preservation rates exceeded those seen with conventional techniques. This confirms that MR-guided adaptive therapy enhances organ preservation while maintaining oncologic effectiveness—offering meaningful benefits, especially for younger patients or those prioritizing functional outcomes.
03 UroStream: What potential breakthroughs and future applications do you foresee for MR-guided adaptive radiotherapy in urologic cancers?
Professor Ningning Lu: Precision dose escalation to local lesions is an important area of expansion.
In postoperative recurrent prostate cancer, altered anatomy, fibrosis, adhesions, and bowel movement often limit the ability of conventional radiotherapy to deliver curative doses safely. Our prospective research using MR-guided adaptive boost to recurrent lesions, followed by conventional treatment to the prostate bed ± pelvic nodes, demonstrated both feasibility and safety. All patients completed treatment without grade ≥3 acute toxicity. MR guidance clearly visualized recurrent disease, enabling precise dose escalation while protecting bowel and bladder, thus offering patients a meaningful chance at salvage cure.
In bladder cancer bladder-preservation therapy, standard radiotherapy doses may not adequately control visible tumors. We have explored adaptive focal boosting to visible bladder wall lesions, followed by standard whole-bladder ± pelvic node irradiation. All patients completed shape-adaptive boost treatments with ideal target coverage and low toxicity. This provides a promising pathway for improving local control while maintaining bladder function.
04 UroStream: For patients with metastatic urologic cancers, what unique role can adaptive radiotherapy play?
Professor Ningning Lu: Evidence increasingly supports aggressive radiotherapy for oligometastatic disease. Studies show that, alongside systemic therapy, radiotherapy to the primary tumor or all metastases can significantly improve outcomes in low metastatic–burden prostate cancer.
We conducted a prospective trial using MR-guided radiotherapy for high-risk, very-high-risk, pelvic node–positive, and oligometastatic patients with whole-disease–coverage hypofractionation, including pelvic irradiation. This was the first study to demonstrate that MR-guided adaptive hypofractionated treatment is technically feasible and safe even when irradiating large target volumes. All patients completed treatment successfully, with low acute and late toxicity and excellent tolerability. Long-term in-field control reached 100%, offering a potent and safe option for advanced disease and new possibilities for sustained disease control.
05 UroStream: In your view, where will the next major breakthroughs in precision radiotherapy emerge?
Professor Ningning Lu: Future progress will focus on achieving both precision and efficiency.
Technically, motion management will be key. Studies worldwide are developing predictive models for prostate, bladder, and rectal motion to enhance accuracy. MR-Linac systems already incorporate intrafraction motion-control modules, improving precision but currently requiring slightly longer treatment times.
In workflow innovation, “simulation-free” one-stop treatments—integrating simulation, planning, and delivery—may revolutionize radiotherapy practice. In the future, treatment times may be reduced to under 15 minutes per session.
From functional preservation in localized prostate cancer, to safe dose escalation in complex recurrences, to lesion eradication in oligometastasis, precision radiotherapy continues to broaden its clinical impact. With ongoing technical refinement and clinical research, we aim to deliver more effective, convenient, and individualized treatment options across all stages of urologic cancers, ultimately improving survival and quality of life.
Professor Ningning Lu
