Benign and malignant brain tumors present significant challenges — but modern technologies such as stereotactic radiosurgery are opening up new treatment avenues. Dr. Christoph Weber, MD, neurosurgeon and specialist in radiosurgery based in Zurich, explains in this exclusive interview how radiosurgery treats brain tumors with high precision, minimal invasiveness, and on an outpatient basis — all while maintaining and improving patients’ quality of life. Dr. Christoph Weber, MD is an experienced neurosurgeon specializing, among other areas, in stereotactic radiosurgery, offering patients an effective and minimally invasive alternative to conventional surgery. Since 2021, Dr. Weber has run his own practice for neurosurgery, spinal surgery, and radiosurgery in Zurich. At the core of his work is the use of cutting-edge intracranial radiosurgery with the ZAP-X system — the first and only one of its kind in Switzerland.
This robotic technology enables outpatient, millimeter-precise irradiation of both benign and malignant tumors in the head and brain. Thanks to the precise concentration of radiation on the tumor while sparing surrounding tissue, radiosurgery offers an especially safe and effective therapeutic option — and compared to alternative treatments, it requires no surgery, no anesthesia, and involves only minimal side effects.
Additionally, Dr. Weber focuses on the treatment of complex spinal conditions. To minimize the burden on patients, he prefers to use minimally invasive and microsurgical techniques. As an attending physician at several renowned clinics in the Zurich area (including Spital Zollikerberg, Hirslanden Klinik im Park, and See Spital Horgen) and through his combination of in-practice consultations and online appointments, Dr. Weber ensures comprehensive, modern, patient-centered care.
In conversation with the Leading Medicine Guide, Dr. Weber offers exclusive insights into the fascinating possibilities of modern radiosurgery.
Tumors in the brain and skull often present a unique challenge: they grow in one of the most delicate areas of the body and — even when benign — can impair vital functions. Today, modern technologies like stereotactic radiosurgery offer new, gentler treatment options: highly precise, outpatient, and often in just a single session. Dr. Christoph Weber, MD, neurosurgeon and radiosurgery expert in Zurich, explains how the innovative ZAP-X system combats tumors effectively and safely.
Dr. Weber, what distinguishes stereotactic radiosurgery from conventional radiation therapy?
Radiation therapy fundamentally aims to deliver a specific dose directly to the tumor. In the past, this involved irradiating the entire brain. Today, there is a clear objective to protect as much healthy surrounding tissue as possible. Especially in the brain, where many sensitive structures must be preserved, this is critical. This is where the concept of “dose fall-off” plays a crucial role: it refers to how quickly radiation intensity decreases outside the tumor. The steeper the dose fall-off, the better the healthy tissue is protected — and that is precisely the unique strength of radiosurgery.
Another key difference concerns the treatment duration: while conventional radiation therapy usually takes place over several weeks with daily sessions, stereotactic radiosurgery is typically performed in a single session lasting less than an hour. This is made possible by a different dosing principle: instead of spreading the radiation dose over time (temporal fractionation) as in conventional radiation, radiosurgery uses “geometric fractionation.” Simply put: in conventional radiation, the dose must be divided across multiple sessions to allow healthy brain tissue to recover between treatments, as the beams always come from the same direction. In radiosurgery, however, many weak beams approach the tumor from different angles. Each individual beam carries too little energy to damage surrounding tissue, but where all the beams converge at the tumor site, their energy sums up. This allows the targeted destruction of tumor cells while maximally sparing healthy tissue.
What technologies do you use?
We work with the state-of-the-art ZAP-X system, which was specifically developed for radiosurgical treatment of tumors in the head. This is the first and only device of its kind in all of Switzerland and represents one of the most innovative advancements in radiosurgery.
What does the radiosurgery treatment process look like?
Each patient receives an individualized treatment plan. Planning is done by an interdisciplinary team consisting of neurosurgeons, radiation oncologists, and medical physicists. First, the tumor is precisely located using high-resolution MRI imaging. The tumor is then accurately mapped on a computer — comparable to a topographic map where contour lines visualize the radiation dose. The goal is to plan the irradiation so that the dose is maximal within the tumor and minimal in the surrounding healthy tissue. Using three-dimensional imaging data and planning software, we calculate the optimal radiation dose and beam angles. Precise targeting and careful planning are crucial to fully leverage the advantages of stereotactic radiosurgery and offer patients a gentle yet highly effective treatment. The outpatient procedure is performed without anesthesia, usually in a single session. During treatment, the patient is gently secured with a custom-fitted face mask to prevent movement. The actual irradiation is completely painless and lasts about 45 to 60 minutes, depending on the tumor size. Afterward, the patient can leave the clinic and resume daily life as usual.
Which types of tumors are particularly suitable for radiosurgery?
Stereotactic radiosurgery is especially suitable for benign tumors such as schwannomas or neurinomas (including vestibular schwannomas, formerly acoustic neuromas), meningiomas, or pituitary adenomas. We also achieve excellent results treating brain metastases from malignant diseases. Additionally, we use this technique for vascular lesions, such as arteriovenous malformations (AVMs) and glomus tumors, as well as for functional disorders like trigeminal neuralgia. Other areas of application include therapy-resistant tremor and epilepsy disorders, and ocular tumors. For primary brain tumors like glioblastoma, surgery is usually the first-line treatment; however, for recurrences, radiosurgery can be a valuable option.
What advantages does radiosurgery offer compared to conventional surgery?
Radiosurgery is a non-invasive treatment method. This eliminates surgical risks such as bleeding, infections, nerve injuries, or complications like cerebrospinal fluid leaks. Patients benefit from faster recovery and avoid lengthy hospital stays. This is a major advantage, particularly for elderly or medically compromised individuals. Moreover, radiosurgery provides an alternative for patients who are hesitant to undergo brain surgery, whether due to fear or other reasons.
Are there risks or side effects?
Severe complications like radiation necrosis are very rare thanks to the high-precision technology. Radiation necrosis typically occurs when a high radiation dose affects a large volume of healthy brain tissue. This is precisely where radiosurgery’s decisive advantage lies: thanks to the steep dose gradient and targeted irradiation from multiple angles, the impact on healthy tissue surrounding the tumor is minimized. Rare side effects, such as mild swelling or inflammatory reactions, can be effectively managed with corticosteroids.
What are the success rates after radiosurgical treatment?
For benign tumors such as vestibular schwannomas, meningiomas, or pituitary adenomas, we achieve tumor control rates of 95 to 98%. Tumor control generally means halting tumor growth. With benign tumors, complete removal is not always necessary. Shrinking or halting further growth is usually sufficient to alleviate existing symptoms and prevent new ones. If growth recurs, we can easily repeat the treatment.
What are the costs of stereotactic radiosurgery, and how do they compare to conventional therapies?
The treatment costs are significantly lower than those of a conventional surgical procedure. Consider this: traditional surgery typically requires hospitalization, possibly intensive care monitoring, and a longer postoperative recovery period. These factors not only result in higher medical costs but also lead to longer downtime for patients. With stereotactic radiosurgery, these expenses are avoided. The procedure is outpatient, and patients can return home the same day and quickly resume their daily routines. In Switzerland, the costs are fully covered by mandatory health insurance. In Germany, they are covered following a prior cost approval request, especially when radiosurgery is considered an equivalent or superior alternative to surgery. Overall, radiosurgery offers a highly attractive solution for many patients, both medically and economically.
Stereotactic radiosurgery marks a significant advance in medical development: it enables treatment outcomes that not only match but often surpass previous standards — all while imposing significantly less burden and fewer side effects on patients and at just a fraction of the usual costs.
Thank you, Dr. Weber, for this fascinating insight into modern radiosurgery!
Benefits of ZAP-X Radiosurgery at a Glance:
- Precise treatment: millimeter-accurate targeting of radiation on the tumor.
- Preservation of healthy tissue: minimal impact on surrounding structures due to steep dose fall-off.
- Outpatient & fast: typically performed in a single session without hospitalization.
- No surgery required: no scalpel, no anesthesia, no surgical risks.
- High success rates: 95–98% for benign brain tumors such as meningiomas and acoustic neuromas.
- Repeatable therapy: re-irradiation possible in case of regrowth.
- Also suitable for recurrence cases or after prior surgery or radiation therapy.
- Also appropriate for inoperable tumors or those located in highly sensitive, functionally critical (so-called eloquent) brain areas.
- Ideal for high-risk patients: particularly suitable for individuals with elevated surgical risk or advanced age.
- High cost-effectiveness, as the treatment incurs only a fraction of the cost of open surgery.
