Frequently Asked Questions

The Radixact System, the next-generation TomoTherapy® platform, has been designed to enable doctors to more effectively and efficiently deliver precise radiation treatments to more patients. The TomoTherapy platform represented a dramatic advance in the radiation oncology field, as the only system specifically designed for integrated 3D daily image-guidance with intensity modulated radiation therapy (IG-IMRT) to help patients control their cancer. The TomoTherapy technology, used in the Radixact System, has more than two decades of clinical evidence and has been used to help thousands of cancer patients. Today, the Radixact System is routinely used to treat a variety of cancers – from routine to complex tumors, those located in hard-to-reach areas, recurrent tumors and cancers of the skin and blood.

The FDA provided clearance for the TomoTherapy technology in 2002 and in 2016 for the Radixact System, the next generation TomoTherapy platform, for the treatment of tumors anywhere in the body, including anal cancers. The use the TomoTherapy technology, as well as IMRT, are supported by published clinical studies.

  • Studies evaluating patients with anal cancer who received simultaneous daily IG-IMRT and a targeted radiation boost delivered using Helical TomoTherapy, found they experienced low treatment-related acute or late toxicities and good local cancer control. This radiation treatment approach, with or without chemotherapy, enabled clinicians to reduce the margins around the tumor receiving radiation, resulting in a significant reduction in certain toxicity rates without impacting treatment outcomes 1, 2.
  • An analysis involving patients with anal cancer found that treatment with IMRT and simultaneous integrated boost radiation resulted in excellent long-term outcomes and tolerability 3.
  • A comparison of patients receiving IMRT or 3D conformal radiation therapy in combination with chemotherapy showed that IMRT as part of the treatment protocol resulted in significantly less incontinence, pain and fatigue, as well as significantly fewer chronic post-treatment toxicities 4.

Radixact treatment is available at many locations worldwide. TomoTherapy treatments are available at hundreds of locations worldwide.

Find a Treatment Center Near You

The helical design of the Radixact System – unique among radiation therapy systems – enables 360-degree radiation dose delivery as the treatment table moves the patient at a deliberate pace through the center of the system. The Radixact System revolves around you while thousands of “beamlets” – smaller than the radiation beams of conventional systems – are delivered to the tumor. Each beamlet can deliver a different dose of radiation. Different doses go to different parts of each tumor, while minimizing doseto surrounding healthy tissue.

Integrated imaging and advanced dose-delivery capabilities enable your treatment team to create a more personalized treatment plan and confidently deliver the most precise dose of radiation, directly to the tumor. Radixact helical delivery also enables treatment of a full range of diseases, including large, more complex tumors, multiple tumors, and recurrent tumors.

Radixact treatments are completed in one to several weeks, similar to conventional radiation therapy.

Helical delivery means that the source of the radiation beam(s) (the linear accelerator or LINAC), can move in multiple 360 degrees around the patient during treatment delivery while the treatment table moves the patient at a deliberate pace through the center of the system. Whereas conventional radiation therapy systems can only deliver radiation from a limited number of points, the helical delivery of the Radixact System helps to allow the clinical team to administer the accurate dose of radiation to the tumor from 360 degrees around the patient.

Radiation therapy is a treatment that uses high-energy X-rays (photons) to destroy cancer cells and control the growth of tumors. Radiation therapy works by damaging cells, disabling them from growing and dividing. The goal of any radiation treatment is to destroy cancer cells while minimizing dose to healthy tissue. As imaging technologies have advanced over the past several decades, radiation therapy has integrated those upgrades to help enhance dose delivery, improve outcomes and reduce the side effects of treatment.

Radiation is a proven cornerstone of effective treatment for many anal cancers, and may be combined with other treatments including chemotherapy. Radiation therapy is constantly evolving with the introduction of new technologies to the market. The Radixact System can deliver a highly advanced type of radiation therapy known as image-guided, intensity-modulated radiation therapy (IG-IMRT).

Intensity-modulated radiation therapy (IMRT) is a specialized form of external beam radiation therapy that varies the intensity of each radiation beam. IMRT can help clinicians shape the delivery of radiation to fit the contours of the tumor more accurately and precisely – and help minimize dose to surrounding organs and tissues.

Image-guided intensity-modulated radiation therapy (IG-IMRT) is a type of targeted external beam radiation therapy that enhances IMRT by using images acquired before each treatment to help ensure accurate patient and tumor positioning before delivery of the radiation treatment.

With daily imaging, clinicians gain the confidence necessary to accurately set-up the patient on the table before treatment and reduce margins throughout the course of the treatment. And by modulating the intensity of the radiation beams/beamlets, IG-IMRT enables clinicians to carefully shape the radiation dose to fit the contours of the target(s), while minimizing dose to surrounding organs and other healthy tissues. This precision and accuracy is particularly valuable when it comes to minimizing the dose tothe digestive tract, bladder and reproductive organs.

There are more options than ever for treating anal cancers, and the right option depends on your specific diagnosis. The Radixact System is an ideal treatment option for a wide range of anal cancers, including the most advanced and complex cases. The best way to determine if Radixact treatment is right for you is to find a Radixact treatment location and make an appointment to discuss your specific details.

Find a Treatment Center Near You

Most radiation side effects are minimal and last only a short time. Side effects can, however, be severe. Possible short-term side effects could include:

  • Diarrhea and pain while going to the bathroom
  • Skin changes in areas being treated
  • Anal irritation and pain (radiation proctitis)
  • Discomfort during bowel movements
  • Vaginal irritation in women
  • Fatigue
  • Nausea
  • Low blood cell counts


Long-term side effects could include:

  • Scar tissue that can keep the anal sphincter muscle from working as it should
  • Fractures of the pelvis or hip
  • Rectal bleeding and pain
  • Infertility
  • Vaginal dryness
  • Narrowing or shortening of the vagina (stenosis), which can make sex painful
  • Swelling in the genitals and legs (lymphedema)
  • Sexual dysfunction


Ask your doctor for more details about the side effects of your specific radiation therapy.

Learn More About Potential Side Effects

You can expect your Radixact treatment to require daily sessions over several weeks. Because the Radixact System can deliver radiation continuously, without requiring interruptions to reposition, the entire treatment process typically lasts 10-20 minutes – including patient set-up time.

Radiation treatment sessions are non-invasive outpatient procedures, and no anesthesia is required. Most patients resume normal activity immediately after treatment sessions.


No anesthesia is required for Radixact treatment and treatment sessions are completed on an outpatient basis.

The majority of patients can continue normal activity during and immediately following Radixact treatment. Just as important, the Radixact System is designed to minimize dose to surrounding healthy tissues and reduce the incidence of side effects, with the goal of improving patient quality of life both during and after treatment. In some circumstances, side effects may occur.

Many patients experience minimal side effects and can quickly return to their daily routines.


A key goal of treatment is to preserve the functioning of the anal sphincter so you can control your bowels and stool, to minimize the impact of treatment on your overall quality of life. Precisely delivering the prescribed radiation dose reduces the risk of irradiating healthy tissues surrounding the tumor, such as the bladder, bowels and genital organs. Additionally, precise dose delivery is essential for optimizing long-term disease control.


Because the precise targeting of the Radixact System significantly reduces irradiation of surrounding healthy tissues, some patients previously treated with conventional radiation therapy systems or IMRT may be candidates for re-irradiation with the Radixact System, in the event of recurrence. Each patient should consult his physician regarding his or her own specific case.


Because the precise targeting of the Radixact System significantly reduces irradiation of surrounding healthy tissues, patients treated with conventional radiotherapy systems may be candidates for re-irradiation with the Radixact System, in the event of recurrence. Each patient should consult his physician regarding his own specific case.

Medicare and private insurance companies in the United States may reimburse image-guided IMRT for anal cancers, however it is subject to medical necessity and your health insurance plan constraints. Patients should contact a Radixact treatment center to determine if this procedure is a covered benefit under their health insurance plan and any out-of-pockets costs such as deductibles, co-insurances, and/or copayments. 

Not every patient’s condition is effectively treated with IG-IMRT. Talk to your physician about the best options and come to a joint decision.


1 Joseph K., Nijjar Y., Warkentin H. et al. Prospective phase II study of tomotherapy based chemoradiation treatment for locally advanced anal cancer. Radiother Oncol. 2015 Nov;117(2):234-9.

2 De Bari B., Jumeau R., Bouchaab H. et al. Efficacy and safety of helical tomotherapy

with daily image guidance in anal canal cancer patients, Acta Oncologica, 55:6, 767-773.

3 Mitra D., Hong T.S., Horick N. et al. Long-term outcomes and toxicities of a large cohort of anal cancer patients treated with dose-painted IMRT per RTOG 0529. Advances in radiation oncology. 2017;2(2):110–117.

4 Fredman E.T., Abdel-Wahab M., Kumar AMS. Influence of radiation treatment technique on outcome and toxicity in anal cancer. J Radiat Oncol. 2017;6(4):413-421.

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Important Safety Statement: Most side effects of radiotherapy, including radiotherapy delivered with Accuray systems, are mild and temporary, often involving fatigue, nausea, and skin irritation. Side effects can be severe, however, leading to pain, alterations in normal body functions (for example, urinary or salivary function), deterioration of quality of life, permanent injury and even death. Side effects can occur during or shortly after radiation treatment or in the months and years following radiation. The nature and severity of side effects depend on many factors, including the size and location of the treated tumor, the treatment technique (for example, the radiation dose), the patient’s general medical condition, to name a few. For more details about the side effects of your radiation therapy, and if treatment with an Accuray product is right for you, ask your doctor.