PROSTATE CANCER

Frequently Asked Questions

The CyberKnife System uses leading-edge robotics and advanced software, but it’s not new. In fact, the system has more than a decade of clinical evidence. The CyberKnife System is the only radiotherapy device supported by years of published clinical follow-up with a large number of patients. Two of these studies1,2, the largest prospective multi-institutional studies conducted to date, were carried out at US community and academic hospitals, providing reassurance to men that excellent clinical results are achievable at any CyberKnife center. The CyberKnife System is helping thousands of men overcome prostate cancer and get back to a healthy, full life, faster.

See The Clinical Proof

The FDA provided clearance for the CyberKnife System in 2001 for the treatment of tumors anywhere in the body, including the prostate. More than 20,000 patients with prostate cancer have been treated to date with the CyberKnife System.3

See The Clinical Proof

CyberKnife treatment is available at hundreds of locations worldwide.

Find a Treatment Center Near You

Treatment with the CyberKnife System is a nonsurgical outpatient procedure that does not require incisions or general anesthesia. Most patients will not require hospitalization or a long recovery period.

The entire CyberKnife treatment for prostate cancer can be completed in as little as 4-5 sessions over 1-2 weeks, compared to conventional radiation therapy which typically takes 30-40 sessions over 8-10 weeks.

Treatment with the CyberKnife System is a non-invasive procedure and avoids the inconvenience and risk associated with a radioactive seed or catheter implants, local anesthesia, potential infection, hospitalization stay and long recovery time.

Radiation therapy is a treatment that uses high-energy x-rays (photons) to kill, shrink or 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 the side effects on healthy tissue. As imaging technologies have improved over the last several decades, radiation therapy has integrated those improvements to enhance dose delivery and minimize side effects.

Radiation may be recommended as a primary treatment alternative to surgery or in addition to other therapies. There are several kinds of radiation therapy. The CyberKnife System delivers a type of radiation therapy known as stereotactic body radiation therapy (SBRT).

Stereotactic Body Radiation Therapy (SBRT) couples a high degree of targeting accuracy with very high doses of extremely precise, externally delivered radiation, thereby maximizing the cell-killing effect on the tumor(s) while minimizing radiation-related injury in adjacent normal tissues.

SBRT treatment takes into account the interaction between prostate cancer cells and radiation. Studies have indicated that prostate cancer cells have a high sensitivity to the amount of radiation delivered in each treatment session. This sensitivity suggests that a larger radiation dose delivered in a smaller number of sessions may result in better long-term control of the disease.4

Additionally, compared to conventional radiation therapy that typically requires approximately 30-40 sessions over 8-10 weeks, prostate SBRT can be completed in 4-5 sessions over 1-2 weeks.

Following a prostate cancer diagnosis, men are faced with numerous options including: active surveillance, radical prostatectomy and radiation therapy. Each man should consult his physician regarding his own specific case. Among the considerations that a physician will factor into a treatment recommendation is the patient’s health, age, lifestyle, and particular cancer aggressiveness, often referred to as “risk” profile.

The American Urological Association (AUA), the American Society for Radiation Oncology (ASTRO), and the Society for Urologic Oncology (SUO) support SBRT (such as the CyberKnife System) for select low- and intermediate-risk prostate cancer.5

Find a Treatment Center Near You

Despite the higher dose rate associated with SBRT, multiple studies have validated that there are no worse side effects with CyberKnife SBRT than with traditional radiation.6 The ability to deliver precise doses of radiation enables clinicians to decrease exposure to surrounding healthy tissue and minimize negative side-effects on urinary, bowel, and sexual function that can reduce a patient’s quality of life. The majority of patients can continue normal activity during and immediately following treatment. Nonetheless, urinary incontinence, bowel issues, and erectile dysfunction are all possible complications with any treatment option, and should be discussed with your physician.

Click Here for More Information on Potential Side Effects

CyberKnife treatment can be completed in as little as 4-5 sessions over 1-2 weeks, compared to conventional radiation therapy, which typically takes 30-40 sessions over 8-10 weeks. Each CyberKnife treatment session typically takes 15 to 20 minutes, compared to conventional radiation therapy which typically lasts 10 to 15 minutes per session.

Treatment with the CyberKnife System is a non-surgical and outpatient procedure that does not require general anesthesia. Most patients will not require hospitalization or a long recovery time. The majority of patients can continue normal activity during and immediately following treatment.

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

The majority of patients can continue normal activity during and immediately following CyberKnife treatment — compared to the typical requirement to limit normal activity for 4-6 weeks with traditional prostate cancer surgery. Importantly, patients treated with the CyberKnife System for prostate cancer reported a return to normal urinary and bowel function by six months post-procedure.7, 8

The majority of patients can continue normal activity during and immediately following CyberKnife treatment — compared to the typical requirement to limit normal activity for three to five weeks with traditional prostate cancer surgery.

The robotic design, combined with real-time imaging, enables the CyberKnife System to deliver a maximum dose of radiation directly to the tumor from virtually any angle with sub-millimeter precision throughout treatment delivery. The CyberKnife System does this by continually tracking, automatically adapting and synchronizing the radiation beam with the movement of the prostate or patient in real-time. Greater precision helps minimize dose to surrounding healthy tissues, reducing the risk of many common side effects.9, 10, 11, 12

The prostate gland can move unpredictably throughout the course of treatment, making the ability to track, detect and correct for motion critically important. In fact, the prostate has been documented to move as much as 5 mm in as little as 30 seconds due to normal patient bodily functions – such as filling of the bladder, gas in the bowel, or even slight patient movement during the procedure.13, 14

That motion is particularly problematic because the prostate is surrounded by sensitive organs and tissues. Failing to synchronize the delivery of radiation dose with prostate movement can result in decreased dose delivered to the target — and increased dose delivered to surrounding healthy tissues. This can impact the overall effectiveness of the treatment, and can potentially increase the incidence and severity of side effects.

Watch How The Cyberknife Synchronizes With Target Motion

Unlike any other radiation treatment, the CyberKnife System continually tracks, automatically adapts and synchronizes treatment delivery with movement of the prostate in real-time throughout the entire treatment session. This helps ensure the radiation dose is delivered precisely to the target — maximizing treatment effectiveness while protecting surrounding tissues to reduce the incidence of side effects.

Precisely delivering the prescribed radiation dose to the target is essential for optimizing long-term cancer control. Additionally, precise dose delivery reduces irradiation of healthy organs and tissues surrounding the target.

Because the prostate is surrounded by sensitive organs and tissues, precise delivery is critically important — reducing the incidence and severity of side effects and protecting quality of life both during and after treatment.

SBRT is a form of hypofractionated radiation therapy. Compared to traditional radiation therapy treatments — commonly called conventional fractionation, which involves the delivery of a relatively lower dose of radiation, typically delivered in 30-40 sessions across 8-10 weeks — hypofractionation entails delivering a higher dose per session (called a fraction) across fewer total sessions. Hypofractionated prostate cancer treatment can typically be completed in as little as 4-5 sessions over just 1-2 weeks. Hypofractionated radiation therapy, such as prostate SBRT, has been proven to deliver clinical outcomes as good as conventional fractionation — while dramatically reducing the number of treatments and the total cost of care for both patients and payers.

Despite the higher dose rate associated with SBRT, multiple studies have validated that there are no worse side effects with CyberKnife SBRT than with traditional radiation.6 The ability to deliver precise doses of radiation enables clinicians to decrease exposure to surrounding healthy organs and tissue and minimize negative side-effects on urinary, bowel, and sexual function that can reduce a patient’s quality of life. The majority of patients can continue normal activity during and immediately following treatment. Nonetheless, urinary incontinence, bowel issues, and erectile dysfunction are all possible complications with any treatment option, and should be discussed with your physician.

Extensive clinical research demonstrates that prostate SBRT with the CyberKnife System delivers excellent long-term cancer control.

At five years following CyberKnife prostate SBRT, the disease-free survival (DFS) rates were:

  • 97% – 100% for low-risk patients, superior to the 92% – 94% from conventional radiation therapy historic data15, 16, 17 and equivalent to low dose rate (LDR) brachytherapy18, 19 and high dose rate (HDR) brachytherapy13 without the inconvenience and risk associated with invasive seed and catheter implants.
  • 88% – 97% for intermediate-risk patients, equal to or higher than the 85% – 90% reported with conventional radiation therapy20, 21 without the inconvenience of daily visits over several weeks.

At 10 years following CyberKnife prostate SBRT, the DFS rates were:

  • 93% for low-risk patients, superior to the 81% – 85%22, 23 from conventional radiation therapy historical data and similar to HDR at 92%.13

Because it can precisely target tumors, the CyberKnife System may provide a safe radiation treatment option even for some previously irradiated patients.

  • Patients treated with the CyberKnife System are candidates for re-treatment, in the event of recurrence.
  • Patients treated with the CyberKnife System may still be candidates for surgical interventions, in the event of recurrence.

Because it can precisely target tumors, the CyberKnife System may provide a safe radiation treatment option even for some previously irradiated patients.

As of January 2020, SBRT treatment for prostate cancer is covered by Medicare in all 50 states and the District of Columbia in the United States. In addition, many private insurance payers cover SBRT treatment for prostate cancer. It is always best to check your insurance policy and if applicable, be sure to review your employee contract to determine if your insurance coverage benefits are limited. The CyberKnife Center that you have chosen to provide your treatment should be able answer insurance related coverage questions.

Not every patient’s prostate cancer is effectively treated with SBRT. Talk to your physician about your best options and come to a joint decision. As an example, if whole-bed pelvic radiation – radiation for disease outside the prostate – is required, Accuray’s Radixact® or TomoTherapy® System may be a good option: Radixact and the TomoTherapy Systems leverage CT-image guidance to ensure highly conformal dose delivery to the tumor with each treatment.

Resources

1 Fuller DB, et. al. “5-year outcomes from a prospective multi-institutional trial of heterogeneous dosing stereotactic body radiotherapy (SBRT) for low- and intermediate-risk prostate cancer.” J Clin Oncol. 2017; 35(6S).

2 Meier R, et al. “Five-Year Outcome From a Multicenter Trial of Stereotactic Body Radiation Therapy for Low- and Intermediate-Risk Prostate Cancer.” Int J Radiat Oncol Biol Phys. 2016; 96(2): S33-S34.

3 Accuray Incorporated, data on file 2020.

4 Fowler JF. “The radiobiology of prostate cancer including new aspects of fractionated radiotherapy.” Acta Oncol. 2005;44(3):265-76.

5 Sanda MG, et. al. Clinical Localized Prostate Cancer: AUA/ASTRO/SUO Guideline. American Urological Association. 2017.

6 King CR, Freeman D, Kaplan I, et al. “Stereotactic body radiotherapy for localized prostate cancer: pooled analysis from a multi-institutional consortium of prospective phase II trials.” Radiother Oncol 2013; 109(2): 217-221.

7 King CR, Collins S, Fuller D, et al. “Health-Related Quality of Life After Stereotactic Body Radiation Therapy for Localized Prostate Cancer: Results From a Multi-institutional Consortium of Prospective Trials.” Int. J. Radiat. Oncol. 2013;87:939–945.

8 Katz A, Ferrer M, et al. “Multicentric Spanish Group of Clinically Localized Prostate Cancer. Comparison of quality of life after stereotactic body radiotherapy and surgery for early-stage prostate cancer.” Radiat. Oncol. 2012;7:194.

9 Drexler and Furweger. “Quality assurance of a robotic, image guided radiosurgery system.” WC 2009, IFMBE Proceedings 25/I, 492-495, 2009.

10 Kilby. W. et al. “The CyberKnife Robotic Radiosurgery system in 2010.” TCRT 2010;9(5):433-452.

11 Yu, C., Main, W., Taylor, D., Kuduvalli, G., Apuzzo, M. L., Adler. J.R. Jr. “An anthropomorphic phantom study of the accuracy of Cyberknife spinal radiosurgery.” Neurosurgery. 2004 55(5):1138-49.

12 Antypas C. and Pantelis E. “Performance evaluation of a CyberKnife G4
image-guided robotic stereotactic radiosurgery system.” Phys Med Biol. 2008 Sep 7;53(17):4697-718. doi: 10.1088/0031-9155/53/17/016.

13 Demanes D. J. et al. “High dose rate monotherapy: safe and effective brachytherapy for patients with localized prostate cancer.” Int J Radiat Oncol Biol Phys 81(5): 1286-1292, 2011.

14 Kupelian P., et al. “Multi-institutional clinical experience with the Calypso System in localization and continuous, real-time monitoring of the prostate gland during external radiotherapy.” Int J Radiat Oncol Biol Phys. 2007 Mar 15;67(4):1088-98.

15 Zelefsky M.J., Chan H et al. “Long-term outcome of high dose intensity modulated radiation therapy for patients with clinically localized prostate cancer.” J Urol 2006; 176:1415-9.

16 Cheung R., Tucker S.L. et al. “Dose-Response Characteristics of Low- and Intermediate-Risk Prostate Cancer Treated with External Beam Radiotherapy.” Int J Radiat Oncol Biol Phys 2005; 61(4): 993-1002.

17 Thames HD, et al. “Increasing external beam dose for T1-T2 prostate cancer: Effect on risk groups.” Int J Radiat Oncol Biol Phys. 2006; 65(4): 975-81.

18 Lawton CA, DeSilvio M, Lee WR, et al. “Results of a phase II trial of transrectal ultrasound-guided permanent radioactive implantation of the prostate for definitive management of localized adenocarcinoma of the prostate (radiation therapy oncology group 98-05).” Int J Radiat Oncol Biol Phys 67:39-47, 2007.

19 Taira AV, Merrick GS, Galbreath RW, et al. “Natural history of clinically staged low-and intermediate-risk prostate cancer treated with monotherapeutic permanent interstitial brachytherapy.” Int J Radiat Oncol Biol Phys 76:349-54, 2010.

20 Michalski JM, Moughan J, Purdy J, et al. “A randomized trial of 79.2 Gy versus 70.2 Gy radiation therapy (RT) for localized prostate cancer.” J Clin Oncol 33(S7): abstr4, 2015.

21 Spratt DE, Pei X, Yamada J, et al. « Long-term survival and toxicity in patients treated with high-dose intensity modulated radiation therapy for localized prostate cancer.” Int J Radiat Oncol Biol Phys 85:686-92, 2013.

22 Alicikus, Z. A., Yamada, Y., Zhang, Z., Pei, X., Hunt, M., Kollmeier, M., Cox, B. and Zelefsky, M. J. (2011). “Ten-year outcomes of high-dose, intensity-modulated radiotherapy for localized prostate cancer.” Cancer, 117: 1429–1437. doi:10.1002/ cncr.25467.

23 Weller MA, et al. “Comparison of Outcomes Between Brachytherapy and Intensity Modulated Radiation Therapy in High-Risk Prostate Cancer.” International Journal of Radiation Oncology • Biology • Physics, Volume 90, Issue 1, S210.

24 Jereczek-Fossa B.A. et. al. “Robotic image-guided stereotactic radiotherapy, for isolated recurrent primary, lymph node or metastatic prostate cancer.” Int J Radiat Oncol Biol Phys 2012; 82(2):889-97.

25 Fuller et al. “Retreatment for Local Recurrence of Prostatic Carcinoma After Prior Therapeutic Irradiation: Efficacy and Toxicity of HDR-Like SBRT.” Int J Radiat Oncol Biol Phys. 2019.10.014.