Cyberknife Linked to Maintaining Cancer Patient Quality of Life Scores Before and After Treatment

As previously mentioned, the Cyberknife is a radiosurgery technique used to target and treat cancerous masses in the body. Although this treatment method has become popular recently, various research studies have been published on the Cyberknife.  For example, past literature has evaluated the precision of the Cyberknife, how it is able to track and correct for patient motion, its efficacy, as well as the overall cost-effect ratio of the system.  In addition to exploring all of these factors, it is incredibly important for researchers to evaluate the impact of the Cyberknife system on quality of life for cancer patients.

Before delving into literature on this topic, it is useful to define the phrase “quality of life,” or QOL.  A hypothesized meaning of the term is the measurement of the difference between a person’s expectations for their lives and their present day life experiences (Calman, 1984).  Past research has been published regarding the impact of the Cyberknife system on quality of life for cancer patients.  For instance, a 2014 study evaluated urinary, bowel, and sexual QOL scores for prostate cancer patients at baseline and numerous times post-treatment (Katz et al., 2013).  Out of the patients assessed, mean urinary and bowel QOL declined 1-month post treatment and returned to baseline after two years; at 6-12 months, sexual QOL declined by a mean of 23% and remained stable afterward (Katz et al., 2013).  Similar findings were reported in a follow-up QOL assessment conducted by Katz (2014).  Thus, this research focused on prostate cancer indicates that the Cyberknife does not have a particularly positive impact on patient quality of life post-treatment.

Figure 1: Quality of life scores for prostate cancer patients post-cyberknife treatment. The graph represents the mean and standard QOL scores for patients at baseline and up to three years post treatment. Bowel, urinary, and sexual QOL were assessed for this patient sample. The graph indicates that bowel and urinary QOL dipped post-treatment but eventually returned to baseline, whereas sexual QOL slightly decreased overtime without returning to baseline. (Katz et al., 2013)

In addition to prostate cancer, research on this topic has been conducted on patients being treated for spinal tumors.  After undergoing Cyberknife treatment, patients with spinal lesions completed quality of life surveys (Gagnon et al., 2009).  Patients exhibited no significant changes in physical quality of life post-treatment, but they did exhibit significantly higher mental quality of life scores post treatment (Gagnon et al., 2009).  Research published by Degen on spinal tumor treatment suggested that mental and physical well-being QOL remained relatively constant both before Cyberknife treatment and up to two years post-treatment (2005).  Both of these studies on spinal tumor treatment indicated that the Cyberknife system had a significant impact on improving patient pain post-treatment (Gagnon et al., 2009; Degan et al., 2005).

Overall, literature regarding the impact of the Cyberknife system on QOL for cancer patients depict quite similar findings. This treatment method does not have a significant impact on improving or reducing QOL post-treatment, but appears to stabilize QOL overtime.  Although findings were not considered significant, QOL for sexual functioning of prostate cancer patients decreased and was maintained at that level numerous years post-treatment (Katz et al., 2013 & 2014).  Although QOL was not significantly effected for cancer patients with spinal lesions, the Cyberknife system did significantly improve patient pain post-treatment (Gagnon et al., 2009; Degan et al., 2005).

Despite the insignificant findings presented, a majority of the research suggests that the Cyberknife essentially maintained QOL scores before and after treatment.  In the future, it would be important for research to compare QOL scores for patients undergoing Cyberknife versus other treatment methods.  Research in this field could help elucidate which treatment method has the best impact on patients perceptions of their physical and mental QOL and would ultimately enable them to return back to their daily lives at a faster pace.

References

Calman, K. C. (1984). Quality of life in cancer patients–an hypothesis. [Abstract]. Journal of Medical Ethics,10(3), 124-127.

Degen, J. W., Gagnon, G. J., Voyadzis, J., Mcrae, D. A., Lunsden, M., Dieterich, S., Henderson, F. C. (2005).CyberKnife stereotactic radiosurgical treatment of spinal tumors for pain control and quality of life [Abstract]. Journal of Neurosurgery: Spine, 2(5), 540-549.

Gagnon, G. J., Nasr, N. M., Liao, J. J., Molzahn, I., Marsh, D., Mcrae, D., & Henderson, F. C. (2009). Treatment Of Spinal Tumors Using Cyberknife Fractionated Stereotactic Radiosurgery [Abstract]. Neurosurgery, 64(2), 297-307.

Katz, A. J., Santoro, M., Diblasio, F., & Ashley, R. (2013). Stereotactic body radiotherapy for localized prostate cancer: Disease control and quality of life at 6 years. Radiation Oncology, 8(1), 118-125.

Katz, A. J., & Kang, J. (2014). Quality of Life and Toxicity after SBRT for Organ-Confined Prostate Cancer, a 7-Year Study. Frontiers in Oncology, 4.