Volumetric Modulated Arc Therapy as an Example of the Advanced Capability of Modern Radiotherapy.

BACKGROUND: Family physicians and internal medicine specialists play an essential role in treating cancer patients. Modern technological advances in radiotherapy are not widely appreciated by primary care physicians. Bone metastases are a frequent complication of cancer. Palliative radiation therapy, as a component of modern advances in radiation treatments, should not subject normal bodily structures to excessive doses of irradiation. The sacrum is a common destination site for bone metastases, yet its concave shape along with its proximity to the rectum, intestines, and femoral heads creates treatment-planning challenges.

OBJECTIVES: To investigated whether the volumetric modulated arc therapy (VMAT) technique is preferable to more conventional radiation strategies.

METHODS: The study comprised 22 patients with sacral metastases who were consecutively treated between 2013 and 2014. Two plans were generated for the comparison: three-dimensional (3D) and VMAT.

RESULTS: The planning target volume (PTV) coverage of the sacrum was identical in VMAT and 3D planning. The median values for the rectal dose for 3D and VMAT were 11.34 ± 5.14 Gy and 7.7 ± 2.76 Gy, respectively. Distal sacral involvement (S4 and S5) was observed in only 2 of 22 cases, while the upper pole of the rectum ended at the level above S3 in just 3 cases.

CONCLUSIONS: Radiation therapy continues to be an integral component of the palliative armamentarium against painful metastases. Radiation oncologist, in conjunction with referral physicians, can tailor treatment plans to reflect the needs of a given patient.