A Prospective Evaluation of Helical Tomotherapy

Glenn Bauman, M.D., F.R.C.P.C. IJROBP Volume 68, Issue 2, Pages 632-641 (1 June 2007)

London Regional Cancer Program, London, Ontario, Canada

Purpose: To report results from two clinical trials evaluating helical tomotherapy (HT).

Methods and Materials: Patients were enrolled in one of two prospective trials of HT (one for palliative and one for radical treatment). Both an HT plan and a companion three-dimensional conformal radiotherapy (3D-CRT) plan were generated. Pretreatment megavoltage computed tomography was used for daily image guidance.

Results: From September 2004 to January 2006, a total of 61 sites in 60 patients were treated. In all but one case, a clinically acceptable tomotherapy plan for treatment was generated. Helical tomotherapy plans were subjectively equivalent or superior to 3D-CRT in 95% of plans. Helical tomotherapy was deemed equivalent or superior in two thirds of dose–volume point comparisons. In cases of inferiority, differences were either clinically insignificant and/or reflected deliberate tradeoffs to optimize the HT plan. Overall imaging and treatment time (median) was 27 min (range, 16–91 min). According to a patient questionnaire, 78% of patients were satisfied to very satisfied with the treatment process.

Conclusions: Helical tomotherapy demonstrated clear advantages over conventional 3D-CRT in this diverse patient group. The prospective trials were helpful in deploying this technology in a busy clinical setting.

 

Examples of novel organ-at-risk sparing enabled by tomotherapy for palliative patients. (a) Whole calvarial radiation with brain sparing; (b) prostate plus nodal radiation with bowel sparing; (c) vertebral body with central cord sparing; (d) chest wall with lung sparing.

Examples of tomotherapy for radically treated patients. (a) Prostate treatment; (b) synchronous treatment of a right-sided acoustic neuroma and a left-sided meningioma; (c) treatment of a medullary thyroid cancer patient with spinal cord and laryngeal sparing; (d) bilateral chest wall treatment.