Helical Tomotherapy Versus 3-Dimensional Conformal Radiation Therapy in High-Risk Prostate Cancer: A Phase 3...

Area of Science:

• Radiation Oncology
• Urologic Oncology

Background:

• High-risk prostate cancer requires advanced radiation techniques for optimal outcomes.
• Comparing helical tomotherapy and 3-dimensional conformal radiation therapy (3D-CRT) is crucial for treatment selection.

Purpose of the Study:

• To present long-term outcomes of a phase 3 randomized controlled trial comparing helical tomotherapy and 3D-CRT for high-risk prostate cancer.
• To evaluate differences in late rectal toxicity and biochemical progression-free survival between the two radiation modalities.

Main Methods:

• A phase 3 randomized controlled trial involving 123 patients with high-risk prostate cancer.
• Patients received radical radiation therapy (RT) with either 3D-CRT or helical tomotherapy, combined with 3 years of adjuvant androgen deprivation.
• The primary endpoint was late rectal toxicity, with secondary endpoints including genitourinary toxicity and biochemical progression.

Main Results:

• After a median follow-up of 161 months, no significant difference in grade ≥ 2 late rectal toxicity was observed between 3D-CRT (8.3%) and tomotherapy (11.1%) arms (P = .83).
• Late genitourinary toxicity rates also showed no significant difference (P = .17).
• There was no significant difference in the hazard of biochemical progression or death between the two treatment groups (P = .17).

Conclusions:

• The incidence of grade ≥ 2 late rectal toxicity was low and comparable between helical tomotherapy and 3D-CRT in high-risk prostate cancer.
• Helical tomotherapy did not demonstrate a significant improvement in biochemical progression-free survival compared to 3D-CRT.
• The study highlights the need for caution in interpretation due to potential type II errors from limited sample size and low event rates.