Trial of Tomotherapy in Breast Cancer

Randomized Trial Comparing Conventional vs Short-course Reduced Volume Conformal Post-surgery Radiation Treatment in Women With Stage I or II Breast Cancer

Tomotherapy is a new radiation therapy system that uses an integrated CT scanner during delivery of radiation treatment to improve the accuracy of the treatment. Furthermore the irradiation is delivered helicoidally allowing highly conformal shaping of dose distribution. However the magnitude of the clinical advantage of using the system in breast cancer is unknown. The purpose of the present study is to investigate whether or not the Tomotherapy can substantially reduce pulmonary and cardiac toxicities, as compared with conventional radiotherapy.

Prior to surgery: histological confirmation; medical imaging.

Localizing markers are placed in case of breast conserving surgery.

After surgery, patients are randomized to one of two treatment arms:

• Arm I: radiotherapy using tangential chest fields, and supraclavicular field in case of nodal involvement, according to our hospital's standard procedure (Voordeckers M et al, Radiother Oncol 2003;68:227 and 2004;70:225). Dose-fractionation: 50 Gy in 25 fractions over 5 weeks, 2 Gy/fraction. Additional boost 16 Gy in 8 fractions over 2 weeks if breast conserving surgery (verify marker/clip localization) and age <= 70 years.
• Arm II: radiotherapy using the Tomotherapy system. Target area (breast, thorax wall, nodal areas) delimited according to pre-operative imaging and pathological description. Dose-fractionation (adapted from Whelan T et al, JNCI 2002;94:1143): 42 Gy in 15 fractions over 3 weeks, 2.8 Gy/fraction. Simultaneous boost 0.6 Gy/fraction if breast conserving surgery.

Physics quality control is integrated during treatment in both arms.

Radiotherapy begins within 6 weeks after the last breast surgery. Concurrent or sequential adjuvant systemic treatments are allowed. In case of sequential adjuvant treatment with chemotherapy first, radiotherapy begins within 6 weeks after completion of the adjuvant chemotherapy.

Quality of life, arm mobility and edema, pulmonary and heart function are assessed prior to radiotherapy, at 1-3 months after completion of radiotherapy, then yearly.

Inclusion Criteria:

• Informed consent
• Histologically proven breast carcinoma
• Stage I or II (T1-3N0 or T1-2N1 M0, AJCC/TNM 6th edition)
• Surgery with clear margins
• Pre-operative medical imaging (at least CT, MRI, and/or PET-scan)

Exclusion Criteria:

• Prior breast or thoracic radiotherapy
• Pregnancy or lactation
• Fertile patients without effective contraception
• Psychiatric or addictive disorders