Effective local control of vertebral metastases by simultaneous integrated boost radiotherapy: preliminary results.
BACKGROUND
The primary endpoint was to improve local tumour control of patients with metastatic spinal tumours by stereotactic body radiotherapy (SBRT) and dose escalation by simultaneous, integrated boost (PTV-boost). We used a whole vertebral body (PTV-elective) contouring approach. Secondary endpoints were severity of acute and chronic adverse effects and overall survival.


METHODS
In all, 33 patients with metastases of the vertebral column were treated at Erlangen University Hospital. SBRT was given in 12 or 10 fractions. The metastatic lesion (PTV-boost) received 3.6 Gy (range 3.0-4.51 Gy) per fraction for a total of 42.0 Gy (24.36-48.0 Gy) and the whole vertebra (PTV-elective) received 2.85 Gy (range 1.8-3.6 Gy) per fraction for a total of 32.39 Gy (range 21.60-38.0 Gy). Patients were followed up every 3 months.


RESULTS
Local control rate of all patients was 93% at 12 and 24 months. The overall survival rate was 54% at 12 months, 38% at 24 months and 18% at 36 months. No radiation myelopathy occurred. The most frequently observed adverse events in 3 cases was oesophagitis grade 2.


CONCLUSIONS
SBRT with simultaneous, integrated boost was associated with excellent local control of 93% after 24 months. This result shows the possibility of delivering escalated doses to the target while still keeping the incidence of side effects low. This study forms the basis for a future randomised controlled trial comparing conventional radiotherapy (10 fractions of 3 Gy) with hypofractionated dose intensified SBRT (12 fractions of 3 Gy + integrated boost 12 fractions of 4 Gy) for improvement of local tumour control and pain.
Department of Radiation Oncology, Erlangen University Hospital, Universitätsstraße 27, 91054, Erlangen, Germany, dorota.lubgan@uk-erlangen.de.
Dorota
D
Lubgan
Anke
A
Ziegaus
Sabine
S
Semrau
Ulrike
U
Lambrecht
Sebastian
S
Lettmaier
Rainer
R
Fietkau
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology; D016634:Radiosurgery; D011880:Radiotherapy Planning, Computer-Assisted; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D015996:Survival Rate