modern radiation treatment
TRANSCRIPT
Modern radiation treatment
Karin Haustermans Department of Radiation Oncology, University Hospitals Leuven, Belgium
On behalf of ESTRO – European Society for Radiotherapy & Oncology
European Prostate Awareness Day 2015
Radiation oncology
• Medical use of ionizing radiation in the treatment of
cancer
• About 50% of all cancer patients receive radiation therapy
at some point during their treatment
• Monotherapy or combined with other treatment modalities
• Curative or palliative setting
Radiation oncology
• Ultimate goal of radiation therapy:
• To maximize tumor targetting,
• While sparing the surrounding normal tissue
• Inevitably some radiation dose is always deposited in the
healthy tissues…
Therapeutic ratio
“Ballistic Equipment”
Rifle
Ammunition
“Game Search”
Binoculars
Experience
“Aiming for the target”
Telescopic sight
Steady Hand
Dose Delivery Target Definition Target Localization
Hunting cancer cells with IR
Dose delivery
2D-RT 3D-CRT IMRT IMAT 1990 2000 2010
2D-RT
3D-CRT
IMRT
IMAT
Dose delivery
• IMAT
• Further optimization of
IMRT technique
• 360° rotation of gantry
• Fast delivery
• Highly conformal
Target definition
• Advances in treatment planning and radiation delivery,
thanks to advances in imaging
Conventional radiotherapy
3D-Conformal radiotherapy
Intensity modulated
radiotherapy
Anatomical imaging
Functional imaging
Multimodality imaging
Target definition
• Anatomical & functional
imaging
T2w MRI DCE MRI
DW MRI:
b1000
DW MRI: ADC
map
PSMA PET-CT
TRUS MR/CT
Target localization
• Importance of target localization
• INTER-fraction: between treatments
• Bowel or bladder filling
• Positioning or set-up errors
• Tumor shrinkage
• Weight loss
• INTRA-fraction: during treatment
• Breathing, swallowing, cardiac motion
• Patient movement (e.g. due to pain)
Target localization
• Imaging for position verification!
• In-room and/or on-board (EPID, cone-beam CT, MV/kV RX)
• Image quality
• Image registration
“Conformal Dose Delivery”
Accurate Dose Delivery
IMRT
“Imaging”
Anatomical Imaging
Functional Imaging
“Motion”
Inter/Intra-fraction
Positioning verification
Dose Delivery Target Definition Target Localization
State-of-the-art summary
Dose delivery
• Adequate dose escalation without increasing toxicity?
• Focal boost to the dominant lesion in addition to standard dose
to the whole organ
• Rationale
• PCa is multifocal
• Dominant lesion is biological driver
• PCa often recurs at the site of the dominant lesion
• Dose-response relationship
Dose delivery
• Hadron therapy: charged particles
Thariat et al Nat Rev Clin Oncol 2013
Dose delivery
• Unique physical and radiobiological properties: Bragg peak
Dose delivery
• Stereotactic body radiotherapy (SBRT)
• Large dose per fraction
• Hypofractionation
• E.g. SBRT for oligometastatic PCa
Ponti E et al Clin Genitourin Cancer 2015
“Physical optimization”
Hadron therapy
SBRT
“Biological optimization”
Focal boosting
“Adaptive therapy”
IGRT
Adaptive RT
Dose Delivery Target Definition Target Localization
Future prospects: summary
