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phenotypes related to local control or risk of relapse after
(chemo)radiotherapy. Clinical implementation of dose
painting, however, is not a trivial task and the success
cannot be guaranteed as there are several potential
challenges and limitations related to the imaging
techniques, the underlying radiobiological aspects and the
current techniques for delivering the heterogeneous dose
distributions. This talk will present a paradigm shift from
focusing on the radiobiological dose prescription, such as
in dose painting approaches, to biologically adapted
radiation therapy, based on tumour responsiveness
assessed with functional imaging. Thus, the general idea
is to use functional information from advanced imaging
modalities for the assessment of the tumour response
early on during the course of the treatment followed by
the adaptation of the treatment for the patients for which
poor response is predicted. A previous study showing that
the early response to treatment of NSCLC patients can be
evaluated by stratifying the patients in good and poor
responders based on calculations of the effective
radiosensitivity derived from two FDG-PET scans taken
before the treatment and during the second week of
radiotherapy will be presented. Complementing studies on
the feasibility of effective radiosensitivity calculations for
H&N cancer patients as well as the identification of the
optimal window during the treatment for assessing the
effective radiosensitivity will also be presented. For the
patient classified as poor responders, the distribution of
the effective radiosensitivity displayed as a map of
response overlapping onto the GTV could be used for
guiding adaptive planning approaches. Thus, the method
to be presented in this talk would allow the delineation of
the sub-volumes expressing lack of response, hence the
sub-volumes that should receive a dose boost as adaptive
treatment based on functional imaging. Several strategies
for treatment adaptation, including photon and proton
irradiation, will be considered. This is an extremely novel
approach to response assessment and treatment
adaptation that opens the way for true treatment
individualisation in radiation therapy.
Symposium: Focus on lung cancer: What a radiotherapy
department should offer their patients
SP-0407 PET/CT artefacts for RT planning
A. Santos
1
1
Hospital Cuf Descobertas- S.A., Nuclear Medicine
Department, Lisboa, Portugal
Nuclear Medicine, along with PET/CT technology has been
playing an important role in the detection, staging and
follow-up of lung cancer. The therapeutic approach to
lung cancer can vary, depending on the staging of the
tumour, being Radiotherapy one of the most important of
the available treatments. The association of PET/CT to
radiotherapy planning has a synergic effect that will
benefit the patient. Nuclear Medicine Technologists (NMT)
that perform PET/CT must be aware of the numerous
artefacts and pitfalls that can influence the acquired
images and the results of the diagnostic procedure. The
equipment must have its quality standards assured,
radiopharmacy aspects must be covered, the patient
should be correctly prepared and also perform all stages
of the procedure accordingly. Anyhow, artefacts and
pitfalls can randomly occur and this is why it is so
important to have theorical knowledge and practical skills
in order to correctly identify the artefacts and correct it
when required. In addition, the active participation of the
Radiotherapy technologists (RTT) in the multidisciplinary
team surely increases the quality of the results. NMT
benefit from the valuable inputs from RTT, since these
professionals are specialists in radiotherapy patient
positioning, and will be the common factor between
PET/CT acquisition and radiotherapy treatment. Also, RTT
commonly have a prior relation with the patient and this
might play an important role in the patient welfare. The
humanization of patient care, along with the state of the
art of the technology, are the focus of the
multidisciplinary team that surrounds the patient.
SP-0408 ART in lung cancer: when and for whom?
P. Berkovic
1
1
C.H.U. - Sart Tilman, Radiotherapy department, Liège,
Belgium
Lung cancer is the most common cause of cancer death
worldwide [1]. Non-small cell lung cancer (NSCLC)
accounts for 80 – 85% of all lung cancers of which about
30% are locally advanced (LA) at diagnosis [2]. Although
concurrent chemoradiotherapy (cCRT) improves survival
compared to sequential one (sCRT) [3], there remains
room for improvement in the treatment of LA-NSCLC.
Within the radiotherapy component, several possible
treatment strategies were investigated, such as altered
fractionation and/or dose escalation. However, dose
escalation is severely hampered by normal tissue toxicity
[4] and can lead to deleterious results when used without
taking patient-, tumor- and treatment characteristics into
account. This hurdle can be overcome by patient-
individualized
treatment
approaches
such
as
individualized dose-escalation using fixed dose constraints
or adapting the treatment-fields to the shrinking tumor.
However, adaptive radiotherapy (ART) is time consuming
and it is not clear which patient is eligible or what the
optimal time point for ART should be. Technical advances,
such as intensity-modulated radiotherapy (IMRT) and
tumor motion strategies, may further improve the
therapeutic ratio. To reach full potential, these strategies
imply the use of image-guided radiotherapy (IGRT), e.g.
by using a cone-beam computed tomography (CBCT). The
latter also allows monitoring tumor volume or -position
changes over the treatment course. In this lecture we will
address both anatomical- and especially tumor volume
changes during chemoradiation and analyse potential
predictive factors of volume and dosimetric parameter
changes, as well as the potential gain to organs at risk
(OARs) while maintaining target volume coverage.
Furthermore, the optimal implementation strategy
regarding selection of patients (who) and timing of
imaging/replanning (when) will be discussed with an
overview of the results, from a physician’s perspective.
References:
[1] Ferlay J et al. Estimates of worldwide burden of cancer
in 2008 : GLOBOCAN 2008. Int J Cancer 2010 ;127: 2893 –
917.
[2] Peters S et al. Metastatic non-small-cell lung cancer
(NSCLC): ESMO Clinical Practice Guidelines for diagnosis,
treatment and follow-up . Ann Oncol 2012 ; 23(Suppl 7) :
vii56 – 64.
[3] Auperin A et al. Meta-analysis of concomitant versus
sequential radiochemotherapy in locally advanced
nonsmall-cell lung cancer . J Clin Oncol 2010 ; 28 : 2181 –
90.
[4] Bradley J. A review of radiation dose escalation trials
for non-small cell lung cancer within the Radiation
Therapy Oncology Group . Semin Oncol 2005 ; 32 : S111 –
3.
SP-0409 Improvements in physics, DIBH in lung
M. Josipovic
1
1
The Finsen Center - Rigshospitalet, Copenhagen,
Denmark
Radiotherapy in deep inspiration breath hold (DIBH) has
been successfully applied in breast cancer patients and
recently also for mediastinal lymphoma, exploring the
benefit of inflated lungs and changed position of the
heart. Patients with lung cancer may benefit