ESTRO 36 Abstract Book

S276

ESTRO 36 2017

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(QoL) becomes very important but studies evaluating QoL

in these patients is lacking. This study evaluates the

course of QoL in patients treated with SBRT for BM with

validated pain and QoL questionnaires.

Material and Methods

At the University Medical Center of Utrecht, the PRESENT

cohort is ongoing: a prospective cohort enrolling all

patients with bone metastases candidate to radiotherapy.

From this cohort, patients treated with SBRT were

selected to evaluate QoL and pain. EORTC C15-PAL and

BM22 questionnaires were administered at baseline, after

4, 8 weeks, 3, 6, and 12 months. BPI questionnaires were

administered together with QoL questionnaires, and

additionally after 2 and 6 weeks. Performance status and

comorbidity index were scored at baseline. Pain flare was

measured during treatment. Questionnaires were scored

according to the scoring manuals and analyzed with

descriptive statistics. QoL changes in time of ≥ 10 points

were considered clinically relevant.

Results

Forty-nine patients with 35 spinal and 27 non-spinal

lesions were included. Thirty-nine patients had

oligometastatic disease. Median follow up was 6 months

(range 1-31 months). Questionnaire return rates were 93%

at baseline and 71-88% during follow up. At baseline, 25

patients had painful lesions with a mean BPI pain score

of 5. During follow up, pain decreased to a score of 3 at 3

months, 2 at 6 months and 1 at 12 months (figure 1). In

general, QoL based on EORTC C15-PAL and BM22 improved

during follow up. No major deteriorations in functional

and symptom scales were observed. At 12 months, further

improvement of all functional and symptom scales was

observed, except for dyspnea. Patients rated their global

health status (GHS) in questionnaire EORTC C15-PAL.

Overall GHS improved at 4 weeks, showed a decrease at 8

weeks and improved steady during follow up. GHS at

baseline was lower in patients with pain than in patients

without pain (58 vs 80 on a scale of 100). The difference

in GHS between patients with and without pain reduced

during follow up (difference of 22 points at baseline vs 2

points after 6 months) (Figure 2). Pain flare was reported

in six patients, but no relevant differences in QoL in

patients with and without pain flare were observed.

Conclusion

After SBRT for BM, our patients showed a clinically

relevant improvement in QoL. At baseline, patients with

pain report worse QoL and higher pain related scores

compared to non-painful patients. SBRT on BM leads to a

substantial reduction of pain scores contributing to a

relevant QoL improvement in painful patients.

Symposium with Proffered Papers: Novel approaches in

colorectal tumour control

SP-0527 State of the art in colorectal cancer

radiobiology

J. Bussink

UMC St Radboud Nijmegen, Radiation Oncology,

Nijmegen, The Netherlands

There is a limited amount of information on

radiobiological data with respect to normal tissues for

colorectal cancer. Experimental data that give an

indication of a/b values are from studies dating back to

the eighties. For acute toxicity the values are low (9-13)

for late toxicity this was in the lower range (3-5). Late

toxicity such as rectal bleeding is also strongly depending

on irradiated volume but also on the topographical

distribution of this volume, i.e. circumferential irradiation

results in more toxicity than non-circumferential

treatment. Tumor response is predominately hampered by

the classical radiation resistance mechanisms such as

intrinsic radioresistance, and hypoxia but also aberrant

signaling by means of EGFR or VEGF may result in reduced

radiation sensitivity. Several studies have investigated

these parameters in the clinical and preclinical setting.

These parameters can only be of relevance if it is possible

to monitor these prior to treatment initiation. To assess

the efficacy of interventions to address resistance ideally

this would be monitored during treatment. Application of

functional imaging by means of PET or MRI during

treatment has been applied to limited extend in colorectal

cancer.

SP-0528 Immunobiology of gastro-intestinal tumours

P. Huber

German Cancer Research Center DKFZ, Clinical

Cooperation Unit Molecular Radiooncology, Heidelberg,

Germany

GI cancers are among the most frequent cancer in the

western world. Many patients have high numbers of tumor

specific T cells (cytotoxic T cells and T helper cells) in

their blood and bone marrow. The molecular

identification of tumor-associated antigens has led to the

development of antigen-specific immunotherapy targeting

these antigens which have so far failed to show efficacy in

the clinic. Potential reasons for this lack of efficacy

include the inefficiency of T cell activation in vivo,

insufficient migration of cytotoxic T cells into the tumor,

the choice of irrelevant antigens, induction or application

of monovalent T cells. Here we will discuss the role of

radiotherapy, the effective non- surgical local cancer

therapeutic, in the immunobiology of GI cancer in the

context of the microenvironment modifications,

endothelial cells, intratumoral lymphocytes or dendritic

cells, alone and in combination with checkpoint inhibitors,

TLR agonists and other immune effectors. We will in

particularly discuss the effects of low dose radiotherapy

on T cell infiltration, macrophages and associated

antitumor immune response in preclinical models and

patients with operable liver metastases and pancreatic

carcinoma.