ESTRO 36 Abstract Book

S869 ESTRO 36 _______________________________________________________________________________________________

International prospective register of systematic reviews on July 12, 2016. 1 Agency for Healthcare research and quality, US department of Health in Human services; https://effectivehealthcare.ahrq.gov/ehc/products/322/ 998/MethodsGuideforCERs_Viswanathan_IndividualStudie s.pdf Results The search strategy resulted in 1095 abstracts ( Figure 1 ) of which 44 studies fulfilled the inclusion criteria and were available in full text (one study was excluded based on study quality criteria). The review is expected to include syntheses of dose-response relationships for seven gastro- intestinal symptoms (bleeding/diarrhea/frequency/incontinence/pain/proctit is/urgency: n=18/3/4/10/3/4/4), three genitourinary symptoms (hematuria/incontinence/obstruction: n=4/4/3), and one sexual dysfunction symptom (erectile dysfunction: n=3) following EBRT. The corresponding figures for BT±EBRT will be two (bleeding/urgency: n=6/2), four (incontinence/obstruction/pain/stricture: n=4/2/3/2), and one symptom (erectile dysfunction: n=2). Results for diarrhea, stool frequency, and defecation urgency following EBRT are presented in Figure 2 . Dose cut points for the rectum and anal canal/sphincter region generally followed the same linear slope for diarrhea/defecation urgency across studies; for stool frequency they were less consistent.

Conclusion We independently validated a radiomic model to distinguish between HPV+ and HPV- OPSCC patients, using standard pre-treatment CT imaging. These results show the potential for a novel quantitative Radiomic biomarker of HPV status to facilitate personalized treatment selection and reinforce the hypothesis that genetic information can be inferred from standard medical images. EP-1609 Tolerance doses for detailed late effects after prostate cancer radiotherapy – a post-QUANTEC review C. Olsson 1 , M. Thor 2 , J.O. Deasy 2 1 University of Gothenburg, Regionalt Cancercentrum RCC väst, Gothenburg, Sweden 2 Memorial Sloan Kettering Cancer Center, Medical Physics, New York, USA Purpose or Objective To review tolerance doses for normal tissue toxicity following external beam radiotherapy (EBRT) for prostate cancer in the post-QUANTEC era with a special emphasis on detailed late effects beyond rectal bleeding, and to identify corresponding relationships following brachytherapy (BT). Material and Methods The electronic database PubMed was scrutinized for full- text articles published in English since the publication of the QUANTEC reviews (Jan 1 st 2010; EBRT only), and since the Emami study (Jan 1 st 1992; including BT). Studies qualifying for inclusion were randomized controlled/case- control/cohort studies with specific non-aggregated symptom assessments, follow-up >3 months, >20 patients, primary standard treatments for localized prostate cancer with dose-volume based data. Two investigators independently assessed study quality according to eight criteria 1 and an additional study-specific criterion incorporating dose-association complexity. Quantitative synthesis for sufficiently homogenous studies was performed for each treatment modality with dose cut points converted into equivalent doses in 2-Gy fractions (α/β=3 Gy). If not explicitly reported, thresholds were derived from suggested models and estimated at a risk level of 10%. The review was registered at PROSPERO

Conclusion Our review demonstrates continuous and innovative activity in the field of late toxicity after prostate cancer