feasibility of cbct-guided online adaptive radiotherapy

Conditions: Prostate Cancer; Cervical Cancer; Bladder Cancer; Lung Cancer; Head and Neck Cancer

Summary: the accuracy of radiotherapy can be increased by correcting for geometric uncertainties and changes between radiotherapy fractions. these corrections are currently done with online adaptive treatment on a specialized linear accelerator (linac) for a small subset of patients. however, patients currently treated on a standard linac could also benefit from online adaptive radiotherapy. the objective is to determine the feasibility of online cbct-guided adaptive radiation therapy on a standard elekta linac.


Eligibility criteria:
general inclusion criteria: * patient, age ≥ 18 years, referred for a radiotherapy schedule as described in one of the cohorts. * who performance score 0-3. * provision of signed, written and dated ic prior to any study specific procedures. specific inclusion criteria for prostate cohort: * accepted for radiotherapy of the prostate and pelvic lymph node areas. * pathology-proven prostate cancer. * ct1-4 * cn1 on psma-pet/ct or pn1 based on node biopsy, sn-procedure or lymph node dissection. * cm0 on psma-pet/ct (except for patients with m1a disease who are still considered for radiotherapy of the prostate and pelvic lymph node areas). specific inclusion criteria for cervical cohort: * accepted for radiotherapy of the cervix (with or without chemotherapy) and pelvic lymph node areas (25 fractions, followed by either a brachytherapy or external radiotherapy boost). * pathology-proven cervical cancer. * figo iia2, ib3 and \> 6cm, iib-iva or n+. or other stage and unfit for surgery. * cm0 or cm1 and accepted for locoregional radical (chemo)radiation in 25 fractions. specific inclusion criteria for bladder cohort: * accepted for radiotherapy of the bladder, either to the entire bladder or with a boost to the tumor area (with or without chemotherapy). * pathology-proven bladder carcinoma. * ct1-4 * cn0 or cn1-2 after induction treatment (with or without lymph node dissection) specific inclusion criteria for lung cohort: * accepted for radiotherapy for lung cancer with lymph node metastases (with or without chemotherapy). * non-small cell lung cancer (either pathology proven or enough clinical suspicion to warrant radiotherapy to primary tumor and pathologic lymph nodes. * ct1-4 and cn1-3. * m0 or m1 and accepted for radical radiotherapy in 24 fractions of 1 or more lymph node metastases and a primary tumor and/or pulmonary metastases. specific inclusion criteria for head and neck cohort: * accepted for radiotherapy for head and neck cancer (with or without chemotherapy). * pathology-proven carcinoma of the pharynx, oral cavity or larynx. * ct1-4 * cn0-3 and indication for elective neck radiation (either 1 or 2 sides). * cm0 general exclusion criteria: * patients who are pregnant. specific for prostate cohort: * patients with a medical condition that severely compromises cbct image quality (mainly hip prostheses). * severe lower urinary tract symptoms that could make the longer treatment time problematic (according to judgement of treating physician). specific for cervical cohort: - patients with a medical condition that severely compromises cbct image quality (mainly hip prostheses). specific for bladder cohort: * patients with a medical condition that severely compromises cbct image quality (mainly hip prostheses). * severe lower urinary tract symptoms that could make the longer treatment time problematic (according to judgement of treating physician). specific for lung cohort: - severe pulmonary complaints that could make the longer treatment time problematic (according to judgement of treating physician). specific for head and neck cohort: * severe complaints that could make the longer treatment time problematic (according to judgement of treating physician). * pulmonary fibrosis