FeASibility of Cbct-guIded ONline Adaptive RadioThErapy

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