Radiation therapists are alert to deviations that affect a patient’s treatment plan and communicate them to the appropriate members of the healthcare team
Attention to changes that affect radiation therapy
- The goal of radiation therapy is to irradiate the tumour volume while minimizing radiation to the surrounding critical structures.1
- Changes that occur over the time that it takes to administer radiation therapy can affect the original treatment plan and/or the treatment intent.
- As a point of contact with the patient, radiation therapists have an important role to play in the recognition of these changes2
- Radiation therapists remain alert to these changes throughout their interactions with patients, which include but are not limited to, changes to:
- Target position and shape (e.g., tumour regression or growth, bladder filling and rectal distension)3
- Anatomic structures (e.g. volume, motion changes)4
- Patient weight gain and/or weight loss
- Reproducibility of the set up
- Treatment intent (e.g., from radical to palliative)
- Accessories used for treatment
- Side effects2
- Each facility, under the direction of the radiation oncologist, should consider establishing a threshold of couch positioning changes above which the physician is required to review the patient setup and images before treatment is delivered.5,6,7
- Radiation therapists should be familiar with the thresholds identified in such a plan and understand the procedures to respond to changes that exceed defined thresholds.
- Methods are in place in each radiotherapy department to detect and act on changes that exceed the determined thresholds over the course of a radiation treatment.3
- In order to maintain the integrity of treatment, radiation therapists undertake thorough assessment of the treatment plan with systematic quality checks:
- Systematic geometric and dosimetric verification is used to ensure that the right radiation dose is being delivered to the right target3
- Information from imaging is used to identify anatomic changes
- Ongoing evaluation of immobilization/repositioning systems is in place to ensure stability and reproducibility of the plan
Response to deviations
- All changes or deviations require documentation and further discussion with the healthcare team, whether they are within tolerance parameters or not.6
- It is important for radiation therapists to note changes in patient separation/ position/anatomy that could result in the need for a prescription adjustment
- Changes in the patient’s condition (i.e., weight loss, tumour shrinkage, etc.) that could affect the treatment plan are noted
- Findings are most effectively communicated as straight fact (e.g., reported signs/symptoms, measurements from imaging: tumour 1cm larger).
- It is beyond the scope of radiation therapist practice to make diagnostic interpretations or conclusions from this information2
- Changes or deviations that might affect a patient’s treatment plan are communicated directly to the appropriate members of the patient’s healthcare team.
- Modifications to a patient’s treatment plan are made in consultation with the radiation oncologist and all appropriate members of the patient’s healthcare team1
- Radiation therapists should not unilaterally make changes to the treatment plan without consultation
- In the event a patient enquires about a change or delay to treatment, radiation therapists should refrain from making interpretative or diagnostic comments, but simply state the facts and explain the consultation process that will occur.8
Gomez D, Chang J. Adaptive radiation for lung cancer. J Oncol. 2011;2011(2011). DOI: http://dx.doi.org/10.1155/2011/898391
American Society of Radiologic Technologists. The Practice Standards for Medical Imaging and Radiation Therapy. ASRT. June 2017. Available from: https://www.asrt.org/docs/default-source/practice-standards-published/ps_rt.pdf?sfvrsn=2. [Accessed 27 Nov 2017]
The Royal College of Radiologists, Institute of Physics and Engineering in Medicine, Society and College of Radiographers. On target: ensuring geometric accuracy in radiotherapy. RCR. Nov 2008. Available from: http://www.rcr.ac.uk/docs/oncology/pdf/BFCO%2808%295_On_target.pdf. [Accessed 24 Nov 2017]
Lu J, Ma Y, Chen J, et al. Assessment of anatomical and dosimetric changes by a deformable registration method during the course of intensity-modulated radiotherapy for nasopharyngeal carcinoma. J Radiat Res. 2014;55(1):97–104. DOI: https://doi.org/10.1093/jrr/rrt076
American College of Radiology. ACR–ASTRO Practice parameter for image-guided radiation therapy (IGRT). ACR.
2009. Updated: 2014. Available from: https://www.acr.org/-/media/ACR/Files/Practice-Parameters/IGRT-RO.pdf?la=en. [Accessed 11 May 2018]
Canadian Partnership for Quality Radiotherapy. Quality Assurance Guidelines for Canadian Radiation Treatment Programs. CPQR. Dec 2015. Available from: http://www.cpqr.ca/wp-content/uploads/2013/09/QRT2015-12-03.pdf. [Accessed 24 Nov 2017]
Franks KN, McNair HA. Implementation of Image-guided Radiotherapy. J Clin Oncol. 2012;24:625-626.
Canadian Association of Medical Radiation Technologists. Sharing Personal Opinions with Patients. CAMRT, Best Practice Guidelines. Nov 2015. Available from: https://camrt-bpg.ca/patient-management/patient-interactions/sharing-personal-opinions-with-patients/. [Accessed 24 Nov 2017]