The clinical introduction of MR-guided radiation therapy from a RTT perspective

The latest development in radiation oncology departments towards high precision and adaptive radiation therapy is the clinical introduction of magnetic resonance image guided radiation therapy (MRgRT). Early 2016, patient treatment using MRgRT was started at Amsterdam UMC, location VU University Medical Center. Introducing this novel technique in clinical practice requires thorough preparation with regard to important topics, such as MR-safety and training, equipping the treatment vault and console room, development of MRgRT workflow and logistical issues. Certainly when MRgRT is combined with daily plan adaptation, this indicates adjusting existing workflows and protocols. The MRgRT workflow requires a multidisciplinary process, and while each discipline has had its own tasks and responsibilities, with growing clinical experience there has been a shift towards RTT responsibilities. In this overview we discuss preclinical training and preparation for the implementation of (adaptive) MRgRT, with a particular focus on the perspective of RTTs. Although the reviewed logistics are partly the result of the decision to perform daily plan re-optimization, our experience can be extrapolated to implementation of alternative approaches for MRgRT

Magnetic Resonance-guided Stereotactic Radiotherapy for Localized Prostate Cancer: Final Results on Patient-reported Outcomes of a Prospective Phase 2 Study

BACKGROUND: The recent introduction of magnetic resonance-guided radiation therapy (MRgRT) has allowed improved treatment planning and delivery of stereotactic body radiotherapy (SBRT) in prostate cancer (PC). The health-related quality of life (HRQoL) outcomes using this novel approach are important in shared decision making for patients. OBJECTIVE: To report HRQoL using both patient- and clinician-reported outcomes at 1 yr following stereotactic MRgRT for patients with localized PC. DESIGN, SETTING, AND PARTICIPANTS: A prospective phase 2 trial included 101 patients with localized PC. INTERVENTION: All patients received 36.25Gy in five fractions of MRgRT delivered within 2 wk. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: HRQoL was prospectively assessed at baseline, at the last fraction, at 6 wk, and at 3, 6, 9, and 12 mo after treatment, by patient-reported outcome measures using European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-PR25 questionnaires, and International Prostate Symptom Score. At the same time points, clinicians reported on symptomatic adverse events (AEs). Effect sizes for changes in HRQoL were calculated with repeated measures analysis of variance. RESULTS AND LIMITATIONS: Availability of HRQoL data exceeded 95% at all study time points. From both questionnaires and the recorded AEs, the largest treatment effects on urinary and bowel symptoms were recorded in the first 6 wk of follow-up. Thereafter, all symptoms decreased and returned to baseline values at 12 mo. No grade ≥3 toxicity was reported. No patient reported any relevant limitation due to urinary symptoms, and only 2.2% of patients reported a relevant impact on daily activities due to bowel problems at 1 yr. The majority of patients had intermediate- or high-risk PC for which androgen deprivation therapy (83.2%) was prescribed, thereby precluding study of MRgRT on sexual function. Longer follow-up is awaited in order to evaluate the oncological outcome. CONCLUSIONS: Delivery of MRgRT for SBRT resulted in low toxicity at 1 yr. PATIENT SUMMARY: All patients completed magnetic resonance-guided radiation therapy, which was well tolerated with only transient early urinary and bowel symptoms, which resolved 1 yr after treatment, as confirmed by patient-reported outcome measures

The role of daily adaptive stereotactic mr-guided radiotherapy for renal cell cancer

Novel magnetic-resonance-guided radiotherapy (MRgRT) permits real-time soft-tissue visualization, respiratory-gated delivery with minimal safety margins, and time-consuming daily plan re-optimisation. We report on early clinical outcomes of MRgRT and routine plan re-optimization for large primary renal cell cancer (RCC). Thirty-six patients were treated with MRgRT in 40 Gy/5 fractions. Prior to each fraction, re-contouring of tumor and normal organs on a pretreatment MR-scan allowed daily plan re-optimization. Treatment-induced toxicity and radiological responses were scored, which was followed by an offline analysis to evaluate the need for such daily re-optimization in 180 fractions. Mean age and tumor diameter were 78.1 years and 5.6 cm, respectively. All patients completed MRgRT with an average fraction duration of 45 min. Local control (LC) and overall survival rates at one year were 95.2% and 91.2%. No grade ≥3 toxicity was reported. Plans without re-optimization met institutional radiotherapy constraints in 83.9% of 180 fractions. Thus, daily plan re-optimization was required for only a minority of patients, who can be identified upfront by a higher volume of normal organs receiving 25 Gy in baseline plans. In conclusion, stereotactic MRgRT for large primary RCC showed low toxicity and high LC, while daily plan re-optimization was required only in a minority of patients

A Prospective Single-Arm Phase 2 Study of Stereotactic Magnetic Resonance Guided Adaptive Radiation Therapy for Prostate Cancer: Early toxicity results

Purpose: Use of stereotactic body radiation therapy (SBRT) is increasing in patients with localized prostate cancer, but concerns about early and late gastrointestinal (GI) and genitourinary (GU) toxicity exist after moderately or extremely hypofractionated radiation therapy schemes. Magnetic resonance guided radiation therapy (MRgRT) was clinically introduced in 2014. MrgRT allows for SBRT delivery with smaller uncertainty margins and permits daily adaptive planning. A phase 2 study in patients with localized prostate cancer was performed to study early GI and GU toxicity after SBRT using MRgRT. Methods and Materials: One hundred one patients with clinical stage T1-3bN0M0 prostate cancer were enrolled in this prospective phase 2 study. All but 4 patients had intermediate- or high-risk prostate cancer, and 82.2% received adjuvant hormonal treatment. MRgRT was delivered in 5 fractions of 7.25 Gy to the target volume using daily plan adaptation with simultaneous relative sparing of the urethra to a dose of 6.5 Gy per fraction. Early toxicity was studied using both clinician- (Common Terminology Criteria for Adverse Events and Radiation Therapy Oncology Group) and patient-reported outcome measurements (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30, Quality of Life Questionnaire PR25, and International Prostate Symptom Scoring). Results: The maximum cumulative grade ≥2 early GU and GI toxicity measured by any symptom at any study time point was 23.8% and 5.0%, respectively. No early grade 3 GI toxicity was observed. Early grade 3 GU toxicity was 0% and 5.9% according to the Common Terminology Criteria for Adverse Events and Radiation Therapy Oncology Group and scoring systems, respectively, as a result of different grading of radiation cystitis. The low incidence of early GI toxicity was confirmed by patient-reported outcome data. GU grade ≥2 toxicity peaked to 19.8% at the end of MRgRT, followed by a return to the baseline average score at 3-month follow-up. Conclusions: This prospective study of MRgRT in patients with localized prostate cancer observed a low incidence of early GI and GU toxicity, both in clinician- and patient-reported outcome measurements

A Prospective Single-Arm Phase 2 Study of Stereotactic Magnetic Resonance Guided Adaptive Radiation Therapy for Prostate Cancer: Early Toxicity Results

Purpose: Use of stereotactic body radiation therapy (SBRT) is increasing in patients with localized prostate cancer, but concerns about early and late gastrointestinal (GI) and genitourinary (GU) toxicity exist after moderately or extremely hypofractionated radiation therapy schemes. Magnetic resonance guided radiation therapy (MRgRT) was clinically introduced in 2014. MrgRT allows for SBRT delivery with smaller uncertainty margins and permits daily adaptive planning. A phase 2 study in patients with localized prostate cancer was performed to study early GI and GU toxicity after SBRT using MRgRT. Methods and Materials: One hundred one patients with clinical stage T1-3bN0M0 prostate cancer were enrolled in this prospective phase 2 study. All but 4 patients had intermediate- or high-risk prostate cancer, and 82.2% received adjuvant hormonal treatment. MRgRT was delivered in 5 fractions of 7.25 Gy to the target volume using daily plan adaptation with simultaneous relative sparing of the urethra to a dose of 6.5 Gy per fraction. Early toxicity was studied using both clinician- (Common Terminology Criteria for Adverse Events and Radiation Therapy Oncology Group) and patient-reported outcome measurements (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30, Quality of Life Questionnaire PR25, and International Prostate Symptom Scoring). Results: The maximum cumulative grade ≥2 early GU and GI toxicity measured by any symptom at any study time point was 23.8% and 5.0%, respectively. No early grade 3 GI toxicity was observed. Early grade 3 GU toxicity was 0% and 5.9% according to the Common Terminology Criteria for Adverse Events and Radiation Therapy Oncology Group and scoring systems, respectively, as a result of different grading of radiation cystitis. The low incidence of early GI toxicity was confirmed by patient-reported outcome data. GU grade ≥2 toxicity peaked to 19.8% at the end of MRgRT, followed by a return to the baseline average score at 3-month follow-up. Conclusions: This prospective study of MRgRT in patients with localized prostate cancer observed a low incidence of early GI and GU toxicity, both in clinician- and patient-reported outcome measurements