Organisational Standards for the Delivery of Intensity-modulated Radiation Therapy in Ontario

A Prospective Randomized Study of Intensity-Modulated Radiation Therapy Versus Three-Dimensional Conformal Radiation Therapy With Concurrent Chemotherapy in Locally Advanced Carcinoma Cervix

Background: External Beam Radiotherapy is the treatment of choice of locally advanced carcinoma cervix (LACC). The two techniques, three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT), have been compared previously in terms of outcomes and toxicities. IMRT has still not shown any benefit over 3DCRT in terms of local control and survival. Hence, the present study was conducted to compare local control and toxicities among both techniques.

Material & Methods: Fifty-four patients of LACC (FIGO IB2-IVA) were randomized to receive 50 Gray in 25 fractions by either 3DCRT or IMRT with concurrent cisplatin-based chemotherapy followed by brachytherapy. Plans were compared for planning target volume (PTV) coverage, dose to organs at risk (OAR), homogeneity index (HI), and conformity index (CI). Patients were assessed for acute toxicity and local control for three months.

Results: Out of 54 patients, 27 received treatment by 3DCRT and 27 by IMRT technique. Dosimetric evaluation for PTV coverage was similar in both arms. D15, D35, and D50 (dose to 15%, 35%, and 50% volume, respectively) for bladder were significantly reduced in the IMRT arm. Dosimetry for rectum and bowel bag was similar in both. There was a significantly decreased dose to femoral heads in the IMRT arm. Patients in the 3DCRT arm had significant grade 1 and 2 anemia and neutropenia compared to the IMRT arm. Local control for three months was similar in both the arms.

Conclusion: IMRT is associated with decreased acute hematological toxicity compared to 3DCRT with similar local control. Long-term follow-up is needed to assess any difference in long-term toxicity and survival between the two arms.

Use of environmental scans in health services delivery research: a scoping review

OBJECTIVE

To examine the extent and nature of evidence on the use of the environmental scan (ES) in the health services delivery literature.

DESIGN

Scoping review.

METHODS

This scoping review followed the five-stage scoping review methodology outlined by Khalil et al. A Peer Review of Electronic Search Strategies was completed. Seven electronic databases and the grey literature were searched. Pairs of researchers independently performed two levels of screening and data extraction. Data were analysed using qualitative content and thematic analysis.

RESULTS

Ninety-six studies were included in the scoping review. Researchers conducted ESs for many purposes, the most common being to examine the current state of programmes, services or policies. Recommendations were informed by ESs in 20% of studies. Most common data collection methods were literature review (71%), key informant or semistructured interviews (46%) and surveys (35%). Over half (53%) of the studies used a combination of passive (looking at information eg, literature, policies, guidelines) and active (looking for information eg, surveys, interviews) approaches to data collection. Person sources of data (eg, healthcare stakeholders, community representatives) and non-person sources of data (eg, documents, electronic databases, the web) were drawn on to a similar extent. The thematic analysis of the definitions/descriptions yielded several themes including instrument of discovery, knowledge synthesis, forward-looking and decision making. Research gaps identified included absence of a standard definition, inconsistencies in terminology and lack of guiding frameworks in the health services delivery context.

CONCLUSION

ESs were conducted to gather evidence and to help inform decision making on a range of policy and health services delivery issues across the continuum of care. Consistency in terminology, a consensus definition and more guidance on ES design may help provide structure for researchers and other stakeholders, and ultimately advance ES as a methodological approach. A working definition of ES in a health services delivery context is presented.

Dosimetric comparison of coplanar and non-coplanar volumetric-modulated arc therapy in head and neck cancer treated with radiotherapy

Purpose

To evaluate the dosimetric variations in patients of head and neck cancer treated with definitive or adjuvant radiotherapy using optimized non-coplanar (ncVMAT) beams with coplanar (cVMAT) beams using volumetric arc therapy.

Materials and Methods

Twenty-two patients of head and neck cancer that had received radiotherapy using VMAT in our department were retrospectively analyzed. Each of the patients was planned using coplanar and non-coplanar orientations using an optimized couch angle and fluences. We analyzed the Conformity Index (CI_RTOG), Dose Homogeneity Index (DHI), Heterogeneity Index (HI_RTOG), low dose volume, target and organs-at-risk coverage in both the plans without changing planning optimization parameters.

Results

The prescription dose ranged from 60 Gy to 70 Gy. Using ncVMAT, CI_RTOG, DHI and HI_RTOG, and tumor coverage (ID_95%) had improved, low dose spillage volume in the body V_5Gy was increased and V_10Gy was reduced. Integral dose and intensity-modulated radiation therapy factor had increased in ncVMAT. In the case of non-coplanar beam arrangements, maximum dose (D_max) of right and left humeral head were reduced significantly whereas apex of the right and left lung mean dose were increased.

Conclusion

The use of ncVMAT produced better target coverage and sparing of the shoulder and soft tissue of the neck as well as the critical organ compared with the cVMAT in patients of head and neck malignancy.

Dosimetric benefits of intensity-modulated radiotherapy and volumetric-modulated arc therapy in the treatment of postoperative cervical cancer patients

As the advantage of using complex volumetric‐modulated arc therapy (VMAT) in the treatment of gynecologic cancer has not yet been fully determined, the purpose of this study was to investigate the dosimetric advantages of VMAT by comparing directly with whole pelvic conformal radiotherapy (CRT) and intensity‐modulated radiotherapy (IMRT) in the treatment of 15 postoperative cervical cancer patients. Four‐field CRT, seven‐field IMRT, and two‐arc VMAT plans were generated for each patient with identical objective functions to achieve clinically acceptable dose distribution. Target coverage and OAR sparing differences were investigated through dose‐volume histogram (DVH) analysis. Nondosimtric differences between IMRT and VMAT were also compared. Target coverage presented by V95% were 88.9% ± 3.8%, 99.9% ± 0.07%, and 99.9% ± 0.1% for CRT, IMRT, and VMAT, respectively. Significant differences on conformal index (CI) and conformal number (CN) were observed with CIs of 0.37 ± 0.07, 0.55 ± 0.04, 0.61 ± 0.04, and CNs of 0.33 ± 0.06, 0.55 ± 0.04, 0.60 ± 0.04 for CRT, IMRT, and VMAT, respectively. IMRT and VMAT decreased the dose to bladder and rectum significantly compared with CRT. No significant differences on the Dmean, V45, and V30 of small bowel were observed among CRT, IMRT, and VMAT. However, VMAT (10.4 ± 4.8 vs. 19.8 ± 11.0, P = 0.004) and IMRT (12.3 ± 5.0 vs. 19.8 ± 11.0, P = 0.02) decreased V40, increased the Dmax of small bowel and the irradiation dose to femoral heads compared with CRT. VMAT irradiated less dose to bladder, rectum, small bowel and larger volume of health tissue with a lower dose (V5 and V10) compared with IMRT, although the differences were not statistical significant. In conclusion, VMAT and IMRT showed significant dosimetric advantages both on target coverage and OAR sparing compared with CRT in the treatment of postoperative cervical cancer. However, no significant difference between IMRT and VMAT was observed except for slightly better dose conformity, slightly less MU, and significant shorter delivery time achieved for VMAT.

Staffing Model for Radiation Therapists in Ontario

PURPOSE

The Cancer Care Ontario's (CCO) Radiation Program Leadership tasked the Radiation Therapy Professional Advisory Committee (RTPAC) to develop a radiation therapist (RT) staffing model to support current radiation therapy practice.

BACKGROUND

A 1999 RT staffing model was outdated. Limitations included: (1) the inability to keep pace with advanced treatment planning and/or delivery techniques, (2) the exclusion of staffing for brachytherapy and orthovoltage, and (3) the omission of vital patient safety activities that are required to support clinical practices.

METHODS

The RTPAC used a comprehensive scientific methodology to develop the new staffing model. A thorough literature review was completed, and an evidence-based model was developed. A unique creativity tool, the simplex process, was used to identify all the RTs' domains of practice that are integral for professional practice. All domains identified were included in the recommended staffing model.

RESULTS

The staffing model recommends basing the number of RTs on equipment and associated clinical activities. The following staffing numbers are recommended: (1) linear accelerators: 4 full-time equivalent (FTEs) RTs per 10-hour day, (2) brachytherapy: 3 FTEs/8-hour day, (3) orthovoltage: 3 FTEs/8-hour day, (4) CT simulator: 3 FTEs/8-hour day and 4 FTEs/10-hour day, (5) dosimetry: 1 FTE/325 courses per year, (6) radiation oncology systems support and technology development implementation: 1 FTE/4 linear accelerator, (7) administration and education: 1 manager, 1 FTE supervisor/30 staff, 1 FTE professional practice leader/8 linear accelerators, 1 FTE staff educator/8 linear accelerators, 1 FTE undergraduate educator/8-10 students, and (8) additional 20% FTEs of the total for vacation, sick time, maternity leaves, and other leaves.

CONCLUSIONS

The recommended staffing model is now more suitable for today's radiation therapy profession by addressing the domains of practice and clinical activities. Further research includes monitoring performance indicators annually to ensure that the staffing model is current. These indicators include wait times, access to care, radiation incidents, technological advances, and the quality of work-life of RTs.

An Examination of Supervisory Structures in Canadian Radiation Therapy Departments Using National Phone Interviews

BACKGROUND

Canadian radiation therapy departments usually have flat organizational structures, with relatively few administrative/managerial levels. The "unit supervisor" level is a typical job role that provides direct supervision of one or more treatment units with a mixture of clinical and administrative duties.

METHODS

At the British Columbia Cancer Agency, the unit supervisor role was recently evaluated. One approach used as part of the evaluative process was a series of telephone interviews to examine similar roles across Canada (n = 9).

RESULTS

Data indicated that departmental administrative tasks seem to be increasing significantly, and there is a move toward the addition of more administrative "middle" roles across the country to deal with these. Unit supervisor roles are subsequently becoming less clinical, but there is an emerging tension with moving away from solely clinical responsibilities and assuming more administrative work.

CONCLUSIONS

The historic unit supervisor role was part of the team and did little administrative work. This model is becoming difficult to sustain, and tensions can arise in this new environment when using old organizational models. Focused departmental clinical expertise is important; however, balancing clinical and administrative expectations within the unit supervisor role can be problematic. Role expectations need to be examined, clarified, and communicated within departments. If unit supervisor roles are deemed clinical experts, then clinical time needs to be protected for expertise to be sustained.

IMRT utilization in Ontario: qualitative deployment evaluation

Purpose

– The purpose of this paper is to describe a jurisdiction-wide implementation and evaluation of intensity-modulated radiation therapy (IMRT) in Ontario, Canada, highlighting innovative strategies and lessons learned.

Design/methodology/approach

– To obtain an accurate provincial representation, six cancer centres were chosen (based on their IMRT utilization, geography, population, academic affiliation and size) for an in-depth evaluation. At each cancer centre semi-structured, key informant interviews were conducted with senior administrators. An electronic survey, consisting of 40 questions, was also developed and distributed to all cancer centres in Ontario.

Findings

– In total, 21 respondents participated in the interviews and a total of 266 electronic surveys were returned. Funding allocation, guidelines and utilization targets, expert coaching and educational activities were identified as effective implementation strategies. The implementation allowed for hands-on training, an exchange of knowledge and expertise and the sharing of responsibility. Future implementation initiatives could be improved by creating stronger avenues for clear, continuing and comprehensive communication at all stages to increase awareness, garner support and encourage participation and encouraging expert-based coaching. IMRT utilization for has increased without affecting wait times or safety (from fiscal year 2008/2009 to 2012/2013 absolute increased change: prostate 46, thyroid 36, head and neck 29, sarcoma 30, and CNS 32 per cent).

Originality/value

– This multifaceted, jurisdiction-wide approach has been successful in implementing guideline recommended IMRT into standard practice. The expert based coaching initiative, in particular presents a novel training approach for those who are implementing complex techniques. This paper will be of interest to those exploring ways to fund, implement and sustain complex and evolving technologies.

Magnetic nanoparticle hyperthermia: Predictive model for temperature distribution

Magnetic nanoparticle (mNP) hyperthermia is a promising adjuvant cancer therapy. mNP's are delivered intravenously or directly into a tumor, and excited by applying an alternating magnetic field (AMF). The mNP's are, in many cases, sequestered by cells and packed into endosomes. The proximity of the mNP's has a strong influence on their ability to heat due to inter-particle magnetic interaction effects. This is an important point to take into account when modeling the mNP's. Generally, more mNP heating can be achieved using higher magnetic field strengths. The factor which limits the maximum field strength applied to clinically relevant volumes of tissue is the heating caused by eddy currents, which are induced in the noncancerous tissue. A coupled electromagnetic and thermal model has been developed to predict dynamic thermal distributions during AMF treatment. The EM model is based on the method of auxiliary sources and the thermal modeling is based on the Pennes bioheat equation. The results of our phantom study are used to validate the model which takes into account nanoparticle heating, interaction effects, particle spatial distribution, particle size distribution, EM field distribution, and eddy current generation in a controlled environment. Preliminary in vivo data for model validation are also presented. Once fully developed and validated, the model will have applications in experimental design, AMF coil design, and treatment planning.

The value of image-guided intensity-modulated radiotherapy in challenging clinical settings

OBJECTIVE

To illustrate the wider potential scope of image-guided intensity-modulated radiotherapy (IG-IMRT), outside of the "standard" indications for IMRT.

METHODS

Nine challenging clinical cases were selected. All were treated with radical intent, although it was accepted that in several of the cases the probability of cure was low. IMRT alone was not adequate owing to the close proximity of the target to organs at risk, the risk of geographical miss, or the need to tighten planning margins, making image-guided radiotherapy an essential integral part of the treatment. Discrepancies between the initial planning scan and the daily on-treatment megavoltage CT were recorded for each case. The three-dimensional displacement was compared with the margin used to create the planning target volume (PTV).

RESULTS

All but one patient achieved local control. Three patients developed metastatic disease but benefited from good local palliation; two have since died. A further patient died of an unrelated condition. Four patients are alive and well. Toxicity was low in all cases. Without daily image guidance, the PTV margin would have been insufficient to ensure complete coverage in 49% of fractions. It was inadequate by >3 mm in 19% of fractions, and by >5 mm in 9%.

CONCLUSION

IG-IMRT ensures accurate dose delivery to treat the target and avoid critical structures, acting as daily quality assurance for the delivery of complex IMRT plans. These patients could not have been adequately treated without image guidance.

ADVANCES IN KNOWLEDGE

IG-IMRT can offer improved outcomes in less common clinical situations, where conventional techniques would provide suboptimal treatment.

Dosimetric comparison of intensity modulated radiotherapy and three-dimensional conformal radiotherapy in patients with gynecologic malignancies: a systematic review and meta-analysis

BACKGROUND

To quantitatively evaluate the safety and related-toxicities of intensity modulated radiotherapy (IMRT) dose-volume histograms (DVHs), as compared to the conventional three-dimensional conformal radiotherapy (3D-CRT), in gynecologic malignancy patients by systematic review of the related publications and meta-analysis.

METHODS

Relevant articles were retrieved from the PubMed, Embase, and Cochrane Library databases up to August 2011. Two independent reviewers assessed the included studies and extracted data. Pooled average percent irradiated volumes of adjacent non-cancerous tissues were calculated and compared between IMRT and 3D-CRT for a range of common radiation doses (5-45 Gy).

RESULTS

In total, 13 articles comprised of 222 IMRT-treated and 233 3D-CRT-treated patients were included. For rectum receiving doses ≥30 Gy, the IMRT pooled average irradiated volumes were less than those from 3D-CRT by 26.40% (30 Gy, p = 0.004), 27.00% (35 Gy, p = 0.040), 37.30% (40 Gy, p = 0.006), and 39.50% (45 Gy, p = 0.002). Reduction in irradiated small bowel was also observed for IMRT-delivered 40 Gy and 45 Gy (by 17.80% (p = 0.043) and 17.30% (p = 0.012), respectively), as compared with 3D-CRT. However, there were no significant differences in the IMRT and 3D-CRT pooled average percent volumes of irradiated small bowel or rectum from lower doses, or in the bladder or bone marrow from any of the doses. IMRT-treated patients did not experience more severe acute or chronic toxicities than 3D-CRT-treated patients.

CONCLUSIONS

IMRT-delivered high radiation dose produced significantly less average percent volumes of irradiated rectum and small bowel than 3D-CRT, but did not differentially affect the average percent volumes in the bladder and bone marrow.

A national survey of the availability of intensity-modulated radiation therapy and stereotactic radiosurgery in Canada

Background

The timely and appropriate adoption of new radiation therapy (RT) technologies is a challenge both in terms of providing of optimal patient care and managing health care resources. Relatively little is known regarding the rate at which new RT technologies are adopted in different jurisdictions, and the barriers to implementation of these technologies.

Methods

Surveys were sent to all radiation oncology department heads in Canada regarding the availability of RT equipment from 2006 to 2010. Data were collected concerning the availability and use of Intensity Modulated Radiation Therapy (IMRT) and stereotactic radiosurgery (SRS), and the obstacles to implementation of these technologies.

Results

IMRT was available in 37% of responding centers in 2006, increasing to 87% in 2010. In 2010, 72% of centers reported that IMRT was available for all patients who might benefit, and 37% indicated that they used IMRT for "virtually all" head and neck patients. SRS availability increased from 26% in 2006 to 42.5% in 2010. Eighty-two percent of centers reported that patients had access to SRS either directly or by referral. The main barriers for IMRT implementation included the need to train or hire treatment planning staff, whereas barriers to SRS implementation mostly included the need to purchase and/or upgrade existing planning software and equipment.

Conclusions

The survey showed a growing adoption of IMRT and SRS in Canada, although the latter was available in less than half of responding centers. Barriers to implementation differed for IMRT compared to SRS. Enhancing human resources is an important consideration in the implementation of new RT technologies, due to the multidisciplinary nature of the planning and treatment process.

Medical physics staffing for radiation oncology: a decade of experience in Ontario, Canada

The January 2010 articles in The New York Times generated intense focus on patient safety in radiation treatment, with physics staffing identified frequently as a critical factor for consistent quality assurance. The purpose of this work is to review our experience with medical physics staffing, and to propose a transparent and flexible staffing algorithm for general use. Guided by documented times required per routine procedure, we have developed a robust algorithm to estimate physics staffing needs according to center‐specific workload for medical physicists and associated support staff, in a manner we believe is adaptable to an evolving radiotherapy practice. We calculate requirements for each staffing type based on caseload, equipment inventory, quality assurance, educational programs, and administration. Average per‐case staffing ratios were also determined for larger‐scale human resource planning and used to model staffing needs for Ontario, Canada over the next 10 years. The workload specific algorithm was tested through a survey of Canadian cancer centers. For center‐specific human resource planning, we propose a grid of coefficients addressing specific workload factors for each staff group. For larger scale forecasting of human resource requirements, values of 260, 700, 300, 600, 1200, and 2000 treated cases per full‐time equivalent (FTE) were determined for medical physicists, physics assistants, dosimetrists, electronics technologists, mechanical technologists, and information technology specialists, respectively.

PACS numbers: 87.55.N‐, 87.55.Qr

Factors affecting the implementation of complex and evolving technologies: multiple case study of intensity-modulated radiation therapy (IMRT) in Ontario, Canada

Background

Research regarding the decision to adopt and implement technological innovations in radiation oncology is lacking. This is particularly problematic since these technologies are often complex and rapidly evolving, requiring ongoing revisiting of decisions regarding which technologies are the most appropriate to support. Variations in adoption and implementation decisions for new radiation technologies across cancer centres can impact patients' access to appropriate and innovative forms of radiation therapy. This study examines the key steps in the process of adopting and implementing intensity modulated radiation therapy (IMRT) in publicly funded cancer centres and identifies facilitating or impeding factors.

Methods

A multiple case study design, utilizing document analysis and key informant interviews was employed. Four cancer centres in Ontario, Canada were selected and interviews were conducted with radiation oncologists, medical physicists, radiation therapists, and senior administrative leaders.

Results

Eighteen key informants were interviewed. Overall, three centres made fair to excellent progress in the implementation of IMRT, while one centre achieved only limited implementation as of 2009. Key factors that influenced the extent of IMRT implementation were categorized as: 1) leadership, 2) training, expertise and standardization, 3) collaboration, 4) resources, and 5) resistance to change.

Conclusion

A framework for the adoption and implementation of complex and evolving technologies is presented. It identifies the key factors that should be addressed by decision-makers at specific stages of the adoption/implementation process.

A review of the clinical evidence for intensity-modulated radiotherapy

AIMS

Intensity-modulated radiotherapy (IMRT) is a development of three-dimensional conformal radiotherapy that offers improvements in dosimetry in many clinical scenarios. Here we review the clinical evidence for IMRT and present ongoing or unpublished randomised controlled trials (RCTs).

METHODS

We identified randomised and non-randomised comparative studies of IMRT and conventional radiotherapy using MEDLINE, hand-searching Radiotherapy and Oncology and the International Journal of Radiation Oncology, Biology and Physics and the proceedings of the American Society for Therapeutic Radiology and Oncology and the European Society for Therapeutic Radiology and Oncology annual meetings. The metaRegister of Controlled Trials was searched to identify completed-unpublished, ongoing and planned RCTs.

RESULTS

Sixty-one studies comparing IMRT and conventional radiotherapy were identified. These included three RCTs in head and neck cancer (205 patients) and three in breast cancer (664 patients) that had reported clinical outcomes; these were all powered for toxicity-related end points, which were significantly better with IMRT in each trial. There were 27 additional non-randomised studies in head and neck (1119 patients), 26 in prostate cancer (>5000 patients), four in breast cancer (875 patients) and nine in other tumour sites. The results of these studies supported those of the RCTs with benefits reported in acute and late toxicity, health-related quality of life and tumour control end points. Twenty-eight completed-unpublished, ongoing or planned RCTs incorporating IMRT were identified, including at least 12,310 patients, of which 15 compared conventional radiotherapy within IMRT as a randomisation or pre-planned stratification.

DISCUSSION

Inverse-planned IMRT maintains parotid saliva production and reduces acute and late xerostomia during radiotherapy for locally advanced head and neck cancer, reduces late rectal toxicity in prostate cancer patients allowing safe dose escalation and seems to reduce toxicity in several other tumour sites. Forward-planned IMRT reduces acute toxicity and improves late clinician-assessed cosmesis compared with conventional tangential breast radiotherapy.