The emerging role of IG-IMRT for palliative radiotherapy: a single-institution experience

Evaluation of the palliative radiotherapy pathway in a single institute: Can an MR Linac improve efficiency?

BACKGROUND

Palliative radiotherapy (RT) is effectively used to relieve cancer related symptoms. The demand for these services is increasing worldwide. Rapid response clinics have been developed as a means to streamline the palliative RT radiotherapy process and increase efficiency and improve patient experiences. Key components to successful rapid response palliative RT are access to care, streamlined services and innovation. To successfully implement a rapid response RT programme, it is essential to identify gaps between currently provided care and ideal or enhanced care. The aims of this work are to audit the current palliative RT workflow at our institution both prior to and during the coronavirus pandemic. This work reports the impact of covid-19 on rate of palliative RT referrals and proposes a radiographer led, MR guided rapid response workflow to reduce wait times METHODS: A retrospective audit of palliative radiotherapy booking forms was completed over a two yearperiod (2019-2020) to assess the current pathway both prior to and during the covid-19 pandemic. This audit identified patients who had received urgent/emergency spinal RT in the specified timeframe. Further data on these patients was collected using departmental oncology information systems to form a detailed analysis of the pathway and wait times. Data was recorded and analysed using Microsoft Excel.

RESULTS

A total of 813 patients met the inclusion criteria for this audit. Data was reported for 2019 and 2020 separately to determine any significant impact caused by the covid-19 pandemic. In 2020 there was an 11.5% increase in referrals for palliative radiotherapy with an equal portion (81%) of total referrals in each year being for single fractions. Timelines from referral to treatment delivery were reported, with those patients receiving same day single fraction RT palliative radiotherapy undergoing further analysis to determine the amount of time spent in the department. Mean wait time for these patients was 5 hours and 20 minutes in 2019 but increased by 20.9% in 2020.

CONCLUSIONS

The increasing demand for palliative RT due to rising global cancer rates and extended life expectancy due to advanced systemic treatments may lead to increased wait times. An increase in both referrals and mean wait time was seen during the covid-19 pandemic. Improving efficiency and access to care is essential for this population. The MR Linac could play a role in streamlining palliative RT workflows due to its ability to employ a scan, plan and treat model in a single session. This work forms preliminary support for the development of a trial one stop palliative program on the MR Linac.

Feasibility and response of helical tomotherapy in patients with metastatic colorectal cancer

Purpose

To investigate the treatment outcome and the toxicity of helical tomotherapy (HT) in patients with metastatic colorectal cancer (mCRC).

Materials and Methods

We retrospectively reviewed 18 patients with 31 lesions from mCRC treated with HT between 2009 and 2013. The liver (9 lesions) and lymph nodes (9 lesions) were the most frequent sites. The planning target volume (PTV) ranged from 12 to 1,110 mL (median, 114 mL). The total doses ranged from 30 to 70 Gy in 10-30 fractions. When the α/β value for the tumor was assumed to be 10 Gy for the biologically equivalent dose (BED), the total doses ranged from 39 to 119 Gy₁₀ (median, 55 Gy₁₀). Nineteen lesions were treated with concurrent chemotherapy (CCRT).

Results

With a median follow-up time of 16 months, the median overall survival for 18 patients was 33 months. Eight lesions (26%) achieved complete response. The 1- and 3-year local progression free survival (LPFS) rates for 31 lesions were 45% and 34%, respectively. On univariate analysis, significant parameters influencing LPFS rates were chemotherapy response before HT, aim of HT, CCRT, PTV, BED, and adjuvant chemotherapy. On multivariate analysis, PTV ≤113 mL and BED >48 Gy₁₀ were associated with a statistically significant improvement in LFPS. During HT, four patients experienced grade 3 hematologic toxicities, each of whom had also received CCRT.

Conclusion

The current study demonstrates the efficacy and tolerability of HT for mCRC. To define optimal RT dose according to tumor size of mCRC, further study should be needed.

Rapid access palliative radiation therapy programs: an efficient model of care

Palliating symptoms of advanced and metastatic cancers are one of the most common indications for radiation therapy (RT), and the demand for palliative RT is increasing. Dedicated rapid access palliative RT programs improve access to care, and can deliver RT in a more efficient and evidence-based manner than standard RT programs. In this narrative review, we discuss the role of palliative RT in comprehensive cancer care, and challenges that have faced patients trying to access it. We describe how rapid access programs developed to address these challenges and provide an overview of dedicated programs worldwide. Finally, we show how these programs can serve as models for multidisciplinary care and education, and sources of exciting research opportunities in clinical care and advanced technologies.

Rapid palliative radiotherapy: comparing IG-IMRT with more conventional approaches

Purpose: To assess the efficiency of an integrated imaging, planning, and treatment delivery system to provide image-guided intensity-modulated radiotherapy (IG-IMRT) for patients requiring palliative radiotherapy (PRT).

Methods: Between December 2006 and May 2008, 28 patients requiring urgent PRT were selected to undergo single-session megavoltage computed tomography (MV-CT) simulation, IMRT treatment planning, position verification and delivery of the first faction of radiotherapy on a helical Tomotherapy® unit. The time required to complete each step was recorded and compared to our standard approach of using either fluoroscopic or CT-based simulation, simplified treatment planning and delivery on a megavoltage unit.

Results: Twenty-eight patients were treated with our integrated IG-IMRT protocol. The median age was 72 years, with 61% men and 39% women. The indications for PRT were: painful bone and soft tissue metastasis (75%); bleeding lesions (14%); and other reasons (11%). The areas treated included the following: hip and/or pelvis (42%); spine (36%); and other areas (21%). The most commonly used dose prescription was 20 Gy in five fractions. Average times for the integrated IG-IMRT processes were as follows: image acquisition, 15 minutes; target delineation, 16 minutes; IMRT treatment planning, 9 minutes; treatment position verification, 10 minutes; and treatment delivery, 12 minutes. The average total time was 62 minutes compared to 66 minutes and 81 minutes for fluoroscopic and CT-simulation-based approaches, respectively. The IMRT dose distributions were also superior to simpler plans.

Conclusions: PRT with an integrated IG-IMRT approach is efficient and convenient for patients, and has potential for future applications such as single-fraction radiotherapy.