Reduction of oesophageal toxicity with VMAT dose-sparing radiotherapy in thoracic metastatic spinal cord compression: A feasibility study

Dosimetric Comparison of Conventional Radiotherapy, Volumetric Modulated Arc Therapy, and Proton Beam Therapy for Palliation of Thoracic Spine Metastases Secondary to Breast or Prostate Cancer

The aim of this planning study was to compare the dosimetric outcomes of Volumetric Modulated Arc Therapy (VMAT), Proton Beam Therapy (PBT), and conventional External Beam Radiation Therapy (cEBRT) in the treatment of thoracic spinal metastases originating from breast or prostate cancer. Our study utilized data from 30 different treatment plans and evaluated target coverage and doses to vital organs at risk (OARs), such as the spinal cord, heart, esophagus, and lungs. The results showed that VMAT and PBT achieved superior target coverage and significantly lower doses to the spinal cord compared to cEBRT (target: median PTVD95%: 75.2 for cEBRT vs. 92.9 and 91.7 for VMAT (p < 0.001) and PBT (p < 0.001), respectively; spinal cord: median Dmax%: 105.1 for cEBRT vs. 100.4 and 103.6 for VMAT (p < 0.001) and PBT (p = 0.002), respectively). Specifically, VMAT was notable for its superior target coverage and PBT for significantly lower doses to heart, lungs, and esophagus. However, VMAT resulted in higher lung doses, indicating potential trade-offs among different techniques. The study demonstrated the relative advantages of VMAT and PBT over traditional RT in the palliative treatment of spinal metastases using conventional fractionation. These findings underscore the potential of VMAT and PBT to improve dosimetric outcomes, suggesting that they may be more suitable for certain patient groups for whom the sparing of specific OARs is especially important.

Quality of life in patients with malignant spinal cord compression: a systematic review

INTRODUCTION

Malignant spinal cord compression (MSCC) is an oncological emergency that may result in a devastating combination of malignancy and disability. Existing quality of life (QoL) questionnaires commonly used in MSCC literature (EORTC QLQ-C30, BM-22, Brief Pain Inventory, and Spine Oncology Study Group Outcomes) may not capture all the commonly reported symptoms and lack specificity to MSCC. The primary objective of this systematic review is to determine unmet patient needs and underreported QoL issues and compile a comprehensive list of QoL issues. The secondary objective of this review is to compile all existing QoL tools and questionnaires and determine whether any QoL issues are not addressed in the existing tools currently used in the literature.

METHODS

A literature search was conducted on Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases between 1946 and February 6, 2023, to compile all QoL issues and existing questionnaires used to assess QoL in patients with MSCC. All study designs were included given that they discussed QoL issues specific to patients with MSCC.

RESULTS

The results of this systematic review identified the most frequently discussed QoL issues in the literature studying MSCC. This included direct symptoms of MSCC such as back pain, paralysis, limb weakness/numbness, and urinary/bowel incontinence. Indirect symptoms coming from radiotherapy treatment such as dysphagia, painful swallowing, mouth pain, dry mouth, diarrhea, fatigue, and nausea/vomiting were also noted. Other symptoms resulting from corticosteroid treatment included difficulty sleeping, blurring of vision, weight gain, and mood disturbance. Patients also experienced psychosocial issues such as anxiety, depression, emotional distress, low self-esteem, concerns about dependence on others, concerns about getting home, and fear about their prognosis and future.

CONCLUSION

This review highlights the QoL issues specific to patients with MSCC and QoL tools capturing these issues. Relevance of QoL issues identified in this systematic review must be prospectively validated by patients and healthcare professionals with experience in treating MSCC.

Interim analysis of patient-reported outcome compliance and dosimetry in a phase 3 randomized clinical trial of oesophagus-sparing spinal radiotherapy

BACKGROUND

The randomized clinical trial ESO-SPARE investigates if oesophagus-sparing radiotherapy (RT) can reduce dysphagia in patients with metastatic spinal cord compression (MSCC). Patient-reported outcome (PRO) is the only follow-up measure. Due to the fragile patient population, low respondent compliance was anticipated. We performed a planned interim analysis of dosimetry and respondent compliance, to ensure that the protocol requirements were met.

METHODS

Patients >18 years referred for cervical/thoracic MSCC radiotherapy in 1-10 fractions were included from two centres. Patients were randomized (1:1) to standard RT or oesophagus-sparing RT, where predefined oesophageal dose constraints were prioritized over target coverage. Patients completed a trial diary with daily reports of dysphagia for 5 weeks (PRO-CTC-AE) and weekly quality of life reports for 9 weeks (QLQ-C30, EQ-5D-5L). According to power calculation, 124 patients are needed for primary endpoint analysis. The sample size was inflated to 200 patients to account for the fragile patient population. The co-primary endpoints, peak patient-reported dysphagia, and preserved ability to walk (EQ-5D-5L), are analysed at 5 and 9 weeks, respectively. The interim analysis was conducted 90 days after the inclusion of patient no 100. Respondent compliance was assessed at 5 and 9 weeks. In all RT plans, oesophagus and target doses were evaluated regarding adherence to protocol constraints.

RESULTS

From May 2021 to November 2022, 100 patients were included. Fifty-two were randomized to oesophagus-sparing RT. In 23% of these plans, oesophagus constraints were violated. Overall, the dose to both target and oesophagus was significantly lower in the oesophagus-sparing plans. Only 51% and 41% of the patients were evaluable for co-primary endpoint analysis at five and nine weeks, respectively. Mortality and hospitalization rates were significantly larger in patients who completed <4 days PRO questionnaires.

CONCLUSION

Compliance was lower than anticipated and interventions to maintain study power are needed.