Cumulative dose, toxicity, and outcomes of spinal metastases re-irradiation : Systematic review on behalf of the Re-Irradiation Working Group of the Italian Association of Radiotherapy and Clinical Oncology (AIRO)

Phase II Clinical Trial of Second Course of Stereotactic Body Radiotherapy for Spinal Metastases

PURPOSE

The optimal method for the second course of stereotactic body radiotherapy (SBRT) for spinal metastases remains poorly established. This single-center, single-arm, phase II trial was conducted to propose a safe and effective salvage spine SBRT.

METHODS

The patients initially treated with SBRT for spine-targeted protocol treatment, or for areas adjacent to the spine, were enrolled. The second SBRT dose was 30 Gy delivered in five fractions; the spinal cord dose constraint was 15.5 Gy at the maximum point dose. The brachial or lumbosacral plexuses were dose-constrained to <30 Gy if the boundary between the nerves and tumors was detected. The primary endpoint was dose-limiting toxicity (DLT) (grade ≥ 3 severe radiation-related toxicity) within a year after the second SBRT.

RESULTS

The second SBRT was administered to the same spinal level in 12 patients and to an adjacent spinal level in 8 patients. SBRT2 was performed for 14 painful lesions, 10 MESCC, and 6 oligometastases, with some lesions having multiple indications. The median interval between SBRT sessions was 21 months (range: 6-51 months). The median follow-up duration was 14 months. No radiation myelopathy or local failure was reported during the follow-up period. DLT was confirmed in two patients (10%) within a year, both of whom developed grade 3 lumbosacral plexopathy. These two patients received SBRT twice to the S1-2 and S1-5 vertebrae, respectively, and both experienced paralysis of the tibialis anterior muscle (L5 level). Grade 3 late adverse effects (including lumbosacral plexopathy and vertebral compression fracture) were observed in 25% of the patients throughout the entire follow-up period.

CONCLUSIONS

The second spine SBRT achieved good local control without causing myelopathy. However, one-quarter of the patients experienced grade 3 late adverse effects, suggesting that the treatment protocol carries a risk of toxicity.

Dosimetric evaluation of a spinal cord dose-limiting 3D-CRT technique for radiotherapy of spinal metastases

BACKGROUND

To evaluate the possible advantages of a simple spinal cord (SC) dose-limiting three-dimensional conformal radiotherapy (3D-CRT) technique in comparison to conventional two-dimensional (2D) techniques and other 3D-CRT techniques for spinal bone irradiation.

METHODS

For 41 spinal target volumes, seven different techniques were evaluated, using a standard schedule of 30 Gy in 10 fractions. The SC dose-limiting 3D-CRT technique 1F2S-18MV using a single posterior field (F) supplemented by two anterior segment fields (S) and 18-MV photon beams was compared to two conventional 2D techniques (a single posterior field, PA, and two opposed anterior-posterior fields, APPA), three other 3D-CRT techniques (a single posterior field supplemented by four segment fields, 1F4S; two wedged fields, WD, and the SC dose-limiting variant using 6 MV, 1F2S-6MV) along with the original clinically applied plans.

RESULTS

1F2S-18MV demonstrated notably better results for all target volume parameters compared to the conventional 2D techniques (p < 0.001). Limitation of the SC dose was significantly superior with 1F2S-18MV in comparison to PA and APPA (SC Dmean: 28.9 ± 0.4  vs. 30.1 ± 0.6 Gy and 30.1 ± 0.4 Gy; SC Dmax: 30.9 ± 0.7  vs. 32.5 ± 1.0 Gy and 31.8 ± 0.7 Gy; SC D1cm3 : 30.1 ± 0.6  vs. 31.7 ± 0.9 Gy and 31.1 ± 0.6 Gy; p < 0.001). Likewise, lower mean SC doses with 1F2S-18MV were observed in comparison to the more treatment time-consuming 3D-CRT techniques (1F4S, WD) and the original plans without relevant compromises on the dose homogeneity in the target volume and the dose exposure to the other OARs.

CONCLUSION

In treatment planning of spinal metastases, simple variants of 3D-CRT-techniques like 1F2S-18MV can offer a significant dose limitation to the SC while providing a sufficient dose coverage of the target volume. Especially in patients with favorable life expectancy and potential need for re-irradiation, such SC dose-limiting 3D-CRT techniques may be a reasonable approach.

Prospective randomized clinical studies involving reirradiation: update of a systematic review

BACKGROUND

Reirradiation is a potentially useful option for many patients with recurrent cancer, aiming at cure or symptom palliation, depending on disease/recurrence type and stage. The purpose of this follow-up study to a previous review from 2016 was to summarize all recently published randomized trials. Points of interest again included identifcation of methodological strengths and weaknesses, practice-changing results, and open questions.

MATERIAL AND METHODS

Systematic review of trials published between 2015 and February 2023.

RESULTS

We reviewed 7 additional trials, most of which addressed reirradiation of head and neck or brain tumours. The median number of patients was 60. Mirroring the previous review, trial design, primary endpoints and statistical hypotheses varied widely. The updated results only impact on decision making for reirradiation of nasopharynx cancer and glioma. Patients with one of these diseases, as well as other head and neck cancers, may benefit from reirradiation-induced local control, e.g. in terms of progression-free survival. For the first time, hyperfractionated radiotherapy emerged as preferred option for recurrent, inoperable nasopharynx cancer. Despite better therapeutic ratio with hyperfractionation, serious toxicity remains a concern after high cumulative total doses. Randomized trials are still lacking for prostate cancer and other sites.

CONCLUSION

Multicentric randomized trials on reirradiation are feasible and continue to refine the current standard of care for recurrent disease after previous radiotherapy. Ongoing prospective studies such as the European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer (ESTRO-EORTC) observational cohort ReCare (NCT: NCT03818503) will further shape the clinical practice of reirradiation.

Reirradiation on spine metastases: an Italian survey on behalf of palliative care and reirradiation study groups of Italian association of radiotherapy and clinical oncology (AIRO)

AIM

This survey derived from the collaboration between the Palliative Care and Reirradiation Study Groups of the Italian Association of Radiotherapy and Clinical Oncology (AIRO). Its aim was to obtain a real "snapshot" on the treatments of spinal metastases, focusing on reirradiation, among radiation oncologists in Italy.

METHODS

The survey was elaborated on SurveyMonkey's online interface and was sent via e-mail to all Radiation Oncologists of AIRO that were invited to anonymously fill in the electronic form within 60 days. The questionnaire was prepared by the AIRO "Palliative care" and "Reirradiation" Study Groups and it consisted of 36 questions, 19 single-choice questions, 10 multiple-choice questions and 6 open questions. The data were analyzed and represented with tables and graphs.

RESULTS

The survey shows that palliative radiotherapy remains a field of interest for most ROs in the Italian centers. 3D Conventional Radiation Therapy (3DCRT) alone or in combination with other techniques is the primary choice for patients with a life expectancy of less than 6 months. For patients with a life expectancy of more than six months, there is an increased use of new technologies, such as Volumetric Modulated Arc Therapy (VMAT). Factors considered for retreatment are time between first and second treatment, dose delivered to spine metastasis and spinal cord in the first treatment, vertebral stability, symptoms, and/or performance status. The most feared complication are myelopathy followed by vertebral fracture and local recurrence. This explain an increasing focus on patient selection and the use of high technology in the treatment of metastatic patients.

CONCLUSION

Stereotactic body radiotherapy (SBRT) and image-guided radiotherapy allow the administration of ablative RT doses while sparing the constraints of healthy tissue in spinal metastases. However, there is still an unclear and heterogeneous reality in the reirradiation of spinal metastases. A national registry with the aim of clarifying the most controversial aspects of vertebral metastasis retreatments will enable better management of these patients and design more targeted study designs.

Dose-escalated radiotherapy with simultaneous integrated boost for bone metastases in selected patients with assumed favourable prognosis

BACKGROUND

Stereotactic body radiotherapy (SBRT) concepts for dose escalation are increasingly used for bone metastases in patients with oligometastatic or oligoprogressive disease. For metastases that are not suitable for SBRT-regimens, a treatment with 30/40 Gy with simultaneous integrated boost (SIB) in 10 fractions represents a possible regimen. The aim of this study was to investigate the feasibility of this concept and the acute and subacute toxicities.

PATIENTS AND METHODS

Clinical records for dose-escalated radiotherapy of all consecutive patients treated with this regimen were evaluated retrospectively (24 patients with 28 target volumes for oncologic outcomes and 25 patients with 29 target volumes for treatment feasibility and dose parameters analysis). Analysis of radiotherapy plans included size of target volumes and dosimetric parameter for target volumes and organs at risk (OAR). Acute and subacute toxicities were evaluated according to Common Terminology Criteria for Adverse Events (CTCAE) V4.0.

RESULTS

The most common localization was the spine (71.4%). The most common histology was prostate cancer (45.8%). Oligometastatic or oligoprogressive disease was the indication for dose-escalated radiotherapy in 19/24 patients (79.2%). Treatment was feasible with all patients completing radiotherapy. Acute toxicity grade 1 was documented in 36.0% of the patients. During follow up, one patient underwent surgery due to bone instability. The 1-year local control and patient-related progression-free survival (PFS) were 90.0 ± 6.7% and 33.3 ± 11.6%, respectively.

CONCLUSIONS

Dose-escalated hypofractionated radiotherapy with simultaneous integrated boost for bone metastases resulted in good local control with limited acute toxicities. Only one patient required surgical intervention. The regimen represents an alternative to SBRT in selected patients.

The Palliative Care in the Metastatic Spinal Tumors. A Systematic Review on the Radiotherapy and Surgical Perspective

Spine represents the most common site for metastatic disease involvement. Due to the close relationship between the spinal cord and critical structures, therapeutical management of metastatic spinal cord disease remains challenging. Spinal localization can lead to neurological sequelae, which can significantly affect the quality of life in patients with a limited life expectancy. The authors conducted a systematic literature review according to PRISMA guidelines in order to determine the impact of the most updated palliative care on spinal metastases. The initial literature search retrieved 2526 articles, manually screened based on detailed exclusion criteria. Finally, 65 studies met the inclusion criteria and were finally included in the systematic review. In the wide scenario of palliative care, nowadays, recent medical or surgical treatments represent valuable options for ameliorating pain and improving patients QoL in such this condition.