Meta-Analysis of STereotactic body radiothERapy in non-spine BONE metastaseS (MASTER-BONES)

PURPOSE

The efficacy and safety of stereotactic body radiation (SBRT) for patients with non-spine bone metastases (NSBM) remains in question. A systematic review and meta-analysis was performed to evaluate SBRT treatment outcomes in NSBM.

METHODS AND MATERIALS

Eligible studies were retrieved from Medline, Embase, Scielo, the Cochrane Library, and annual meeting proceedings until July 6, 2023. We adhered to the PRISMA and MOOSE guideline recommendations. Quantitative synthesis was performed using a random effects model.

RESULTS

Seven retrospective studies, with a total of 807 patients (1048 lesions) treated with stereotactic body radiation were included, with median follow-up ranging from 7.6-26.5 months. The most common stereotactic body radiation sites were pelvis (39.2%), ribs (25.8%), femur (16.7%), and humerus/shoulder region (8.7%). At 1-year, the LF and FR were 7% (95%CI 5.5-8.5%; I2=0, n= 75/1048), and 5.3% (95%CI 3-7.5%;I2=0, n= 65/1010). The 2-year cumulative LF incidence was 12.1% (95% CI: 10-15.5%). The OS and PFS at 1-year were 82% (95%CI 75-88%;I2=82%, n= 746/867), and 33.5%(95%CI 26-41%;I2=0%, n= 51/152), with a median of 20.2 months (95%CI: 10.9-49.1 months) and 8.3 months (95% CI: 6.3-10.3%) for OS and PFS, respectively. Meta-regression analysis revealed a significant relationship between planning target volume and fracture rate (p<0.05). Ribs 2.5% followed by the femur 1.9% (95%CI:0-6.1%) were the most common fracture sites. The occurrence of pain flare, fatigue and dermatitis were 7 %, 5.4 %, and 0.65 %, respectively.

CONCLUSIONS

Stereotactic body radiation proves both safety and efficacy for non-spine bone metastases and serious complications (grade 3) are infrequent. Careful consideration of target volume is crucial due to its link with a higher fracture risk.

Stereotactic body radiotherapy to treat breast cancer oligometastases: A systematic review with meta-analysis

OBJECTIVES

Stereotactic ablative radiotherapy (SABR) has been reported to be an effective treatment for oligometastatic disease from different primary cancer sites. Here we assess the effectiveness and safety of SABR for oligometastatic breast cancer patients by performing a meta-analysis.

METHODS

Following PRISMA and MOOSE guidelines, a systematic review and meta-analysis was performed. Eligible studies were identified on Medline, Embase, Cochrane Library, and annual meetings proceedings from 1990 to June 2021. A meta-regression analysis was performed to assess if there was a correlation between moderator variables and outcomes, and a p-value <0.05 was considered significant.

RESULTS

Ten studies met criteria for inclusion, comprising 467 patients and 653 treated metastases. The 1- and 2-year local control rates were 97% (95% CI 95-99%), and 90% (95% CI 84-94%), respectively. Overall survival (OS) was 93% (95% CI 89-96%) at 1 year, 81% (95% CI 72-88%) at 2 years. The rate of any grade 2 or 3 toxicity was 4.1 % (95% CI 0.1-5%), and 0.7% (0-1%), respectively. In the meta-regression analysis, only prospective design (p = 0.001) and bone-only metastases (p = 0.01) were significantly associated with better OS. In the subgroup analysis, the OS at 2y were significantly different comparing HER2+, HR+/HER2(-) and triple negative breast cancer 100%, 86% and 32%, p = 0.001. For local control outcomes, hormone receptor status (p = 0.01) was significantly associated on meta-regression analysis.

CONCLUSION

SABR for oligometastatic breast cancer is safe and associated with high rates of local control. Longer follow-up of existing data and ongoing prospective trials will help further define the role of this management strategy.

Intensity modulated radiotherapy (IMRT) or conformational radiotherapy (3D-CRT) with conventional fractionation for prostate cancer: Is there any clinical difference?

Purpose:

To compare the treatment outcomes of a cohort of prostate cancer patients treated with conventional schedule using IMRT or 3DRT technique.

Materials and Methods:

Between 2010-2017, 485 men with localized prostate cancer were treated with conventional radiotherapy schedule with a total dose ≥74Gy using IMRT (231) or 3DCRT (254). Late gastrointestinal (GI) and genitourinary (GU) toxicity were retrospectively evaluated according to modified RTOG criteria. The biochemical control was defined by the Phoenix criteria (nadir + 2ng/mL). The comparison between the groups included biochemical recurrence free survival (bRFS), overall survival (OS) and late toxicity.

Results:

With a median follow-up of 51 months (IMRT=49 and 3DRT=51 months), the maximal late GU for >=grade- 2 during the entire period of follow-up was 13.1% in the IMRT and 15.4% in the 3DRT (p=0.85). The maximal late GI ≥ grade- 2 in the IMRT was 10% and in the 3DRT 24% (p=0.0001). The 5-year bRFS for all risk groups with IMRT and 3D-CRT was 87.5% vs. 87.2% (p=0.415). Considering the risk-groups no significant difference for low-, intermediate- and high-risk groups between IMRT (low-95.3%, intermediate-86.2% and high-73%) and 3D-CRT (low-96.4%, intermediate-88.2% and high-76.6%, p=0.448) was observed. No significant differences for OS and DMFS were observed comparing treatment groups.

Conclusion:

IMRT reduces significantly the risk of late GI severe complication compared with 3D-CRT using conventional fractionation with a total dose ≥74Gy without any differences for bRFS and OS.

Palliative radiotherapy for gastric cancer: Is there a dose relationship between bleeding response and radiotherapy?

The aim of this study was to evaluate whether there is a relationship between bleeding response and radiotherapy dose to palliate patients with local recurrence or progression of gastric cancer (GC). To this end, we conducted a systematic review and meta-analysis of observational studies that evaluated the bleeding response in patients with GC with local recurrence or progression. A meta-regression analysis between biological effective dose (BED) and bleeding response was performed, as was subgroup analysis to evaluate the outcome by BED level and radiotherapy (RT) technique. A p-value <0.05 was considered significant. Ten non-comparative retrospective studies and one prospective study were included. In general, RT was effective at controlling tumor bleeding, and the bleeding response rate was 0.77 (95% confidence interval (CI), 0.73-0.81). Meta-regression analysis demonstrated a linear correlation between BED Gy 10 and bleeding response (p=0<0001). Studies using conformational RT had a significant bleeding response rate compared to those using 2D (0.79; 95%CI, 0.74-0.84 vs 0.65; 95%CI, 0.56-0.75; p=0.021). In terms of the BED level, a significant difference in BR was identified on comparing BED Gy10 ≥40 (0.79; 95%CI, 0.7-0.8), BED Gy10 30-39 (0.79, 95%CI, 0.71-0.86), and BED Gy10 <30 (0.64; 95%CI, 0.5-0.7; p=0.0001). The mean survival time was 3.31 months (95%CI, 2.73-3.9) months, and the responders had a significantly longer survival (longer by 2.5 months) compared to the non-responders (95%CI, 1.7-3.3; p<0.0001). Palliative RT is effective at controlling bleeding due to local recurrence/progression from GC. Our findings reveal a relationship between BR and BED. BED <30 Gy 10 should not be recommended, and 3DRT should be indicated instead in order to improve the result.

Patterns of recurrence and outcomes of glioblastoma multiforme treated with chemoradiation and adjuvant temozolomide

OBJECTIVES

To assess the patterns of failure and prognostic factors in Brazilian patients with glioblastoma multiforme (GBM) treated with radiotherapy (RT) and concurrent and adjuvant temozolomide (TMZ).

METHODS

Patients with diagnosed GBM post-resection received postoperative RT. TMZ was administered concurrently at 75 mg/m2/day for 28 consecutive days and adjuvant therapy at 150-200 mg/m2/day for 5 days every 28 days. Radiographic failure was defined as any new T1-enhancing lesion or biopsy-confirmed progressive enhancement inside of the radiation field. When possible, patients with recurrence were salvaged with metronomic TMZ, either in combination with a local treatment or alone (surgery or re-irradiation). Several prognostic factors were evaluated for overall survival (OS). Univariate and multivariate analyses were performed to identify significant factors. A p-value <0.05 was considered significant.

RESULTS

This study included 50 patients. The median follow-up time was 21 months. The median RT dose was 60 Gy and all patients received concomitant TMZ. During follow-up, 41 (83.6%) failures were observed, including 34 (83%) in-field, 4 (9.7%) marginal, and 3 (7.3%) distant failures. Metronomic TMZ was used as salvage treatment in 22 (44%) cases and in combination with local treatment in 12 (24%) cases. The median OS and progression-free survival times for the entire cohort were 17 and 9 months, respectively. In univariate analysis, the following factors were significant for better OS: maximal surgical resection (p=0.03), Karnofsky Performance Score (KPS)>70 at diagnosis (p=0.01), metronomic TMZ treatment (p=0.038), recursive partitioning analysis class III (p=0.03), and time to failure >9 months (p=0.0001). In multivariate analysis, the following factors remained significant for better OS: metronomic TMZ (p=0.01) and time to failure >9 months (p=0.0001).

CONCLUSION

The median OS of Brazilian patients with GBM treated with RT and TMZ was satisfactory. Although TMZ therapy has become the standard of care for patients with newly diagnosed GBM, the recurrence rate is extremely high. Metronomic TMZ as salvage treatment improved survival in these patients.

Salvage radiotherapy for biochemical recurrence after radical prostatectomy: does the outcome depend on the prostate cancer characteristics?

OBJECTIVE

To build a model to evaluate the impact of salvage radiotherapy (SRT) in men with PSA rise or persistent PSA after undergoing radical prostatectomy (RP).

MATERIALS AND METHODS

The study included 107 node-negative patients treated with SRT after RP at a single institution. Patients received SRT for either prostate-specific antigen (PSA) rising, or PSA persistence after RP. All patients received local radiation to the prostate / seminal vesicle bed. The primary measured outcome was the biochemical recurrence (BCR) free survival. Multivariable Cox regression analysis was used to develop a risk-stratification group to identify predictive factors associated with the probability of BCR at 5yr.

RESULTS

At a median follow-up of 52 months, the BCR free survival rate and overall survival in 5 years was 73% and 94%, respectively. At multivariable analysis, pre-SRT PSA level > 0.35ng / mL (p = 0.023), negative margins (p = 0.038), and seminal vesicles invasion (p = 0.001) were significantly associated with BCR free survival. Three risk groups using regression analysis for SRT administration was built. Low-, intermediateand the high-risk groups had a BCR free survival in 5-years of 96%, 84%, and 44% (p = 0.0001), respectively.

CONCLUSIONS

We developed a risk group stratification to show the impact of SRT based on prostate cancer characteristics. SRT showed to be extremely beneficial for patients with low- and intermediate-risk tumors. Moreover, the risk-group built could identify patients classified as high-risk who might benefit from more aggressive treatment for SRT.