Local Progression-free Survival Research Articles

SURG-17. SALVAGE SURGERY FOR LOCAL PROGRESSION AFTER RADIATION THERAPY OF BRAIN METASTASES

Abstract Recent advances in cancer treatments have prolonged survival after the onset of brain metastases (BM), and this trend increases the risk of local progression (LP) after radiotherapy (RT)of BM. Salvage options include surgical resection, re-irradiation and medical therapies, but there is no standard management for this clinical setting. This study aimed to evaluate the outcome of salvage surgery. We performed surgical resection for intracranial metastases in 221 cases in a single institution between Apr 2014 and Mar 2024. Of those, the data of the cases underwent initial surgery after irradiation for BM were extracted. After excluding duplicated cases and those underwent surgery within one month after irradiation, we finally analyzed 49 cases. Overall survival (OS) and local progression free survival (LPFS) were evaluated by Kaplan-Meier method. All but two cases had a history of stereotactic radiosurgery/radiotherapy for BM. Histopathological diagnosis of surgical specimens was tumor recurrence in 33 cases and radiation necrosis (RN) in 16 cases. RN cases showed longer duration between radiation and LP, when comparing with recurrent cases (median 42.3. vs. 9.3 months). OS was longer in RN cases than in tumor recurrent cases (median 68.5 vs. 26.9 months). In the recurrent cases, preoperative poor KPS (under 70), active state of extracranial lesions and RPA class were associated with shorter OS. Extent of resection, postoperative chemotherapy and local irradiation did not have significant impact on OS. Twenty cases experienced local recurrence after salvage surgery, and LPFS was 7.0 months. Any of extent of removal, postoperative chemotherapy and RT were not associated with LPFS. We reported relatively long survival after salvage surgery for local failure of BM after irradiation. Salvage surgery should be considered especially in patients with good extracranial control and performance status. High recurrence rate after salvage treatment urges the development of additional treatment approaches.

RADT-08. THIRD RECURRENT WHO 1 SPINAL MENINGIOMAS. CASE SERIES AND CLINICAL OUTCOMES FOLLOWING SURGERY OR DEFINITIVE RADIOTHERAPY

Abstract INTRODUCTION Spinal meningiomas (SM) account for approximately 1.2–12.7% of all meningiomas and 25% of spinal cord tumors. Most are benign (WHO grade 1), but a small percentage are atypical (WHO grade 2) or anaplastic (WHO grade 3). These tumors are typically solitary and non-invasive with low recurrence rates post-surgery. This study aims to compare the efficacy of definitive radiotherapy (RT) versus third surgery for recurrent SM WHO grade 1, focusing on local control, progression-free survival (PFS), and toxicity. METHODS A retrospective review approved by the Institutional Review Board included patients diagnosed with recurrent SM WHO grade 1 who underwent second surgery between 2008-2020. Patients who received radiation after the first surgery or upgraded to WHO grade 2 or 3 were excluded. Data on demographics, tumor characteristics, surgical techniques, and radiation therapy details were analyzed using descriptive and inferential statistics. RESULTS The study included 48 cases of third progression SM WHO grade 1. The median age was 53 years, and 70.8% were female. Tumor locations were primarily thoracic (75%). There was no significant difference in PFS between the third surgery and RT groups, with 36-month PFS rates of 77.4% and 76.4%, respectively. RT-related toxicities were manageable, and neurological improvements were noted in both groups, with more pronounced improvements in the surgical group. RT showed better pain control outcomes. CONCLUSION Both definitive RT and third surgery are effective for managing recurrent SM WHO grade 1, with comparable PFS. RT is a viable alternative, especially for high-risk surgical patients, providing effective pain control and manageable toxicities. Further studies with larger cohorts and longer follow-ups are recommended to validate these findings and refine treatment protocols for recurrent SM, ultimately improving patient outcomes and quality of life.

A comparison of isolated limb infusion/perfusion, immune checkpoint inhibitors, and intralesional therapy as first-line treatment for patients with melanoma in-transit metastases.

Isolated limb infusion and perfusion (ILI/ILP) has been a mainstay treatment for unresectable melanoma in-transit metastases (ITM), but increased use of immune checkpoint inhibitors (ICI) and intralesional therapy (talimogene laherparepvec [TVEC]) introduced several different management options. This study compares first-line ILI/ILP, ICI, and TVEC. Retrospective review from 12 international institutions included patients treated from 1990 to 2022 with first-line ILI/ILP, ICI, or TVEC for unresectable melanoma ITM. A total of 551 patients were treated, with ILI/ILP (n=356), ICI (n=125), and TVEC (n=70) with median follow-up of 5.5 years. Tumor burden was highest with ILI/ILP and lowest with TVEC (p =.002). Breslow thickness was lowest with TVEC (p =.007). TVEC was mostly used in stage IIIB disease versus IIIC for ILI/ILP and ICI (p =.01). Using ICI as the reference category, TVEC had the highest odds of a complete response (CR) (odds ratio, 1.96; p =.029) and a longer local progression-free survival (PFS) (hazard ratio [HR], 0.40; p =.003). ILI/ILP had shorter local PFS (HR, 1.72; p =.012), PFS (HR, 1.79; p <.001), distant metastasis-free survival (DMFS) (HR, 1.75; p =.014), overall survival (HR, 1.82; p =.009), and melanoma-specific survival (HR, 2.29; p =.004). Stage IIIB disease had longer DMFS (HR, 0.24; p <.001) compared to IIIC/D. TVEC as first-line therapy for unresectable melanoma ITM was associated with superior CR rates and local PFS. Notably, TVEC was used in patients with a lower Breslow thickness, disease stage, and tumor burden. Therefore, when compared to ILI/ILP and ICI, TVEC should be considered as first-line therapy for unresectable stage IIIB melanoma ITM with minimal tumor burden and lower Breslow thickness.

Is intercalary frozen autograft augmented with intramedullary cement and bridging plates fixation a durable reconstruction?

AimsWe analysed the survival, complications, and function of frozen autograft augmented with intramedullary cement and bridging plates fixation for intercalary bone defect reconstruction in primary bone sarcomas.Patients and MethodsA retrospective cohort study was conducted on 72 patients with primary bone sarcomas (34 males, 38 females) between January 2016 and June 2023. The average age was 22.0 ± 13.6 years (6 to 61 years) and the pathological type included osteosarcoma (55), followed by adamantinoma (5), Ewing’s sarcoma (4), undifferentiated pleomorphic sarcoma (4), chondrosarcoma (3), and malignant tenosynovial giant cell tumor (1). The oncological outcomes included local control, metastasis, progression-free survival and overall survival. The functional outcomes were evaluated by the Musculoskeletal Tumor Society Score (MSTS-93), the Toronto Extremity Salvage Score (TESS), and the motion of the joint.ResultsThe mean follow-up time was 50.0 ± 27.4 months (12 to 99 months). 10 patients died of the disease, 9 patients were alive with disease and 53 patients were alive with no evidence of disease. The average 5-year overall survival of autograft was 85.8% (95% CI, 72.1-93.1%). The average MSTS-93 score was 96% ( 67–100%) and the average TESS score was 98% (74–100%). Twenty-four patients (33.3%) had at least one complication in the follow-up period. The most common complications were nonunion (9.7%, 7/72) and local recurrence (9.7%, 7/72), followed by leg length discrepancy (6.9%, 5/72), infection (5.6%, 4/72), implant failure (4.2%, 3/72), delayed union (2.8%, 2/72), and graft fractures (1.4%, 1/72). Tumor site was an independent risk factor for bone nonunion (OR, 22.23; p = 0.006).ConclusionsWe presented a large technique series for preventing autograft-related complications (especially for autograft fractures) of intercalary frozen autograft reconstruction. This method showed promising functional outcomes and provided durable reconstruction.Level of evidencelevel IV therapeutic study.

Response of Spontaneous Oral Tumors in Canine Cancer Patients Treated with Stereotactic Body Radiation Therapy (SBRT).

To describe outcome and toxicity for dogs with oral tumors, specifically oral malignant melanoma (OMM), squamous cell carcinoma (SCC), and soft tissue sarcoma (STS) after stereotactic body radiation therapy (SBRT). A single institution retrospective study was conducted. Outcomes were analyzed using Kaplan-Meier analysis and Cox proportional hazard analysis. Treatment responses at different time points were evaluated with Pearson's Chi-squared test to identify prognostic factors. Acute and late toxicities were recorded according to VRTOG criteria and were analyzed to identify risk factors. Adverse events other than acute and late toxicities were recorded. A total of 98 patients met the inclusion criteria (OMM n = 37; SCC n = 18; STS n = 43). The SBRT prescription was 1-6 fractions, with a total dose range of 12-40 Gy. Local progression-free survival (PFS) for OMM, SCC, and STS was 187, 253, and 161 days, respectively. Overall PFS was 152 days and median survival time (MST) was 270 days, with no statistical difference between tumor types. The presence of lymph node metastasis and the use of elective nodal irradiation (ENI) were associated with shorted PFS and MST. Severe acute toxicities to organs at risk affected 10/85 (11.8%) of patients. Osteoradionecrosis and oronasal fistula formation occurred in 23/81 (28.4%) of patients and was significantly associated with tumor type (SCC, P = 0.006). BRT can be offered as a treatment option for oral tumors in dogs. Toxicities were common and warrant risk factor considerations and adjustments to current SBRT protocols.

Safety and Efficacy of Percutaneous Cryoablation for Recurrent or Metastatic Soft-Tissue Sarcoma in Adult Patients.

BACKGROUND. Treatment options are limited in patients with recurrent or metastatic disease after initial treatment of soft-tissue sarcoma (STS) by surgical resection, radiation, or systemic therapy. Percutaneous cryoablation may provide a complementary minimally invasive option in this setting. OBJECTIVE. The purpose of this article was to assess the safety and efficacy of percutaneous cryoablation performed for local control of treatment-refractory recurrent or metastatic STS. METHODS. This single-institution retrospective study included adult patients who underwent percutaneous cryoablation from January 2016 to April 2023 to achieve local control of recurrent or metastatic STS after earlier treatment (surgery, radiation, or chemotherapy). For each treated lesion, a single interventional radiologist rereviewed intraprocedural images to assess for adequate coverage by the ice ball of the entire lesion and a 5-mm or greater margin in all dimensions. Complications and outcomes were extracted from medical records. The primary end point for procedure efficacy was 1-year local progression-free survival. RESULTS. The study included 141 patients (median age, 66 years; 90 women, 51 men) who underwent 217 cryoablation procedures to treat 250 recurrent or metastatic STS lesions. The most common STS histologic types were leiomyosarcoma (56/141) and liposarcoma (39/141). Lesions had a mean long-axis diameter of 2.0 cm (range, 0.4-11.0 cm). Adequate ice-ball coverage was achieved for 82% (204/250) of lesions. The complication rate was 2% (4/217), including three major complications and one minor complication. Patients' median postablation follow-up was 25 months (range, 3-80 months). Local progression-free survival rate was 86% at 1 year and 79% at 2 years. The chemotherapy-free survival rate was 45% at 1 year and 31% at 2 years. The overall survival (OS) rate was 89% at 1 year and 80% at 2 years. In Kaplan-Meier analysis, leiomyosarcoma, in comparison with liposarcoma, had significantly higher local progression-free survival but no significant difference in OS. In multivariable analysis, factors independently associated with an increased risk for local progression included inadequate ice-ball coverage (HR = 7.34) and a lesion location of peritoneum (HR = 3.63) or retroperitoneum (HR = 3.71) relative to lung. CONCLUSION. Percutaneous cryoablation has a favorable safety and efficacy profile in patients with recurrent or metastatic STS after earlier treatments. CLINICAL IMPACT. Percutaneous cryoablation should be considered for local control of treatment-refractory STS.

Microwave Ablation after VATS in Patients with Multiple Pulmonary Nodules.

The management of residual nodules after video-assisted thoracoscopic surgery (VATS) for multiple pulmonary nodules (MPNs) is challenging. Microwave ablation (MWA), which is highly repeatable and minimally invasive, has garnered widespread attention in the treatment of MPNs. Ninety-one patients with MPNs who underwent VATS for resection of high-risk nodules followed by MWA for residual nodules were examined. Clinical efficacy and complications were assessed. The primary end points were MWA success rate and complete ablation rate. Secondary end points were local progression-free survival (LPFS), overall survival (OS), and complications. MWA was successfully completed in all patients. Mean tumor diameter, ablation time, and ablation output power were 0.81 cm, 3.4 minutes, and 39 W, respectively. LPFS was 100% at 3, 6, 12, and 24 months, respectively. OS was 100% at 12 and 24 months, respectively. No intraoperative or postoperative deaths occurred. Complications with MWA were infrequent. Pneumothorax was most common, occurring in 31 patients (34.07%); among these, seven (7.69%) required closed thoracic drainage. Pleural effusion occurred in six patients (6.59%), hydropneumothorax in five (5.49%), and pneumonia in three (3.30%). The pain level after MWA was moderate-to-severe in 29 patients (31.87%). MWA is safe and feasible for treating residual nodules in patients with MPNs who have undergone VATS. The incidence of complications was low, and most complications were mild.

Retrospective Evaluation of GEC-ESTRO Constraints for Definitive Radiochemotherapy with Brachytherapy and Correlation with Oncologic Outcome in Cervical Cancer: A Monocenter Study.

This study aims to evaluate patients with locally advanced cervical cancer who underwent definitive radiochemotherapy, including brachytherapy, at the University Hospital of Muenster (UKM), focusing on target volume coverage, oncologic outcome parameters, and organs at risk (OAR) toxicities. Results are compared with the Gyn GEC-ESTRO (GGE) recommendations. Of a cohort of 48 patients, treated between 2013 and 2023, the physical radiation treatment planning with application of CT and MRI and oncologic follow-up data was analyzed. Target volume structures, comprising the high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume (IR-CTV), Point A, and corresponding EQD2(α/β=10) doses were determined. Endpoints included local tumor control, overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS). Total OAR (D2cc) EQD2(α/β=3) doses were correlated with adverse events defined by CTCAE v5.0 and LENT-SOMA criteria. Median follow-up was 58.0 months (95% CI [27.6, 88.4]). FIGO stage I was present in 7 (15%) patients, II in 13 (27%), and III in 28 (58%) patients. A total of 38 (79%) patients showed a complete remission 3 months after treatment. The 5-year event-free rate was 67.4% (95% CI [49.3, 80.3]) for OS, 77.0% (95% CI [56.7, 88.6]) for RFS and 68.1% (95% CI [49.7, 80.9]) for PFS. Incomplete radiation treatment and advanced tumor stages led to worse outcomes. Meeting Point A GGE recommendations increased chances for complete remission and could decrease chances of an event occurring for OS, PFS, and RFS. Compliance with GGE recommendations lowered the chances of OAR toxicity occurring. MRI-based target volume definition for brachytherapy in cervical cancer may improve patients' OS, PFS, and RFS. Time-to-event endpoints are consistent with comparable studies, and adherence to current ESGO/ESTRO/ESP guidelines is endorsed.

Adaptive stereotactic radiosurgery for cerebral metastases of non-small cell lung cancer: a retrospective study

INTRODUCTION: Non-small cell lung cancer (NSCLC) is a common cause of brain metastases (BM). Adaptive stereotactic radiosurgery (ASRS) may be a useful option in the treatment of patients with large unresectable brain metastases (BM), but to date there are only a limited number of studies evaluating the effectiveness of this method.OBJECTIVE: To analyze the effectiveness of ASRS in patients with large BM NSCLC not subject to surgical resection.MATERIAL AND METHODS: We retrospectively analyzed data from 37 patients suffering from NSCLC with 45 large (&gt;2 cm in diameter, volume &gt;4 cm3) unresectable BM treated with the Gamma Knife Perfexion model using two- and three-fraction ASRS. Of these, 14 foci (31.1%) were metastases of squamous cell lung cancer, 31 (68.9%) were metastases of adenocarcinoma. The median volume of lesions treated with ASRS was 9.8 (range 4.6–30.6 cm3). The dynamics of volume changes between fractions and the cumulative incidence of local relapses (CILR) were studied, and ROC analysis was performed for the tumor volume parameter. Intracranial progression-free survival (iPFS) and overall survival (OS) were assessed. Statistics: To establish statistical significance of differences for related variables, the Wilcoxon test for pairwise comparisons and the Friedman test for three or more groups were used. The Kaplan-Meier method was used to calculate local control, PFS, and OS rates. The log-rank test was used to compare survival data in two groups.RESULTS: The median follow-up period was 19.4 months. With two-fraction ASRS, the median volume of metastasis decreased by 28.6% by the second session, with three-fraction — by 40.0% by the third session. The 1-year and 2-year CILR rates were 8.6±6.1%, respectively; 26.1±12.3%. In ROC analysis, the area under the curve (AUC) for tumor volume was 0.80 (95% CI 0.6– 1.0) with an optimal cutoff of 18.5 cm3. The differences in CILR between the groups with metastasis volume &lt;18.5 cm3 and ≥18.5 cm3 were statistically significant (p&lt;0.001). Median iPFS was 8.3 (95% CI 5.9–10.7) months, 1-year iPFS was 33.5±8.1%;2-year — 7.8±5.2%. Median OS was 13.2 (95% CI 9.0–17.4) months; 1-year OS — 52.9±8.7%, 2-year — 22.4±8.8%.DISCUSSION: Using two- and three-fraction ASRS, we delivered doses to large BM sufficient for a high level of local control with an acceptable risk of neurotoxicity: 1-year local control was 91.4%; 2-year — 73.9%; the incidence of radionecrosis is 8.5%. A statistically significant effect of lesion volume ≥18.5 cm3 on the risk of local recurrence was found. The iPFS and OS indicators after ASRS can be considered satisfactory for this group of patients.CONCLUSION: ASRS is an effective and perhaps optimal strategy for the treatment of large unresectable BM in patients with NSCLC, but comparison with other modern radiotherapy modalities such as stereotactic hypofractionated radiotherapy and WBRT with simultaneous integrated boost is needed.

Radiotherapy with 15 × 2.633 Gy vs. 20 × 2.0 Gy in Patients with Malignant Spinal Cord Compression and Favorable Survival Prognoses: A Secondary Analysis of the RAMSES-01 Trial.

Many patients with malignant spinal cord compression (MSCC) who are not candidates for neurosurgery receive radiotherapy alone. This study compared 15 × 2.633 Gy over three weeks to 20 × 2.0 Gy over four weeks in patients with favorable survival prognoses. The outcomes of 34 patients treated with 15 × 2.633 Gy (equivalent dose 41.6 Gy10) in the RAMSES-01 trial were compared to 239 patients from an existing database receiving 20 × 2.0 Gy using propensity-score-adjusted Cox and logistic regression models. All patients had favorable survival prognoses. Endpoints included local progression-free survival (LPFS), improvement of motor function, post-treatment ambulatory status, and overall survival (OS). After propensity score adjustment, the 12-month rates of LPFS and OS were 98.1% (RAMSES-01 cohort) vs. 91.6% (p = 0.265) and 79.1% vs. 82.2% (p = 0.704), respectively. Regarding improvement of motor function, 15 × 2.633 Gy appeared superior (p = 0.073). No significant difference was observed regarding ambulatory status (p = 0.822). The three-week regimen for MSCC has similar outcomes and reduces treatment time when compared to a four-week regimen.

7960 Clinical Outcomes of Image-Guided Therapies In Patients With Adrenocortical Carcinoma: A Tertiary Referral Center Retrospective Study

Abstract Disclosure: B. Chahla: None. K. Pal: None. V. Balderrama Brondani: None. F. Yaylaci Mert: None. M. Campbell: None. R. Sheth: None. M.A. Habra: None. Background: Image-guided therapies (IGTs) such as cryoablation or embolization are commonly used in oncology, but their role in adrenocortical carcinoma (ACC) is not well-defined. Materials and Methods: A retrospective review of ACC patients treated with IGTs. We assessed time to next line of systemic therapy, disease control rate (DCR), local tumor progression-free survival (LTPFS), and complications of IGTs.Treatment efficacy was assessed based on RECIST v1.1. Complications were categorized based on the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Results: The study cohort included 26 patients (median age 56 years [range 38-76]; n=18 female) who had 51 IGT sessions to treat 86 lesions. The median Ki-67 is 20 (range 2-79), and median Weiss score is 6 (range 3-9). Seventeen patients received systemic therapy including mitotane, chemotherapy, immunotherapy, and other treatments prior to the first IGT and 10 patients received systemic therapy concurrently with first IGT. IGT modalities included cryoablation (n = 49), microwave ablation (n = 21), combined microwave and bland transarterial embolization (n = 8), bland transarterial embolization alone (n = 3), radioembolization (n = 3), and radiofrequency ablation (n = 2). Treated sites included the liver (n=37), intraperitoneal (n=11), adrenalectomy bed (n=10), lung (n=6), lymph nodes (n=6), retroperitoneal soft tissue (n=6) and other soft tissues (n=10). The median largest pre-IGT anteroposterior tumor dimension was 2.3 cm (range 0.5-8.6). DCR was 81.4% (70 out of 86), of which 66.3% of tumors showed complete response, 18.6% showed progressive disease, 8.1% showed partial response, and 7.0% showed stable disease. LTPFS rates were 73% and 63% at 1 and 2 years, respectively. Fourteen lesions needed re-ablation. Ten patients did not require systemic therapy while 16 patients (61.5%) received new systemic therapy following IGT, with a median time from first IGT to systemic therapy of 12.5 months (95% CI: 8.6 months- upper limit not reached). There was 1 reported CTCAE grade 3 adverse event (biloma) following IGT. Conclusion: IGT use in properly selected ACC lesions is safe and associated with prolonged disease control and delay in the need for systemic therapy. Presentation: 6/2/2024

Tailored management of advanced thyroid cancer patients treated with lenvatinib or vandetanib: the role of a multimodal approach.

In differentiated/poorly differentiated (DTC/PDTC) or medullary thyroid cancer (MTC) treated with kinase inhibitors (KIs), additional treatments (ATs) can be performed in selected cases. We retrospectively analysed all the ATs performed in our center in KI-treated TC patients, evaluating the subsequent KI modulation, the local PD in case of loco-regional procedure (LRP) and the AT-related complications. DTC/PDTC patients with or without progressive disease before the first AT (PD and NO PD GROUP, respectively) were analysed separately. In our center, 32 ATs (30 LRPs and 2 radioactive iodine treatments) were performed in 14 DTC/PDTC patients and 4 MTC subjects after the start of systemic therapy with lenvatinib or vandetanib (27 and 5 ATs, respectively). Brain was the most treated site (11/30 LRPs) and external beam radiation was the most employed LRP (18/30 LRPs). KIs dose reduction or discontinuation of KI therapy (at least transient) was performed after 50% of ATs in DTC/PDTC NO PD GROUP. The KI was maintained at the same dosage after 75% and 50% of the ATs performed in DTC/PDTC PD GROUP and MTC, respectively. During the follow-up, local PD was detected after 14 LRPs. Local progression-free survival (LPFS) was significantly shorter in DTC/PDTC PD GROUP in comparison to NO PD GROUP (12 month-LPFS 91.7% versus 15.2%); in patients with MTC, 12 month-LPFS was 50%. AT-related AEs were mostly G1-G2. In selected DTC/PDTC without previous PD and treated with a multimodal strategy, local disease control is generally maintained regardless the KI dose modulation. In DTC/PDTC patients with previous limited PD and in MTC subjects, the choice of performing a LRP and continue the ongoing KI therapy must consider the risk of early local progression. AT-related AEs in KI treated patients were mild in most cases.

Treatment strategies with electrochemotherapy for limb in-transit melanoma: Real-world outcomes from a European, retrospective, cohort study

BackgroundThis study analysed treatment strategies with electrochemotherapy (ECT) in melanoma with limb in-transit metastases (ITM). MethodsWe audited AJCC v.8 stage IIIB-IIID patients treated across 22 centres (2006–2020) within the International Network for Sharing Practices of ECT (InspECT). Results452 patients were included, 58 % pre-treated (93 % had lower limb ITM, 44 % had ≤10 metastases [median size 1.5 cm]. Treatment strategies included first-line ECT (n = 145, 32 %), ECT with concurrent locoregional/systemic treatment (n = 163, 36 %), and salvage ECT (n = 144, 32 %). The objective response rate was 63 % (complete response [CR], 24 %), increasing to 74 % (CR, 39 %) following retreatment (median two ECT, range 1–8). CR rate in treatment-naïve and pre-treated patients was 50 % vs 32 % (p < 0.001). Bleomycin de-escalation was associated with lower CR (p = 0.004). Small tumour number and size, hexagonal electrode, retreatment, and post-ECT skin ulceration predicted response in multivariable analysis. At a median follow-up of 61 months, local and locoregional recurrence occurred in 55 % and 81 % of patients. Median local progression-free, new lesions-free, and regional recurrence-free survival were 32.9, 6.9, and 7.7 months. Grade-3 toxicity was 15 %. Concurrent treatment and CR correlated with improved regional control and survival. Concomitant checkpoint inhibition did not impact toxicity or survival outcomes. The median overall survival was 5.7 years. ConclusionsAmong patients with low-burden limb-only ITM, standard-dose bleomycin ECT results in durable local response. Treatment naivety, low tumour volume, hexagonal electrode application, retreatment, and post-ECT ulceration predict response. CR and concurrent treatment correlate with improved regional control and survival outcomes. Combination with checkpoint inhibitors is safe but lacks conclusive support.

Microwave Ablation of Refractory Oligometastatic Non–Small Cell Lung Cancer in the Liver

PurposeTo evaluate safety and effectiveness of microwave ablation (MWA) in the treatment of liver metastases (LMs) secondary to non–small cell lung cancer (NSCLC). Materials and MethodsThis retrospective study included patients with NSCLC who underwent MWA of LM from March 2015 to July 2022. Local tumor progression-free survival (LTPFS) and overall survival (OS) were estimated using competing risk analysis and the Kaplan-Meier method. Postprocedural adverse events were recorded according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0. ResultsTwenty-three patients with 32 LMs were treated in 27 MWA sessions. The mean dimension of the largest index tumor was 1.96 cm (SD ± 0.75). Technical success was 100%. Technical effectiveness was achieved in 26 (81.3%) of 32 tumors. The median length of follow-up was 37.7 months (interquartile range, 20.5–54.5 months). The median LTPFS was 16.3 months (95% confidence interval [CI], 7.87–44.10 months). The median OS was 31.7 months (95% CI, 11.1–65.8 months). Ablation margin was a significant factor for LTPFS, with tumors ablated without a measurable margin being more likely to progress than those with measurable margins (subdistribution hazard ratios [HRs], 0.008–0.024; P < .001). Older age (HR, 1.18; 95% CI, 1.09–1.28; P < .001) and presence of synchronous lung metastases (HR, 14.73; 95% CI, 1.86–116.95; P = .011) were significant predictors of OS. Serious adverse events (CTCAE Grade ≥3) within 30 days occurred in 2 (7.4%) of 27 sessions, including pulmonary embolus and severe abdominal pain. ConclusionsPercutaneous MWA is a safe treatment for NSCLC LM, with longer survival noted in younger patients and those without synchronous lung tumors.

Outcomes and Complications of Image-Guided Percutaneous Tumour Ablation for Hepatocellular Carcinoma at the Irish National Liver Transplant Centre.

Background: Image-guided tumour ablation is a minimally invasive treatment for early stage hepatocellular carcinoma (HCC). Our study reviews the complications and long term outcomes in patients treated at a tertiary referral centre. Methods: Retrospective study. All patients with HCC who underwent microwave ablation (MWA) or radiofrequency ablation (RFA) from 1st January 2014 to 31st December 2022 were identified. Treatment response of target lesion, complications, and survival were recorded. Results: One hundred seventy ablations were performed in 118 patients; 70% MWA, 30% RFA. Median radiological follow-up 21 months (range 3-107). Follow-up imaging was reported using LI-RADS and mRECIST. At first follow-up imaging, 94 patients had complete response (primary efficacy rate 80.3%) while 19.7% (n = 23) had residual disease. Fifteen of these had repeat ablation; 10 had complete response (secondary efficacy rate 85.6%). By end of study duration, 70.5% (n = 79) achieved sustained local complete response from single ablation without documented recurrence. 14.3% (n = 16) required more than one ablation of target lesion. Overall, 84.8% (n = 95) demonstrated long term local complete response to ablation. Complication occurred in 5.9% (n = 10); 40.0% Grade I, 40.0% Grade II, 10.0% Grade III, 10.0% Grade IV as per the CIRSE Classification. 1-, 3-, and 5-year overall survival (OS) rate was 97%, 68%, and 61% respectively. Mean OS was 5.3 years (median 4.7). No difference in OS (P = .7) or local progression free survival (P = .5) between patients treated with MWA versus RFA. Conclusion: This study demonstrates excellent long-term response to TA, with acceptable complication profile. No difference in survival between RFA versus MWA.

Dosimetric and Clinical Prognostic Factors in Single-Isocenter Linac-Based Stereotactic Radiotherapy for Brain Metastases.

Background/Objectives: To report on predictive factors in Linac-based SRT for single and multiple BM. Methods: Consecutive patients receiving either one or three fractions of single-isocenter coplanar VMAT SRT were retrospectively included. The GTV-PTV margin was 1-2 mm. The delivered target dose was estimated by recalculating the original plans on roto-translated CT according to errors recorded by post-treatment CBCT. The Kaplan-Meier method estimated local progression-free survival (LPFS), intracranial progression-free survival (IPFS), and overall survival (OS). Log-rank and Wilcoxon-Mann-Whitney tests evaluated inter-group differences, whereas Cox regression analysis assessed prognostic factors. Results: Fifty females and fifty males, with a median age of 69 years, received 107 SRTs. A total of 213 BM (range, 1-10 per treatment) with a median volume of 0.22 cc were irradiated with a median minimum BED of 59.5 Gy. The median delivered GTV D95 reduction was -0.3%. The median follow-up was 11 months. Nineteen LP events and a 1-year LC rate of 90.1% were observed. The GTV coverage did not correlate with LC, while the GTV volume was a risk factor for LP, with the 1-year rate dropping to 73% for volumes ≥ 0.88 cc. The median LPFS, IPFS, and OS were 6, 5, and 7 months, respectively. Multivariate analysis showed that patients with melanoma histology and those receiving a second or subsequent systemic therapy line had the worst outcomes, whereas patients with adenocarcinoma histology and mutations showed better results. Conclusions: The accuracy and efficacy of the Linac-based SRT approach for BM were confirmed, but the dose distribution alone failed to predict the treatment response, suggesting that other factors must be considered to maximize SRT outcomes.

Definitive particle therapy using protons or carbon ions for dedifferentiated liposarcoma

BackgroundParticle therapy is effective for the treatment of soft tissue sarcomas. However, the clinical outcomes of definitive particle therapy, particularly for dedifferentiated liposarcoma (DDLS), remain unknown. PurposeTo analyze the treatment outcomes of proton and carbon ion particle therapies for DDLS. MethodsWe retrospectively included patients with DDLS who were treated with particle therapy between 2008 and 2022. The local control (LC), progression-free survival (PFS), and overall survival (OS) rates were evaluated. ResultsFifty-seven patients were included in this analysis. The median patient age was 68 years (range, 36–91 years). The most common tumor site was the retroperitoneum (n = 37), with a median gross tumor volume (GTV) of 181 cm3. Twenty-nine patients received proton therapy, and 28 patients received carbon ion therapy. The most common fractionation dose was 70.4 Gy (relative biological effectiveness) in 32 fractions (72.7 Gy equivalent dose in 2 Gy fractions [EQD2]). The median follow-up time was 33 months (range, 1–128 months). The 3-year LC, PFS, and OS rates were 73.1 %, 44.6 %, and 70.6 %, respectively. Patients who received a higher prescribed dose (≥72.7 Gy EQD2) showed significantly better LC (p = 0.04) than did those who received a lower prescribed dose. Moreover, those with a larger GTV (≥181 cm3) had significantly worse OS (p = 0.04) than did those with a smaller GTV. Late adverse events occurred in five (9 %) patients. ConclusionsParticle therapy using protons or carbon ions for the treatment of DDLS is safe and provides good OS and LC. However, further studies with longer follow-up periods and larger cohorts are warranted.

Dose Deintensified 3-Day Photon, Proton, or Brachytherapy: A Nonrandomized Controlled Partial Breast Irradiation Trial

BackgroundThe optimal approach for partial breast irradiation (PBI) is unknown. We investigated a novel de-intensified 3-fraction PBI regimen for photons, protons, and brachytherapy. MethodsA multicenter nonrandomized controlled trial with primary outcome of adverse cosmesis at 3 years versus pre-PBI. Eligibility criteria were ≥ age 50 years treated with breast-conserving surgery for node-negative estrogen receptor positive (ER+) invasive breast cancer or any ductal carcinoma in-situ (DCIS) measuring ≤ 2.5 cm. Photon and proton PBI were prescribed 21.9 Gy (RBE) and brachytherapy 21 Gy in 3 fractions. Radiotherapy technique and use of adjuvant endocrine therapy was selected at physician and patient discretion. ResultsBetween June 17, 2015 and July 13, 2017, 161 eligible patients were treated with photons (56), protons (49), or brachytherapy (56). Median patient age was 66.8 years. 126 (78.3%) had invasive breast cancer (all ER+) and 35 (21.7%) had DCIS (88.6% ER+). 54.0% of patients with invasive breast cancer and 25.8% of patients with ER+ DCIS initiated and adhered to prescribed endocrine therapy. The proportion of patients with adverse cosmesis (by trained nurse assessment) was 14.5% at baseline, 2.3% at 3 years (difference -12.2%, 95% CI (-100%, -6.4%)). Adverse cosmesis at last-follow-up, with median follow-up 5 years, was 5.7% by nurse assessment, 5.6% by panel assessment of digital photographs, and 5.2% by patient self-report. There were no observed clinically meaningful changes in other patient reported outcomes, and just two grade 2 or higher adverse events, both grade 2, in the brachytherapy cohort. 5-year local recurrence-free and progression-free survival were 98.0% and 95.5%, respectively. There were no local recurrences amongst 60 patients with invasive breast cancer and Ki67 ≤ 13.25%. ConclusionsDe-intensified 3-day PBI provided favorable disease control, tolerability, and cosmetic outcomes, meeting the pre-specified criteria for acceptability. This approach is an attractive option for small node-negative ER+ BC and DCIS patients. Trial registrationClinicalTrials.gov identifier NCT02453737

Stereotactic Ablative Radiation Therapy for Oligometastatic Ovarian Cancer Lymph Node Disease: The MITO-RT3/RAD Phase II Trial

PurposeMITO-RT3/RAD (NCT04593381) is a prospective multicenter Phase II trial designed to assess the effectiveness and safety of stereotactic body radiotherapy (SBRT) in patients diagnosed with oligometastatic ovarian cancer (oligo-MPR-OC). In this report, we provide the results of the trial in the setting of lymph node disease. MethodsThe primary endpoint was the complete response (CR) rate, secondary endpoints included local control (LC), progression-free survival (PFS), overall survival (OS), treatment-free interval (TFI), and toxicity rates. Sample size was based on a previous study reporting an average 70.0% CR with SBRT. The study was powered to detect an improvement in the CR rate from 70.0% to 85.0%, with an α error of 0.05 (one-side) and a β error of 0.1. ResultsThe study met its primary endpoint of a statistically significant improvement of CR. 135 patients with 249 lesions were enrolled across fifteen Institutions from May 2019 to November 2023. CR were observed in 194 lesions (77.9%), PR in 40 (16.1%), SD in 14 (5.6%), and Progressive Disease (PD) in one lesion (0.4%). The ORR was 94%, with an overall clinical benefit rate of 99.6%. CR lesions exhibited a significantly higher LC rate than partial or not responding lesions (12-month LC: 92.7% vs. 63.1%, p<0.001). The 12-months actuarial rates for PFS and for OS were 36.6% (CR 38.3% vs not-CR 18.8%; p: 0.022) and 97.2% (CR 97.8% vs not-CR 93.8%; p: 0.067), respectively. The 12-months actuarial rate for Treatment Free Interval was 52.7% (CR 58.4% vs not-CR 24.4%; p: 0.004). CR was substantially associated with higher PFS (p: 0.036) and TFI (p: 0.006) rates at the univariate analysis. Twenty-three patients (17.0%) experienced mild acute toxicity. Late toxicity was reported in 9 patients (6.7%), mostly Grade 1. ConclusionsThis trial confirms the efficacy of ablative SBRT, with minimal toxicity observed. SBRT offered a high CR rate, promising long-term outcomes and systemic-therapy-free survival rate for complete responders.

Recent update of proton beam therapy for hepatocellular carcinoma: a systematic review and meta-analysis.

Although access to proton beam therapy (PBT) is limited worldwide, its use for the treatment of hepatocellular carcinoma (HCC) is gradually increasing with the expansion of new facilities. Therefore, we conducted a systematic review and metaanalysis to investigate the updated evidence of PBT for HCC. The MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were systematically searched for studies that enrolled patients with liver-confined HCC that were treated with PBT for a cure up to February 2024. A total of 1,858 HCC patients receiving PBT from 22 studies between 2004 and 2023 were selected for this meta-analysis. The median proportion of Child-Pugh class A was 86% (range, 41-100), and the median tumor size was 3.6 cm (range, 1.2-9.0). The median total dose ranged from 55 GyE to 76 GyE (median, 69). The pooled rates of 3- and 5-year local progression-free survival after PBT were 88% (95% confidence interval [CI], 85-91) and 86% (95% CI, 82-90), respectively. The pooled 3- and 5-year overall rates were 60% (95% CI, 54-66) and 46% (95% CI, 38-54), respectively. The pooled rates of grade 3 hepatic toxicity, classic radiationinduced liver disease (RILD), and non-classic RILD were 1%, 2%, and 1%, respectively. The current study supports PBT for HCC and demonstrates favorable long-term survival and low hepatic toxicities compared with other published studies on other radiotherapy modalities. However, further studies are needed to identify the subgroups that will benefit from PBT.