Intraoperative electron-beam radiation therapy with or without external-beam radiotherapy in the management of paraaortic lymph-node oligometastases from gynecological malignancies

Intraoperative Radiation Therapy (IORT) in Gynecologic Cancers: A Scoping Review

OBJECTIVE

We aimed to analyze the current literature for IORT in gynecological cancers and summarized clinical outcomes regarding patient selection.

METHODS

A systematic search was conducted utilizing PUBMED, Embase, and CINAHL to identify studies following PRISMA-ScR guidelines. A PICOS structure was utilized: population: patients with epithelial gynecological cancers; intervention: IORT; C: a comparator was not required, as we aimed to analyze patient selection; outcome: clinical outcomes and overall survival; and S: experimental and quasi-experimental analytical observational studies and descriptive observational studies, excluding case series published in English and limited to the last 10 years. Data extraction was conducted for patient selection, IORT, oncological outcomes, and morbidity.

RESULTS

A total of 707 results were identified, and 509 studies were uploaded to Covidence for screening after removing duplications. Of the 21 eligible studies, 9 were included in the final review. The total number of patients included was 348. The studies were retrospective single-institution studies, except for one. There was significant heterogeneity in their design and protocols. IORT was exclusively used for recurrent and advanced stage gynecological cancers adjunct to pelvic exenteration or laterally extended endopelvic resections with variable indications across institutions. The mean number of IORT patients per study was 2.8 per year. Survival rates were variable and dependent on the surgical margin. Endometrial cancer had a favorable outcome compared to vulvar and cervical cancers.

CONCLUSIONS

Current clinical practice, as demonstrated by the research, is consistent with NCCN guidelines that endorse the application of IORT in instances of recurrent cervical, vaginal, and vulvar malignancies; however, there are no established recommendations for primary tumors. The analysis shows that there are gaps in our knowledge, mainly regarding the status of the margins, the criteria used to choose patients, and the outcomes that are specific to each histology. The standardization of protocols and prospectively powered studies are needed to refine patient selection criteria.

The value of a multimodal approach combining radical surgery and intraoperative radiotherapy in the recurrence treatment of gynecological malignancies - analysis of a large patient cohort in a tertiary care center

BACKGROUND

Recurrent and locally advanced gynecological malignancies have a poor prognosis. In particularly, pelvic local recurrence after previous radiotherapy and/or positive resection margins during surgical treatment for recurrent disease result in low survival rates. Consequently, locoregional control is of utmost importance in this cohort of patients. The aim of this study was to analyze treatment outcomes and determine prognostic factors for patients treated with surgery and intraoperative radiotherapy (IORT) for recurrent and locally advanced gynecological malignancies.

METHODS

40 patients who underwent surgical treatment and IORT between 2010 and 2022 were eligible for inclusion. The median follow-up time was 22 months. The outcomes measured were locoregional control (LRC), overall survival (OS), and survival without distant metastases (DMFS). The Cox proportional hazards model was used for univariate and multivariate analysis to assess the impact of patient variables and treatment factors on the endpoints mentioned. The following variables were analyzed: age at surgical treatment and IORT and initial diagnosis (< 65 vs. ≥65 years, each), disease-free interval (DFI) between initial diagnosis and first recurrence, DFI to surgical treatment and IORT, grading, histology, IORT dose (≤ 13 vs. >13 Gy) and technique (high dose radiotherapy (HDR) vs. IORT using electrons, (IOERT)). Survival curves were generated using the Kaplan-Meier method.

RESULTS

The mean IORT dose was 13.8 Gy (range 10-18 Gy). Cervical carcinoma was most frequently found in 27.5% of patients followed by endometrial carcinoma and vulvar carcinoma in 25% respectively. The final histopathologic results after surgery with IORT showed no residual tumour in 24 patients (60%), microscopic residual disease in 5 patients (12.5%), resection status could not be evaluated in three patients (7.5%) and the resection status was unknown in eight patients (20%). Subsequently, 27.5% of patients also received adjuvant radiotherapy of the local recurrence bed. However, after IORT, 65% of the women suffered a recurrence. Of these, the recurrences were localized: in-field 32.5%, out-of-field 22.5% and margin-of-field 12.5%. The 3- and 5-year OS was 69% and 55% respectively. The 3- and 5-year LRC was 56% respectively. The 3- and 5-year DMFS was 66% and 49%. Whereas the comparison between groups by IORT dose level (≤ 13 vs. >13 Gy) showed a non-significant trend in favor of the higher dose only for OS (p = 0.094), but not in LRC and DMFS (p > 0.05). OS and DMFS, but not LRC, differed significantly between the HDR-IORT and IOERT groups (p = 0.06 and p = 0.03,) in favor of the HDR-IORT technique. For HDR-IORT technique a trend towards superior OS and LRC was observed in the univariate analysis: HR 3.76, CI 95%: 0.95-14.881, p = 0.059 and HR 2.165 CI 95%: 0.916-5.114, p = 0.078 CONCLUSIONS: The survival rate for pelvic recurrence in gynecological malignancies remains poor and comparable with historical data from the last two decades. Particularly HDR-IORT, appears to provide a long-term oncological benefit in carefully selected patients.

Outcomes of surgical resection and intraoperative electron radiotherapy for patients with para-aortic recurrences of gastrointestinal and gynecologic malignancies

BACKGROUND

Para-aortic lymph node (PALN) metastases from primary pelvic malignancies are often treated with resection, but recurrence is common. We report toxicity and oncologic outcomes for patients with PALN metastases from gastrointestinal and gynecologic malignancies treated with resection and intraoperative electron radiotherapy (IORT).

METHODS

We retrospectively identified patients with recurrent PALN metastases who underwent resection with IORT. All patients were included in the local recurrence (LR) and toxicity analyses. Only patients with primary colorectal tumors were included in the survival analysis.

RESULTS

There were 26 patients with a median follow up of 10.4 months. The rate of para-aortic local control (LC) was 77% (20/26 patients) and the rate of any cancer recurrence was 58% (15/26 patients). Median time from surgery and IORT to any recurrence was 7 months. The LR rate for those with positive/close margins was 58% (7/12 patients) versus 7% (1/14 patients) for those with negative margins (p = 0.009). 15% (4/26 patients) developed surgical wound and/or infectious complications, 8% (2/26 patients) developed lower extremity edema, 8% (2/26 patients) experienced diarrhea, and 19% (5/26 patients) developed an acute kidney injury. There were no reported nerve injuries, bowel perforations, or bowel obstructions. For patients with primary colorectal tumors (n = 19), the median survival (OS) was 23 months.

CONCLUSIONS

We report favorable LC and acceptable toxicity for patients receiving surgical resection and IORT for a population that has historically poor outcomes. Our data show disease control rates similar to literature comparisons for patients with strong risk factors for LR, such as positive/close margins.

Practice-oriented solutions integrating intraoperative electron irradiation and personalized proton therapy for recurrent or unresectable cancers: Proof of concept and potential for dual FLASH effect

Background

Oligo-recurrent disease has a consolidated evidence of long-term surviving patients due to the use of intense local cancer therapy. The latter combines real-time surgical exploration/resection with high-energy electron beam single dose of irradiation. This results in a very precise radiation dose deposit, which is an essential element of contemporary multidisciplinary individualized oncology.

Methods

Patient candidates to proton therapy were evaluated in Multidisciplinary Tumor Board to consider improved treatment options based on the institutional resources and expertise. Proton therapy was delivered by a synchrotron-based pencil beam scanning technology with energy levels from 70.2 to 228.7 MeV, whereas intraoperative electrons were generated in a miniaturized linear accelerator with dose rates ranging from 22 to 36 Gy/min (at Dmax) and energies from 6 to 12 MeV.

Results

In a period of 24 months, 327 patients were treated with proton therapy: 218 were adults, 97 had recurrent cancer, and 54 required re-irradiation. The specific radiation modalities selected in five cases included an integral strategy to optimize the local disease management by the combination of surgery, intraoperative electron boost, and external pencil beam proton therapy as components of the radiotherapy management. Recurrent cancer was present in four cases (cervix, sarcoma, melanoma, and rectum), and one patient had a primary unresectable locally advanced pancreatic adenocarcinoma. In re-irradiated patients (cervix and rectum), a tentative radical total dose was achieved by integrating beams of electrons (ranging from 10- to 20-Gy single dose) and protons (30 to 54-Gy Relative Biological Effectiveness (RBE), in 10-25 fractions).

Conclusions

Individual case solution strategies combining intraoperative electron radiation therapy and proton therapy for patients with oligo-recurrent or unresectable localized cancer are feasible. The potential of this combination can be clinically explored with electron and proton FLASH beams.

CT-guided 125I brachytherapy for recurrent ovarian cancer

This retrospective study was to evaluate the local control and survival of ¹²⁵I brachytherapy for recurrent ovarian cancer. 52 ¹²⁵I brachytherapy procedures were performed in 47 patients with 51 recurrent ovarian cancer lesions. The follow-up period was 1-55 months (median 12 months). The local control rate (LC) of 3, 6, 12, 24 and 36 months was 93.3%, 77.7%, 58.9%, 38.7% and 19.3%, respectively. Patients with tumor size ≤ 4cm (85.7% vs 40.0%, P = 0.037) and actual D90 between 110 to 130Gy (47.4% vs 66.7% vs 62.5%, P = 0.029) had better LC. The 1, 2 and 3 years of overall survival (OS) was 79.3%, 63.0% and 52.5%, respectively. The poor performance status (HR 3.821, 95% CI 1.383-10.555; P = 0.010), concurrent distant metastasis (HR 9.222, 95% CI 1.710-49.737; P = 0.010) and large postoperative residual tumor size (HR 6.157, 95% CI 1.438-26.367; P = 0.014) were closely correlated with a poor OS. Our data indicate thatCT-guided ¹²⁵I brachytherapy is an effective and safe modality for the local treatment of recurrent ovarian cancer.