Metabolic response after 68Ga-PSMA-PET/CT-directed IGRT/SBRT for oligometastases prostate cancer.

BACKGROUND: We used 68Ga PSMA PET/CT in the current investigation to assess the metabolic response and local control of metastasis in patients with oligometastatic prostate cancer receiving SBRT. MATERIALS AND PROCEDURES: We performed a retrospective evaluation of the medical data of all patients with oligometastatic prostate cancer who underwent stereotactic body radiation therapy (SBRT) between 2017 and 2021. Our analysis only included medical records of patients who had SBRT for oligometastatic prostate cancer and had pre and post-SBRT 68Ga PSMA PET/CT images. Patient-related (age), disease-related (Gleason score, location of metastases), and treatment-related (factors and outcomes) data were collected from the medical files. RESULTS: A total of 17 patients (28 lesions) with a median age of 69 years were included in the research. A median follow-up of 16.6 months was used (range 6-36 months). The median follow-up period for 68 Ga PSMA PET/CT was 8 months (the range was 5-24 months). The median pre-treatment PSA level was 1.7 ng/mL (range 0.39-18.3 ng/mL) compared to the post-treatment PSA nadir of 0.05 ng/mL (0.02-4.57). During the follow-up period, local control was 96%, and there was a link between PSMA avidity on PET. In the treated lesions, there were no recurrences. During follow-up, none of the patients experienced toxicities of grade 3 or above. CONCLUSIONS: SBRT is a highly successful and safe way of treating patients with oligometastatic prostate cancer. Additional research is needed to examine 68Ga PSMA PET/CT to assess further for demarcation and follow-up.

A single-institution retrospective analysis of intraoperative radiation boost during breast-conservation treatment for breast cancer.

BACKGROUND: As part of a breast-conservation strategy for breast cancer, there are presently no data from randomized controlled studies on the use of intraoperative radiation (IORT) as a tumor bed boost. The effectiveness and safety of IORT as a boost therapy at a tertiary cancer center were retrospectively reviewed in this study. METHODS: Patients had breast-conserving surgery from 2012 to 2016 that included staging of the axillary lymph nodes, a single dose of 20 Gy IORT with 50-kV photons, whole-breast irradiation (WBI), and (neo-)adjuvant systemic treatment (if applicable). During the follow-up patients were monitored for the assessment of acute and late toxicities (using the Common Terminology Criteria for Adverse Events version 4.03). Results included ipsilateral (IBTR), contralateral (CBE), and distant metastasis-free (DMFS) breast progression-free survival, as well as overall survival (OS). RESULTS: The 68 patients had a median follow-up of 91.5 months (with a range of 9-125). Most patients (n = 51) had T1 disease and were clinically node negative. Only a small number of individuals had triple negative or high-grade illness. The majority of patients had sentinel node biopsy, and three (4.4%) had to have their tumors removed again since their original margins were positive. Finally, there were no distinct tumor bed margins. Neoadjuvant chemotherapy was administered to ten (14.7%). The median duration from BCS to WBI was 54.5 days, and conventionally fractionated WBI was used to accomplish WBI most frequently (n = 57, 96.6%). IORT was administered in a single 20 Gy dosage. 50 Gy was the median WBI dosage (range 40.05-50.4 Gy). There were no grade 4 adverse events for any patients in. Toxicities following surgery were minimal. There were only one patient with grade 3 toxicity (radiation dermatitis) to observe. Five tumor bed recurrences and two contralateral breast incident each occurred. CONCLUSION: This work adds to the preliminary evidence already in the literature and supports the use of IORT in boost settings. When randomized trials like TARGIT-B are eventually published, these hopeful findings should be prospectively evaluated.

A single-center experience with linear accelerator-based stereotactic radiotherapy for meningiomas: hypofractionation and radiosurgery.

PURPOSE: Meningioma is a common type of benign tumor that can be managed in several ways, ranging from close observation, surgical resection, and various types of radiation. We present here results from a 10 year experience treating meningiomas with a hypofractionated approach. MATERIALS AND METHODS: To define the rate of tumor control and factors associated with the relief of symptoms and radiation-related complications after radiosurgery and hypofractionated radiosurgery for patients with imaging-defined intracranial meningiomas. We reviewed the charts of 48 patients treated with stereotactic radiosurgery (SRS) or hypofractionated stereotactic radiotherapy (SRT) from 2002 to 2018. A total of 37 (82%) patients had WHO Grade 1 disease, and 11 (22%) had Grade 2. Outcomes that were analyzed included local control rates and the rate and grade of any reported toxicity. RESULTS: Only 36 patients with 38 lesions, who underwent the follow-up regime, were enrolled in the retrospective analysis. The follow-up mean was 40 months (12-120 months). 25/34 patients had surgery before the radiotherapy. Sixteen underwent SRS with a median dose of 13, 5, and 20 received hypofractionated SBRT with a median dose of 26.9 (22-45 Gy) in median six fractions (5-13 fractions). Local control at 2 and 5 years for all patients was 90 and 70%, respectively. No patient suffered from toxicity > 2 CTC. 21/36 patients showed stable disease, while 8/36 patients showed partial Remission. 7/36 developed recurrent meningioma (five in-field), only one patient with grade 1 meningioma, in a median of 22 months (13-48 months). CONCLUSION: SFRT was superior to SRS for local control in our analysis of Grade I meningiomas. This might be due to a tendency for higher EQD2 in the PTV with SFRT compared to SRS, which was reduced to avoid brain necrosis in large PTVs. Therefore, SFRT appears preferable for typical meningioma PTVs.

Nodal and osseous oligometastatic prostate cancer: a cohort including the introduction of PSMA-PET/CT-guided stereotactic and hypofractionated radiotherapy with elective nodal therapy.

PURPOSE: Oligometastatic prostate cancer is heavily investigated, and conventionally fractionated elective nodal treatment appears to increase biochemical relapse-free (bRFS) survival. The novelty of this report is to present elective nodal radiotherapy (ENRT) with simultaneous integrated boost with stereotactic (SBRT) or hypofractionated radiotherapy (HoFRT) for tolerance and for bRFS which we compared with SBRT of the involved field (IF) only. MATERIALS AND METHODS: Patients between 2018 and 2021 with and oligometastatic prostate cancer treated with SBRT or hypofractionation were eligible. A radiobiologically calculated simultaneous integrated boost approach enabled to encompass elective nodal radiotherapy (ENRT) with high doses to PSMA-positive nodes. A second group had only involved field (IF) nodal SBRT. RESULTS: A total of 44 patients with 80 lesions of initially intermediate- (52%) or high-risk (48%) D'Amico omPC were treated with SBRT to all visible PSMA-PET/CT lesions and 100% of the treated lesions were locally controlled after a median follow-up was 18 months (range 3-42 months). Most lesions (56/80; 70%) were nodal and the remainder osseous. Median bPFS was 16 months and ADT-free bPFS 18 months. ENRT (31 patients) versus IF (13 patients) prevented regional relapse more successfully. At univariate analysis, both initial PSA and length of the interval between primary diagnosis and biochemical failure were significant for biochemical control. Treatment was well tolerated and only two patients had toxicity ≥ grade 3 (1 GU and 1 GI, each). DISCUSSION/CONCLUSION: SBRT and hypofractionated radiotherapy at curative doses with ENRT was more effective to delay ADT than IF, controlled all treated lesions and was well tolerated.

Linac-based stereotactic radiosurgery for brain arteriovenous malformations.

PURPOSE: Linac stereotactic radiosurgery (SRS) is gaining popularity as a form of radiation treatment for cerebral arteriovenous malformations (AVMs) since the theory of combined radiosurgical and endovascular treatment poses much uncertainty and due to significant technical progress for SRS. This study focuses on how to evaluate obliteration and re-bleeding rates, and to determine factors and adverse effects influencing obliteration after linac-based SRS for cerebral AVMs. MATERIAL AND METHODS: From a statistical record of 71 patients, 31 had partial embolisation, five surgery and 29 had no prior treatment. Using Kaplan-Meier survival and life table analyses, actuarial obliteration and annual bleeding hazard rates were calculated after SRS. RESULTS: After a follow up of 1, 2 and 3 years the actual obliteration rates were 22, 59 and 66%, respectively whereby it was noted that prior embolization had no effect on the obliteration rate. Annual bleeding hazard rates were further analyzed after stereotactic radiosurgery to be 2.1% and 1.4% for the first and second year respectively. Asymptomatic abnormalities were detected after imaging in 33.9% of patients. A dose of less than 18 Gy significantly reduced the obliteration probability. CONCLUSION: SRS is a therapeutic option for intracerebral AVM. In general, there is a low rate of morbidity and a high probability of nidus obliteration.