PSMA PET/CT to evaluate response to SBRT for prostate cancer bone metastases

Background: In the current study we evaluated 68Ga PSMA PET/ CT to measure local control of bone metastasis in oligometastatic prostate cancer patients treated with SBRT.  Materials and methods: After the institutional review board approval, a retrospective review of medical records of consecutive prostate cancer patients treated between 2014 and 2018 was conducted. Only medical records of patients that were treated with SBRT for bone metastasis and had pre-and post-SBRT 68Ga PSMA PET/CT scans were included in our study. Data extracted from the medical files included patient-related (age), disease-related (Gleason score, site of metastasis), and treatment-related factors and outcomes. Results: During the study period, a total of 12 patients (15 lesions) were included, with a median age of 73 years. The median follow-up was 26.5 months (range 13–45 months). Median time of 68Ga PSMA PET/ CT follow up was 17.0 months (range 3–39 months). The median pre-treatment PSA was 2 ng/mL (range 0.56–44 ng/mL) vs. post treatment PSA nadir of 0.01 ng/mL (0.01–4.32) with a median time to nadir of 7 months (range, 2–12). Local control was 93% during the follow up period and there was correlation with PSMA avidity on PET. None patients developed recurrences in the treated bone. None of the patients had grade 3 or more toxicities during follow-up. Conclusions: SBRT is a highly effective and safe method for treatment of prostate cancer bone metastases. More studies are required to determine if SBRT provides greater clinical benefit than standard fractionation for oligometastatic prostate cancer patients. 68Ga PSMA PET/CT should be further investigated for delineation and follow-up

Comparative effectiveness of intensity modulated radiation therapy to 3-dimensional conformal radiation in locally advanced lung cancer: pathological and clinical outcomes.

OBJECTIVE: Intensity-modulated radiotherapy (IMRT) has better normal-tissue sparing compared with 3-dimensional conformal radiation (3DCRT). We sought to assess the impact of radiation technique on pathological and clinical outcomes in locally advanced non-small cell lung cancer (LANSCLC) treated with a trimodality strategy. METHODS: Retrospective review of LANSCLC patients treated from August 2012 to August 2018 at Sheba Medical Center, Israel. The trimodality strategy consisted of concomitant chemoradiation to 60 Gray (Gy) followed by completion surgery. The planning target volume (PTV) was defined by co-registered PET/CT. Here we compare the pathological regression, surgical margin status, local control rates (LC), disease free (DFS) and overall survival (OS) between 3DCRT and IMRT. RESULTS: Our cohort consisted of 74 patients with mean age 62.9 years, male in 51/74 (69%), adenocarcinoma in 46/74 (62.1%), stage 3 in 59/74 (79.7%) and chemotherapy in 72/74 (97.3%). Radiation mean dose: 59.2 Gy (SD ± 3.8). Radiation technique : 3DCRT in 51/74 (68.9%), IMRT in 23/74 (31%). Other variables were similar between groups.Major pathological response (including pathological complete response or less than 10% residual tumor cells) was similar: 32/51 (62.7%) in 3DCRT and 15/23 (65.2%) in IMRT, p=0.83. Pathological complete response (pCR) rates were similar: 17/51 (33.3%) in 3DCRT and 8/23 (34.8%) in IMRT, p=0.9. Surgical margins were negative in 46/51 (90.1%) in 3DCRT vs. 17/19 (89.4%) in IMRT (p=1.0).The 2-year LC rates were 81.6% (95% CI 69-89.4%); DFS 58.3% (95% CI 45.5-69%) and 3-year OS 70% (95% CI57-80%). Comparing radiation techniques, there were no significant differences in LC (p=0.94), DFS (p=0.33) and OS (p=0.72). CONCLUSION: When used to treat LANSCLC in the neoadjuvant setting, both IMRT and 3DCRT produce comparable pathological and clinical outcomes. ADVANCES IN KNOWLEDGE: This study validates the real-world effectiveness of IMRT compared to 3DCRT

Available Infrastructure

Radiation therapy, being an integral part of the treatment of most non-metastatic breast cancer patients and contributing to the management in the metastatic setting (e.g. pain and other symptoms relief, palliation for skin involvement, ablative treatment in oligometastatic patients), requires a broad understanding by the entire breast team. This section focusses on the infrastructure needed for breast radiation therapy units