Adaptive radiation therapy (ART) for patients with limited?stage small cell lung cancer (LS?SCLC): A dosimetric evaluation

Background: Adaptive radiation therapy (ART) refers to redesigning of radiation therapy (RT) treatment plans with respect to dynamic changes in tumor size and location throughout the treatment course. In this study, we performed a comparative volumetric and dosimetric analysis to investigate the impact of ART for patients with limited-stage small cell lung cancer (LS-SCLC). Methods: Twenty-four patients with LS-SCLC receiving ART and concomitant chemotherapy were included in the study. ART was performed by replanning of patients based on a mid-treatment computed tomography (CT)-simulation which was routinely scheduled for all patients 20� days after the initial CT-simulation. While the first 15 RT fractions were planned using the initial CT-simulation images, the latter 15 RT fractions were planned using the mid-treatment CT-simulation images acquired 20� days after the initial CT-simulation. In order to document the impact of ART, target and critical organ dose-volume parameters acquired from this adaptive radiation treatment planning (RTP) were compared with the RTP based solely on the initial CT-simulation to deliver the whole RT dose of 60 Gy. Results: Statistically significant reduction was detected in gross tumor volume (GTV) and planning target volume (PTV) during the conventionally fractionated RT course along with statistically significant reduction in critical organ doses with incorporation of ART. Conclusion: One-third of the patients in our study who were otherwise ineligible for curative intent RT due to violation of critical organ dose constraints could be treat

Evaluatıon of hypofractıonated stereotactıc radıotherapy (HFSRT) to the resectıon cavıty after surgıcal resectıon of braın metastases: A sıngle center experıence

INTRODUCTON: Adjuvant radiotherapy after surgical resection is used for the treatment of patients with brain metastasis. In this study, we assessed the use of adjuvant hypofractionated stereotactic radiotherapy (HFSRT) to the resection cavity for the management of patients with brain metastasis. MATERIALS AND METHODS: A total of 28 patients undergoing surgical resection for their brain metastasis were treated using HFSRT to the resection cavity. A total HFSRT dose of 25–30 Gray (Gy) was delivered in 5 consecutive daily fractions. Patients were retrospectively assessed for toxicity, local control, and survival outcomes. Kaplan-Meier method and log-rank test were used for statistical analysis. RESULTS: Median planning target volume (PTV) was 27.2 cc (range: 6–76.1 cc). At a median follow-up time of 11 months (range: 2–21 months.), 1-year local control rate was 85.7%, and 1-year distant failure rate was 57.1% (16 patients). Median overall survival was 15 months from HFSRT. Higher recursive partitioning analysis class (P = 0.01) and the presence of extracranial metastases (P = 0.02) were associated with decreased overall survival on statistical analysis. There was no radiation necrosis observed during follow-up. CONCLUSION: HFSRT to the resection cavity offers a safe and effective adjuvant treatment for patients undergoing surgical resection of brain metastasis. With comparable local control rates, HFSRT may serve as a viable alternative to whole brain irradiation.

Fractionated stereotactic radiosurgery for locally recurrent brain metastases after failed stereotactic radiosurgery

AIMS AND BACKGROUND: There is scant data on the utility of repeated radiosurgery for management of locally recurrent brain metastases after upfront stereotactic radiosurgery (SRS). Most studies have used single-fraction SRS for repeated radiosurgery, and the use of fractionated stereotactic radiosurgery (f-SRS) in this setting has been poorly addressed. In this study, we assessed the utility of f-SRS for the management of locally recurrent brain metastases after failed upfront single-fraction SRS and report our single-center experience. METHODS AND STUDY DESIGN: A total of 30 patients receiving f-SRS for locally recurrent brain metastases after upfront single-fraction SRS at our department between September 2011 and September 2017 were retrospectively evaluated for local control (LC), toxicity, and overall survival outcomes. RESULTS: Median age and Karnofsky performance status were 57 (range: 38–78 years) and 80 (range: 70–100) at repeated radiosurgery (SRS2). The median time interval between the two radiosurgery applications was 13.5 months (range: 3.7–49 months). LC after SRS2 was 83.3%. Radionecrosis developed in 4 of the 30 lesions after SRS2, and total rate of radionecrosis was 13.3%. Statistical analysis revealed that the volume of planning target volume (PTV) at SRS2 was significantly associated with radionecrosis (P = 0.014). The volume of PTV was >13 cm3 at SRS2 in all patients with radionecrosis. CONCLUSION: A repeated course of radiosurgery in the form of f-SRS may be a viable therapeutic option for the management of locally recurrent brain metastases after failed upfront SRS with high LC rates and an acceptable toxicity profile despite the need for further supporting evidence.