We aimed to report the clinical outcomes following stereotactic body radiation therapy (SBRT) using photon or proton equipment in early-stage lung cancer. We retrospectively reviewed 202 cT1-2N0M0 lung cancer patients who underwent SBRT with 60 Gy in four consecutive fractions between 2010 and 2019 at our institution: 168 photon SBRT and 34 proton SBRT. Patients who underwent proton SBRT had relatively poor baseline lung condition compared to those who underwent photon SBRT. Clinical outcomes were comparable between treatment modalities: 5-year local control (90.8% vs. 83.6%, p = 0.602); progression-free survival (61.6% vs. 57.8%, p = 0.370); overall survival (51.7% vs. 51.9%, p = 0.475); and cause-specific survival (70.3% vs. 62.6%, p = 0.618). There was no statistically significant difference in grade ≥ 2 toxicities: radiation pneumonitis (19.6% vs. 26.4%, p = 0.371); musculoskeletal (13.7% vs. 5.9%, p = 0.264); and skin (3.6% vs. 0.0%, p = 0.604). In the binary logistic regression analysis of grade ≥3 radiation pneumonitis, poor performance status and poor baseline diffusion capacity of lung for carbon monoxide were significant. To summarize, though patients with high risk of developing lung toxicity underwent proton SBRT more frequently, the SBRT techniques resulted in comparable oncologic outcomes with similar toxicity profiles. Proton SBRT could be considered for patients at high risk of radiation pneumonitis.

Systemic inflammatory markers (SIMs) are known to be associated with carcinogenesis and prognosis of hepatocellular carcinoma (HCC). We evaluated the significance of SIMs in intrahepatic recurrence (IHR) of early-stage HCC after curative treatment. This study was performed using prospectively collected registry data of newly diagnosed, previously untreated HCC between 2005 and 2017 at a single institution. Inclusion criteria were patients with Barcelona Clinic Liver Cancer stage 0 or A, who underwent curative treatment. Pre-treatment and post-treatment values of platelet, neutrophil, lymphocyte, monocyte, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and lymphocyte/monocyte ratio (LMR) were analyzed with previously well-known risk factors of HCC to identify factors associated with IHR-free survival (IHRFS), early IHR, and late IHR. Of 4076 patients, 2142 patients (52.6%) experienced IHR, with early IHR in 1018 patients (25.0%) and late IHR in 1124 patients (27.6%). Pre-treatment platelet count and PLR and post-treatment worsening of NLR, PLR, and LMR were independently associated with IHRFS. Pre-treatment platelet count and post-treatment worsening of NLR, PLR, and LMR were significantly related to both early and late IHR. Pre-treatment values and post-treatment changes in SIMs were significant factors of IHR in early-stage HCC, independent of previously well-known risk factors of HCC.

This study evaluated the impact of respiratory movement on four-dimensional computed tomography (4D-CT) acquisition and radiotherapy delivery. QUASAR^™ Respiratory Motion Phantom with nine sinusoidal waveforms that combined three amplitudes (10, 20, and 30 mm) and three breaths per minute (BPMs) (10, 15, and 20) was used. We acquired 4D-CT for nine respective waveforms and measured and compared geometrical factors (volume, shape, and motion) to reference static CT. We optimized and delivered radiotherapy plans on a Vital Beam and evaluated gamma for dose distribution analysis with three acceptance criteria: 3%/3 mm, 3%/3 mm, and 5%/5 mm. Geometrical analysis revealed that an increase in amplitude decreased 4D-CT acquisition accuracy. Geometrical factors for an amplitude of ≤ 20 mm were within tolerance limits, however, amplitude 30 mm resulted in significant deviations over tolerance limits. BPM had a minimal effect on geometrical accuracy when accurate pitch values for respective BPMs were selected for scanning. Dose distribution analysis also indicated that an increase in amplitude decreased the gamma passing rates. Amplitude 30 mm failed to achieve a 95% passing rate for all three gamma evaluation criteria adopted in the present study. Overall, our results demonstrate that respiratory motion has significant effects on the accuracy of both 4D-CT acquisition and planned radiotherapy delivery. Small amplitude of ≤ 20 mm is required to ensure accuracy.

Goh MJ, et al. J Korean Med Sci. 2024 Jul;39:e251. https://doi.org/10.3346/jkms.2024.39.e251

Purpose: This study aimed to evaluate treatment outcomes with associated prognostic factors, and to guide treatment strategies in colorectal cancer patients with oligometastatic disease (OMD) treated with stereotactic body radiotherapy (SBRT). Materials and Methods: This retrospective study included 74 colorectal cancer patients who received SBRT for 113 lesions (88 lung, 19 liver, and 6 lymph node). Each OMD was considered a separate case for patients repeatedly diagnosed with OMD. The log-rank test and Cox proportional hazards model were used to assess prognostic factors for progression-free survival (PFS). Results: A total of 84 cases were analyzed. The median follow-up period was 32.2 months (range, 8.2 to 89.3 months). The 2-year PFS, widespread failure-free survival (WSFFS), and overall survival (OS) rates were 35.1%, 67.4%, and 80.8%, respectively. In the multivariable analysis, oligometastatic status (repeat/induced vs. de novo; hazard ratio [HR], 2.66; 95% confidence interval [CI], 1.40 to 5.04; p = 0.003) and planning target volume (PTV) volume (≥17.6 vs. <17.6 cm 3 ; HR, 1.99; 95% CI, 1.09 to 3.62; p = 0.025) were significant prognostic factors for PFS. Cases with two risk factors for PFS demonstrated significantly worse OS and WSFFS (p < 0.05), whereas those with one risk factor did not show a significant difference compared to cases with no risk factors. Conclusion: SBRT for oligometastatic colorectal cancer showed favorable clinical outcomes. Oligometastatic status and PTV volume were significantly associated with PFS. Risk stratification based on the number of poor prognostic factors of PFS may help guide treatment strategies for colorectal cancer patients with OMD.

Background/Objectives: To evaluate the role of postoperative radiotherapy (PORT) in the management of localized head and neck mucosal melanoma (HNMM). Methods: We retrospectively reviewed 33 patients who underwent surgery for localized HNMM between 2006 and 2023. PORT was delivered to affected anatomical structures, and elective nodal irradiation was not performed. Treatment outcomes, including local recurrence-free survival (LRFS), progression-free survival (PFS), and overall survival (OS), were analyzed. Results: After surgery, 14 patients (41.4%) received PORT. During follow-up, 87.9% of patients experienced recurrence, with local and distant failures being the most common. PORT significantly improved LRFS (p = 0.047) but did not impact PFS or OS. PORT (HR 0.14, p = 0.005) and resection margin status (HR 8.71, p < 0.001) were significantly associated with LRFS in multivariable analysis. Conclusions: PORT for localized HNMM improved local control. Regional recurrence was rare (one patient, 3.4%) even though ENI was not performed. PORT without ENI could improve clinical outcomes for localized HNMM.