Radiation Oncology Journal最新文献

Purpose: To perform the analysis of the peripheral blood lymphocyte changes after stereotactic ablative radiotherapy (SABR) in patients with oligometastatic cancers.

Materials and methods: The dynamics of the immune status in peripheral blood was prospectively evaluated in 46 patients with lung (17 cases) or liver (29 cases) metastases treated by SABR. Flow cytometry of peripheral blood lymphocyte subpopulations was performed before SABR, 3-4 weeks and 6-8 weeks after the end of SABR: 3 fractions of 15-20 Gy or 4 fractions of 13.5 Gy. The number of treated lesions varied from 1 (32 patients) to 2-3 (14 patients).

Results: SABR induced a significant increase of T-lymphocytes (CD3+CD19-) (p = 0.001), T-helper (CD3+CD4+) (p = 0.004), activated cytotoxic T-lymphocytes (CD3+CD8+HLA-DR+) (p = 0.001), activated T-helpers (CD3+CD4+HLA-DR+) (p < 0.001). A significant decrease of T-regulated immune suppressive lymphocytes (CD4+CD25brightCD127low) (p = 0.002) and NKT-cells (CD3+CD16+CD56+) (p = 0.007) was recorded after the SABR. The comparative analysis demonstrated that lower doses of SABR (EQD2Gy(α/β=10) = 93.7-105.7 Gy) induced significant increase of T-lymphocytes, activated cytotoxic T-lymphocytes, and activated CD4+CD25+ T-helpers, while SABR with higher doses (EQD2Gy(α/β=10) = 150 Gy) was not associated with these effects. A more efficient activations of T-lymphocytes (p = 0.010), activated T-helpers (p < 0.001), and cytotoxic T-lymphocytes (p = 0.003) were associated with SABR to a single lesion. A significant increase of T-lymphocytes (p = 0.002), T-helpers (p = 0.003), and activated cytotoxic T-lymphocytes (p = 0.001) was observed after SABR for hepatic metastases in contrast to SABR for lung lesions.

Conclusion: Changes in peripheral blood lymphocytes after SABR could be influenced by the location or the number of irradiated metastasis, and the dose of SABR.

Purpose: Nasopharyngeal cancer (NPC) has a higher prevalence of regional nodal metastasis than other head and neck cancers; however, level IB lymph node involvement is rare. We evaluated the safety and feasibility of level IB-sparing radiotherapy (RT) for NPC patients.

Materials and methods: We retrospectively reviewed 236 patients with NPC who underwent definitive intensity-modulated RT with or without chemotherapy between 2004 and 2018. Of them, 212 received IB-sparing RT, and 24 received non-IB-sparing RT. We conducted a propensity score matching analysis to compare treatment outcomes according to IB-sparing status. In addition, dosimetric analysis of the salivary glands was performed to identify the relationship between xerostomia and the IB-sparing RT.

Results: The median follow-up duration was 78 months (range, 7 to 194 months). Local, regional, and distant recurrences were observed in 11.9%, 6.8%, and 16.1% of patients, respectively. Of the 16 patients with regional recurrence, 14 underwent IB-sparing RT. The most common site categorization of regional recurrence was level II (75%), followed by retropharyngeal lymph nodes (43.8%); however, there was no recurrence at level IB. In the matched cohorts, IB-sparing RT was not significantly related to treatment outcomes. However, IB-sparing RT patients received a significantly lower mean ipsilateral and contralateral submandibular glands doses (all, p < 0.001) and had a lower incidence of chronic xerostomia compared with non-IB-sparing RT patients (p = 0.006).

Conclusion: Our results demonstrated that IB-sparing RT is sufficiently safe and feasible for treating NPC. To reduce the occurrence of xerostomia, IB-sparing RT should be considered without compromising target coverage.

Purpose: This study aimed to evaluate the clinical infrastructure and utilization of radiotherapy (RT) services in Korea between 2017 and 2019.

Materials and methods: We extracted the data of patients who underwent RT between 2017 and 2019 from the Health Insurance Review and Assessment Service. We further analyzed this data according to the diagnosis and treatment modalities of patients diagnosed with International Classification of Disease 10 (ICD-10) diagnostic codes C00-C97 and D00-D48. In addition, we collected statistics on RT facilities in Korea using a nationwide survey.

Results: The total number of patients who received RT in 2017, 2018, and 2019 were 77,901, 81,849, and 87,460, respectively. The number of patients diagnosed with ICD 10 C- and D-codes in 2019 was 86,339, of whom 39,467 were men and 46,872 women. The rate of utilization of RT among cancer patients was 30.4% in 2017 and 2018 and 30.9% in 2019. In 2019, the most common types of cancers treated with RT were breast, lung, prostate, colorectal, and liver cancers. Regarding the RT infrastructure in Korea, there were 95 radiation oncology centers, 237 megavoltage (MV) teletherapy units, 35 brachytherapy units, and two proton accelerators in 2019. There were 4.5 MV teletherapy machines per million.

Conclusion: The number of patients treated with RT has increased consistently from 2017 to 2019. As the number of patients with cancer increases, it is expected that the RT infrastructure will be further expanded in Korea.

Purpose: The safety of online contouring and planning for adaptive radiotherapy is unknown. This study aimed to evaluate the dosimetric difference of the organ-at-risk (OAR) according to the extent of contouring in stereotactic magnetic resonance image-guided adaptive RT (SMART) for pancreatic cancer.

Materials and methods: We reviewed the treatment plan data used for SMART in patients with pancreatic cancer. For the online contouring and planning, OARs within 2 cm from the planning target volume (PTV) in the craniocaudal direction were re-controlled daily at the attending physician's discretion. The entire OARs were re-contoured retrospectively for data analysis. We termed the two contouring methods the Rough OAR and the Full OAR, respectively. The proportion of dose constraint violation and other dosimetric parameters was analyzed.

Results: Nineteen patients with 94 fractions of SMART were included in the analysis. The dose constraint was violated in 10.6% and 43.6% of the fractions in Rough OAR and Full OAR methods, respectively (p = 0.075). Patients with a large tumor, a short distance from gross tumor volume (GTV) to OAR, and a tumor in the body or tail were associated with more occult dose constraint violations-large tumor (p = 0.027), short distance from GTV to OAR (p = 0.061), tumor in body or tail (p = 0.054). No dose constraint violation occurred outside 2 cm from the PTV.

Conclusion: More occult dose constraint violations can be found by the Full OAR method in patients with pancreatic cancer with some clinical factors in the online re-planning for SMART. Re-contouring all the OARs would be helpful to detect occult dose constraint violations in SMART planning. Since the dosimetric profile of SMART cannot be represented by a single fraction, patient selection for the Full OAR method should be weighted between the clinical usefulness and the time and workforce required.

Pigmented villonodular synovitis (PVNS) is a proliferative, recurrent and locally invasive disease of the synovium. The symptoms of the disorder are not typical and thus it is very often misdiagnosed. Most of the times, magnetic resonance imaging presents the nodular model of development and sets the basis for the diagnosis. The final diagnosis will be set by the pathological evaluation of the lesion's biopsy. PVNS may be localized (nodule with a clear boundary with/without presence of single pedicle) or diffuse (extensive involvement of the adjacent nerves and vessels). Depending on the extension of the PVNS, a different management approach is performed, lesion excision vs. resection, followed by radiotherapy respectively. We report a case of diffuse PVNS in the knee joint, treated with surgical excision and adjuvant radiotherapy as well as follow-up imaging after a time period of 3 years.

Purpose: Optimal radiotherapy treatment volumes for patients with locally advanced hypopharynx squamous cell carcinoma should ensure maximal tumor coverage with minimal inclusion of normal surrounding structures. Here we evaluated the effectiveness of a direct 3-mm high-dose gross tumor volume to planning target volume expansion on clinical outcomes for hypopharynx cancers.

Materials and methods: We performed a retrospective analysis of patients with hypopharynx carcinoma treated between 2004 and 2018 with primary radiotherapy using a direct high-dose gross tumor volume to planning target volume expansion and with or without concurrent systemic therapy. Diagnostic imaging of recurrences was co-registered with the planning CT. Spatial and volumetric analyses of contoured recurrences were compared with planned isodose lines. Failures were initially defined as in field, marginal, elective nodal, and out of field. Each failure was further classified as central high-dose, peripheral high-dose, central intermediate/low-dose, peripheral intermediate/low-dose, and extraneous. Clinical outcomes were analyzed by Kaplan-Meier estimation.

Results: Thirty-six patients were identified. At a median follow-up at 52.4 months, estimated 5-year overall survival was 59.3% (95% confidence interval [CI], 36.3%-74.1%), 5-year local and nodal control was 71.7% (95% CI, 47.1%-86.3%) and 69.9% (95% CI, 57.0%-82.6%), respectively. The most common failure was in the high-dose primary target volume. The gastrostomy tube retention rate at 1 year among patients without recurrence was 13.0% (95% CI, 3.2%-29.7%).

Conclusion: Minimal high-dose target volume expansions for hypopharynx cancers were associated with favorable locoregional control. This approach may enable therapy intensification to improve clinical outcomes.

Historical conventional fractionated radiation therapy (RT) for breast cancer consisted of 1.8-2.0 Gy per fraction with a total dose of 45-60 Gy over 5-7 weeks. Based on radiobiological characteristics, a low α/β is suspected of breast cancer resulting in sensitivity to higher dose per fraction (2.5-3.0 Gy). Over the past 10 years, multiple clinical trials support the application of shorter treatment regimen with hypofractionated RT (HypoRT). Recently, ultra-HypoRT with 5 fractions showed favorable outcomes. Although the safety and efficacy of HypoRT has been supported by high-quality randomized trials, there are still some worries and doubts around HypoRT from radiation oncologists. However, the radiation oncology community have now reached an important timepoint for adopting HypoRT during the COVID-19 pandemic. The aim of this review is to provide an overview of HypoRT in breast cancer based on prospective randomized trials and discuss the special consideration regarding HypoRT.

Purpose: Specific radiation delivered to tumors by stereotactic radiosurgery (SRS) has become widely used in the treatment of brain metastasis. This study aimed to compare radiation therapy planning and its parameters from SRS using three different modalities: helical tomotherapy (HT), volumetric modulated arc therapy (VMAT), and cone-based linac radiosurgery (Cone-based).

Materials and methods: Each contouring dataset of patents who experienced one to four brain metastasis received SRS in our center was re-planned to create radiation therapy planning in all three treatment systems (HT, VMAT, and Cone-based). The parameters of conformity index (CI), homogeneity index (HI), CI50, and gradient index (CGI) were analyzed to compare the effects of the three techniques. Decision score analysis was used to evaluate the performance on dosimetric and organs-at-risk parameters among the different techniques by applying the Cone-based technique as a benchmark.

Results: A total of 21 patients with 39 lesions were included in this study. The results from the decision score analysis demonstrated statistically identical CI, CI50, and CGI values between Cone-based and VMAT for single lesions. For multiple lesions, VMAT also provided better CI when compared to Cone-based technique while HT exhibited the poorest dosimetric parameters. Moreover, VMAT exhibited the lowest BrainV5Gy value and displayed the shortest beam-on time calculation.

Conclusion: We have conducted a comprehensive comparison of SRS planning approaches. The Cone-based technique revealed the highest HI value, while VMAT provided the best estimated beam-on time value. HT displayed a feasible SRS modality for single lesions, but not for multiple lesions.

Mucoepidermoid carcinoma (MEC) is most common malignancy of minor salivary glands in adults. Pulmonary MEC is extremely uncommon comprising of only 0.1%-0.2% of the primary lung malignancies and <1% of primary bronchial tumors. It is even rarer in children and literature limited to few case reports only. Here we present a case report of a 9-year-old boy diagnosed with primary MEC of trachea along with review of the literature. A 9-year-old male child presented with complaint of dry cough for two years which was later associated with shortness of breath after one year. Bronchoscopic examination revealed a growth arising from right lateral wall of carina occluding 50% of the lumen and detailed histopathological examination revealed it to be a MEC of the trachea. Patient underwent local excision of the tumor with primary anastomosis. In view of positive margins adjuvant radiotherapy of 60 Gy in 30 fractions were given to the tumor bed. Patient tolerated the treatment well and is disease free at 6 months follow-up. Experience with MEC of the trachea in children is limited and optimal treatment protocols have not been defined, with current treatment mainly extrapolated from MEC of the salivary glands.