Myonecrosis as a rare side effect of stereotactic body radiotherapy for bone metastases: Report of two cases and a comprehensive literature review.

Stereotactic body radiotherapy is a highly effective form of radiation therapy for palliation of bone metastases, but it can also lead to rare but severe side effects, such as myonecrosis. According to the literature, the incidence of myonecrosis after stereotactic body radiotherapy is low and mostly dose dependent. It is crucial to consider the potential impact of immunotherapy and other systemic therapies in the assessment. The course of radiation myonecrosis can vary, and corticosteroids or vascular endothelial growth factor inhibitors may potentially play a role in its treatment. Herein, we report two patients presenting with myonecrosis after stereotactic body radiotherapy for bone metastasis.

Online Adaptive Magnetic Resonance-guided Radiation Therapy for Gynaecological Cancers: Preliminary Results of Feasibility and Outcome.

AIMS: To present the preliminary results on the clinical utilisation of an online daily adaptive magnetic resonance-guided radiation therapy (MRgRT) for various gynaecological cancers. MATERIALS AND METHODS: Twelve patients treated between September 2018 and June 2022 were included. Six patients (50%) were treated with pelvic radiation therapy followed by MRgRT boost as brachytherapy boost was ineligible or unavailable, three patients (25%) were treated with pelvic MRgRT followed by high dose rate brachytherapy, two patients (16.7%) were treated with only MRgRT, one patient (8.3%) was treated with linear accelerator-based radiation therapy followed by MRgRT boost for bulky iliac lymph nodes. RESULTS: The median age was 56.5 years (range 31-86 years). Eight patients (66.7%) had a complete response, three patients (25%) had a partial response and one patient (8.3%) died due to acute renal failure. The mean follow-up time was 11.2 months (range 3.1-42.6 months). The estimated 1-year overall survival was 88.9%. The median treatment time was 47 days (range 10-87 days). During external beam radiation therapy, 10 (83.3%) patients had concomitant chemoradiotherapy. Pelvic external beam radiation therapy doses for all cohorts were 45-50.4 Gy with a fraction dose of 1.8 Gy. The median magnetic resonance-guided boost dose was 32 Gy (range 20-50 Gy) and fraction doses ranged between 4 and 10 Gy. Three patients were treated with intracavitary high dose rate brachytherapy (26-28 Gy in four to five fractions). None of the patients had grade >3 late genitourinary toxicities. CONCLUSION: MRgRT is reliable and clinically feasible for treating patients with gynaecological cancers alone or in combination with brachytherapy with an acceptable toxicity and outcome. MRgRT boost could be an option when brachytherapy is not available or ineligible.

Impact of radiotherapy on survival in resected or unresectable anaplastic thyroid carcinomas, a Rare Cancer Network study.

PURPOSE: Anaplastic thyroid carcinomas (ATC) are a heterogenous group of tumors of overall dismal prognosis. We designed models to identify relevant prognostic factors of survival of irradiated ATC patients including radiotherapy modalities (field size, dose). MATERIAL AND METHODS: Between 2000 and 2017, 166 ATC patients' treatments were divided into surgery and postoperative radiotherapy (poRT) or definitive radiotherapy (RT). Multiple imputation approach was used for missing data. Prognostic factors were identified using Lasso-penalized Cox modelling and predicted risk scores were built. RESULTS: Patients undergoing RT (n=70) had more adverse patient and disease characteristics than those undergoing poRT (n=96). Corresponding median survival rates were 5.4 and 12.1 months, respectively. PoRT patients undergoing poRT more likely received extended-field radiotherapy with prophylactic nodal irradiation, but rather received platinum- vs. adriamycin-based chemoradiotherapy. Radiotherapy was conventionally fractionated, delivered >60Gy in 51.9% and 61.7% and used extended fields in 88.5% and 71.2% of patients with poRT or RT. Radiotherapy interruption rates for toxicity were similar in the two groups. The best poRT-group model identified age>45yo, PS≥1, pathologic tumor stage≥pT4b,>N1 and R2 resection as poor prognostic factors. The best RT-group model (C-index of 0.72) identified PS≥3,>N1 and extended-field radiotherapy with prophylactic nodal irradiation (as opposed to tumour-bed irradiation only) as poor prognostic factors. CONCLUSION: In patients undergoing poRT, radiotherapy parameters had little influence over their survival irrespective of patient, disease characteristics, and quality of resection. In patients undergoing RT, extended-field radiotherapy improved survival in addition to PS and nodal stage.

Dosimetric comparison of robotic and conventional linac-based stereotactic lung irradiation in early-stage lung cancer.

We aimed to compare dosimetric characteristics of conventional linear accerator-based treatment plans to those created using the robotic CyberKnife® (CK) treatment planning system for patients with early-stage lung cancer. Eight early-stage lung cancer patients treated with stereotactic body radiotherapy (SBRT) using a conventional linac-based (LIN) system were included in this study. New treatment plans were created for the patients with the CK treatment planning system in order to compare the two platforms' dosimetric characteristics. Planning computed tomographies (CT) were obtained in three phases: free-breathing, full exhalation and inhalation. The three GTVs were then added together for internal target volume (ITV) with LIN, whereas no ITV was used for CK. Planning target volumes (PTV) were constituted by adding 5-mm margin to GTV and ITV. Treatment plan was 54 Gy in three fractions. Five-field, seven-field, and dynamic-conformal arc planning techniques were used in LIN plans. Plans were compared according to dose heterogenity (D(max)-maximum dose), volume of 54 Gy (V54) and 27 Gy isodose (V27), conformity index (CI(54) and CI(27)) and lung volumes. PTVs were significantly smaller in CK plans (p=0.012). D(max) was significantly lower in ARC plans (p=0.01). Among all plans, CK had significantly tightest isodose shell received 54 Gy and 27 Gy (p=0.0001). Among LIN plans, V54 was significantly (p=0.03) smaller in ARC plans; but no difference was observed for V27 values. LIN plans have better plan quality (CI(27) and CI(54)) than CK. No statistically significant difference was observed for lung volumes. CK plans had superior V54 and V27 values compared to LIN plans due to smaller PTV. LIN plans had better CI(27) and CI(54) values. Advantages of LIN treatment were no neccessity for fiducial marker use, which may cause pneumothorax, and significantly shorter beam-on treatment times. Both CK and LIN methods are suitable for lung SBRT.

Postoperative radiotherapy in the treatment of uterine sarcomas: long-term results and analysis of prognostic factors.

PURPOSE: To evaluate the role of postoperative radiotherapy (RT) in local control and survival and to identify treatment-related prognostic factors in uterine sarcomas. METHODS: Sixty patients with uterine sarcomas treated with postoperative RT were retrospectively analyzed. Median age was 49.5 years (range 24-78). The stage distribution was as follows: stage I: 60%, II: 11.7%, and III: 28.3%. All patients were treated with pelvic irradiation (dose range 45.6-54.6 Gy). Pelvic control (PC), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were calculated. Age, stage, histology, tumor size, type of surgery, residual disease, time interval between surgery and RT were selected as possible prognostic factors for PC and OS. Age, total treatment time, pelvic dose, dose per fraction, and acute side effects were analyzed as probable prognostic factors for late complications. RESULTS: Median follow-up was 84 months. The 10-year PC, DMFS, DFS and OS rates were 84, 67.3, 64 and 61.5%, respectively. Univariate analysis showed that age, residual disease, type of surgery and stage were significant factors for PC; residual disease, type of surgery and stage were significant factors for DMFS; stage was found as the only significant factor for DFS and OS. Total treatment time, pelvic dose, dose per fraction, and acute side effects were significant factors for late complications. CONCLUSION: Although our results suggest improved PC, the role of postoperative RT should be tested in prospective randomized trials.

Epidural metastasis of Ewing's sarcoma: a rare localisation.

Epidural spinal metastasis of Ewing's sarcoma is rarely observed. We report on a rare case of purely epidural spinal metastasis of Ewing's sarcoma with pain and paraplegia, and describe the treatment and final outcome of the patient.

Unusual metastasis of renal cell carcinoma to the nasal cavity.

Metastasis of renal cell carcinoma (RCC) to the nose and paranasal sinuses is very rare. We present two cases of RCC metastatic to the nose who were treated with palliative radiotherapy. Although the prognosis was poor for both of the patients, the main symptoms (epistaxis and unilateral airway obstruction) were successfully palliated with irradiation.