Survival Benefit of Stereotactic Radiotherapy in the Complex Management of Metastatic Melanoma.

BACKGROUND/AIM: Targeted therapy and immunotherapy, with additional stereotactic radiation therapy (SRT) have revolutionized the management of metastatic malignant melanoma (mMM). We aimed to analyze the effectiveness and safety of SRT and determine its role in the complex management of mMM. PATIENTS AND METHODS: We treated 24 patients with solitary metastasis, 15 with oligometastatic disease and one with multiple metastases. The primary endpoint was to investigate the possible effect of stereotactic radiotherapy for metastatic lesions on patients' survival taking the systemic therapy into consideration. RESULTS: The median overall survival (OS) for the entire group was 30.07 months; 50% of them received immunotherapy, 32% received targeted therapy. Complete remission of the irradiated lesions was observed in six patients, partial tumor response was achieved in 13, while stable disease was detected in 10; tumor progression occurred in four cases. Compartmental recurrence (recurrence in the brain in a not previously irradiated region) developed in seven patients. OS was significantly longer in those with extracranial metastases treated with stereotactic body radiotherapy in comparison to brain SRT. We found a strong correlation between tumor response and mean OS (42.5 months after complete or partial remission versus 11.8 months in those with stable or progressive disease). No OS difference was observed according to the number of irradiated lesions or type of systemic therapy before SRT (no therapy: 43.6 months, with therapy: 25.7 months). Significant OS advantage was shown when immunotherapy was administered post-SRT (mean OS: with immunotherapy: 39.6 months, no immunotherapy: 18.5 months). CONCLUSION: In the case of oligometastatic MM, SRT can be used safely and with good efficiency in addition to targeted therapy/anti-programmed cell death protein 1 therapy. Improved survival warrants including SRT in the complex management of mMM, however, further studies are needed for SRT optimization.

Magnetic Resonance Imaging-Based Delineation of Organs at Risk in the Head and Neck Region.

Purpose: The aim of this article is to establish a comprehensive contouring guideline for treatment planning using only magnetic resonance images through an up-to-date set of organs at risk (OARs), recommended organ boundaries, and relevant suggestions for the magnetic resonance imaging (MRI)-based delineation of OARs in the head and neck (H&N) region. Methods and Materials: After a detailed review of the literature, MRI data were collected from the H&N region of healthy volunteers. OARs were delineated in the axial, coronal, and sagittal planes on T2-weighted sequences. Every contour defined was revised by 4 radiation oncologists and subsequently by 2 independent senior experts (H&N radiation oncologist and radiologist). After revision, the final structures were presented to the consortium partners. Results: A definitive consensus was reached after multi-institutional review. On that basis, we provided a detailed anatomic and functional description and specific MRI characteristics of the OARs. Conclusions: In the era of precision radiation therapy, the need for well-built, straightforward contouring guidelines is on the rise. Precise, uniform, delineation-based, automated OAR segmentation on MRI may lead to increased accuracy in terms of organ boundaries and analysis of dose-dependent sequelae for an adequate definition of normal tissue complication probability.

Prone Positioning on a Belly Board Decreases Rectal and Bowel Doses in Pelvic Intensity-Modulated Radiation Therapy (IMRT) for Prostate Cancer.

The presence of normal tissues in the irradiated volume limits dose escalation during pelvic radiotherapy (RT) for prostate cancer. Supine and prone positions on a belly board were compared by analyzing the exposure of organs at risk (OARs) using intensity modulated RT (IMRT). The prospective trial included 55 high risk, localized or locally advanced prostate cancer patients, receiving definitive image-guided RT. Computed tomography scanning for irradiation planning was carried out in both positions. Gross tumor volume, clinical and planning target volumes (PTV) and OARs were delineated, defining subprostatic and periprostatic rectal subsegments. At the height of the largest antero-posterior (AP) diameter of the prostate, rectal diameters and distance from the posterior prostate wall were measured. IMRT plans were generated. Normal tissue exposure and structure volumes were compared between supine and prone plans using paired t-test. In the volumes of the prostate, PTV, colon and small bowel, no significant differences were found. In prone position, all rectal volumes, diameters, and rectum-prostate distance were significantly higher, the irradiated colon and small bowel volume was lower in dose ranges of 20-40 Gy, and the exposure to all rectal segments was more favorable in 40-75 Gy dose ranges. No significant difference was found in the exposure of other OARs. Prone positioning on a belly board is an appropriate positioning method aiming rectum and bowel protection during pelvic IMRT of prostate cancer. The relative reduction in rectal exposure might be a consequence of the slight departure between the prostate and rectal wall.

Daily Setup Accuracy, Side-effects and Quality of Life During and After Prone Positioned Prostate Radiotherapy.

BACKGROUND/AIM: Exposure of organs at risk with prostate radiotherapy (RT) is lower in the prone position. This study is a prospective evaluation of setup accuracy, side-effects, and quality of life (QOL) during and after prone positioned RT. PATIENTS AND METHODS: Image-guided (IG) intensity-modulated (IM) RT was administered in prone position on belly-board to 55 high-risk prostate cancer (PC) patients. Rectum diameters were measured in two areas of the symphysis at the beginning of RT and during it. Side-effects, QOL, and prostate specific symptoms (PSS) were evaluated. RESULTS: Setup accuracy was similar to that reported in the literature. In the upper area of symphysis rectal diameters were significantly changed during treatment, but in the prostate region, no difference was detected. No change was detected in patients' QOL and PSS during treatment, but after RT, they improved. CONCLUSION: Prone positioned IG-IMRT is feasible with tolerable side-effects for high-risk PC patients. Changes in QOL and PSS are insignificant during RT, while improvement after RT suggests a rapid recovery.

Acute oesophageal toxicity related to paclitaxel-based concurrent chemoradiotherapy for non-small cell lung cancer.

BACKGROUND: Dosimetric data and acute oesophageal toxicity (AET) during chemoradiotherapy (CRT) were evaluated in patients with non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Fifty patients were treated with paclitaxel-based conformal CRT with a mean ± SD dose of 60.7 ± 9.8 Gy. The oesophageal toxicity was prospectively registered and evaluated in relation to the maximal dose (Dmax), mean dose (D(mean)), length and volume of oesophagus irradiated with 35-60 Gy (V(35-60Gy)), and according to the seriousness of AET. RESULTS: Dmax and D(mean) to the oesophagus were 57.0 ± 10.8 Gy and 24.9 ± 9.0 Gy, respectively. AET of grade 1, 2 and 3 developed in 16 (32%), 14 (28%) and three (6%) cases, respectively. The Dmax, D(mean), length and the V(35-60Gy) were all related to dysphagia (p<0.001). V(45Gy) was the most reliable predictor of AET of grade 2 or more. CONCLUSION: Our results indicate that keeping oesophageal V(45Gy) below 32.5% can prevent severe AET during CRT of NSCLC.