The role of stereotactic body radiotherapy in switching systemic therapy for patients with extracranial oligometastatic renal cell carcinoma

BACKGROUND

Targeting oligometastatic lesions with metastasis-directed therapy (MDT) using stereotactic-body radiotherapy (SBRT) may improve treatment outcomes and postpone the need for second-line systemic therapy (NEST). We looked at the results of oligometastatic renal cell carcinoma (RCC) patients who had five or fewer lesions and were treated with SBRT.

METHODS

We examined the treatment outcomes of 70 extracranial metastatic RCC (mRCC) patients treated at two oncology centers between 2011 and 2020. The clinical parameters of patients with and without NEST changes were compared. The prognostic factors for overall survival (OS), progression-free survival (PFS), and NEST-free survival were evaluated.

RESULTS

Median age was 67 years (range 31-83 years). Lung and bone metastasis were found in 78.4% and 12.6% of patients, respectively. With a median follow-up of 21.1 months, median OS was 49.1 months and the median PFS was 18.3 months. Histology was a prognostic factor for OS, BED, and treatment switch for PFS in univariate analysis. In multivariate analysis, the significant predictor of poor OS was clear cell histology, and a lower BED for PFS. Following SBRT for oligometastatic lesions, 19 patients (27.2%) had a median NEST change of 15.2 months after MDT completion. There were no significant differences in median OS or PFS between patients who had NEST changes and those who did not. No patient experienced grade ≥ 3 acute and late toxicities.

CONCLUSIONS

The SBRT to oligometastatic sites is an effective and safe treatment option for ≤ 5 metastases in RCC patients by providing favorable survival and delaying NEST change.

Patterns of care for lung cancer in radiation oncology departments of Turkey

PURPOSE

To determine the patterns of care for lung cancer in Turkish radiation oncology centers.

METHODS AND MATERIALS

Questionnaire forms from 21 of 24 (87.5%) centers that responded were evaluated.

RESULTS

The most frequent histology was non-small cell lung cancer (NSCLC) (81%). The most common postoperative radiotherapy (RT) indications were close/(+) surgical margins (95%) and presence of pN2 disease (91%). The most common indications for postoperative chemotherapy (CHT) were ">/= IB" disease (19%) and the presence of pN2 disease (19%). In Stage IIIA potentially resectable NSCLC, the most frequent treatment approach was neoadjuvant concomitant chemoradiotherapy (CHRT) (57%). In Stage IIIA unresectable and Stage IIIB disease, the most frequent approach was definitive concomitant CHRT (91%). In limited SCLC, the most common treatment approach was concomitant CHRT with cisplatin+etoposide for cycles 1-3, completion of CHT to cycles 4-6, and finally prophylactic cranial irradiation in patients with complete response (71%). Six cycles of cisplatin + etoposide CHT and palliative thoracic RT, when required, was the most commonly used treatment (81%) in extensive SCLC. Sixty-two percent of centers did not have endobronchial brachytherapy (EBB) facilities.

CONCLUSION

There is great variation in diagnostic testing, treatment strategies, indications for postoperative RT and CHT, RT features, and EBB availability for LC cases. To establish standards, national guidelines should be prepared using a multidisciplinary approach.

Parotid gland stem cells: Mini yet mighty

BACKGROUND

Our aim was to evaluate the correlation between the radiation doses to parotid gland (PG) stem cells and xerostomia.

METHODS

Patients diagnosed with head and neck cancer (HNC) were retrospectively evaluated, and xerostomia inventory (XI) was applied to these patients. PG stem cells were delineated on the treatment planning CT, and the mean doses to the PG stem cells calculated.

RESULTS

The total test score and mean doses to bilateral PGs were significantly correlated (r = .34, P = .001), and the mean doses to bilateral PG stem cell niches were significantly correlated with the total test score (r = .32, P = .002).

CONCLUSIONS

In this study, we found that the mean dose to PG stem cells can predict dry mouth as much as the mean dose to the PG.

Feasibility study of an electronic portal imaging based in vivo dose verification system for prostate stereotactic body radiotherapy

PURPOSE

We evaluated the feasibility of electronic portal imaging based 3D in-vivo dosimetry for stereotactic body radiation therapy (SBRT) technique in prostate cancer.

METHODS AND MATERIALS

To investigate error detectability limitations of iViewDose™ v.1.0.1 (Elekta, Stockholm, Sweden) for prostate SBRT cases, ten prostate cancer patients were selected and in-vivo electronic portal imaging devices dosimetry was performed. Also possible error scenarios including dose calibration, setup, collimator, multi leaf collimator and patient anatomy related inaccuracies were created to investigate detectability of EPID. For this purpose, a SBRT treatment was planned on BrainLab pelvis phantom (BrainLab Medical Systems, Westchester, IL) and irradiated after proving setup with cone beam computer tomography. After that incorrect plans were irradiated and obtained results were compared with original in vivo measurements.

RESULTS

Mean gamma analysis (γ% ≤ 1) passing rate of ten patients was found as 96.2%. Additionally, mean dose reference point difference between measurement and calculated in treatment planning system for clinical target volume, rectum, bladder, left and right femur heads were found as 1.4%, 8%, 20.8%, 2.3% and 4.5%, respectively. Phantom measurements showed that positional errors can be escape from detection. However, the incorrect treated plans including linac calibration, MLC positions and patient anatomy based errors could not have passed the in vivo dosimetry analysis.

CONCLUSIONS

EPID-based 3D in vivo dosimetry software (iViewDose) provides an efficient safety check on the accuracy of dose delivery during prostate SBRT treatments. However, phantom results showed some limitation of the system.

High-grade glioma in children and adolescents: a single-center experience

PURPOSE

The aim of this study was to report the outcome in children with high-grade astrocytoma outside the brain stem and spinal cord that were treated at a single center.

MATERIALS AND METHODS

The study included 26 patients with anaplastic astrocytoma and 37 patients with glioblastoma; all patients were aged ≤18 years. At initial diagnosis, 18 of the patients with glioblastoma received only temozolomide (TMZ), 14 received other chemotherapies, and 5 did not receive any chemotherapy. Among the patients with anaplastic astrocytoma, 9 received TMZ, 9 received other chemotherapy regimens, and 8 patients did not receive any chemotherapy. The median radiotherapy dose in all patients was 60 Gy.

RESULTS

Median age of the patients was 12.5 years. Median overall survival was 20 months and mean progression-free survival was 4.7-11.3 months (median: 8 months) in all patients. Patients with a Karnofsky performance score (KPS) ≥70 had median overall survival of 32 months, versus 7 months in those with a KPS < 70. Patients aged <15 years had median survival of 38 months, versus 16 months in those aged 15-18 years. Patients with anaplastic astrocytoma that received TMZ, other chemotherapy regimens, and no chemotherapy had median survival of 21 months, 132 months, and 11 months, respectively. Patients with glioblastoma that received TMZ, other chemotherapy regimens, and no chemotherapy had median survival of 32 months, 12 months, and 8 months, respectively.

CONCLUSION

In the present study, patients with anaplastic astrocytoma treated with chemotherapy protocols other than TMZ had the longest OS; however, in the glioblastoma group, OS was 32 months in those treated with standard TMZ and 12 months in those treated with other protocols (P = 0.493). Although TMZ is less toxic than PCV, it was not shown to be superior.

Do grape and black mulberry molasses have an effect on oral mucositis and quality of life in patients with head and neck cancer?

OBJECTIVE

We aimed to investigate the effect of black mulberry and grape molasses on the prevention and treatment of oral mucositis and quality of life (QoL) in patients with head and neck cancer (HNC).

METHODS

Patients treated for HNC between 2010 and 2018 in our department were divided into three groups (group 1 = control (n = 14), group 2 = grape molasses (n = 40), and group 3 = black mulberry molasses (n = 40)). Oral mucositis, pain scoring, and weight loss were evaluated weekly. The European Organization for Research and Treatment of Cancer (EORTC) General QoL Questionnaire (QLQ-C30) and EORTC Head and Neck Cancer QoL Module (QLQ-HN35) were used to evaluate QoL.

RESULTS

The mean body weight, scores of oral mucositis, and pain were similar among the groups throughout the treatment. Both groups 2 and 3 were associated with improved outcomes for swallowing, opening mouth, and weight loss in the EORTC HN35, and these parameters were not significantly different between groups 2 and 3. Global health score was higher in group 3 at the 6th week of RT compared to that of group 2. Both groups 2 and 3 had improved scores for role functioning, emotional and social functioning, fatigue, appetite loss, and pain throughout the treatment compared to group 1.

CONCLUSIONS

Both grape and black mulberry molasses improved the QoL in HNC patients. No significant difference between black mulberry and grape molasses was found with regard to the healing of oral mucositis.

Does Internal Mammary Node Irradiation for Breast Cancer Make a Significant Difference to the Diameter of the Internal Mammary Artery? Correlation with Computed Tomography

OBJECTIVE

Lymphatic irradiation in breast cancer improves locoregional control and has been shown to decrease distant metastasis. However, irradiation also accelerates the formation of atherosclerosis and can cause stenosis, not only in the coronary arteries but also in the internal mammary artery (IMA). The aim of this study was to investigate the effects of radiation on IMAs via computed tomography (CT).

METHODS

We reviewed the data of 3,612 patients with breast cancer treated with radiotherapy (RT) between January 2010 and December 2016. We included 239 patients with appropriate imaging and nodal irradiation in the study. All patients were treated with lymphatic irradiation of 46-50 Gy, and a boost dose (6-10 Gy) to the involved internal mammary nodes (IMNs) when imaging studies demonstrated pathological enlargement. Bilateral IMA diameter and the presence of calcification were assessed via thin contrast-enhanced CT and those of ipsilateral irradiated IMAs were compared with those of contralateral nonirradiated IMAs.

RESULTS

The mean diameter of irradiated IMAs was significantly shorter than that of nonirradiated IMAs, regardless of laterality. All vascular calcifications were determined on the irradiated side. A boost dose of radiation to the IMNs and radiation technique did not significantly affect the IMA diameter or the presence of calcification.

CONCLUSIONS

The diameter of the IMA is decreased due to RT regardless of laterality, radiation technique, and administration of a boost dose. Evaluation of vessels on CT before coronary artery bypass graft or flap reconstruction can help the surgeon select the most appropriate vessel.

Evaluation of Photoneutron Dose Measured by Bubble Detectors in Conventional Linacs and Cyberknife Unit: Effective Dose and Secondary Malignancy Risk Estimation

This study aims to reduce the uncertainty about the photoneutron dose produced over a course of radiotherapy with high-energy photon beams and evaluate photoneutron contamination-based secondary malignancy risk for different treatment modalities. Dosimetric measurements were taken in Philips SL25/75, Elekta Synergy Platform (Elekta AB, Stockholm, Sweden), Varian Clinac DHX High Performance systems (Varian Medical Systems, Palo Alto, CA), and Cyberknife Robotic Radiosurgery Unit (Accuray Inc., Sunnyvale, CA) using bubble detector for neutron dosimetry. The measurement data were used to determine in-field and out-of-field neutron equivalent dose in 6-MV 3D conformal radiotherapy, sliding window-intensity-modulated radiotherapy, and stereotactic body radiotherapy and to calculate the effective dose in 18-MV 3D conformal radiotherapy and sliding window-intensity-modulated radiotherapy techniques for patients with prostate cancer undergoing a standard treatment. For the 18-MV treatment techniques, the secondary malignancy risk due to the neutron contamination was estimated using the risk factors published by The International Commission on Radiological Protection. The neutron contamination-based secondary malignancy risk for the 18-MV 3D conformal radiotherapy and sliding window-intensity-modulated radiotherapy modalities was found to be 0.44% and 1.45% for Elekta Synergy Platform and 0.92% and 3.0% for the Varian Clinac DHX High Performance, respectively. For 6-MV 3D conformal radiotherapy, sliding window-intensity-modulated radiotherapy, and stereotactic body radiotherapy treatment techniques, neutron equivalent doses inside the treatment field were found to be lower than 40 mSv. Our measurements reveal that equivalent dose and effective dose due to the neutron contamination are at a considerable level for 18-MV sliding window-intensity-modulated radiotherapy treatments, while 6-MV photon beams used in different modalities still induce only negligible photoneutrons. The secondary malignancy risk based on photoneutron should be therefore taken into consideration in case of selecting 18-MV photons in a sliding window-intensity-modulated radiotherapy treatment instead of 6 MV.

The management of gastric adenocarcinoma with postoperative chemoirradiation. A non-randomized comparison of oral UFT and 5-FU

AIMS AND BACKGROUND

We assessed the therapeutic results and tolerability of postoperative chemoradiotherapy with either oral UFT or 5-fluorouracil for carcinoma of the stomach.

METHODS AND STUDY DESIGN

Forty-six patients treated with chemoradiotherapy following total or subtotal gastrectomy for gastric carcinoma formed the cohort evaluated. The group included 39 males and 7 females whose ages ranged from 21 to 74 years (median, 53 years). In all patients, surgical therapy was the initial approach with a curative intent. The types of operations performed were total gastrectomy in 11 or subtotal gastrectomy in 35 patients. Radiotherapy began from 14 to 161 days after surgery (median, 55 days). Twenty patients received concomitant oral UFT (200 mg/m2), and 26 patients were given 5-fluorouracil (425 mg/m2, iv bolus) concurrently with irradiation consisting of one or two cycles, usually as a 3-day bolus at the start and last 3 days of irradiation therapy for radiosensitizing purposes. The patients were treated using either cobalt-60 or 6 MV photons, and irradiation doses delivered to the tumor bed and regional lymphatics ranged from 40 to 50 Gy (median, 46 Gy).

RESULTS

Median follow-up for the entire group was 24 months (range, 2-67). The 2-year overall survival of the entire group of patients was 64%. The 2-year overall survival rates for 5-fluorouracil and oral UFT groups were 72% and 66%, respectively (P = 0.3). Treatment-related factors were reviewed to identify any impact on survival. Analyses included type of surgery and dissection, fraction size, the total dose of irradiation and the type of chemotherapy. A significant detrimental effect in survival in the patients treated with D2 dissection compared to the patients treated with D1 dissection was noted (P = 0.01). Overall grade II-III toxicity of oral UFT was significantly lower than 5-FU (4 patients vs 14 patients, P = 0.03).

CONCLUSIONS

Concomitant use of oral UFT with radiation seems to be more tolerable and an equally effective regimen in the treatment of locally advanced gastric cancer compared with 5-fluorouracil. D2 dissection was found to have detrimental effects on survival in this cohort.

The effect of glutamine and arginine-enriched nutritional support on quality of life in head and neck cancer patients treated with IMRT

BACKGROUND AND AIMS

Oral mucositis and esophagitis are common acute toxicities of radiotherapy (RT) for head and neck cancer (HNC). In order to decrease the rates of these toxicities, we compared quality of life in HNC patients that did and did not receive a glutamine and arginine-enriched solution (GAES) during RT.

METHODS

A total of 29 patients received intensity-modulated radiotherapy (IMRT); 15 used GAES b.i.d. during the treatment, and a matched cohort of 14 patients did not. Patients were administered the EORTC QLQ-C30, QLQ-H&N35 and QLQ-OES18 questionnaires on the 1st, 15th, and last days of IMRT.

RESULTS

The global health status, functional and symptom scale scores were similar in both groups on the 1st day of IMRT. On the 15th and last days, the scores of social functions (p = 0.01 and p = 0.012), pain (p = 0.002 and p = 0.002), appetite (p = 0.01 and p = 0.02), dry mouth (p = 0.001 and p = 0.03), sticky saliva (p = 0.003 and p = 0.04), trouble with taste (p = 0.001 and p = 0.03), trouble with social eating (p = 0.004 and p = 0.006), and swallowing problems (p = 0.002 and p = 0.046) were significantly worse in the control group.

CONCLUSIONS

Quality of life is negatively affected by IMRT; however, use of GAES may mediate this negative effect.

Dosimetric comparison of three-dimensional conformal radiotherapy and intensity-modulated radiotherapy for left-sided chest wall and lymphatic irradiation

INTRODUCTION

The aim of this study was to compare five different techniques for chest wall (CW) and lymphatic irradiation in patients with left-sided breast carcinoma.

METHODS

Three-dimensional conformal radiotherapy (3DCRT), forward-planned intensity-modulated radiotherapy (FP-IMRT), inverse-planned IMRT (IP-IMRT; 7- or 9-field), and hybrid IP-/FP-IMRT were compared in 10 patients. Clinical target volume (CTV) included CW and internal mammary (IM), supraclavicular (SC), and axillary nodes. Planning target volumes (PTVs), CTVs, and organs at risks (OARs) doses were analyzed with dose-volume histograms (DVHs).

RESULTS

No differences could be observed among the techniques for doses received by 95% of the volume (D95%) of lymphatics. However, the FP-IMRT resulted in a significantly lower D95% dose to the CW-PTV compared to other techniques (P = 0.002). The 9-field IP-IMRT achieved the lowest volumes receiving higher doses (hotspots). Both IP-IMRT techniques provided similar mean doses (Dmean) for the left lung which were smaller than the other techniques. There was no difference between the techniques for maximum dose (Dmax) of right breast. However, FP-IMRT resulted in lower Dmean and volume of right breast receiving at least 5 Gy doses compared to other techniques.

CONCLUSION

The dose homogeneity in CW-CTV was better using IMRT techniques compared to 3DCRT. Especially 9-field IP-IMRT provided a more homogeneous dose distribution in IM and axillary CTVs. Moreover, the OARs volumes receiving low radiation doses were larger with IP-IMRT technique, while volumes receiving high radiation doses were larger with FP-IMRT technique. Hybrid IMRT plans were found to have the advantages of both FP- and IP-IMRT techniques.

Prognostic significance of castrate testosterone levels for patients with intermediate and high risk prostate cancer

BACKGROUND

Testosterone level of < 50 ng/dL has been used to define castrate level after surgery or after androgen deprivation treatment (ADT) in metastatic prostate cancer (PC).

AIM

To evaluate the effect of two different castrate testosterone levels, < 50 and < 20 ng/dL, on biochemical relapse free survival (BRFS) in patients with non-metastatic intermediate and high risk PC receiving definitive radiotherapy (RT) and ADT.

METHODS

Between April 1998 and February 2011; 173 patients with intermediate and high risk disease were treated. Radiotherapy was delivered by either three-dimensional-conformal technique to a total dose of 73.4 Gy at the ICRU reference point or intensity modulated radiotherapy technique to a total dose of 76 Gy. All the patients received 3 mo of neoadjuvant ADT followed by RT and additional 6 mo of ADT. ASTRO Phoenix definition was used to define biochemical relapse.

RESULTS

Median follow up duration was 125 months. Ninety-six patients (56%) had castrate testosterone level < 20 ng/dL and 139 patients (80%) had castrate testosterone level < 50 ng/dL. Both values are valid at predicting BRFS. However, patients with testosterone < 20 ng/dL have significantly better BRFS compared to other groups (P = 0.003). When we compare two values, it was found that using 20 ng/dL is better than 50 ng/dL in predicting the BRFS (AUC = 0.63 vs 0.58, respectively).

CONCLUSION

Castrate testosterone level of less than 20 ng/dL is associated with better BRFS and is better in predicting the BRFS. Further studies using current standard of care of high dose IMRT and longer ADT duration might support these findings.

Bone-only oligometastatic renal cell carcinoma patients treated with stereotactic body radiotherapy: a multi-institutional study

PURPOSE

This study aimed to analyze the prognostic factors associated with overall survival (OS) and progression-free survival (PFS) in patients with bone-only metastatic renal cell carcinoma (RCC) who have five or fewer lesions treated with stereotactic body radiotherapy (SBRT).

METHODS

The clinical data of 54 patients with 70 bone metastases undergoing SBRT treated between 2013 and 2020 with a dose of at least 5 Gy per fraction and a biologically effective dose (BED) of at least 90 Gy were retrospectively evaluated.

RESULTS

The majority of lesions were located in the spine (57.4%) and had only one metastasis (64.8%). After a median follow-up of 22.4 months, the 1‑ and 2‑year OS rates were 84.6% and 67.3%, respectively, and median OS was 43.1 months. The 1‑ and 2‑year PFS rates and median PFS were 63.0%, 38.9%, and 15.3 months, respectively. In SBRT-treated lesions, the 1‑year local control (LC) rate was 94.9%. Age, metastasis localization, and number of fractions of SBRT were significant prognostic factors for OS in univariate analysis. In multivariate analysis, patients with spinal metastasis had better OS compared to their counterparts, and patients who received single-fraction SBRT had better PFS than those who did not. No patient experienced acute or late toxicities of grade 3 or greater.

CONCLUSION

Despite excellent LC at the oligometastatic site treated with SBRT, disease progression was observed in nearly half of patients 13 months after metastasis-directed local therapy, particularly as distant disease progression other than the treated lesion, necessitating an effective systemic treatment to improve treatment outcomes.

Evaluation of the effects of mediastinal radiation therapy on autonomic nervous system

In this prospective study, the effects of mediastinal radiation therapy (RT) on autonomic nervous system (ANS) were investigated by heart rate variability (HRV) analysis that is accepted as a non-invasive indicator of ANS. Study was performed with the eligible patients had a histopathologically confirmed diagnosis of malignant disease with no known congestive heart failure, coronary heart disease, hypertension, valvular cardiac disease or arrhythmia history. Electrocardiograms of 14 voluntary patients were recorded for duration of 5 min just before and after irradiation for the first and the 15th fractions. ANS-related HRV analysis parameters were calculated as which were recommended by Task Force of ESC/NASPE (Circulation 93:1043-1065, 1996). HRV parameters that belong to pre- and post-RT treatment of patients were compared statistically. We found that there is not effect of single-dose radiation on HRV parameter. The mean RRI (782.29 ± 115.65-738.93 ± 111.01, P < 0.014) and HF power of HRVs PSD (156.94 ± 229.37-60.71 ± 77.99, P < 0.045) decreased, and LF/HF ratio (1.38 ± 0.79-2.03 ± 1.25, P < 0.039) increased significantly with 28-Gy external radiation dose. As the effect of cumulative dose was investigated on HRV parameters, the above changes were continued to increase with 30-Gy external radiation dose. We found that mediastinal RT involving heart directly in the radiation field decreased vagal and sympathetic ANS activities, and autonomic balance shifted toward sympathetic dominance.

1,25-Dihydroxy vitamin D3: can it be an effective therapeutic option for aggressive fibromatosis

Aggressive fibromatosis (AF), also known as desmoid tumor is a monoclonal fibroblastic proliferation in a collagen matrix that arises in musculoaponeurotic structures. Though considered as benign, they are locally invasive and their propensity for recurrence after conservative surgery is well documented. Addition of postoperative adjuvant radiotherapy produces higher local control rates, although recurrence rates are still high in patients with positive margins. The antineoplastic activity of vitamin D has been demonstrated both in vitro and in vivo models of several cancers. The proposed mechanisms for antineoplastic activity include inhibition of proliferation associated with cell cycle arrest, induction of apoptosis and reduction in invasiveness and angiogenesis. It has also been shown that vitamin D has a negative impact on collagen homeostasis by inhibiting the formation and increasing its degradation. Since vitamin D has an antineoplastic activity and negative effect on collagen synthesis and deposition, it is proposed that 1,25-dihydroxy vitamin D3 can be a right therapeutic option for the management of desmoid tumors.

Stereotactic body radiotherapy in patients with early-stage non-small cell lung cancer: Does beam-on time matter?

PURPOSE

Stereotactic body radiotherapy (SBRT) is an effective treatment option for patients with early-stage non-small cell lung cancer (NSCLC). In this study, we evaluated the treatment results using two different SBRT techniques and the effect of beam-on time (BOT) on treatment outcomes.

METHODS

Between July 2007 and January 2018, 142 patients underwent SBRT for primary NSCLC. We have delivered SBRT using either respiratory tracking system (RTS) or internal-target-volume (ITV)-based motion management techniques. The effect of age, tumor size, pretreatment tumor SUVmax value, presence of tissue diagnosis, histopathological subtype, operability status, tumor location, motion management technique, BED10 value, BOT on overall survival (OS), loco-regional control (LRC), event-free survival (EFS) and primary tumor control (PTC) were evaluated.

RESULTS

Median age of the patients was 70 years (range, 39-91 years). Most of the patients were inoperable (90%) at the time of SBRT. Median BED10 value was 112.5 Gy. With a median follow-up of 25 months, PTC was achieved in 91.5% of the patients. Two-year estimated OS, LRC, PTC and EFS rates were 68, 63, 63 and 53%, respectively. For the entire group, OS was associated with BOT (P = 0.027), and EFS was associated with BOT (P = 0.027) and tumor size (P = 0.015). For RTS group, OS was associated with age (P = 0.016), EFS with BOT (P = 0.05) and tumor size (P = 0.024), LRC with BOT (P = 0.008) and PTC with BOT (P = 0.028). The treatment was well tolerated in general.

CONCLUSION

SBRT is an effective and safe treatment with high OS, LRC, EFS and PTC rates in patients with primary NSCLC. Protracted BOT might deteriorate SBRT outcomes.

Hypofractionated radiotherapy for non-metastatic bone and soft tissue sarcomas

PURPOSE

To evaluate the efficacy and toxicity of hypofractionated radiotherapy in non-metastatic soft tissue and bone sarcomas.

PATIENTS AND METHODS

Thirty patients underwent hypofractionated radiotherapy between 2007 and 2015. Overall, 17 patients underwent primary hypofractionated radiotherapy, nine underwent hypofractionated radiotherapy for reirradiation, and four received a boost dose via hypofractionated radiotherapy after external beam radiotherapy. Most common disease sites were head and neck and retroperitoneum. Hypofractionated radiotherapy was administered with a definitive, adjuvant, or neoadjuvant intent.

RESULTS

Median age was 37 years (range: 11-82 years). Median hypofractionated radiotherapy dose was 35Gy (range: 20-50Gy) in three to five fractions. Median follow-up was 21 months (range: 1-108 months). One- and 2-year overall survival rate was 75% and 52%, respectively. One- and 2-year local recurrence-free survival rate was 59% and 48%, with local recurrence rates of 16% and 33% in 1 and 2 years, respectively. Univariate analysis revealed tumour size (P=0.04), hypofractionated radiotherapy intent (P=0.016) and reirradiation (P=0.001) as prognostic factors for local recurrence-free survival. Severe late toxicity was observed in one patient as grade 3 trismus.

CONCLUSION

Hypofractionated radiotherapy as the primary treatment or for reirradiation has been shown to be safe in the treatment of bone and soft tissue sarcomas. It can provide relatively good local control and survival rates.

Evaluation of MLC leaf positioning accuracy for static and dynamic IMRT treatments using DAVID in vivo dosimetric system

Accuracy and precision of leaf positioning in multileaf collimators (MLCs) are significant factors for the accuracy of IMRT treatments. This study aimed to inves-tigate the accuracy and repeatability of the MLC leaf positioning via the DAVID invivo dosimetric system for dynamic and static MLC systems. The DAVID system was designed as multiwire transmission ionization chamber which is placed in accessory holder of linear accelerators. Each wire of DAVID system corresponds to a MLC leaf-pair to verify the leaf positioning accuracy during IMRT treatment and QA. In this study, verifications of IMRT plans of five head and neck (H&N) and five prostate patients treated in a Varian DHX linear accelerator with 80-leaf MLC were performed using DAVID system. Before DAVID-based dosimetry, Electronics Portal Imaging Device (EPID) and PTW 2D ARRAY dosimetry system were used for 2D verification of each plan. The measurements taken by DAVID system in the first day of the treatments were used as reference for the following measurements taken over the next four weeks. The deviations in leaf positioning were evaluated by "Total Deviation (TD)" parameter calculated by DAVID software. The delivered IMRT plans were originally prepared using dynamic MLC method. The same plans were subsequently calculated based on static MLC method with three different intensity levels of five (IL5), 10 (IL10) and 20 (IL20) in order to compare the performances of MLC leaf positioning repeatability for dynamic and static IMRT plans. The leaf positioning accuracy is also evaluated by analyzing DynaLog files based on error histograms and root mean square (RMS) errors of leaf pairs' positions. Moreover, a correlation analysis between simultaneously taken DAVID and EPID measurements and DynaLog file recordings was subsequently performed. In the analysis of DAVID outputs, the overall deviations of dynamic MLC-based IMRT calculated from the deviations of the four weeks were found as 0.55% ± 0.57% and 1.48% ± 0.57% for prostate and H&N patients, respectively. The prostate IMRT plans based on static MLC method had the overall deviations of 1.23% ± 0.69%, 3.07% ± 1.07%, and 3.13% ± 1.29% for intensity levels of IL5, IL10, and IL20, respectively. Moreover, the overall deviations for H&N patients were found as 1.87% ± 0.86%, 3.11% ± 1.24%, and 2.78% ± 1.31% for the static MLC-based IMRT plans with intensity levels of IL5, IL10 and IL20, respectively. Similar with the DAVID results, the error rates in DynaLog files showed upward movement comparing the dynamic IMRT with static IMRT with high intensity levels. In respect to positioning errors higher than 0.005 cm, static prostate IMRT plans with intensity levels of IL10 and IL20 had 1.5 and 2.6 times higher error ratios than dynamic prostate IMRT plans, respectively, while these values stepped up to 8.4 and 12.0 for H&N cases. On the other hand, according to the leaf pair readings, reconstructed dose values from DynaLog files had significant correlation (r = 0.80) with DAVID and EPID readings while a stronger relationship (r = 0.98) was found between the two dosimetric systems. The correlation coefficients for deviations from reference plan readings were found in the interval of -0.21-0.16 for all three systems. The dynamic MLC method showed higher performance in repeatability of leaf positioning than static MLC methods with higher intensity levels even though the deviations in the MLC leaf positioning were found to be under the acceptance threshold for all MLC methods. The high intensity levels increased the position-ing deviations along with the delivery complexity of the static MLC-based IMRT plans. Moreover, DAVID and EPID readings and DynaLog recordings showed mutually strong correlation, while no significant relationship was found between deviations from reference values.

Radiotherapy-induced alterations in vitreous humor: A new potential critical structure

Vitreous humor (VH) is not considered as a critical structure in the radiotherapy planning process. In the present study, an experimental animal model was performed to examine the effects of radiotherapy on VH. The right eyes of twelve New Zealand rabbits were irradiated to 60 Gy in 3 fractions in accordance with the scheme used in the treatment of uveal melanoma in our clinic, and contralateral (left) eyes were considered as control. Weekly ophthalmologic examination was performed after irradiation, for three months. At the end of the third month, enucleation and vitreous collection were conducted. The vitreous samples were subjected to metabolomic analyses, ELISA analyses, viscosity measurements, and electron microscopic examination. In control and experimental vitreous samples, 275 different metabolites were identified, and 34 were found to differ significantly between groups. In multivariate analyzes, a clear distinction was observed between control and irradiated vitreous samples. Pathway analysis revealed that nine pathways were affected, and these pathways were mainly related to amino acid metabolism. A significant decrease was observed in the expressions of type II, V, and XI collagens in protein level in the ELISA. There was a non-significant decrease in type IX collagen and viscosity. Electron microscopic examination revealed disrupted collagen fibrillar ultra-structure and dispersed collagen fragments in the experimental vitreous. An intact vitreous is essential for a healthy eye. In this study, we observed that radiation causes changes in the vitreous that may have long-term consequences.

The effect of tianeptine in the prevention of radiation-induced neurocognitive impairment

Radiation-induced neurocognitive impairment is an undesirable radiation-induced toxicity and a common health problem in patients with primary or metastatic brain tumor. It greatly impairs quality of life for long-term brain tumor survivors. Hippocampus is the most important brain structure for neurocognitive functions. It has been shown that radiation affects the hippocampal neurogenesis due to either induce the apoptosis or reduce the precursor cell proliferation in the hippocampus. Radiation-induced microglial inflammatory response is also negative regulator of neurogenesis. Tianeptine is a clinically effective antidepressant that induces neurogenesis. It has also been shown that tianeptine is able to reduce apoptosis and cytoprotective against the effects of proinflammatory cytokines in the hippocampus. Given the putative role of impaired hippocampal neurogenesis in radiation-induced neurocognitive impairment we think that tianeptine can be effective for preventing radiation-induced neurocognitive impairment by increasing hippocampal neurogenesis.

Robotic Stereotactic Body Radiation Therapy in Patients With Recurrent or Metastatic Abdominopelvic Tumors: A Single Institute Experience

BACKGROUND

The aim of this study was to evaluate the efficacy and toxicity of robotic CyberKnife (Accuray Incorporated, Sunnyvale, California)-based stereotactic body radiation therapy (SBRT) in patients with recurrent or metastatic abdominopelvic tumors.

METHODS AND MATERIALS

A total of 69 patients treated between May 2008 and January 2011 were evaluated retrospectively. Indication for SBRT was persistent disease in 3 (4%) patients, local recurrence in 29 (42%) patients, regional recurrence in 13 (19%) patients, and oligometastatic disease in 24 (35%) patients. Forty-two (61%) patients were previously irradiated to the same region and 27 (39%) patients were treated for the first time. The median age was 59 years (range, 24-86 years). There were 31 (45%) male and 38 (55%) female patients. The median total dose was 30 Gy (range, 15-60 Gy) delivered with a median 3 fractions (range, 2-5 fractions). The tumor response to treatment was assessed by computed tomography, magnetic resonance imaging, or positron emission tomography.

RESULTS

At the 12-month (range, 2-44 months) median follow-up, local control was 65% and median overall survival (OS) was 20 months. A larger gross tumor volume (≥ 67 cm(3)) was significantly correlated with worse 1-year OS (81% vs 48%, P = .03). The patients with local recurrence occurring <11 months had a significantly shorter 1-year local control rate than patients with ≥ 11 months (31% vs 91%, P < .001). Grade 3-4 acute and late toxicities were seen in 7% and 15% of patients, respectively. The patients with previous radiotherapy history had significantly higher rate of acute toxicity (19% vs 0%, P = .019). Late toxicity was significantly higher in pelvic tumors than in abdominal tumors (3% vs 28%, P = .004).

CONCLUSION

The SBRT seems to be feasible and resulted in good treatment outcomes in patients with recurrent or metastatic abdominopelvic tumors.

Determination of gonad doses during robotic stereotactic radiosurgery for various tumor sites

PURPOSE

The authors evaluated the absorbed dose received by the gonads during robotic stereotactic radiosurgery (SRS) for the treatment of different tumor localizations.

METHODS

The authors measured the gonad doses during the treatment of head and neck, thoracic, abdominal, or pelvic tumors in both RANDO phantom and actual patients. The computerized tomography images were transferred to the treatment planning system. The contours of tumor and critical organs were delineated on each slice, and treatment plans were generated. Measurements for gonad doses were taken from the geometric projection of the ovary onto the skin for female patients, and from the scrotal skin for male patients by attaching films and Thermoluminescent dosimeters (TLDs). SRS was delivered with CyberKnife (Accuray Inc., Sunnyvale, CA).

RESULTS

The median gonadal doses with TLD and film dosimeter in actual patients were 0.19 Gy (range, 0.035-2.71 Gy) and 0.34 Gy (range, 0.066-3.18 Gy), respectively. In the RANDO phantom, the median ovarian doses with TLD and film dosimeter were 0.08 Gy (range, 0.03-0.159 Gy) and 0.05 Gy (range, 0.015-0.13 Gy), respectively. In the RANDO phantom, the median testicular doses with TLD and film dosimeter were 0.134 Gy (range 0.056-1.97 Gy) and 0.306 Gy (range, 0.065-2.25 Gy).

CONCLUSIONS

Gonad doses are below sterility threshold in robotic SRS for different tumor localizations. However, particular attention should be given to gonads during robotic SRS for pelvic tumors.

Turkish translation and validation of the Xerostomia Inventory

OBJECTIVES

The Xerostomia Inventory (XI) was developed to assess the severity of dryness in patients with xerostomia. It has a long and a short form with three- and five-point Guttman-type response options. In this study, we aimed to translate the XI into Turkish, to assess the validity and reliability of both response options in patients with head & neck cancer (HNC) or Sjögren syndrome (SS), and to select the optimal version for Turkish patients.

PATIENTS AND METHODS

Between January 2019 and June 2019, the XI was translated into Turkish (XI-T) and applied to patients aged ≥18 years with HNC and SS. All patients were applied two tests including both the three- and five-point options. The internal consistency was assessed by Cronbach alpha and test-retest reliability by intraclass correlation coefficients (ICCs). Content validity was based on expert opinion and patient reviews.

RESULTS

A total of 186 patients (109 males, 77 females; median age: 54 years; range, 19 to 78 years) answered the XI-T. The number of patients with HNC and SS was 143 (77%) and 43 (23%), respectively. Median XI-T score was 17 for the three-point, and 24 for the five-point option, respectively. Overall internal consistency was satisfactory for both options (α=0.81 and α=0.89, respectively). Overall test-retest reliability was satisfactory and ICCs ranged between 0.71 and 0.92 for the three-point, and 0.36 and 0.94 for the five-point option, respectively. Assessments based on expert opinions and patient reviews also favored the content validity of the scale.

CONCLUSION

The XI-T with both three- and five-point options is a valid and reliable tool to evaluate the presence and severity of dryness in patients with HNC and SS who experience xerostomia. The three-point option is more comprehensible and can be preferred over the five-point option in the Turkish population.