Hypofractionated stereotactic re-irradiation for progressive glioblastoma: twelve years' experience of a single center

PURPOSE

We aimed to evaluate the prognostic factors and the role of stereotactic radiotherapy (SRT) as a re-irradiation technique in the management of progressive glioblastoma.

METHODS

The records of 77 previously irradiated glioblastoma patients who progressed and received second course hypofractionated SRT (1-5 fractions) between 2009 and 2022 in our department were evaluated retrospectively. Statistical Package for the Social Sciences (SPSS) version 23.0 (IBM, Armonk, NY, USA) was utilized for all statistical analyses.

RESULTS

The median time to progression from the end of initial radiotherapy was 14 months (range, 6-68 months). The most common SRT schedule was 30 Gy (range, 18-50 Gy) in 5 fractions (range, 1-5 fractions). The median follow-up after SRT was 9 months (range, 3-80 months). One-year overall (OS) and progression-free survival (PFS) rates after SRT were 46% and 35%, respectively. Re-irradiation dose and the presence of pseudoprogression were both significant independent positive prognostic factors for both OS (p = 0.009 and p = 0.04, respectively) and PFS (p = 0.008 and p = 0.04, respectively). For PFS, progression-free interval > 14 months was also a prognostic factor (p = 0.04). The treatment was well tolerated without significant acute toxicity. During follow-up, radiation necrosis was observed in 17 patients (22%), and 14 (82%) of them were asymptomatic.

CONCLUSION

Hypofractionated SRT is an effective treatment approach for patients with progressive glioblastoma. Younger patients who progressed later than 14 months, received higher SRT doses, and experienced pseudoprogression following SRT had improved survival rates.

Stereotactic radiotherapy for head and neck paragangliomas: How long should we wait for treatment response?

BACKGROUND AND PURPOSE

Stereotactic radiotherapy (SRT) is an effective treatment for head & neck (H&N) paragangliomas. Nevertheless, the timeline for achieving a tumor-volume-reduction (TVR) remains unclear.

MATERIALS AND METHODS

Sixty-three cases with H&N paragangliomas received definitive SRT and were evaluated retrospectively. Statistical Package for the Social Sciences (SPSS) v23.0 (IBM, Armonk, NY, USA) was used for statistics.

RESULTS

Sixty-eight lesions were irradiated, with glomus jugulotympanicum being the most common location (44 %). Median tumor diameter and volume were 3 cm (range, 1-7.6 cm) and 15.4 cm3 (range,1-185 cm3), respectively. Median dose was 25 Gy (range, 12-37.5 Gy) in 5 fractions (range, 1-5 fractions). Median follow-up was 40 months (range, 3-184 months). Treatment response, evaluated at a median 4.6 months post-SRT (range: 3-11 months), revealed TVR in 26 cases (41 %). During follow-up, 13 additional cases showed TVR, resulting in an overall TVR rate of 62 %. The median duration for attaining TVR was 9 months (range, 3-36 months) after SRT, and TVR occurred ≥ 12 months in 42 % of cases. Patients without prior surgery (p = 0.03) and with a longer follow-up (p = 0.04) demonstrated a higher rate of TVR. The likelihood of TVR tends to increase as the SRT dose increases (p = 0.06). Overall local control (LC) rate was 100 %. No ≥ grade 3 acute or late toxicities were observed.

CONCLUSION

While SRT demonstrates an excellent LC rate for H&N paragangliomas, it's important to note that the response to treatment may require time. TVR may last beyond the initial year of treatment in a substantial proportion of patients.

The effect of P53 expression and smoking/alcohol in P16(+) and P16(-) oropharyngeal carcinoma and risk classification: the Turkish Society of Radiation Oncology Head & Neck Study Group 01-002

OBJECTIVE

The aim of this study is to categorize the risk groups of patients with oropharyngeal carcinoma (OPC) according to p16 and p53 status, smoking/alcohol consumption history, and other prognostic factors.

STUDY DESIGN

The immunostaining of p16 and p53 of 290 patients was retrospectively evaluated. The history of smoking/alcohol consumption of each patient was noted. p16 and p53 staining patterns were reviewed. The results were compared with demographic findings and prognostic factors. Risk groups have been classified for the p16 status of patients.

RESULTS

The median follow-up was 47 months (range 6-240). Five-year disease-free survival (DFS) rates for patients with p16 (+) and (-) were 76% and 36%, and overall survival rates were 83% vs 40%, respectively (HR = 0.34 [0.21-0.57], P < .0001), HR = 0.22 [0.12-0.40] P < .0001, respectively). p16(-), p53(+), heavy smoking/alcohol consumption, performance status; advanced T and N stages in patients with p16(-), and continuing smoking/alcohol consumption after treatment were found to be unfavorable risk factors. Five-year overall survival rates were 95%, 78%, and 36% for low, intermediate, and high-risk groups, respectively.

CONCLUSIONS

The results of our study have shown that p16 negativity in patients with oropharyngeal cancer was found to be an important prognostic factor, especially for those with lower p53 expression and not smoking/consuming alcohol.

Role of sarcopenia on survival and treatment-related toxicity in head and neck cancer: a narrative review of current evidence and future perspectives

PURPOSE

The purpose of this article is to provide an up-to-date summary of sarcopenia and its clinical implications for patients with head and neck cancer (HNC).

METHODS

We conducted a literature review of recent studies investigating the prevalence of sarcopenia in HNC patients, its detection using MRI or CT scans, and its association with clinical outcomes such as disease-free and overall survival time, radiotherapy-related side effects, cisplatin toxicity, and surgical complications.

RESULTS

Sarcopenia, characterized by low skeletal muscle mass (SMM), is a prevalent condition in HNC patients and can be effectively detected using routine MRI or CT scans. Low SMM in HNC patients is associated with increased risks of shorter disease-free and overall survival times, as well as radiotherapy-related side effects such as mucositis, dysphagia, and xerostomia. In addition, cisplatin toxicity is more severe in HNC patients with low SMM, leading to higher dose-limiting toxicity and treatment interruptions. Low SMM may also predict higher risks of surgical complications in head and neck surgery. Identifying sarcopenic patients can aid physicians in better riskstratifying HNC patients for therapeutic or nutritional interventions to improve clinical outcomes.

CONCLUSIONS

Sarcopenia is a significant concern for HNC patients and can impact their clinical outcomes. Routine MRI or CT scans can effectively detect low SMM in HNC patients. Identifying sarcopenic patients can aid physicians in better risk-stratifying HNC patients for therapeutic or nutritional interventions to improve clinical outcomes. Further research is needed to explore the potential of interventions to mitigate the negative effects of sarcopenia in HNC patients.

Intracerebral de novo arterio-venous malformations as a side effect of bevacizumab

INTRODUCTION

Bevacizumab is a monoclonal antibody for the vascular endothelial growth factor receptor and is utilized in the treatment of various tumors. Gastrointestinal perforation/fistula, heart failure, hemorrhage, hypertension, proteinuria/nephrotic syndrome, thromboembolism, posterior reversible encephalopathy syndrome, and necrotizing fasciitis are serious side effects of bevacizumab. Bevacizumab associated de novo brain arterio-venous malformation formation has not been documented in the literature.

CASE REPORT

Here, we presented a 35-year-old female patient with recurrent high-grade glial tumor who developed multiple supra- and infratentorial de novo arterio-venous malformations after receiving the last dose of bevacizumab.

MANAGEMENT & OUTCOME

Intervention options for the adverse effect were limited. In fact, there was no chance of intervention because the patient died for another reason.

DISCUSSION

Based on this experience, it can be hypothesized that bevacizumab may induce de novo arterio-venous malformations in the brain as a result of arterial and venous thrombotic effects. Additional studies should be done to clarify the causal relationship between bevacizumab and arterio-venous malformations in primary brain tumors.

Evaluation of sarcopenia as a prognostic biomarker in locally advanced head and neck squamous cell carcinoma

Background: We aimed to evaluate the effect of sarcopenia on survival in head and neck squamous cell carcinoma patients treated with chemoradiotherapy. Materials & methods: Disease-free survival and overall survival were compared according to cervical computed tomography for radiotherapy in 123 sarcopenic and non-sarcopenic patients with locally advanced head and neck squamous cell carcinoma treated with chemoradiotherapy with weekly cisplatin. Results: In multivariate analyses, pretreatment sarcopenia was associated with lower disease-free survival (hazard ratio: 2.60; 95% CI: 1.38-4.87; p = 0.003) and overall survival (hazard ratio: 2.86; 95% CI: 1.40-5.85; p = 0.004). Sarcopenic patients experienced more frequent radiotherapy-related toxicities and platinum-related side effects than non-sarcopenic patients. Conclusion: Sarcopenia could be a potential biomarker to predict prognosis and treatment toxicity in head and neck squamous cell carcinoma.

The Effect of Video-Based Education on Anxiety of Patients Receiving Stereotactic Radiosurgery and Stereotactic Body Radiation Therapy

Patients receiving stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) may have an anxiety due to unknown aspects of the treatment. We aimed to reduce patient anxiety by using video-based education. Forty patients were divided into 2 groups, with one-to-one information session (n = 20) and one-to-one information session plus video-based education (n = 20). The patients completed the State-Trait Anxiety Inventory (STAI) and visual facial anxiety scale before and after information sessions and after treatment. The setup time and disruptions during treatment sessions were recorded for patients receiving treatment with Novalis® and Cyberknife®, respectively. The patient characteristics and STAI scores before education were similar between groups. The anxiety level was significantly lower in group 1 after treatment (median 38, interquartile range (IQR) 27-45) compared to before (median 43, IQR 36-47) (p = 0.003) and after information sessions (median 42, IQR 36-47) (p = 0.004); however, any difference was not observed in anxiety levels between before and after information sessions (p = 0.317). The anxiety level was significantly lower in group 2 after video-based education (median 25, IQR 22-33) and after treatment (median 25, IQR 20-30) compared to before video-based education (median 35, IQR 31-42) (p < 0.001 for both), while there was no significant difference in anxiety levels between after video-based education and after the treatment (p = 0.407). The interruptions during treatment were observed in 9 (60%) patients in group 1 and 6 (40%) patients in group 2 (p = 0.038). Video-based educations significantly reduce patient anxiety before SRS/SBRT and increase their compliance with the treatment.

Post-induction lymph node delineation in nasopharyngeal cancer: A single-center experience

BACKGROUND

We routinely delineate the gross tumor volume (GTV) for the lymph nodes (LN) based on post-induction chemotherapy (IC) MRI in nasopharyngeal carcinoma (NPC). Herein, we investigated the sufficiency of this method, particularly in high-risk LNs.

METHODS

Eighty-one LNs with a high-risk of clinical extranodal extension and/or ≥3-cm diameter in 58 patients were evaluated. A new GTV covering the pre-IC LN volume was delineated for each LN.

RESULTS

The median volume reduction was 72.5% for the GTV and 53.1% for the planning target volume. After a median 43 months, the overall LN local control rate was 97.5%. The 2- and 5-year LN recurrence-free survival, overall survival, and disease-free survival rate was 88.3% and 84.4%, 92.5% and 85.1%, and 86.8% and 79.2%, respectively.

CONCLUSION

IC yields a significant reduction in nodal target volumes, and post-IC nodal volume-based radiotherapy provides excellent LC in NPC, even in high-risk LNs.

The association between pan-immune-inflammation value and survival in head and neck squamous cell carcinoma

PURPOSE

A significant portion of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) relapse despite multimodality treatment denoting the need for biomarkers. The pan-immune-inflammation value (PIV) is a recently developed blood count-based prognostic biomarker. We evaluated the relationship between PIV and survival in locally advanced HNSCC patients treated with chemoradiotherapy (CRT).

METHODS

A total of 199 patients who underwent CRT at Hacettepe University Oncology Hospital were included. The relationship between clinical and laboratory parameters with overall survival (OS) and disease-free survival (DFS) was analyzed by multivariate analyses.

RESULTS

The median age was 59 years and 90.5% of the patients were male. 66.8% of the patients had laryngeal primaries, and 78.9% had T3-T4 disease. 84.9% of the patients received CRT with cisplatin. The optimal PIV threshold value was calculated as 404 in ROC analyses. This PIV value had 75.8% sensitivity and 70.4% specificity for OS prediction (AUC 0.781; 95% CI 0.715-0.846; p < 0.001). In multivariate analyses, high PIV levels (≤ 404 vs. > 404, HR 2.862; 95% CI 1.553-5.276; p = 0.001), higher NLR (≤ 2.5 vs. > 2.5, HR 1.827; 95% CI 1.017-3.281; p = 0.044) levels and ECOG performance score of 2 (HR 2.267; 95% CI 1.385-3.711; p = 0.001) were associated with shorter OS. These factors were associated with shorter DFS also (HR for PIV 2.485, 95% CI 1.383-4.467, p = 0.002).

CONCLUSIONS

We observed shorter OS and DFS in locally advanced HNSCC patients with high PIV levels. If prospective studies support our findings, the PIV score could be a prognostic biomarker in HNSCC.

Every other day stereotactic radiation therapy for the treatment of uveal melanoma decreases toxicity

BACKGROUND AND PURPOSE

To report the long-term results of stereotactic radiosurgery and fractionated stereotactic radiation therapy (SRS/FSRT) in patients with uveal melanoma (UM).

MATERIALS AND METHODS

We retrospectively evaluated the results of patients treated between 2007 and 2019. The primary endpoints were local control (LC), local recurrence-free survival (LRFS), enucleation-free survival (EFS) and treatment toxicity.

RESULTS

443 patients with 445 UMs were treated via CyberKnife®. According to the COMS classification, 70% of the tumors were small/medium and 30% were large. Median total RT dose was 54 Gy, median BED10 was 151 Gy. After a median 74-months follow-up, SRS/FSRT yielded an 83% overall LC rate. The 5- and 10-year LRFS rate was 74% and 56%, respectively. Patient age and the COMS size were prognostic for all survival endpoints. An increased SRS/FSRT dose was associated with higher LRFS and EFS rates. SRS/FSRT-related toxicity was observed in 49% of the eyes. Median visual acuity (VA) significantly deteriorated after SRS/FSRT in 76% of the treated eyes. The overall eye preservation rate was 62%, and the 5- and 10-year EFS rate was 64% and 36%, respectively. The delivery of FSRT every other day resulted in a significantly lower rate of toxicity and enucleation compared to FSRT on consecutive days.

CONCLUSION

A total dose of ≥45 Gy and BED_10Gy ≥ 112.5 SRS/FSRT is associated with a higher LC rate in patients with UM. Despite the favorable outcomes, treatment toxicity is the major limitation of this treatment. Toxicity and enucleation can be minimized by treating the eye every other day.

Stereotactic body radiotherapy optimization to reduce the risk of carotid blowout syndrome using normal tissue complication probability objectives

Purpose

To determine the possibility of further improving clinical stereotactic body radiotherapy (SBRT) plans using normal tissue complication probability (NTCP) objectives in order to minimize the risk for carotid blowout syndrome (CBOS).

Methods

10 patients with inoperable locally recurrent head and neck cancer, who underwent SBRT using CyberKnife were analyzed. For each patient, three treatment plans were examined: (1) cone‐based without delineation of the ipsilateral internal carotid (clinical plan used to treat the patients); (2) cone‐based with the carotid retrospectively delineated and spared; and (3) Iris‐based with carotid sparing. The dose–volume histograms of the target and primary organs at risk were calculated. The three sets of plans were compared based on dosimetric and TCP/NTCP (tumor control and normal tissue complication probabilities) metrics. For the NTCP values of carotid, the relative seriality model was used with the following parameters: D₅₀ = 40 Gy, γ = 0.75, and s = 1.0.

Results

Across the 10 patient plans, the average TCP did not significantly change when the plans were re‐optimized to spare the carotid. The estimated risk of CBOS was significantly decreased in the re‐optimized plans, by 14.9% ± 7.4% for the cone‐based plans and 17.7% ± 7.1% for the iris‐based plans (p = 0.002 for both). The iris‐based plans had significant (p = 0.02) reduced CBOS risk and delivery time (20.1% ± 7.4% time reduction, p = 0.002) compared to the cone‐based plans.

Conclusion

A significant improvement in the quality of the clinical plans could be achieved through the delineation of the internal carotids and the use of more modern treatment delivery modalities. In this way, for the same target coverage, a significant reduction in the risk of CBOS could be achieved. The range of risk reduction varied depending on the proximity of carotid artery to the target.

Results of concurrent radiotherapy and immunotherapy in recurrent and metastatic head and neck cancer: A single-center experience

OBJECTIVES

In metastatic and recurrent head and neck cancer (M/R HN-SCC), the median survival is less than a year and locoregional recurrence is the main cause of death. Our aim was to evaluate the results of concurrent stereotactic body radiotherapy (SBRT) and immunotherapy (ICI) in these patients.

MATERIALS AND METHODS

Fifteen patients diagnosed with M/R HN-SCC were evaluated retrospectively. All patients received SBRT (3x8 Gy) to all recurrent and metastatic foci with concurrent ICI.

RESULTS

Six months overall survival (OS) rates and progression-free survival (PFS) rates were 93% and 86%, respectively. Local control (LC) rate in the site of SBRT was 96%. Higher survival and LC rates were achieved with lower doses of radiotherapy with the synergistic effect of SBRT and ICI.

CONCLUSION

Concurrent ICI and SBRT was feasible with excellent LC.

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.

Does Combined Fractionated Stereotactic Radiotherapy and Immunotherapy Change the Outcome of Recurrent High-Grade Gliomas?

Background

Radiotherapy (RT) with immune checkpoint inhibitors (ICI) has yielded good responses in many cancers. We aimed to report the results of combined fractionated stereotactic radiotherapy (FSRT) and ICI in patients with recurrent high-grade glioma.

Methodology

Patients were treated with FSRT and nivolumab which were continued until progression or toxicity. The Response Assessment in Neuro-oncology and Immunotherapy Response Assessment in Neuro-oncology criteria were used to assess treatment response on magnetic resonance imaging. Treatment-related toxicity was noted in all patients.

Results

A total of eight patients were included. Recurrence was detected after a median of 5.8 months following the first RT, all in the treatment field. FSRT (3 × 8 Gy) was applied with neoadjuvant, concurrent, and adjuvant nivolumab. After a median follow-up of 21.3 months from diagnosis and 12.6 months from recurrence, one patient was alive and seven succumbed to the disease. The median overall survival was 20.9 months after diagnosis and 12.9 months after recurrence. The median progression-free interval was 2.3 months after FSRT. The local control (LC) rate was 62.5% with a median local recurrence-free survival of nine months. Progression in other regions of the brain was observed in four patients with a median progression-free survival of 2.1 months. Acute toxicity was not observed. ICI-related grade 3 late pneumonitis was observed in two patients, and grade 1 late thyroid toxicity in two patients. One patient with pneumonitis also developed osteoporosis and radiation necrosis.

Conclusions

A high LC rate was achieved with concurrent FSRT and ICI with a severe late toxicity rate of 25%. This combination can be an option in recurrent high-grade gliomas.

Radiation Recall Dermatitis in Patients Treated With Immune Checkpoint Inhibitors: A Case Report and Literature Review

Radiation recall dermatitis (RRD) is defined as a skin reaction in the previously irradiated area triggered by a systemic agent's administration. The use of immune checkpoint inhibitors (ICI) alone and in combination with other treatments is increasing in many cancers. ICI-associated radiation recall reactions such as dermatitis, pneumonia, and myelitis have been reported so far. We report a case of nivolumab (anti-programmed cell death protein-1 antibody) induced RRD in a patient with head and neck cancer and review the publications reporting RRD associated with other ICI in the literature. The patient was diagnosed with neck metastasis of unknown primary origin and underwent surgery followed by adjuvant chemoradiotherapy (CRT). During the follow-up, radiotherapy (RT) was performed to the left parotid region, right neck level 1b, and the left neck skin due to recurrence. After three months of the last RT session, she was started on nivolumab due to the metastatic disease. Four weeks later, she was represented with erythematous squamous plaque-like lesions starting from the left temporomandibular region and spreading to the anterior chest, which corresponded to the previously irradiated area. A biopsy was performed with the differential diagnosis of skin metastases which revealed subacute spongiotic dermatitis. The lesions completely regressed in two weeks with the use of topical steroids and antihistamine tablets. Nivolumab treatment was not interrupted, and no reaction was observed during or after the next cycle. Although RRD is rarely encountered clinically, it is a diagnosis that should be kept in mind while continuing treatment with systemic agents in patients with a history of RT. With the widespread use of ICI, RRD associated with these treatments could be better defined and appropriately managed.

Dosimetric comparison and secondary malignancy risk estimation for linac-based and robotic stereotactic radiotherapy in uveal melanoma

It was aimed to investigate the dosimetric differences among linac-based and robotic stereotactic radiotherapy (SRT) techniques for the treatment of uveal melanoma and to evaluate secondary malignancy risks for these different SRT techniques. Ten patients who received robotic SRT with CyberKnife were retrospectively included in this study. A total dose of 54 Gy in three fractions was prescribed to the planning target volume (PTV). For each patient, non-coplanar micro-multileaf collimator based dynamic conformal arc (DCA), intensity-modulated radiotherapy (IMRT) and circular cone based DCA (cDCA) plans were generated. During the analysis dose-volume histogram (DVH) parameters, homogeneity index, new conformity index, the volume received more than or equal to 30% and 50% of the prescribed dose were compared. Additionally, secondary malignancy risk for each technique was estimated using the risk factors recommended by The International Commission on Radiological Protection. Robotic SRT plans provided a high degree of conformity within the PTV and better normal tissue sparing compared to linac-based treatment plans. However, dose distribution was more heterogeneous in robotic SRT plans than that in linac-based techniques. Estimated secondary malignancy risk was also found as 3.4%, 1.4%, 1.4% and 1.6% for robotic SRT and linac-based IMRT, DCA, cDCA plans, respectively. Treatment parameters of uveal melanoma patients planned with robotic SRT had superior conformity and organ-at-risk (OAR) sparing compared with those planned with the linac-based system. However, estimated secondary malignancy risk was almost two-times higher in robotic SRT than that in linac-based techniques.

A hesitated approach: primary radiotherapy for keloids-a case series

PURPOSE

To assess the efficacy and toxicity of hypofractionated radiotherapy (RT) alone in treatment-resistant symptomatic keloids.

METHODS

Six patients with a total of 13 inoperable large keloid lesions and no response to previous treatments were admitted to our department between 2017 and 2019. All patients were examined for detailed wound localization, size, contour, and color assessment, and for objective and subjective symptoms. Response to treatment was graded as "complete remission" in case of full symptomatic relief and >75% decrease in lesion size, as "partial remission" in case of partial symptomatic relief and 25-75% decrease in lesion size, and as "stable disease" in case of no symptomatic relief or <25% decrease in lesion size. Patients were followed up monthly for the first 3 months and every 3 months thereafter by physical examination.

RESULTS

A total dose of 37.5 Gy external RT in five fractions was prescribed by 6‑MeV electrons in 4 patients and 6‑MV photons in 2 patients. Complete response was obtained in all patients at the 6‑month control. All patients were satisfied with cosmetic results at their last control. Grade 2 dermatitis developed in all patients during the second week of RT but resolved completely in all after 6 months following the end of RT.

CONCLUSION

In keloids that are unresponsive to standard treatment, hypofractionated RT using a total dose of 37.5 Gy in five fractions is feasible.

A systematic review and practical considerations of stereotactic body radiotherapy in the treatment of head and neck cancer

OBJECTIVES

Stereotactic radiotherapy (SBRT) is gaining popularity although its use in head and neck cancer (HNC) is not well defined. The primary objective was to review the published evidence regarding the use of stereotactic radiotherapy in HNC.

METHODS

A literature search was performed by using MEDLINE and EMBASE databases for eligible studies from 2000 to 2019 and 26 relevant studies were identified.

RESULTS

Literature demonstrates a heterogeneous use of this technique with regards to patient population, primary or salvage treatment, dose fractionation regimens, outcomes and follow-up protocols. Carotid blow out syndrome is a risk as with other forms of reirradiation but alternative treatment regimens may reduce this risk.

CONCLUSION

At present there is a lack of evidence regarding SBRT as a primary treatment option for HNC and definitive answers regarding efficacy and tolerability cannot be provided but there is growing evidence that SBRT reirradiation regimens are safe and effective. In lieu of evidence from large Phase III trials, we define appropriate organ at risk constraints and prescription doses, with accurate plan summation approaches. Prospective randomised trials are warranted to validate improved treatment outcomes and acceptable treatment morbidity.

ADVANCES IN KNOWLEDGE

This article provides a comprehensive review of evidence of use of stereotactic radiotherapy in HNC site (either as a primary treatment or as reirradiation). We also provide an evidence-based approach to the implementation and practical consideration of stereotactic radiotherapy in HNC.

Single shot echo planar imaging (ssEPI) vs single shot turbo spin echo (ssTSE) DWI of the orbit in patients with ocular melanoma

OBJECTIVES

Diffusion weighted imaging (DWI) has become important for orbital imaging. However, the echoplanar imaging (EPI) DWI has inherent obstacles due to susceptibility to magnetic field inhomogeneities. We conducted a comparative study assessing the image quality of orbits in a patient cohort with uveal melanoma (UM). We hypothesized that single shot turbo spin echo (ssTSE) DWI would have better image quality in terms of less distortion and artifacts and yield better tissue evaluation compared to ssEPI-DWI.

METHODS

ssEPI-DWI and ssTSE-DWI of orbits were obtained from 50 patients with uveal melanoma who were prospectively enrolled in the study. Distortion ratio (DR), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), diffusion signal properties, and apparent diffusion coefficient (ADC) values were collected and compared between ssEPI-DWI and ssTSE-DWI. Two reviewers evaluated and compared the geometric distortion, susceptibility and ghosting artifacts, resolution, demarcation of ocular mass, and overall quality.

RESULTS

A higher DR was found in ssEPI-DWI compared to ssTSE-DWI (p < 0.001). SNR and CNR were lower for the temporal lobe cortex (p ≤ 0.004), but higher for melanoma in ssEPI-DWI than ssTSE-DWI (p ≤ 0.037). Geometric distortion and artifacts were more common in ssEPI-DWI (p < 0.001). Resolution (p ≤ 0.013) and overall quality (p < 0.001) were better in ssTSE-DWI. Ocular masses were demarcated better on ssEPI-DWI (p ≤ 0.002). Significant negative correlations between T1 and T2 signal intensities (r = -0.369, p ≤ 0.008) and positive correlations between T2 and both DWI signal intensities (r = 0.686 and p < 0.001 for ssEPI-DWI, r = 0.747 and p < 0.001 for ssTSE-DWI) were revealed.

CONCLUSION

With less geometric distortion and susceptibility artifacts, better resolution, and overall quality, ssTSE-DWI can serve as an alternative to ssEPI-DWI for orbital DWI.

ADVANCES IN KNOWLEDGE

ssTSE-DWI can be a better alternative of diffusion imaging of orbits with less susceptibility artifact and geometric distortion compared to ssEPI-DWI.

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.

Role of Hypofractionated Stereotactic Radiosurgery in Recurrent Pineal Parenchymal Tumors of Intermediate Differentiation: A Case Report and Review of the Literature

A pineal parenchymal tumor of intermediate differentiation (PPID) is a rare entity, and optimal treatment is still unclear. Combined multimodality treatment should be considered in PPID due to high recurrence rates. Gross total resection is the first choice of treatment, however, it may not be feasible in every case due to location. Stereotactic radiosurgery (SRS) can be considered for the treatment of primary and recurrent disease, as it enables us to deliver a high radiation dose to the target while minimizing radiation exposure to normal tissue. In this report, we present a case treated with hypofractionated SRS for recurrent/metastatic PPID after the primary tumor was controlled with the combination of surgery and conventionally fractionated radiotherapy.

Abscopal Effect, From Myth to Reality: From Radiation Oncologists' Perspective

The abscopal effect is mediated by a systemic anti-tumor immune response and reflects the regression of non-irradiated metastatic lesions at a distance from the primary site of irradiation. This review will focus on understanding the biological rationale behind the abscopal effect of radiotherapy (RT), which has a recently renewed interest as a result of the successes achieved with immunotherapy and RT in combination. Both RT and immunotherapy are standard components of modern treatment regimens. Combination of these two modalities results in an increased response in the irradiated lesions themselves and the metastatic regions distant from the site of irradiation. We will summarize the abscopal effect of radiotherapy, in particular, the synergistic effect of RT and immunotherapy.