Glomus jugulotympanicum tumor treated with radiation therapy: A case report with review of literature.

Glomus tumors (or paragangliomas) are rare, benign tumors of neuroendocrine origin that appear in tissues of paraganglionic origin. This clinical entity poses a significant treatment challenge due to its proximity to critical neurovascular structures, thus the potential of morbid functional damage caused by disease progression and/or treatment approach. While surgery remains the standard of care for such cases, there has been an increasing trend toward management with radiotherapy or close observation. Here, we present a case of a large and irregularly shaped glomus jugulotympanicum tumor that was treated with volumetric arc radiotherapy. Given the risk of cranial neuropathy with surgery, radiation was the preferred treatment modality. This case demonstrated the safety and efficacy of volumetric arc radiotherapy in the management of a large glomus tumor with a complex shape.

Volumetric Intensity-Modulated Arc Stereotactic Radiosurgery Boost in Oligometastatic Patients with Spine Metastases: a Dose-escalation Study.

AIMS: To report the final results of a dose-escalation study of volumetric intensity-modulated arc stereotactic radiosurgery (VMAT-SRS) boost after three-dimensional conformal radiation therapy in patients with spine metastases. MATERIALS AND METHODS: Oligometastatic cancer patients bearing up to five synchronous metastases (visceral or bone, including vertebral ones) and candidates for surgery or radiosurgery were considered for inclusion. 25 Gy was delivered in 10 daily fractions (2 weeks) to the metastatic lesion, affected vertebrae and adjacent ones (one cranial and one caudal vertebra). Sequentially, the dose to spinal metastases was progressively increased (8 Gy, 10 Gy, 12 Gy) in the patient cohorts. Dose-limiting toxicities were defined as any treatment-related non-hematologic acute adverse effects rated as grade ≥3 or any acute haematological toxicity rated as ≥ 4 by the Radiation Therapy Oncology Group scale. RESULTS: Fifty-two lesions accounting for 40 consecutive patients (male/female: 29/11; median age: 71 years; range 40-85) were treated from April 2011 to September 2020. Most patients had a primary prostate (65.0%) or breast cancer (22.5%). Thirty-two patients received 8 Gy VMAT-SRS boost (total BED α/ß10: 45.6 Gy), 14 patients received 10 Gy (total BED α/ß10: 51.2 Gy) and six patients received 12 Gy (total BED α/ß10: 57.6 Gy). The median follow-up time was over 70 months (range 2-240 months). No acute toxicities > grade 2 and no late toxicities > grade 1 were recorded. The overall response rate based on computed tomography/positron emission tomography-computed tomography/magnetic resonance was 78.8%. The 24-month actuarial local control, distant metastases-free survival and overall survival rates were 88.5%, 27.1% and 90.3%, respectively. CONCLUSION: A 12 Gy spine metastasis SRS boost following 25 Gy to the affected and adjacent vertebrae was feasible with an excellent local control rate and toxicity profile.

An experience with simultaneous integrated boost-volumetric-modulated arc therapy in the definitive treatment of head and neck cancer: An Indian data.

Background: There are very few prospective studies comparing simultaneous integrated boost versus sequential boost in the setting of definitive treatment modality of head and neck squamous cell cancer (HNSCC), especially in the Indian scenario. Materials and Methods: We prospectively randomized 50 patients with biopsy-proven squamous cell carcinoma of the oropharynx, hypopharynx, and larynx malignancies, stage T1-3, enlarged node measuring ≤3 cm that are planned for definitive radiotherapy with chemotherapy into either hypo-fractionated simultaneous integrated (Hypo-SIB VMAT) boost arm or conventional (Conv-VMAT) boost arm. Results: Most of the patients were men and aged less than 50 years. Patients with nodal involvement were 76% in Hypo-SIB VMAT and 80% in Conv-VMAT arm. The overall stage group distribution of II, III, and IVA were 16%, 44%, 40%, and 12%, 56%, and 32%, respectively, in both arms. All patients completed the intended treatment in both arms. Overall survival at the end of 2 years was 84% in Hypo-SIB VMAT arm and 80% in the Conv-VMAT arm (P = 0.25); disease-free survival (DFS) was 88% and 72%, respectively (P = 0.12); and locoregional recurrence-free survival (LRFS) was 92% and 84%, respectively (P = 0.38). All the acute and chronic toxicities in both the arms were comparable with no significant difference in any of the toxicities. The average overall treatment time (OTT) in Hypo-SIB VMAT arm is 39.4 days and in Conv-VMAT arm is 50.2 days (P = 0.00001) which is statistically significant. Conclusions: Accelerated Hypo-SIB VMAT has similar response and toxicities as compared to Conv-VMAT in the setting of definitive concurrent chemoradiation of HNSCC patients with the advantage of less OTT, faster treatment delivery, and patient compliance.

Treatment planning of total marrow irradiation with intensity-modulated spot-scanning proton therapy.

Purpose: The goal of this study is to investigate treatment planning of total marrow irradiation (TMI) using intensity-modulated spot-scanning proton therapy (IMPT). The dosimetric parameters of the intensity-modulated proton plans were evaluated and compared with the corresponding TMI plans generated with volumetric modulated arc therapy (VMAT) using photon beams. Methods: Intensity-modulated proton plans for TMI were created using the Monte Carlo dose-calculation algorithm in the Raystation 11A treatment planning system with spot-scanning proton beams from the MEVION S250i Hyperscan system. Treatment plans were generated with four isocenters placed along the longitudinal direction, each with a set of five beams for a total of 20 beams. VMAT-TMI plans were generated with the Eclipse-V15 analytical anisotropic algorithm (AAA) using a Varian Trilogy machine. Three planning target volumes (PTVs) for the bones, ribs, and spleen were covered by 12 Gy. The dose conformity index, D80, D50, and D10, for PTVs and organs at risk (OARs) for the IMPT plans were quantified and compared with the corresponding VMAT plans. Results: The mean dose for most of the OARs was reduced substantially (5% and more) in the IMPT plans for TMI in comparison with VMAT plans except for the esophagus and thyroid, which experienced an increase in dose. This dose reduction is due to the fast dose falloff of the distal Bragg peak in the proton plans. The conformity index was found to be similar (0.78 vs 0.75) for the photon and proton plans. IMPT plans provided superior superficial dose coverage for the skull and ribs in comparison with VMAT because of increased entrance dose deposition by the proton beams. Conclusion: Treatment plans for TMI generated with IMPT were superior to VMAT plans mainly due to a large reduction in the OAR dose. Although the current IMPT-TMI technique is not clinically practical due to the long overall treatment time, this study presents an enticing alternative to conventional TMI with photons by providing superior dose coverage of the targets, increased sparing of the OARs, and enhanced radiobiological effects associated with proton therapy.

Evaluation of an automated template-based treatment planning system for radiotherapy of anal, rectal and prostate cancer.

Background and purpose: The Ethos system has enabled online adaptive radiotherapy (oART) by implementing an automated treatment planning system (aTPS) for both intensity-modulated radiotherapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) plan creation. The purpose of this study is to evaluate the quality of aTPS plans in the pelvic region. Material and Methods: Sixty patients with anal (n = 20), rectal (n = 20) or prostate (n = 20) cancer were retrospectively re-planned with the aTPS. Three IMRT (7-, 9- and 12-field) and two VMAT (2 and 3 arc) automatically generated plans (APs) were created per patient. The duration of the automated plan generation was registered. The best IMRT-AP and VMAT-AP for each patient were selected based on target coverage and dose to organs at risk (OARs). The AP quality was analyzed and compared to corresponding clinically accepted and manually generated VMAT plans (MPs) using several clinically relevant dose metrics. Calculation-based pre-treatment plan quality assurance (QA) was performed for all plans. Results: The median total duration to generate the five APs with the aTPS was 55 min, 39 min and 35 min for anal, prostate and rectal plans, respectively. The target coverage and the OAR sparing were equivalent for IMRT-APs and VMAT-MPs, while VMAT-Aps.demonstrated lower target dose homogeneity and higher dose to some OARs. Both conformity and homogeneity index were equivalent (rectal) or better (anal and prostate) for IMRT-APs compared to VMAT-MPs. All plans passed the patient-specific QA tolerance limit. Conclusions: The aTPS generates plans comparable to MPs within a short time-frame which is highly relevant for oART treatments.