Near complete resolution of COVID-19 pneumonia lesions in a patient of carcinoma lung treated with volumetric modulated arc therapy.

A 49-year-old male presented with non-small cell lung cancer in right upper lobe lung with solitary brain metastasis. He developed COVID-19 infection and received domiciliary treatment for 3 weeks. Three weeks after testing negative for RT-PCR test, he received stereotactic radiosurgery (SRS) to brain metastasis. He then presented in emergency with pain in the epigastrium and was detected with amoebic liver abscess. Subsequently, he developed recurrent hemoptysis for which he was planned for palliative radiation to right lung mass. Planning CT scan showed COVID-19 pneumonia lesions involving bilateral lungs in addition to right upper lobe tumour. Palliative radiation 8 Gy/1 fraction was delivered to lung tumour with VMAT technique. He showed near total resolution of COVID-19 lesions with low-dose scatter radiation and relief of haemoptysis.

Stereotactic ablative radiotherapy (SABR) for recurrent and previously irradiated head and neck cancers.

OBJECTIVE: To assess the response and toxicity of stereotactic ablative radiotherapy (SABR) in patients with recurrent head and neck cancer (HNC), who had previously received radiation for their primary tumor. METHODS: Between 2014 and 2018, patients who received SABR to recurrent HNC within the previously irradiated region were retrospectively reviewed. Mean age was 60 years (range 30-78 Years). Histology was confirmed in all patients. MRI and /or CT-positron emission tomography were done to evaluate local extent and to rule out metastasis. Response was assessed as per RECIST/PERCIST Criteria. Cox proportional hazards regression and the Kaplan-Meier methods were used for statistical analysis. RESULTS: 32 patients received SABR. RPA Class II, III patients were 20 and 12 respectively. 87% patients received a dose of ≥30 Gy/5 fractions. Median follow-up was 12 months. Estimated 1 year and 2 years local control was 64.2 and 32% and 1 year and 2 years overall survival was 67.5 and 39.5% respectively. Acute Grade 2 skin and Grade 3 mucosal toxicity was seen in 31.3 and 28% patients respectively. Late Grade 3 toxicity was seen in 9.3% patients. CONCLUSION: Re-irradiation with SABR yields high local control rates and is well tolerated. It compares favorably with other treatment modalities offered to patients with recurrent HNC. It is also suitable for patients of RPA Class II and III. There is need for novel systemic agents to further improve the survival. ADVANCES IN KNOWLEDGE: Treatment of patients with recurrent HNC is challenging and is more difficult in previously radiated patient. More than 50% patients are unresectable. Other options of salvage treatment like re-irradiation and chemotherapy are associated with poor response rates and high incidence of acute and late toxicity (Gr ≥3 toxicity 50-70%). SABR is a novel technology to deliver high dose of radiation to recurrent tumor with high precision. It yields high local control rates with less toxicity compared to conventionally fractionated radiation.

Development and Validation of a MATLAB Software Program for Decoding the Treatment Errors in Real-time Position Management™ Gating-generated Breathing Trace.

INTRODUCTION: The Real-time Position Management™ (RPM) is used as a motion management tool to reduce normal tissue complication. However, no commercial software is available to quantify the "beam-on" errors in RPM-generated breathing traces. This study aimed to develop and validate an in-house-coded MATLAB program to quantify the "beam-on" errors in the breathing trace. MATERIALS AND METHODS: A graphical user interface (GUI) was developed using MATLAB (Matrix Laboratory Ra2016) software. The GUI was validated using two phantoms (Varian-gated phantom and Brainlab ET gating phantom) with three regular motion profiles. Treatment time delay was calculated using regular sinusoidal motion profile. Ten patient's irregular breathing profiles were also analyzed using this GUI. RESULTS: The beam-on comparison between the recorded reference trace and irradiated trace profile was done in two ways: (1) beam-on time error and (2) beam-on displacement error. These errors were ≤1.5% with no statistical difference for phase- and amplitude-based treatments. The predicated amplitude levels of reference phase-based profiles, and the actual amplitude levels of amplitude-based irradiated profiles were almost equal. The average treatment time delay was 47 ± 0.003 ms. The irregular breathing profile analysis showed that the amplitude-based gating treatment was more accurate than phase based. CONCLUSION: The developed GUI gave the same and acceptable results for all regular profiles. These errors were due to the lag time of the linear accelerator with gating treatment. This program can be used as to quantifying the intrafraction "beam-on" errors in breathing trace with both mode of gating techniques for irregular breathing trace, and in addition, it is capable to convert phase-based gating parameters to amplitude-based gating parameters for treatment.

The Composite Planning Technique in Left Sided Breast Cancer Radiotherapy: A Dosimetric Study.

OBJECTIVE: The aim of this retrospective study is to reduce the dose of heart, both lung and opposite breast and left anterior descending artery (LAD) and avoid long term complication and radiation induced secondary malignancies in radiotherapy left breast/chest wall without losing homogeneity and conformity of the Planning Target Volume (PTV), contoured using Radiotherapy Oncology Group (RTOG 1005) guideline. MATERIALS AND METHODS: The treatment plans were generated retrospectively by TFIF, VMAT and Composite techniques for 30 patients. Dose-Volume Histograms (DVHs) were evaluated for PTV and organs at risk (OAR's) and analyzed in two groups BCS and MRM using Wilcoxon signed rank test. RESULTS: The homogeneity index (HI) was improved in Composite technique by 32.72% and 21.81% of VMAT, 50.66% and 49.41% of TFIF in BCS and MRM group respectively. The Conformity Index (CI) for composite plan was statistically same as VMAT and superior by 27.94% and 41.37% of TFIF in BCS and MRM group respectively. The low dose volume V5Gy and V10Gy of the heart were improved in Composite plan by 47.9% and 26.1% of VMAT respectively in BCS group and in MRM group, improved by 21.2% and 45.6% of VMAT. The V5Gy and V10Gy of ipsilateral lung were improved in Composite plan by 16% and 13.7% of VMAT respectively in BCS and 8.4% and 3% of VMAT respectively in MRM group. CONCLUSION: The Composite plan consisting of VMAT and TFIF plan with an optimum selection of fractions can achieve lower low dose exposure to the OAR's without compromising coverage compared to VMAT.

Stereotactic ablative body radiotherapy (SABR) for inoperable, chemorefractory retroperitoneal lymph node relapse from non seminomatous germ cell tumour of testis: a case report.

We describe a case of non-seminomatous germ cell tumour (NSGCT) of the testis with oligorecurrence in para-aortic nodal mass, which was inoperable and chemorefractory. Conventionally fractionated radiotherapy in this setting is generally believed to achieve poor results, because the dose is limited by the tolerance of surrounding normal tissues. Use of stereotactic ablative body radiotherapy (SABR) for para-aortic nodal recurrence from a few sites has been reported; its application in NSGCT has not been described in literature to our knowledge. SABR allowed us to deliver highly precise, ablative dose of radiation to the recurrent para-aortic nodal mass with long-term disease control (more than 6 years). The ablative dose delivered with SABR proved to be effective in NSGCT, traditionally considered radioresistant. While, in the present case SABR was delivered due to the inoperability of the lesion, further data on its successful use in NSGCT recurrences is warranted.

Significance of perineural invasion in locally advanced bucco alveolar complex carcinomas treated with surgery and postoperative radiation ± concurrent chemotherapy.

BACKGROUND: The purpose of this study was to evaluate prognostic factors, locoregional control, and survival in locally advanced bucco-alveolar complex cancers. METHODS: A retrospective review of 83 patients treated between January 2009 and December 2012 with bucco-alveolar complex cancers was conducted. All patients had surgery and adjuvant radiotherapy with intensity-modulated radiotherapy (IMRT) with/without concurrent chemotherapy. Survival analysis was performed using Kaplan-Meier and multivariable Cox regression model. RESULTS: On univariate and multivariate analysis, perineural invasion (PNI) was found to be an independent adverse risk factor. Patients with PNI-positive disease had significantly worse 2-year disease-free survival (DFS), locoregional failure free survival, and overall survival (OS) as compared to patients with PNI-negative disease (P < 0. 001, 0.001 and < 0. 001) respectively. CONCLUSION: Compared with patients with PNI-negative disease, patients with PNI-positive disease had much worse outcome despite aggressive adjuvant treatment. It warrants escalation of therapy and modification in radiation portals to cover neural pathways in patients with PNI-positive disease.