Correlation of tumour and treatment characteristics to dose received by cochlea in volumetric arc therapy.

PURPOSE: This is a radiation field simulation study using CT images designed to see the cochlear dosimetry and its correlation with tumour and treatment characteristics during radiotherapy for head and neck cancers (HNC) for identifying the factors associated with a higher dose delivered to the cochlea. METHODS: From 2018 to 2020, 80 patients with HNC underwent volumetric arc therapy (VMAT) to a dose of 66-70 Gy at 2 Gy per fraction with bilateral cochlea contoured for VMAT optimization as an organ at risk. Minimum, mean and maximum planned radiation dose to the cochlea based on tumour and treatment characteristics and dose-volume histogram variables of VMAT plans were analysed. RESULTS: Mean (standard deviation, SD) cochlear volume was 0.14 (0.06) cm3 with maximum and mean planned doses of 10.3 (SD = 11.6) Gy and 8.5 (SD = 9.8) Gy, respectively. We found a statistically significant correlation between mean dose received by bilateral cochlea (P-0.000, rright-0.84, rleft-0.78, rmidline-0.92). Tumours of the paranasal sinuses, and the parotids and more advanced T stages were associated with a higher mean dose to cochlea but was not significant statistically. The dose received by the 95% target nodal volume (D95%) showed a significant correlation with the cochlear mean dose (P-0.000, rright-0.85, rleft-0.77, rmidline-0.93) CONCLUSION: With VMAT we have achieved a better sparing of cochlea. The mean dose to the cochlea of one side significantly differed from the other side in patients with lateralized cancers. D95% of nodal volume also showed a significant correlation with the cochlear mean dose.

Pushing the Envelope: The Role of Radiation Therapy in Non-muscle-Invasive Bladder Cancer.

The standard of care for non-muscle-invasive bladder cancer (NMIBC) is transurethral resection followed by risk stratified use of intravesical immune- or chemotherapy and for multifocal, recurrent and high grade disease, radical cystectomy with high rates of cure. Bladder preservation analogous to the trimodality therapy approach in muscle-invasive bladder cancer (MIBC) has not been adequately explored but the available data suggests that NMIBC is a radioresponsive malignancy and that in a proportion of patients bladder preservation would be possible. Combination modality with chemotherapy, hypoxia sensitisation, hyperthermia and immunotherapy are all approaches which have been shown effective. Unfortunately the quality of the available data is poor. Although there are many putative prognostic biomarkers for progression in NMIBC none have emerged in clinical use and there are none predictive for response to non-surgical treatment. This would be an important component of future large scale studies to evaluate the precise role of radiotherapy within a multimodality schedule for bladder reservation in NMIBC.

Early Clinical Outcomes in Patients of Carcinoma Cervix Treated With Volumetric Modulated Arc Therapy.

Objective Carcinoma cervix is one of the major cancers affecting Indian women. Concurrent chemo-radiotherapy is the standard of care in the treatment of carcinoma cervix. We aimed to study the outcomes and toxicity profile of volumetric modulated arc therapy (VMAT), an advanced modality of radiation delivery when used to treat patients with carcinoma cervix. Materials and methods Patients of carcinoma cervix belonging to FIGO (The International Federation of Gynecology and Obstetrics) stages IB2- IVA were recruited into the study. The patients were treated with VMAT to an EBRT (External Beam Radiation Therapy) dose of 50.4Gy in 28 fractions, which was followed by a brachytherapy schedule of 8Gy for each fraction to point A for three fractions. Toxicities were monitored weekly during the course of treatment and thereafter at every follow-up visit. A response assessment CECT (Contrast Enhanced Computed Tomography) scan was done three months after treatment and the response was recorded using RECIST (Response Evaluation Criteria In Solid Tumors) criteria. Results Sixty-four patients were available for analysis and most of the patients belonged to stage IIB (50.3%) followed by stage IIIB (28.5%). The complete response rate was 90.6% at three months and at a median follow-up of 12 months, the overall survival was 100% and disease-free survival was 89.1%. An analysis of clinically significant toxicities (grade 2 or worse) showed that diarrhea was the most common (20.3%) followed by proctitis (14%) and anemia (9.3%). Conclusion The results of the study established that volumetric modulated arc therapy is an acceptable modality of treatment of carcinoma cervix with an attractive toxicity profile. However, longer follow-ups will provide valuable information regarding the long-term disease control and late toxicities of the treatment.

Palliative radiotherapy in cancers of female genital tract: Outcomes and prognostic factors.

BACKGROUND AND PURPOSE: Metastatic and incurable cancers of the gynaecological tract (FGTC) represent a major global health burden. Systemic treatment has modest efficacy and radiotherapy is often used for local symptoms. This study combines experience from two large UK centres in palliative radiotherapy for gynaecological cancers. MATERIALS AND METHODS: Pooled data from two major centres was analysed. Advanced FGTC patients who received at least one fraction of palliative radiotherapy to the pelvis between 2013 and 2018 were included. Data collected included demographic and tumour details, radiotherapy dose fractionation and details of previous and subsequent treatment. Response was defined in terms of toxicity, symptomatic response and survival. Comorbidities were recorded using a modified ACE 27 score which is adjusted for the presence of uncontrolled FGTC in all the patients. RESULTS: A total of 184 patients were included for treatment response and toxicity; survival data was available for 165 patients. Subjective response in pre-radiotherapy symptoms was documented in 80.4%. Grade 3 or worse gastrointestinal, urinary and other (vomiting, fatigue, pain) toxicity incidence was 2.2%, 3.8%, and 2.7% respectively. No statistically significant correlation between the prescribed EQD210 and symptom control or toxicity was seen. 1 year overall survival was 25.1% (median 5.9 months). Absent distant metastases, completion of the intended course of radiotherapy, response to radiotherapy, and receipt of further lines of treatment were independent prognostic factors. CONCLUSION: Palliative radiotherapy is effective for symptoms of advanced FGTC with low toxicity. The absence of a dose response argues for short low dose palliative radiotherapy schedules to be used.

Dosimetric comparison of coplanar and non-coplanar volumetric-modulated arc therapy in head and neck cancer treated with radiotherapy.

PURPOSE: To evaluate the dosimetric variations in patients of head and neck cancer treated with definitive or adjuvant radiotherapy using optimized non-coplanar (ncVMAT) beams with coplanar (cVMAT) beams using volumetric arc therapy. MATERIALS AND METHODS: Twenty-two patients of head and neck cancer that had received radiotherapy using VMAT in our department were retrospectively analyzed. Each of the patients was planned using coplanar and non-coplanar orientations using an optimized couch angle and fluences. We analyzed the Conformity Index (CIRTOG), Dose Homogeneity Index (DHI), Heterogeneity Index (HIRTOG), low dose volume, target and organs-at-risk coverage in both the plans without changing planning optimization parameters. RESULTS: The prescription dose ranged from 60 Gy to 70 Gy. Using ncVMAT, CIRTOG, DHI and HIRTOG, and tumor coverage (ID95%) had improved, low dose spillage volume in the body V5Gy was increased and V10Gy was reduced. Integral dose and intensity-modulated radiation therapy factor had increased in ncVMAT. In the case of non-coplanar beam arrangements, maximum dose (Dmax) of right and left humeral head were reduced significantly whereas apex of the right and left lung mean dose were increased. CONCLUSION: The use of ncVMAT produced better target coverage and sparing of the shoulder and soft tissue of the neck as well as the critical organ compared with the cVMAT in patients of head and neck malignancy.

Teleoncology: The Youngest Pillar of Oncology.

The core pillars of multimodal care of patients with cancer are surgical, radiation, and medical oncology. The global pandemic of coronavirus disease 2019 (COVID-19) has suddenly resurrected a new pillar in oncology care: teleoncology. With oncologists reaching out to patients through telemedicine, it is possible to evaluate and fulfill patients' needs; triage patients for elective procedures; screen them for influenza-like illness; provide them with guidance for hospital visits, if needed; and bridge oral medications and treatments when a hospital visit is not desirable because of any high risk-benefit ratio. Teleoncology can bring great reassurance to patients at times when reaching an oncology center is challenging, and more so in resource-constrained countries. Evidence-based treatment protocols, dispensable by teleoncology, already exist for many sites of cancer and they can provide a bridge to treatment when patients are unable to reach cancer centers for their standard treatment. The young pillar of teleoncology is going to remain much longer than COVID-19.

Adjuvant Irradiation in Carcinoma Breast Patients: Comparison of 3DCRT and Semi-automated Complex VMAT Hypofractionated Plans.

OBJECTIVE: Adjuvant radiotherapy is required for most post MRM breast cancer patients. Aim of treatment is to target radiation to region of interest while sparing Organs at Risk (OARs). Attempts are being made to decrease dose to OARs without compromising target coverage by evolving radiation techniques. In this study, a comparison of traditional 3DCRT plans is done with semi-automated complex VMAT plans for dose received by OARs namely Contralateral Breast (CLB), Ipsilateral lung (I/LL), and Contralateral Lung (C/LL). MATERIALS AND METHODS: It was planned for 30 post MRM breast cancer patients for chest wall, ipsilateral axilla and supraclavicular lymph node. The PTV dose was 42.5 Gy in 16 fractions, 2.66 Gy/fraction, 5 days a week. For each patient traditional 3DCRT and semi-automated complex VMAT plans (conventional + tangential VMAT plans) were prepared and evaluated by radiation oncologists. RESULTS: Dose evaluation of CLB shows higher Dmax for 3DCRT plans, while, Dmean was lower for the 3DCRT plan. Difference between D2 was not significant. V2.5 was significantly less in 3DCRT, while, difference between V5 and V10 were not significant. For C/LL Dmean, V2.5, V5, and V10 were higher for the VMAT plan. For I/LL Dmean, V5 and V10 were higher, while V20 and V30 were lower for VMAT plans. DISCUSSION AND CONCLUSION: The VMAT technique described here is a useful treatment option available for difficult planning situations. OARs stated above had a mixed result showing VMAT plans to be inferior at lower dose metrics, while, superior at higher dose metrics.

Primary small cell carcinoma of the vagina: a rare instance of prolonged survival.

Small cell carcinoma (SmCC) of the vagina is a rare and aggressive tumour. It comprises only 1% -2% of all gynaecological malignancies 85% of the patients with SmCC vagina die within a year of diagnosis. Here we report the case of a 65-year-old woman with stage III primary neuroendocrine carcinoma of vagina who was treated with chemoradiotherapy. The patient survived 1 year and 10 months after the initial presentation. SmCC of the vagina is very rare and despite being aggressive, the local disease can be controlled with a chemoradiation regimen.