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The newer cancer treatment technologies hold the potential of providing improved health outcomes at an additional cost. So it becomes obligatory to assess the costs and benefits of a new technology, before defining its clinical value. We assessed the cost-effectiveness of intensity-modulated radiotherapy (IMRT) as compared to 2-dimensional radiotherapy (2-DRT) and 3-dimensional radiotherapy (3D-CRT) for treating head and neck cancers (HNC) in India. The cost-effectiveness of 3-DCRT as compared to 2-DRT was also estimated.
Methods
A probabilistic Markov model was designed. Using a disaggregated societal perspective, lifetime study horizon and 3 percent discount rate, future costs and health outcomes were compared for a cohort of 1000 patients treated with any of the three radiation techniques. Data on health system cost, out of pocket expenditure, and quality of life was assessed through primary data collected from a large tertiary care public sector hospital in India. Data on xerostomia rates following each of the radiation techniques was extracted from the existing randomized controlled trials.
Results
IMRT incurs an incremental cost of $7,072 (2,932–13,258) and $5,164 (463–10,954) per quality-adjusted life year (QALY) gained compared to 2-DRT and 3D-CRT, respectively. Further, 3D-CRT as compared to 2-DRT requires an incremental cost of $8,946 (1,996–19,313) per QALY gained.
Conclusion
Both IMRT and 3D-CRT are not cost-effective at 1 times GDP per capita for treating HNC in India. The costs and benefits of using IMRT for other potential indications (e.g. prostate, lung) require to be assessed before considering its introduction in India.
Radiation therapy (RT), in combination with chemotherapy, is the mainstay in the treatment for locally advanced oropharyngeal cancer. We analysed the tumour response and the toxicity profiles in patients having locally advanced oropharyngeal cancers receiving hypofractionated intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy with Cisplatin investigating the feasibility and radiobiological efficacy of the regimen, along with its use as a resource-sparing alternative for a high-volume centre.
Material and Methods:
The records of 41 eligible patients with locally advanced squamous cell carcinoma of oropharynx, registered from September 2015 to April 2017, treated with hypofractionated IMRT with concurrent Cisplatin, were analysed from the hospital database. Patients received concurrent chemo-radiation with 2 cycles of 3-weekly cisplatin on day 1 and day 22 along with hypofractionated IMRT, 55 Gy delivered in 20 fractions over 4 weeks. Patients were observed for any radiation reaction or chemotherapy toxicity at least once a week during the course of radiation therapy.
Results:
Twenty-nine patients (70·7%) achieved complete response and remaining 12 showed partial response. Acute grade 3 toxicity was observed mostly in the form of oral mucositis and radiation dermatitis. Both grade 3 oral mucositis and radiation dermatitis were seen in 15 patients (36·6%) and 7 patients (17%), respectively. The most common late toxicities were dysphagia and dry mouth. Twenty-five patients (61%) completed the overall treatment within 4 weeks’ duration.
Conclusion:
This hypofractionated regimen is feasible and was associated with tolerable acute and late morbidity and satisfactory locoregional response. Larger prospective, multi- institutional studies examining similar schedules may be undertaken to establish this as a standard practice, particularly for a high-volume centre.
In advanced radiotherapy techniques such as intensity-modulated radiation therapy (IMRT), the quality assurance (QA) process is essential. The aim of the study was to assure the treatment planning dose delivered during delivery of complex treatment plans. The QA standard is to perform patient-specific comparisons between planned doses and doses measured in a phantom.
Materials and method
The Delta 4 phantom (Scandidos, Uppsala, Sweden) has been used in this study. This device consists of diode matrices in two orthogonal planes inserted in a cylindrical acrylic phantom. Each diode is sampled per beam pulse so that the dose distribution can be evaluated on segment-by-segment, beam-by-beam, or as a composite plan from a single set of measurements. Ninety-five simple and complex radiotherapy treatment plans for different pathologies, planned using a treatment planning system (TPS) were delivered to the QA device. The planned and measured dose distributions were then compared and analysed. The gamma index was determined for different pathologies.
Results
The evaluation was performed in terms of dose deviation, distance to agreement and gamma index passing rate. The measurements were in excellent agreement between with the calculated dose of the TPS and the QA device. Overall, good agreement was observed between measured and calculated doses in most cases with gamma values above 1 in >95% of measured points. Plan results for each test met the recommended dose goals.
Conclusion
The delivery of IMRT and volumetric-modulated arc therapy (VMAT) plans was verified to correspond well with calculated dose distributions for different pathologies. We found the Delta 4 device is accurate and reproducible. Although Delta4 appears to be a straightforward device for measuring dose and allows measure in real-time dosimetry QA, it is a complex device and careful quality control is required before its use.
The purpose of this study was to develop the patient-specific quality control (QC) process by most commonly used dosimeters in Bangladesh and recommend a suitable passing rate for QC, irrespective of the dosimetric tools used.
Materials and methods
Intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans of five head-and-neck (HN) and five prostate patients were selected for the patient-specific QC. These plans were generated using the Eclipse TPS v11·0 (Varian Medical Systems, Inc., Palo Alto, CA, USA) 6 MV X-ray from a Varian TrueBeam linear accelerator (Varian Medical Systems, Inc.) for each case. Each IMRT and VMAT plans were measured by two-dimensional (2D) ion chamber arrays (I’matriXX) and electronic portal imaging devices (EPID), respectively. The passing rates of the dosimetric tools were calculated using criteria of 3%/3 mm.
Results
The average passing rates (±SD) of I’matriXX for prostate and HN were 97·9±0·76 and 98·88±0·24, respectively. For VMAT verification, the average passing rates of EPID for prostate for arc1 and arc2 were 96·15±0·49 and 97·8±0·70, respectively; similarly, for HN the rates were 97·85±0·63 and 97·2±0·56, respectively.
Conclusion
The results showed that both the dosimeters can be used in patient-specific QC, although the EPID-based IMRT and VMAT QC is more advantageous in terms of time-saving and ease of use. Hence, for patient-specific QC, one can use the ion chamber arrays (I’matriXX) or EPID in hospital, but the systems need to be cross-checked.
Whole breast irradiation is an essential treatment after breast-conserving surgery (BCS). However, there are some adverse effects from inhomogeneity and dose to adjacent normal tissues.
Objective
Aim of this study was to compare dosimetry among standard technique, three-dimensional conformal radiotherapy (3D-CRT), and advanced techniques, electronic compensator (ECOMP), inverse intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT).
Methods
Whole breast irradiation treatment plans of patients who had underwent BCS and whole breast irradiation were re-planned with all four techniques. Clinical target volume was contoured according to the Radiation Therapy Oncology Group atlas for breast only in patients who had negative node or ductal carcinoma in situ and breast with chest wall for patients with positive node. Planning target volume was non-uniformly expanded. Dose prescription was 50 Gy in 25 fractions with 6 MV photon energy.
Results
In total, 25 patients underwent whole breast irradiation with computed tomography simulation from November 2013 to November 2014 were included. Six patients with positive nodes were re-planned for breast with chest wall irradiation and 19 patients with negative nodes were re-planned for breast only irradiation. Primary outcome, radical dose homogeneity index (HI) of 3D-CRT, ECOMP, IMRT and VMAT were 0·865, 0·889, 0·890 and 0·866, respectively. ECOMP and IMRT showed significant higher HI than 3D-CRT (p-value<0·001). Secondary outcome, conformity index (CI) of advanced technique were significantly better than 3D-CRT. Lung V20, mean ipsilateral lung dose (MILD), mean heart dose (MHD), heart V25, heart V30 of advanced techniques were also lower than 3D-CRT. ECOMP had better mean lung dose (MLD), mean contralateral lung dose (MCLD) and mean contralateral breast dose (MCBD) when compared with 3D-CRT. Monitor units of advanced techniques were significantly higher than 3D-CRT.
Conclusions
HI of ECOMP and IMRT were significantly higher than 3D-CRT technique. All advanced techniques showed statistically better in CI. Lung V20, MILD, heart V25 and heart V30 of advanced techniques were lower than 3D-CRT. However, only ECOMP showed decreased MLD, MHD, MCLD and MCBD when compared with 3D-CRT.
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