Alopecia; X-Rays Clinical Trial
Official title:
Radiation- Induced Alopecia in Patients Undergoing Radiation Therapy to the Brain: A Prospective Clinical and Dosimetric Study of Primary and Metastatic Brain Tumour Patients
Study will be conducted on patients receiving Whole brain(WB) / Partial Brain(PB) radiotherapy using volumetric modulated arc therapy or intensity modulated radiotherapy at Department of Radiation Oncology, Fortis Memorial Research Insititute, Gurgaon, Haryana with end points. 1) Primary - To observe degree of alopecia at conclusion of radiotherapy compared to pre- radiotherapy status using scalp sparing radiotherapy technique. 2) Secondary 1)Recording the temporal dose levels causing radiation associated alopecia and dose range acceptable for reversible radiation-induced alopecia and determine dose volume threshold for the same 2)Recording of scalp doses by in vivo dosimetry and correlation with radiation induced alopecia Methods: Study includes 50 patients of partial / whole brain radiation therapy to be followed consecutively for radiation- induced alopecia. Contouring: For WB radiation entire scalp will be contoured. For PB irradiation contouring of partial scalp to be done by drawing 2-3 cm beyond the PTV edge in all directions. Planning: The treatment planning and delivery to be done as per existing practice in department. Contouring at Monaco / Brain Lab Contouring stations and planning on Monaco Treatment planning system (TPS) Version 5.11.01. Duration: 18 months for patient accrual; in this observational study patients undergoing radiation therapy to brain will be evaluated clinically and objectively for degree of alopecia. Photographic and Clinical record of four views of scalp- Right lateral, Left lateral, top and rear to be taken at intervals- a)Pre-Radiotherapy (RT) b) RT Conclusion c) First follow-up at 1 month. Hair loss quantified using Severity of Alopecia Tool (SALT) Score. Dosimetric measurements having subcomponents - measurement of surface dose uses optically stimulated luminescence dosimeters to be placed over scalp for first 5 fractions in case of conventional or fractionated SRT, for the entire duration of short course treatments and for first 5 fractions in case of palliative whole brain radiation given over 10 fractions. TPS measurements: Average, maximum dose and dose per unit volume will be reported for whole and partial scalp. Outcomes 1. Quantify the degree of alopecia at the conclusion of radiotherapy as compared to pre- radiotherapy status. 2. To record the radiation dose levels causing alopecia. 3. Obtain in vivo dosimetry values for scalp doses in modern radiotherapy treatment
Patients with primary or metastatic cancers to the brain need to undergo partial or whole
brain radiotherapy. Alopecia is an inadvertent side effect of Radiation therapy to the brain.
Much of this alopecia occurs in patches and is often associated with permanent loss of hair.
Irradiation-induced epilation is due to high susceptibility of anagen follicles to radiation.
Loss of hair can be stressful and distressing for cancer patients.
Various studies have tried to address the issue of threshold dose for radiotherapy induced
alopecia. The severity and type of skin response and consequent alopecia to radiation is
decided by multitude of factors - total dose and dose fractionation, quality of radiation,
area or volume of tissue irradiated, anatomic site and vascular response. Studies have shown
that 3Gy produces complete, reversible anagen alopecia and permanent alopecia begins to occur
at 5Gy.
At higher dose rates the susceptibility of hair melanocytes is much more than epidermal
melanocytes. Freysz et al in a retrospective analysis of 18 patients deduced that a
cumulative dose as high as 12Gy results in alopecia that is reversible.Temporary alopecia is
seen in most patients receiving WBRT with conventional fractionation. Most of these studies
are either small reports or were done before the advent of modern technology. The advent of
precision radiotherapy techniques has made it possible to utilize techniques that reduce the
dose to the scalp in an attempt to minimize the chances of radiation- induced alopecia.
In a first, a phase II dosimetric and clinical study by De Puysseleyr et al concluded that
Volumetric Modulated Arc Therapy (VMAT)- WBRT delivers lower scalp doses as compared to
conventional parallel opposed fields but the study was closed prematurely as it failed to
show any clinical benefit in terms of preventing alopecia. They however, concluded that the
threshold Treatment Planning System (TPS) dose for temporary alopecia is around 10Gy in 5
fractions.
In a study by Ting et al alopecia was observed in half of the patients undergoing Whole Brain
Radiotherapy (WBRT) to a dose of 30Gy/10 fractions did not have significant alopecia. The
remaining half had mild alopecia. In the study by Mahadevan A et al, hippocampus sparing WBRT
also spares hair follicle bearing regions of the scalp while maintaining strict compliance to
hippocampus avoidance zone. There is no consensus regarding the threshold TPS dose for
alopecia as the study of dose received by hair follicles during intensity modulated
radiotherapy for whole brain is limited by lack of knowledge of dose-effect relation of
temporary alopecia.
Rivero M et al have reported zero incidence of alopecia in the departmental protocol that
they have developed for patients undergoing WBRT using 20Gy/5#s using SIB (40Gy/5#s) by VMAT.
The different dose weightage and dose volumes practiced in their department have yielded
excellent cosmetic outcomes.
The objective alopecia scoring scales have their own issues of inter-observer variability.
EORTC BN20 questionnaire though a validated tool, is largely subjective. Since the
expectation of a patient being treated by VMAT despite adequate counseling may be
disproportionate to the reality of treatment outcomes, there may be marked deviation of
scores to extremes. Severity of Alopecia Tool (SALT Score) is more objective with again the
limitation of inter-observer variability. In order to minimize subjectivity, we will use SALT
scoring system to analyze the degree of alopecia. SALT Score of 0 indicates no alopecia
whereas score of 100 indicates complete baldness.
The investigators have been been using scalp contouring and scalp sparing radiotherapy
technique to decrease the dose to the scalp with the aim to reduce alopecia.
This study aims to prospectively study the extent of alopecia by modern treatment techniques
and assess the factors affecting the same.
Aims and Objectives:
This study will be conducted on patients receiving Whole brain radiotherapy (WBRT)/ Partial
Brain RT using volumetric modulated arc therapy (VMAT) or intensity modulated radiotherapy
(IMRT) at Radiation Oncology Department of FMRI, Gurgaon, Haryana with the following end
points
Materials and Methods The study will include 50 patients undergoing partial / whole brain
radiation therapy who will be assessed prospectively for radiation- induced alopecia.
Contouring: For whole brain radiation only, the whole scalp will be contoured. For partial
brain irradiation contouring of lateral lesions partial scalp will be done. Partial scalp
contouring shall be done by drawing 2-3 cm beyond the PTV edge in all directions. Partial
scalp shall be considered as an organ at risk (OAR).
Planning: The treatment planning and treatment delivery of patients shall be done as per
existing routine in the department. All contouring will be done at Monaco / BrainLab
Contouring stations and planning will be done on Monaco Treatment planning system Version
5.11.01 using full or partial arc Volumetric modulated arc therapy (VMAT) technique. Patients
treated by other techniques such as IMRT and 3-D CRT will also be included in this study and
analysed. During radiotherapy planning dose constraints will be given without affecting the
PTV coverage.
Following measurements shall be done -
1. Objective, Clinical and photographic analysis- Photographic and Clinical review record
of the scalp(excluding the face of the patient) will include four views- Right lateral,
Left lateral, top view and rear view of the scalp. These shall be done at following
intervals- a) Before starting RT b) RT Conclusion c) First follow-up at 1 month. Hair
loss will be quantified using the SALT Score. (14)
2. Dosimetric measurements: This shall have two subcomponents
1. A measurement of surface dose uses optically stimulated luminescence (OSL)
dosimeters that shall be placed over the scalp for first 5 fractions in case of
conventional or fractionated Stereotactic Radiotherapy (SRT), for the entire
duration of short course treatments and for first 5 fractions in case of palliative
whole brain radiation given over 10 fractions. OSL will be placed on the scalp at
the centre of arc span of the beams lateral and AP-PA views at the beam entry
points. For reproducibility, OSL position will be marked on the Thermoplastic mask.
Dose to OSL will be calculated after taking measurements during delivery of
therapeutic dose.
2. Treatment Planning system (TPS) measurements: In the TPS, the average, maximum dose
and dose per unit volume will be reported for the whole scalp and partial scalp. In
addition the routing measurements of dosimetry related to planning target
volume(PTV) and organs at risk (OAR) shall be done as per existing norms
Statistical Methods Mean dose to the point of the OSL will be calculated from the Treatment
planning system (TPS), and further the statistical co-relation between the measured and
calculated dose will be evaluated by student t test using a 95% confidence interval. Mean
scalp dose will be evaluated from the TPS. Further mean TPS calculated dose, measured dose
and clinical outcome (degree of alopecia using SALT score) will be co-related using paired
sample t test.
;