Dr Trinanjan Basu, Consultant Radiation Oncologist, HCG Cancer Centre Mumbai reviews the many changes in both surgical and non-surgical approaches in dealing with prostate cancer. He believes that we need nationwide awareness in terms of role of modern radiotherapy for prostate cancers and in specific training and research related to prostate SBRT
Prostate cancer is the second most frequently diagnosed cancer among men globally and fifth most common cause of death. Most of the prostate cancer cases get diagnosed at the age of ≥65 years. However effective and simple screening methods like digital rectal examination (DRE) coupled with serum prostate-specific antigen (PSA) estimation can detect and cure many at an early stage. Early detection has been also possible through improvement in diagnostic abilities and effective treatment options ramified over the last two decades.
In India however the data about actual incidence is limited by less population based registries and non-notifiable disease status. Urban national cancer registry programmes report an increase in absolute and age standardised incidence in recent times. ICMR and National Council on Radiation Protection and Measurements (NCRP) reported increasing trends in each 5 years from 2010 and prostate cancer cases increasing from 25,000-35,000 annually. Several cities across India show varying incidences with Chennai topping the list. Lifestyle, obesity, comorbidities, family history all been implicated in its rising trend.
The recent trend of early age diagnosis, need of treatment since average life expectancy has increased; diagnosed at higher PSA level and also higher stage have been worrisome. A disease which can be cured if detected early can as well have very limited life span and extreme morbidity of left untreated or diagnosed in advanced stage.
There has been a huge change in both surgical and non-surgical approaches in dealing with prostate cancer. As robotic surgeries predominates the field of curative prostate cancer surgery, robotic and advanced image guided modulated radiotherapy (image-guided radiation therapy (IGRT), stereotactic body radiation therapy (SBRT)) also plays a crucial role in management of localised and curative prostate cancer. The aim to “hit the right target” and to hit it really strong and accurate have been made possible with evolution in sophisticated radiation techniques, available technical and clinical expertise aptly supported by national and international level 1 evidences.
Gone are the days when radiotherapy treatment was considered simple palliative for bone metastases in prostate cancer or a technique incurring uncontrollable bladder and bowel side effects on patients resulting in poor quality of life. There has been a real paradigm shift in the way radiation treatment been perceived and delivered in recent times. The diagnostic refinement in multi-parametric MRI guiding us for better delineation of prostate cancer, availability of guidelines and technology to delineate the disease in 3-dimensional volumetric manner, the ability to deliver high dosage of radiotherapy to prostate and sparing surrounding bladder, rectum and small bowel and also to assess and correct in real time the patients movement while on treatment by image guidance.
All of these can be done in overall short duration (5-7 days treatment) with very high dose (SBRT) with a modulated radiotherapy planning (VMAT) and adequate image guidance to check bladder and rectal filling in relation to prostatic disease (IGRT). We as radiation oncologists call it stereotactic radiotherapy (SBRT). There have numerous recent literatures supporting SBRT’s curative role in localised prostate cancer, locally advanced and node positive and also in limited low volume / oligometastatic disease. It’s a safe treatment delivery for patients in terms of overall duration (5-20 minutes each session over 7-10 days), safety (non-invasive) and effectiveness (IGRT real time). The treatment is also well tolerated with hormonal injections which are required for certain cohorts of patients. There are no contraindications related to age, comorbidities, prior trans-urethral resection (TURP) or other associated interventions.
IGRT remains a key determinant to effective delivery and outcome in prostate cancer modern radiotherapy. It allows for precise target delivery, avoid geographical miss, can check real time bladder and rectal filling and all these combined leads to a balance between effective outcome and good quality of life.
However SBRT definitely requires a rigorous training and expertise for radiation oncologists, sophisticated treatment delivery platforms in terms of radiation machines equipped with IGRT-VMAT capabilities, refinement in medical physics and radiation technologists training in terms of accurate planning and treatment delivery and also cost to patients. The treatment capability also is not widely available in India like in the western countries. We definitely need nationwide awareness in terms of role of modern radiotherapy for prostate cancers and in specific training and research related to prostate SBRT.
The future for prostate cancer radiotherapy remains extremely exciting with advancements on terms of diagnostic aids, genomics, newer treatment delivery systems with real time IGRT (MRI-Linac) and focused precise radiotherapy (Proton). MRI Linac guided SBRT would be an exciting delivery methods for prostate as it will give real time prostate motion data and its relation to bladder and rectum. Several dosimetric and feasibility studies have been performed supporting its effectiveness. Proton beam radiotherapy due to its sharp dose fall off between target and organs at risk demonstrated favourable QOL in many studies. Both these would predominate in the horizon for prostate cancer radiotherapy in the next decade.