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PAGE C2 Under The Microscope SALUBRIS July / August 2009 ADVANCES IN RADIOTHERAPY IN THE MANAGEMENT OF EARLY PROSTATE CANCER Continued from page C1. IMAGE GUIDED RADIOTHERAPY The prostate is a very mobile organ. Its position varies from day to day depending on the contents in the rectum and bladder. In the past, the uncertainty of the prostate’s position was dealt with by using larger treatment volumes. But this would mean a greater volume of normal tissue being irradiated. However, if the position of the prostate can be determined before each treatment, then smaller margins can be applied in the treatment volume. Methods of prostate localisation include ultrasound and the use of fiducial markers implanted within the prostate. In the latter method, images taken using the treatment machine’s on-board imaging device are compared with the images obtained during treatment planning. If the prostate is found to have shifted, then adjustments are made to align the radiation beam with the organ. This procedure is critical to IMRT as it helps ensure that the high-dose volume is accurately delivered to the prostate while the smaller margins required helps reduce the side-effects even when high doses are given. The most accurate method currently available is Dynamic Targeting Image Guided Radiotherapy where treatment machines are equipped with an on-board CT facility which is used to do scans of patients each day before treatment. These scanned images are the most accurate representation of the shape and position of a patient’s tumour or involved organ at the time of treatment. Adjustments based on these images help maximise the dose to the targeted organ while minimising the damage to the surrounding normal tissues. Gold fiducial markers have been used in the treatment of prostate cancer here since 2004 and NCCS installed its first dynamic targeting IGRT machine in 2007. HORMONES Prostate cancer is generally a hormone-responsive disease and there is much experience in the use of hormones in the treatment of advanced or metastatic disease. There is now also evidence to show that in selected patients the addition of androgen suppression therapy to radiotherapy improves disease-free survival and possibly even overall survival. BRACHYTHERAPY Brachytherapy is a method of radiation where radioactive seeds are implanted into the prostate to effect treatment from within. In the past, its use was limited by the inability to properly implant these radioactive sources into the prostate. With improvement in technology, we now have good imaging equipment to plan as well as monitor the placement of the seeds and modern devices which facilitates very good implantation transperineally with the use of needles. The advantage of this method of treatment is that much higher radiation doses can be concentrated in the prostate while sparing the surrounding tissue. THE FUTURE – CHARGED PARTICLE IRRADIATION? Charged particles such as protons or carbon ions can be focused even much more highly compared to photons and have the potential for even greater relative sparing of the surrounding normal tissues. Their biological effectiveness is also higher than the usual x-rays used in radiotherapy. This makes dose escalation to even higher doses feasible with even lesser morbidity to surrounding normal tissues. They, however, require very expensive facilities and are available in only very few research centres around the world. With the accumulation of experience from these centres and hopefully with technology becoming more affordable with time, it is hoped that such treatment would become more widely available for the treatment of prostate as well as other cancers in the future.
RATIONAL APPROACH TO TESTICULAR SWELLING PAGE C3 Spotlight SALUBRIS July / August 2009 Conditions of the scrotum and its contents often worry the individual enough to seek medical attention. Most scrotal conditions are benign and self-limiting, but it is important to diagnose the odd testicular malignancy that is potentially fatal if missed. The clinician evaluating should differentiate benign from malignant diseases, pursue a cost-effective diagnostic evaluation, and initiate appropriate urological referral when indicated. By Dr Lee Fang Jaan Registrar, Dept of Urology Dr Tan Yeh Hong Consultant, Director of Endourology, Director of Laparoscopy, Dept of Urology <strong>Singapore</strong> General Hospital Patients with a palpable mass in the testis should be suspected of having testicular cancer; especially if there is a previous history of undescended testis, even if surgically repaired. Differential causes of testicular swelling include torsion and infection. When the swelling can be felt separate from the testis, differential diagnoses to consider include incarcerated hernia, spermatocele and varicocele. Acute pain in the testis suggests torsion. Painful enlargement may be due to scrotal abscess. Pain and tenderness adjacent to the testis may be due to epididymitis or a varicocele. Tenderness of the testis itself may reflect orchitis. However, an underlying neoplasm should always be considered. Accurate diagnosis requires a careful history and structured physical examination, including urinalysis. Radiological studies such as scrotal ultrasound and Doppler blood flow are performed in selected patients with uncertain diagnosis. Examination of the scrotum is best performed with patient standing. A warm room and warm examining hands helps as cold temperature causes contraction of the dartos and cremasteric muscle and elevation of the testis toward the external inguinal ring. The left testis usually lies lower than the right and the scrotal sac is hypoplastic when its gonad is absent. Palpation is carried out by systematically examining the testis, epididymis, and cord for size and consistency. The exact nature and location of scrotal mass should be determined. When transilluminated, fluid filled structures (e.g. hydrocele) radiate a reddish glow. Testicular pain should always be considered an emergency. Evaluation should not be delayed if testicular damage from torsion of the spermatic cord and subsequent ischemia are to be avoided. Differentiation between testicular torsion and epididymitis is usually possible on the basis of the presentation and physical findings. Testicular pain should always be considered an emergency. Evaluation should not be delayed if testicular damage from torsion of the spermatic cord and subsequent ischemia are to be avoided. Continued on page C4.
Page 1 and 2: Issue No. 05 • MICA (P) 207/10/20
Page 3 and 4: PAGE A3 In Other Words SALUBRIS Jul
Page 5: ADVANCES IN RADIOTHERAPY IN THE MAN
Page 9 and 10: 40th SMA National Medical Conventio
Page 11 and 12: WHERE DID YOUR FINGERPRINTS GO? PAG

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