ONCOTHESIS

Breast cancer irradiation: optimisation of treatment techniques and evaluation of toxicity

Summary

Radiotherapy plays an important role in the treatment of breast cancer patients as it has shown to improve both local control and survival.¹ To further improve the therapeutic ratio, it is important to optimise radiotherapy dose distributions using modern radiotherapy techniques. This is particularly true when the locoregional lymph nodes are included in the target volume, as the resulting complex target volume, in close proximity of the heart and lungs, makes treatment planning more challenging.² With improving survival rates for breast cancer patients, prevention of long-term treatment-related toxicity becomes more important. Therefore, a better understanding of the occurrence of radiotherapy-induced late cardiopulmonary side-effects is needed.

(BELG J MED ONCOL 2013;7(4):123–6)

Clinical implementation of frameless radiosurgery

Summary

Stereotactic radiosurgery is a treatment technique that uses a single high ablative dose of radiation to benign and malignant laesions while sparing healthy brain tissue. Several systems have been developed to perform this technique, and these differed in the way the irradiation was performed. An accurate positioning, immobilisation of the patient and a precise localisation of the laesion are essential. Traditionally, this was performed with a headring screwed onto the patient’s skull (frame-based technique). The positioning is achieved using a localiserbox, mounted on the invasive headring and stereotactic coordinates, obtained through the planning system. With recent developments in radiotherapy, this high precision positioning can nowadays also be performed without the invasive headring. This non-invasive approach, called frameless, improves patient comfort and uses a mask system to immobilise the patient and image-guidance to accurately position the patient on the basis of anatomy. The Novalis system (Brainlab AG) at the UZ Brussel can use both a frame-based and frameless approach. Frameless radiosurgery is carried out with a mask device and two stereoscopic x-ray images. This innovative frameless positioning technique showed equivalent positioning accuracy and immobilisation characteristics to the invasive frame-based technique.

(BELG J MED ONCOL 2013;7(3):93–97)

Introducing Intensity-Modulated Arc Therapy in the multimodality treatment of pelvic gynaecological tumours: thinking out of the box

Summary

The need for an efficient, fast technique to irradiate large concave targets lead to the introduction of intensity-modulated arc therapy in the multimodality treatment of pelvic gynaecological tumours. Postoperatively irradiated cervical and endometrial cancer patients benefit by reduced toxicity rates. In locally advanced cervical cancer the use of intensity-modulated arc therapy with a simultaneously integrated boost allows for a safe hysterectomy, resulting in promising control and survival rates. In chemotherapy-resistant ovarian cancer patients with peritoneal carcinomatosis, the use of intensity-modulated arc therapy facilitates a safe whole abdominopelvic irradiation, one of the few effective solutions for patients with bowel obstruction. Continuing efforts should be made to further decrease toxicity and increase response rates and survival in the multimodality treatment of pelvic gynaecological tumours.

(BELG J MED ONCOL 2013;7(2):53–56)

Real-life outcome of optimally treated patients with malignant glioma

Most outcome studies of malignant glioma are performed in tertiary referral centres and suffer from extensive selection and referral bias. The results are difficult to interpret due to combined data of maximally treated patients and partially treated patients. We prospectively studied the outcome of an unselected sequential cohort of 29 patients with malignant glioma who received maximal treatment according to present standard of care defined as macroscopic resection followed by chemoradiotherapy and adjuvant temozolomide. The median overall survival in our cohort was 13,3 months (SD 10,9 months). 6-month survival rate of 82,7%, and 12-month survival rate of 65,5%. 6-month progression free survival rate (PFS) of 75,8%. 12-months PFS of 48,3%. 2-year survival was 10,3%. However, the 5-year survival was 0%. In our unselected sequential cohort of newly diagnosed malignant glioma patients we observed good tumour control at one year, but not at two years. (BELG J MED ONCOL 2012;6:204–206)

Prognostic factors in ductal carcinoma in situ (DCIS)

Ductal carcinoma in situ of the breast (DCIS) is a clinical entity which is discovered as microcalcifications on screening mammography, it rarely represents a palpable disease. Asymptomatic women with DCIS receive treatments that are similar to women with invasive breast cancer and therefore experience substantial psychological distress despite the fact that they have an excellent prognosis and normal life-expectancy. It is also true that, in spite of aggressive treatment approaches, some patients do recur.

In analogue with invasive breast cancer, DCIS is a heterogeneous disease with different prognostic profiles. The high incidence of DCIS and variations in its treatment with different outcomes led to the introduction of the Van Nuys Prognostic index (VNPI) developed in 1996 by Silverstein. This index is a simple decision-making tool to improve or at least standardise DCIS care and had been incorporated in our daily practice since 1997. Data on that experience were analysed. We tried to obtain a better understanding of the molecular behaviour of DCIS laesions and looked for predictive and prognostic markers associated with disease-free survival (DFS). The next step was the use of micro-array analysis with the Genomic Grade Index (GGI), based on four proliferation genes, and the proliferation index Ki-67. These two indices, which are considered to be predictive for the behaviour of invasive breast cancer, were incorporated into the VNPI. Furthermore, we looked if the tumour microenvironment might play a crucial role in local relapse of DCIS and risk of subsequent invasive disease. (BELG J MED ONCOL 2012;6:164–168)

Preferences of advanced lung cancer patients for information and participation in medical decision-making: a longitudinal multicentre study

The main objective of this dissertation was to gain insight into the preferences of advanced lung cancer patients for receiving information and participating in decision-making concerning treatment options, health-care setting transfers and end-of-life decision-making (ELDs).

In the course of one year, physicians in thirteen hospitals in Flanders, Belgium, recruited patients with initial non-small-cell lung cancer, stage IIIb or IV. The patients were interviewed with a structured questionnaire every two months until the fourth interview and every four months until the sixth interview.

At inclusion, 128 patients were interviewed at least once; thirteen were interviewed six consecutive times. Nearly all patients wanted information about diagnosis, treatment and prognosis and a small majority wanted information about palliative care and ELDs. Preferences regarding participation varied according to the type of decision. Some preferences, more specifically the preferences for information about prognosis, palliative care and ELDs and the preferences for shared decision-making, were regularly not well met by the physician. Preferences were variable over time, at least when it concerned information preferences about palliative care, ELDs and participation preferences. Family was important in medical decision-making to 69% of the patients and to almost all patients in case of incompetence.

Doctors should ask their advanced lung cancer patients at the beginning of their illness how much information and participation they want, and should keep on asking because preferences do change over time in ways they might not expect. (BELG J MED ONCOL 2012;6:132–135)

Clinical implementation of intensity-modulated and image-guided radiotherapy in colorectal cancer

The concept of intensity-modulated and image-guided radiotherapy (IMRT-IGRT) with a simultaneous integrated boost (SIB) by the TomoTherapy Hi-Art II System in preoperative RT of rectal cancer was implemented in our department. Two pilot studies demonstrated its ability to minimize the setup margin, which led to a significant decrease in the irradiated volume of small bowel and bladder. Besides, this technique allows the delivery of a SIB in patients at high-risk for local failure, this as an alternative strategy to the concomitant administration of chemotherapy. The synergism of improved dose distributions by IMRT and correction of daily treatment uncertainties by IGRT resulted in a limited acute toxicity profile and promising local control in a phase II study with a total accrual of 108 locally advanced rectal cancer patients. Finally, the implementation of this novel modality appeared to be attractive in inoperable oligometastatic colorectal cancer, by displaying a promising response rate and limited toxicity in a phase II trial. (BELG J MED ONCOL 2012;6:70–72)