Partial breast irradiation techniques in early breast cancer

Adjuvant intraoperative radiotherapy for selected breast cancers in previously irradiated women: Evidence for excellent feasibility and favorable outcomes

BACKGROUND

The present report provides preliminary outcomes with intraoperative radiotherapy delivered to women with breast cancer included in a re-irradiation program.

MATERIALS AND METHODS

From October 2010 to April 2014, thirty women were included in a re-irradiation protocol by exploiting IORT technique. The median time between the two irradiations was 10 years (range 3-50). All patients underwent conservative surgery, sentinel lymph node excision and IORT with electron beam delivered by a mobile linear accelerator. Primary endpoint was esthetic result and consequential/late toxicity; secondary endpoints were local control (LC), disease free survival (DFS) and overall survival (OS).

RESULTS

With a median follow up of 47 months (range 10-78), we analyzed 29 patients (1 lost at follow up). Twenty-seven patients (90%) had presented breast cancer local relapse or a new primary cancer in the same breast after a previous conservative surgery plus radiation treatment; three patients (10%) had previously received irradiation with mantle field for Hodgkin Lymphoma. Esthetic result was excellent in 3 pts (10%), good in 12 pts (41%), fair in 8 pts (28%) and poor in 6 pts (21%). 12 (41%) patients showed subcutaneous fibrosis at the last follow-up. LC, DFS and OS at five years was 92.3%, 86.3% and 91.2%, respectively.

CONCLUSION

Although we analyzed a small number of patients, our results are satisfactory and this approach is feasible even if it could not be considered the standard treatment. Further clinical trials exploring IORT are needed to identify possible subgroups of patients that might be suitable for this type of approach.

Single high-dose vs. fractionated radiotherapy: Effects on plant growth rates

AIM

To evaluate the differential effects of fractionated vs. high-dose radiotherapy on plant growth.

BACKGROUND

Interest in hypofractionated radiotherapy has increased substantially in recent years as tumours (especially of the lung, prostate, and liver) can be irradiated with ever greater accuracy due to technological improvements. The effects of low-dose ionizing radiation on plant growth have been studied extensively, yet few studies have investigated the effect of high-dose, hypofractionated radiotherapy on plant growth development.

MATERIALS AND METHODS

A total of 150 plants from the genus Capsicum annuum were randomized to receive fractionated radiotherapy (5 doses of 10 Gy each), single high-dose (SHD) radiotherapy (single 50 Gy dose), or no radiotherapy (control group). Irradiation was delivered via linear accelerator and all samples were followed daily for 26 days to assess and compare daily growth.

RESULTS

On day 26, plants in the control, fractionated, and SHD groups had grown to a mean height of 7.55 cm, 4.32 cm, and 2.94 cm, respectively. These differences in overall growth were highly significant (P = 0.005). The SHD group showed the least amount of growth.

CONCLUSIONS

SHD effectively stunts plant growth and development. Despite the evident differences between plant and animal cells, ionizing radiation is believed to work in a similar manner in all biological cells. These findings highlight the need to continue investigating the use of hypofractionated schemes in humans to improve cancer treatment outcomes.

Clinical and technological transition in breast cancer

This article is a summary of the conference "Clinical and technological transition in breast cancer" that took place in the Congress of the Spanish Society of Radiation Oncology, placed in Vigo (Spain) on June 21, 2013. Hugo Marsiglia and Philip Poortmanns were the speakers, the first discussed about "Clinical and technological transition" and the second about "EORTC clinical trials and protocols".

Intraoperative radiation therapy as part of breast conserving therapy of early breast cancer-Results of one-year follow-up

AIM

The aim of this study was to assess the therapeutic effect of intraoperative radiotherapy, describe the method, and examine the occurrence of side effects and quality of life.

BACKGROUND

Breast conserving therapy has recently become a standard treatment modality in patients with early invasive cancer. Radiotherapy, along with surgery, is an integral part of such treatment. The important thing of radiotherapy is to deliver a high dose to the tumour bed. One of the methods is the intraoperative radiotherapy.

MATERIALS AND METHODS

The analysis comprised sixty Tis-T2N0-1A breast cancer patients treated with breast conserving surgery. Patients' mean age was 57 years (range: 32-73 years). Intraoperative radiation therapy was delivered in the operating theatre during surgery and involved a single dose of 10 Gy with an electron beam of 4, 6, 9 or 12 MeV. After that, all patients were treated with whole breast irradiation. During one year observation photos and side effects examination were made.

RESULTS

Physical and imaging examinations performed during a one-year follow-up revealed no local or distant relapse and good tolerance of IORT. Acute mild responses to the radiotherapy occurred in 23.3% of patients. Based on the examination, a good and very good cosmetic effect was found in 78.3%, with 83.3% of patients evaluating their treatment effects in the same way.

CONCLUSIONS

Due to its exceptional physical and radiobiological properties, intraoperative radiation therapy can be a good alternative to other methods of boosting dose to the post-operative site in management of low stage breast cancer, enabling a precise therapy to the tumour bed.

New perspectives in radiation oncology: Young radiation oncologist point of view and challenges

AIM

To assess the role of the young radiation oncologist in the context of important recent advancements in the field of radiation oncology, and to explore new perspectives and competencies of the young radiation oncologist.

BACKGROUND

Radiation oncology is a field that has rapidly advanced over the last century. It holds a rich tradition of clinical care and evidence-based practice, and more recently has advanced with revolutionary innovations in technology and computer science, as well as pharmacology and molecular biology.

MATERIALS AND METHODS

Several young radiation oncologists from different countries evaluated the current status and future directions of radiation oncology.

RESULTS

For young radiation oncologists, it is important to reflect on the current practice and future directions of the specialty as it relates to the role of the radiation oncologist in the comprehensive management of cancer patients. Radiation oncologists are responsible for the radiation treatment provided to patients and its subsequent impact on patients' quality of life. Young radiation oncologists must proactively master new clinical, biological and technical information, as well as lead radiation oncology teams consisting of physicists, dosimetrists, nurses and technicians.

CONCLUSIONS

The role of the young radiation oncologist in the field of oncology should be proactive in developing new competencies. Above all, it is important to remember that we are dealing with the family members and loved ones of many individuals during the most difficult part of their lives.

Primary squamous cell carcinoma of the breast: A rare case report

BACKGROUND

Squamous cells are normally not found inside the breast. Therefore, a primary squamous cell carcinoma of the breast is an exceptional phenomenon and the management of this type of disease is still debated.

AIM

Clinical outcome assessment of a patient with squamous cell carcinoma of the breast.

MATERIALS AND METHODS

We report a case of primary squamous cell carcinoma of the breast (T1cN0M0) in a 51-years-old woman who underwent breast conserving surgery plus adjuvant chemotherapy and radiation therapy (RT).

RESULTS

With a follow up of 43 months, the patient is alive with no evidence of local or distant recurrence. The patient had Grade 2 acute skin toxicity. No late skin or respiratory toxicity was observed.

CONCLUSIONS

Pure primary squamous cell carcinoma of the breast is a rare and aggressive disease, often treatment-refractory. Our case shows that the addition of RT after breast conserving surgery, allows to achieve a high local control without adding severe toxicity. A multidisciplinary approach seems to be the optimal management for early stages in this rare disease.

Accelerated partial breast irradiation using external beam radiotherapy-A feasibility study based on dosimetric analysis

AIM

To investigate the feasibility of using External Beam radiotherapy for accelerated partial breast irradiation by a comparative tumour and normal tissue dose volume analysis with that of high dose rate interstitial brachytherapy.

BACKGROUND

Accelerated Partial Breast Irradiation (APBI) is more clinically appealing because of the reduced treatment course duration and the irradiated area. Brachytherapy application is more dependent on the clinician's expertise when it is practised free hand without image guidance and a template. It happens to be an invasive procedure with the use of local anaesthesia which adds patient discomfort apart from its cost compared to External Beam Radiotherapy. But APBI with brachytherapy is more commonly practised procedure compared to EBRT owing to its previous reults. Hence in this research study, we intend to explore the use of EBRT with the radiobiological corrections for APBI in the place of brachytherapy. It is done as a dosimetric comparison of Brachytherapy treatment plans with that of EBRT plans.

MATERIALS AND METHODS

The computed tomography images of 15 patients undergoing ISBT planning were simulated with conformal photon fields. Various dose volume parameters of each structure were obtained from the DVH generated in the brachytherapy and the simulated external beam planning which can correlate well with the late toxicity. The plan quality indices such as conformity index and homogeneity index for the target volume were computed from the dosimetric factors. The statistical p values for CI, HI and normal tissue dosimetric parameters were calculated and the confidence levels achievable were analysed. The dose prescribed in brachytherapy was 3400cGy in ten fractions. The equivalent prescription dose for the external beam radiotherapy planning was 3000cGy in five fractions applied with radiobiological correction.

RESULTS

All the fifteen patients were with complete lung data and six were with left sided tumours having complete cardiac data. The lung dosimetry data and the cardiac dosimetry data of the patients were studied. Lower percentages of lung and cardiac V 20 and V 5 volumes were obtained with conformal planning. The conformity of radiation dose to the tumour volume was akin to the interstitial brachytherapy planning. Moreover the external beam planning resulted in more homogenous dose distribution. For the sampled population, the statistical analysis showed a confidence level of 95% for using EBRT as an alternate to multi catheter ISBT.

CONCLUSION

The EBRT planning for Accelerated Partial Breast Irradiation was found to be technically feasible in the institution where the interstitial brachytherapy happens to be the only available technique as evident from the dose volume parameters and the statistical analysis.

Underestimation of cancer in case of diagnosis of atypical ductal hyperplasia (ADH) by vacuum assisted core needle biopsy

BACKGROUND

With the introduction of mammography screening, we are more often dealing with the diagnosis of precancerous and preinvasive breast lesions. An increasing number of patients are observed to show a premalignant change of ADH (atypical ductal hyperplasia). It also involves a wider use of the vacuum assisted core biopsy as a tool for verifying nonpalpable changes identified by mammography.

AIM

This paper describes our experience of 134 cases of ADH diagnosed at Mammotome(®) vacuum core needle biopsy.

MATERIAL AND METHODS

Of 4326 mammotomic biopsies performed at our institution in 2000-2006, ADH was diagnosed in 134 patients (3.1%). Patients underwent surgery to remove the suspected lesion. All histopathological blocks were again reviewed by one pathologist. Clinical, radiological and pathological data were collected for statistical evaluation.

RESULTS

Underestimation of invasive changes occurred in 12 patients (9%). The only clinicopathologic feature of statistical significance radiologically and pathologically was the presence of radial scar in the mammography.

CONCLUSIONS

More frequent diagnosis of precancerous changes in the mammotomic breast biopsy forces us to establish a clear clinical practice. The problem is the underestimation of invasive changes. The occurrence of radial scar on mammography for diagnosis of the presence of ADH increases the risk of invasive changes.

Segmented photon beams technique for irradiation of postmastectomy patients

AIM

To present the segmented photon beams technique (SPBT) for irradiation of postmastectomy patients.

BACKGROUND

In majority of techniques for irradiation of posmastectomy patients, a few adjacent photon or electron beams were usually implemented in order to encompass different parts of the target. In the presented SPBT technique, the radiotherapy plan consists of 6 isocentric photon beams and the area CTV includes both the chest wall and the supraclavicular area. This makes it possible to provide a uniform dose to the CTV with no hot and cold points and enables the determination of doses for the entire volume of critical organs.

METHODS AND MATERIAL

The treatment forward-IMRT plan comprises six isocentric 4 and 15 MV photon beams. Modulation of the dose distribution for each field was obtained by applying three segments on average. The total dose of 45 Gy was administered in 20 fractions. Dose distributions in target volume and organs at risk were evaluated for 70 randomly chosen patients.

RESULTS

On average, 94.8% of the CTV volume received doses within 95-107% of the prescribed dose. The average volume of the heart receiving a dose of 30 Gy and lager was 2% for patients with left breast cancer. The average dose to the lung on the irradiation side was always lower than 15.5 Gy and the average V20 Gy was below 35.5%.

CONCLUSIONS

The SPBT complies with requirements for high dose homogeneity within the target volume and satisfactory level of sparing of organs at risk.