Sebastian Lettmaier

Radiation exposure of the heart, lung and skin by radiation therapy for breast cancer: A dosimetric comparison between partial breast irradiation using multicatheter brachytherapy and whole breast teletherapy

BACKGROUND AND PURPOSE Accelerated partial breast irradiation by means of multicatheter brachytherapy shows great promise in the modern treatment of early breast cancer combining high efficacy in preventing tumour recurrence with low levels of toxicity. The present work attempts a dosimetric comparison between this treatment modality and conventional whole breast external beam radiotherapy by looking at differences in risk organ exposure to radiation. PATIENTS AND METHODS The planning CT data sets of 16 consecutive patients with left-sided breast cancer who received external beam radiotherapy to the whole breast followed by a boost to the tumour bed using multicatheter interstitial brachytherapy after breast conserving surgery were used to create two independent physical treatment plans - one for an external radiotherapy, one for sole partial breast brachytherapy in each case assuming a total reference dose of 50Gy for each patient. Dose-volume parameters D(0.1cc), D(0.5cc), D(1cc,)D(2cc), D(5cc,)D(10cc), D(25cc), D(50cc), V(100), V(90), V(50), V(10), V(5) for the ipsilateral lung, the heart and the adjacent skin were calculated and compared between the two treatment modalities. RESULTS All organs at risk showed a substantially lower radiation exposure in the brachytherapy plan. This was most pronounced for the heart with values differing by a factor of four. Although somewhat less marked this was also true for the ipsilateral lung and the adjacent skin with exposure ratios of three and two, respectively. CONCLUSIONS With the use of multicatheter interstitial brachytherapy substantial reductions in the radiation exposure of risk organs can be achieved in comparison to whole breast external beam radiotherapy. These are likely to translate into profound clinical benefits.

Intraluminal brachytherapy in oesophageal cancer: defining its role and introducing the technique

Intraluminal brachytherapy plays an important role in the treatment of oesophageal tumours. This article aims to define this role in the curative as well as in the palliative treatment settings drawing on data from the literature, and also emphasizing its potential for harm when used inexpertly. It also provides a short introduction to practical aspects of the treatment procedure and treatment planning.

High-grade histology as predictor of early distant metastases and decreased disease-free survival in salivary gland cancer irrespective of tumor subtype.

The purpose of this study was to evaluate risk factors that influence overall survival (OS)/disease‐free survival (DFS)/locoregional recurrence‐free survival (LRFS), and distant metastases‐free survival (DMFS) in patients with high‐risk primary salivary gland carcinoma who underwent surgery and postoperative (chemo)radiotherapy with curative intention.

Effective local control of advanced soft tissue sarcoma with neoadjuvant chemoradiotherapy and surgery: A single institutional experience.

PURPOSE There is a sound theoretical basis but little clinical evidence substantiating the benefits of concurrent chemoradiotherapy with two-drug chemotherapy for locally advanced soft tissue sarcomas. Our five-year data on the feasibility and effectiveness of neoadjuvant chemoradiotherapy with systemically effective doses of adriamycin and ifosfamide combined is presented here. PATIENTS AND METHODS Between 2000 and 2011, 53 patients with UICC (2010) stage I (n=1, 1.9%), II (n=12, 22.7%) or III (n=40, 75.5%) nonmetastatic soft tissue sarcoma received neoadjuvant chemoradiotherapy with ifosfamide (1.5 g/m(2)/day, d1-5, q28) and doxorubicin (50mg/m(2)/day, d3, q28) plus concurrent radiotherapy with a target dose of 50-64 Gy (median 60 Gy). The treatment of 34 patients (64.2%) was combined with hyperthermia. RESULTS At five years, the local control rate was 89.9% (± 5.7%), distant metastasis-free survival 66.6% (± 7.6%), and survival 83.3% (± 6%). The R0 resection rate was 81.1%. Radiotherapy was completed as planned in all patients and chemotherapy in 42/53 (70.2%). Grades III (n=21, 29.6%) and IV (n=18, 34%) leukopenia was the main acute adverse event. All acute and chronic non-hematologic toxicities were moderate. CONCLUSION Neoadjuvant chemoradiotherapy for soft tissue sarcoma is associated with good feasibility, manageable acute and late toxicities, and high local efficacy.

Quantification of an External Motion Surrogate for Quality Assurance in Lung Cancer Radiation Therapy

The purpose of this work was to validate the stability of the end exhale position in deep expiration breath hold (DEBH) technique for quality assurance in stereotactic lung tumor radiation therapy. Furthermore, a motion analysis was performed for 20 patients to evaluate breathing periods and baseline drifts based on an external surrogate. This trajectory was detected using stereo infrared (IR) cameras and reflective body markers. The respiratory waveform showed large interpatient differences in the end exhale position during irradiation up to 18.8 mm compared to the global minimum. This position depends significantly on the tumor volume. Also the baseline drifts, which occur mostly in posterior direction, are affected by the tumor size. Breathing periods, which depend mostly on the patient age, were in a range between 2.4 s and 7.0 s. Fifteen out of 20 patients, who showed a reproducible end exhale position with a deviation of less than 5 mm, might benefit from DEBH due to smaller planning target volumes (PTV) compared to free breathing irradiation and hence sparing of healthy tissue. Patients with larger uncertainties should be treated with more complex motion compensation techniques.

Long-Term Survival after Salvage Surgery for Local Failure after Definitive Chemoradiation Therapy for Locally Advanced Non-small Cell Lung Cancer

Background The incidence of local failure and residual tumor after definitive chemoradiation therapy (dCRT) for locally advanced non‐small‐cell lung cancer remains high, irrespective of applied radiation dose (>59 Gy). So‐called salvage surgery has been suggested as a feasible treatment option after failure of definitive chemoradiation for locally advanced non‐small cell lung cancer (NSCLC). Experience with salvage lung surgery (SLS) is limited, and long‐term survival is rarely reported. Patient selection criteria for surgical lung salvage are not defined. The aim of this study was to assess postoperative survival and perioperative morbidity/mortality to identify prognostic factors and to define patient selection criteria. Patients and Methods Records of 13 consecutive patients with locally advanced NSCLC, who underwent SLS at a single institution between March 2011 and November 2016, were reviewed. Descriptive statistics were applied for patient characteristics and surgical and oncological outcome. Survival rates were calculated using the Kaplan‐Meier method and were compared with the long‐rank test. Results All patients initially received curative‐intent definitive chemoradiation with median radiation doses of 66 Gy (range 59.4–72) and concurrent platinum‐based chemotherapy. Clinical tumor stage before definitive chemoradiation was IIIA in 9, IIIB in 3, IV in 1 patients. Median interval between definitive chemoradiation and salvage surgery was 6.7 months. Perioperative morbidity and 30‐days‐mortality was 38% and 7.7%, respectively. The median postoperative survival and estimated 5‐year survival rate were 29.7 months and 46%, respectively. Conclusion SLS in patients with locally advanced non‐small cell lung surgery following dCRT is feasible, prolongs long‐term survival and allows local tumor control. Selection criteria remain undefined and patients should be considered surgical candidates during multidisciplinary team conference.

Pathologic complete response after induction therapy—the role of surgery in stage IIIA/B locally advanced non-small cell lung cancer

Background Pathologic complete response (pCR) is dominant prognostic factor determining favorable outcome in locally advanced non-small cell lung cancer (NSCLC) after induction therapy (IT). There is no non-operative diagnostics that adequately estimates the pCR. Aim of this retrospective study was to assess the correlation between clinical and pathological factors in patients with pCR. Methods Twenty-five patients with pCR after curative lung resection following IT were assessed using univariate and multivariate Cox regression and descriptive analysis. The survival rate was estimated by Kaplan-Meier method. Results The IT included chemoradiation with median doses of 50.4 Gy (range, 45-59.4 Gy) combined with platinum-based chemotherapy in 23 patients (92%) and induction platinum-based chemotherapy in 2 patients (8%). Clinical tumor stage before IT was IIIA in 21, IIIB in 4 patients. Mean interval between IT and surgery was 8.1±3.0 weeks. Perioperative morbidity and 30-day mortality was 32% and 4%, respectively. There was no significant correlation of pCR and different clinical and pathological factors. The estimated 5-year long-term survival (LTS) and progressive-free survival (PFS) was 57% and 54%, respectively. The median LTS and PFS was not reached. Conclusions pCR in patients with locally advanced NSCLC following IT is an independent prognostic factor, without correlation with pathological and clinical factors. Non-operative accurate assessment of pCR is currently impossible. Surgical resection enables secure identification of pCR and might improve the patient stratification for additive therapy.

Long-Term Results of a Prospective Dose Escalation Phase-II Trial: Interstitial Pulsed-Dose-Rate Brachytherapy as Boost for Prostate Cancer

Purpose: We reviewed our ten-year single institution experience with pulsed dose rate brachytherapy by dose escalation Phase-II study in patients with intermediateand high-risk prostate cancer (according the definition by d’Amico). Materials andMethods:We treated a total of 130 patients for intermediate and high risk prostate cancer between 2000 and 2007 using PDRbrachytherapy as a boost after conformal external beam radiation therapy to 45-50 Gy. Boost brachytherapy doses ranged from 25 to 35 Gy e 33 pts. received 25 Gy (total dose 70 Gy), 63 pts. 30 Gy (total dose 75-80 Gy) and 34 pts. 35 Gy,(total dose 85 Gy) given in one session (dose per pulse was 0.60 -0.70 Gy delivered for 24 h per day, night and day, with a time interval of 1 h between two pulses, total time 48-50 hours). PSArecurrence-free survival according to Kaplan-Meier was calculated and changes in American Urological Association symptom scores and also acute and chronic toxicities according Common Toxicity Criteria scale were assessed. Results: At the time of analysis with a median followup of 66 months local control according to the Phoenix definition was achieved by 88% of patients e only 16/130 patients (12,3%) developed a biochemical relapse. A strong correlation between frequency of a local control according to the Phoenix definition and the brachytherapy dose has been documented: At time of analysis 82%, 86% and 97% of our patients were disease-free for boost doses in values of 25 Gy, 30 Gy and 35 Gy, respectively. The side effects of therapy were negligible: There were 18 cases (14%) of grade 1/2 rectal proctitis, one case (0.8%) grade 3 proctitis, 18 cases (14%) of grade 1/2 cystitis, no cases (0%) with dysuria grade 3. No patient had new onset incontinence or a bulbourethral stricture requiring dilation. Conclusions: Image-guided conformal PDR-brachytherapy as boost after external beam radiation therapy is a very effective treatment option with very lowmorbidity by patientswith intermediate or high risk prostate cancer.