Method of predicting the mean lung dose based on a patient׳s anatomy and dose-volume histograms

PURPOSE: To determine the changes in pulmonary function tests (PFTs) 0 to 48 months after treatment for breast cancer and lymphoma. PATIENTS AND METHODS: The alveolar volume (VA), vital capacity, forced expiratory volume in 1 second, and corrected transfer factor of carbon monoxide (TL,COc) were measured in 69 breast cancer and 41 lymphoma patients before treatment and 3, 18, and 48 months after treatment with radiotherapy alone or radiotherapy in combination with chemotherapy (mechlorethamine, vincristine, procarbazine, prednisone, doxorubicin, bleomycin, vinblastine; cyclophosphamide, epidoxorubicin, fluorouracil; cyclophosphamide, thiotepa, carboplatin; cyclophosphamide, methotrexate, fluorouracil). The three-dimensional dose distribution in the lung of each patient was converted to the mean lung dose. Statistical analysis was used to evaluate the changes in PFT values over time in relation to age, sex, smoking, chemotherapy, and the mean lung dose. RESULTS: After an initial reduction in PFT values at 3 months, significant recovery was seen at 18 months for all patients. Thereafter, no further improvement could be demonstrated. Reductions in spirometry values and VA were related to the mean lung dose only (0.9% per Gy at 3 months and 0.4% per Gy mean dose at 18 months). TL,COc decreased 1.1% per Gy mean dose and additionally decreased 6% when chemotherapy was given after radiotherapy. Chemotherapy administered before radiotherapy reduced baseline TL,COc values by 8% to 21%. All patients showed an improvement of 5% at 18 months. CONCLUSION: On the basis of the mean lung dose and the chemotherapy regimen, the changes in PFT values can be estimated before treatment within 10% of the values actually observed in 72% to 85% of our patients with healthy lungs.

Download Full-text

The Association Between the Mean Heart Dose, Mean Lung Dose, Tumor Location and RT-associated Heart and Lung Toxicity

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2005.07.075 ◽

2005 ◽

Vol 63 ◽

pp. S42 ◽

Cited By ~ 7

Author(s):

L.B. Marks ◽

Z. Kocak ◽

S. Zhou ◽

X. Yu ◽

K. Light ◽

...

Keyword(s):

Tumor Location ◽

Lung Toxicity ◽

Lung Dose ◽

Heart Dose ◽

The Mean ◽

Mean Lung Dose ◽

Mean Heart Dose

Download Full-text

Modeling fecal incontinence symptoms 6 years after high-dose radiation for prostate cancer: Clinical and dosimetric predictors.

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.5_suppl.71 ◽

2012 ◽

Vol 30 (5_suppl) ◽

pp. 71-71

Author(s):

Giovanni Fellin ◽

Tiziana Rancati ◽

Claudio Fiorino ◽

Vittorio Vavassori ◽

Emanuela Cagna ◽

...

Keyword(s):

Prostate Cancer ◽

Fecal Incontinence ◽

Drug Prescription ◽

Surrogate Endpoint ◽

Continuous Variable ◽

High Dose ◽

Dose Volume Histograms ◽

Dose Volume ◽

The Mean ◽

Pre Treatment

71 Background: To evaluate the incidence of late fecal incontinence (linc) after high-dose radiotherapy (RT) in prostate cancer patients (pts) accrued in AIROPROS 0102 trial (RT doses: 70-80Gy, 1.8-2Gy/fr) and to model the relationship between linc and clinical/dosimetric factors. Methods: Self-reported questionnaires of 515 pts with a minimum follow up of 6 yrs were analyzed with respect to linc. G1 linc was scored if unintentional stool discharge was “sometimes” experienced, G2 linc if unintentional stool discharge was “often” experienced or if pts sporadically used sanitary pads; G3 if pts reported daily unintentional stool discharge or use of sanitary pad >2 times/week. Correlation between pre-treatment morbidities, hormonal therapy, drug prescription, presence of diabetes or hypertension, abdominal surgery prior to RT (SURG), presence of G2-G3 acute fecal incontinence (ACUINC), pelvic nodes and seminal vesicles irradiation, mean rectal dose, dose-volume histograms constraints (from V20Gy to V75Gy) and linc was investigated by uni- and multivariate (MVA) logistic analyses. 347/515 pts had at least 3 toxicity questionnaires in the first 36 mos after the end of RT. Correlation between the mean score of fecal incontinence in the first 36 mos and linc at 6 yrs was also investigated. Results: 50/515 G1, 3/515 G2 and 3/515 G3 linc were reported. In MVA, V40Gy (continuous variable, p=0.09, OR=1.015), use of antihypertensives (protective factors, p=0.005, OR=0.38), SURG (p=0.004, OR=4.7), presence of haemorrhoids (p=0.008, OR=2.6) and ACUINC (p=0.007, OR=4.4) resulted to be correlated to linc. Based on MVA results, a nomogram was developed. Linc at 6 yrs was also correlated to the mean incontinence scores in the first 36 mos (p<0.0001): pts without linc at 6 yrs had a mean score of 0.1 during the first 36 mos, while pts with G1 and with G2-G3 linc at 6 yrs had a mean score of 0.5 and 0.78 during the first 36 mos, respectively. Conclusions: Mean score for incontinence during the first 36 mos after RT can be used as a surrogate endpoint for late (>6yrs) fecal incontinence. Linc is correlated to clinical and dosimetric risk factors and individualised toxicity prediction can be performed through a nomogram.

Download Full-text

Dosimetric evaluation of organs at risk to toxicities between multicatheter accelerated partial-breast irradiation and whole-breast external beam radiotherapy.

Journal of Clinical Oncology ◽

10.1200/jco.2014.32.26_suppl.94 ◽

2014 ◽

Vol 32 (26_suppl) ◽

pp. 94-94

Author(s):

Tabitha Y Chan ◽

Poh Wee Tan ◽

Chek Wee Tan ◽

Johann I Tang

Keyword(s):

External Beam Radiotherapy ◽

Accelerated Partial Breast Irradiation ◽

Partial Breast Irradiation ◽

Lung Dose ◽

Ipsilateral Lung ◽

Heart Dose ◽

Peak Dose ◽

The Mean ◽

Mean Lung Dose ◽

Mean Heart Dose

94 Background: This study aims to quantify the dosimetric reduction to the heart and lung when comparing Whole Breast External Beam Radiotherapy(WBEBRT) with Multicatheter Accelerated Partial Breast Irradiation(MCAPBI) for early stage left sided breast cancer. Methods: Planning CT data sets of 13 patients with left breast cancer receiving multicatheter brachytherapy post breast conserving surgery were used to create two independent treatment plans – WBEBRT prescribed to 50Gy/25fractions and MCAPBI prescribed to 34Gy/10fractions. Dose parameters for (i) heart, (ii) left anterior descending(LAD) artery and (iii) ipsilateral lung were calculated and compared between the two treatment modalities. Results: After adjusting for Equivalent Dose in 2Gy Fractions(EQD2), comparing MCAPBI with WBEBRT, the largest dose reduction was for the LAD artery whose point dose differed by a factor of 4.9. Although somewhat less pronounced, this was also true for the mean lung dose of the ipsilateral lung and mean heart dose with a factor of 3.8 and 2.1 respectively. Compared to WBEBRT, the mean MCAPBI heart D0.1cc (representing the dose received by the most highly exposed 0.1 cc of the risk organ, i.e. the dose peak) was significantly lower(16.43Gy vs 48.82Gy;p<0.01) as well as mean heart dose(MHD) was significantly lower(2.33Gy vs 4.85Gy; p<0.01). Similarly, mean point dose for MCAPBI LAD was significantly lower compared to WBEBRT(9.85Gy vs 47.92Gy; p<0.05). Peak dose and mean lung dose(MLD) for ipsilateral lung was also lower for MCAPBI compared to WBEBRT (Peak dose: 22.19Gy vs 50.45Gy(p<0.05); MLD: 2.31Gy vs 8.73Gy(p<0.05). Conclusions: Compared to WBEBRT, MCAPBI showed a significant reduction in radiation dose for the heart and lung. This may translate into better cardiac and pulmonary toxicities for patients undergoing MCAPBI.

Download Full-text

Pilot study: rectal contouring variability in patients treated with radical radiotherapy for prostate cancer: impact on rectum dose–volume histograms

Journal of Radiotherapy in Practice ◽

10.1017/s1460396908006419 ◽

2008 ◽

Vol 7 (3) ◽

pp. 173-184

Author(s):

Jacqueline E. Martin ◽

P. Kirkbride

Keyword(s):

Pilot Study ◽

Radiotherapy Planning ◽

Anterior Rectal Wall ◽

Observer Variability ◽

Prostate Radiotherapy ◽

Dose Volume Histograms ◽

Dose Volume ◽

Inter Observer Variability ◽

Rectal Volume ◽

The Mean

AbstractPurpose: The organ at risk in prostate radiotherapy is the anterior rectal wall . This pilot study was conducted to quantify the inter-observer variability of rectal contouring in conformal prostate radiotherapy planning using four contouring methods and to determine a standard rectal contouring definition.Methods and materials: Ten patients with T1/T2 disease and six clinical oncologists were recruited. Two cross-sectional and two length limits generated four rectal volumes. Each clinician contoured the four volumes for each patient and the dose–volume histograms (DVHs) were analysed. The percentage rectal volume receiving 20%, 50%, 80%, 90% and 95% of the total delivered dose and the mean and median rectal doses were calculated. Data were presented as mean ± 2 standard deviations.Results: The Sh Rec method (contouring the rectum including its contents extending from 2 cm above the upper limit of the prostate to 2 cm below the prostatic apex) was the least variable in the 80%, 90% and 95% percentage ranges. The mean difference in Sh Rec-contoured volume was 18.7 cm3 (± 22.3 cm3).Conclusions: The Sh Rec-contouring method showed the least inter-observer variability. The results are informative and will help define a standard rectal contouring method.

Download Full-text

Dosimetric comparison of the Leksell Gamma Knife Perfexion and 4C

Journal of Neurosurgery ◽

10.3171/jns/2008/109/12/s3 ◽

2008 ◽

Vol 109 (Supplement) ◽

pp. 8-14 ◽

Cited By ~ 29

Author(s):

Josef Novotny ◽

Jagdish P. Bhatnagar ◽

Ajay Niranjan ◽

Mubina A. Quader ◽

M. Saiful Huq ◽

...

Keyword(s):

Gamma Knife ◽

Single Shot ◽

Functional Disorders ◽

Dose Volume Histograms ◽

Beam Geometry ◽

Dose Volume ◽

Output Factors ◽

Irradiation Geometry ◽

The Mean ◽

Gamma Knife Perfexion

Object The recently introduced Leksell Gamma Knife (LGK) Perfexion is an entirely new system with a different beam geometry compared with the LGK 4C. The new Perfexion system has 192 cobalt-60 sources that are fixed on 8 sectors (each sector has 24 sources). Each sector can be moved independently of the others and can be set to 1 of 5 different positions: 3 positions defining collimator sizes of 4, 8, and 16 mm; an off position (sources are blocked); and a home position. The purpose of this study is to compare the dosimetric characteristics of the GK 4C and the Perfexion models. This comparison is important especially for the treatment of functional disorders when only a single shot with the 4- or 8-mm collimator is used. Methods A 160-mm-diameter spherical polystyrene phantom was used for all measurements and calculations. The irradiation geometry consisted of the placement of a single shot at the center of this phantom. Comparisons were made among different dosimetric parameters obtained from calculations performed using Leksell GammaPlan v. 8.0 and measurements performed using film dosimetry. The dosimetric parameters investigated were dose profiles for all collimators in all 3 stereotactic planes (x, y, and z) including the full width at half maximum and the penumbra for each profile, cumulative dose–volume histograms, the volume encompassed by the 50% isodose surface, the mean doses delivered to a defined matrix volume, and relative output factors for all collimator sizes. Results There was excellent agreement between the dosimetric parameters of GK 4C and Perfexion for the 4- and 8-mm collimators. Conclusions The results of this study suggest that consistent treatments of functional disorders will be delivered using either GK 4C or Perfexion.

Download Full-text

Brachial plexopathy in breast cancer: is it radiation related? An analysis technique and dose volume parameters to brachial plexus in breast cancer radiotherapy

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20170134 ◽

2017 ◽

Vol 5 (2) ◽

pp. 469

Author(s):

Beena Kunheri ◽

Anand Radhakrishnan ◽

Toyce Stephen ◽

Renil Mon ◽

Anjali Menon

Keyword(s):

Breast Cancer ◽

Brachial Plexus ◽

Maximum Dose ◽

Mean Value ◽

Brachial Plexopathy ◽

Dose Volume Histograms ◽

Dose Volume ◽

Supraclavicular Fossa ◽

Patient Reported ◽

The Mean

Background: Brachial plexus dysfunction is a rare but well-recognized complication of breast cancer surgery and radiotherapy. Most of the time it presents as paraesthesia of the arm. In an earlier publication Dan Lundstedt et al from Sweden, quantitatively assessed the radiation related brachial plexopathy (mainly paraesthesia) with the help of dose volume histograms and its co relation between patient reported paraesthesia. Paraesthesia was reported by 25% after radiation therapy to the supraclavicular fossa, with a V40 Gy 13.5 cm3 and maximum dose to brachial plexus (Dmax) was not found to correlate with paraesthesia. In order to predict the risk brachial plexopathy in our patients we decided to analyze the dose volume parameters for brachial plexus in carcinoma breast patients treated at our institution with modern radiotherapy techniques.Methods: Twenty five consecutive patients who received post mastectomy radiation during the period September 2015 to January 2016 with a dose of 50Gy in 25 fractions were included for this analysis. Brachial plexus contoured using RTOG guidelines, and dose volume parameters for brachial plexus were documented from the existing treatment plans.Results: The maximum dose to the brachial plexus ranged from 5045cGy to 5679cGy with a mean value of 5312.8cGy. The mean dose received by the brachial plexus ranged from 3093cGy to 4714cGy and the mean value was 4137.28cGy. Volume receiving 40Gy, that is V40, ranged from 2.0078cc to 11.56cc with a mean value of 7.57cc.Conclusions: Maximum dose and V40 Gy values were well below the tolerance limit of plexus, and hence post mastectomy irradiation with modern techniques is unlikely to produce significant brachial plexus neuropathy.

Download Full-text

The mean lung dose (MLD)

Strahlentherapie und Onkologie ◽

10.1007/s00066-015-0833-3 ◽

2015 ◽

Vol 191 (7) ◽

pp. 557-565 ◽

Cited By ~ 2

Author(s):

Thomas Herrmann ◽

Peter Geyer ◽

Steffen Appold

Keyword(s):

Lung Dose ◽

The Mean ◽

Mean Lung Dose

Download Full-text