Open Access

Definition of fields margins for the optimized 2D radiotherapy of prostate carcinoma

  • Authors:
    • Milly Buwenge
    • Mariangela Perrone
    • Giambattista Siepe
    • Ilaria Capocaccia
    • Aynalem Abraha Woldemariam
    • Tigeneh Wondemagegnhu
    • Kamal A.F.M. Uddin
    • Mostafa A. Sumon
    • Elena Galofaro
    • Gabriella Macchia
    • Francesco Deodato
    • Savino Cilla
    • Alessio G. Morganti
  • View Affiliations

  • Published online on: May 8, 2019     https://doi.org/10.3892/mco.2019.1855
  • Pages: 37-42
  • Copyright: © Buwenge et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )


Abstract

Prostate cancer (PCa) is one of the most common malignancies in men both in western and developing countries. Radiotherapy (RT) is an important therapeutic option. New technologies (including 3D, intensity modulated RT, image‑guided RT and, volumetric modulated arc therapy) have been introduced in the last few decades with progressive improvement of clinical outcomes. However, in many developing countries, the only treatment option is the traditional two‑dimensional (2D) technique based on standard simulation. The guidelines for 2D field definition are still based on expert's opinions.  The aim of the present study was to propose new practical guidelines for 2D fields definition based on 3D simulation in PCa. A total of 20 patients were enrolled. Computed tomography‑simulation and pelvic magnetic resonance images were merged to define the prostate volumes. Clinical Target Volume (CTV) was defined using the European Organisation for Research and Treatment of Cancer guidelines in consideration of the four risk categories: Low, intermediate, and high risk with or without seminal vesicles involvement, respectively. Planning Target Volume (PTV) was defined by adding 10 mm to the CTV. For each category, two treatment plans were calculated using a cobalt source or 10 MV photons. Progressive optimization was achieved by evaluating 3D dose distribution. Finally, the optimal distances between field margins and radiological landmarks (bones and rectum with contrast medium) were defined. The results were reported in tabular form. Both field margins (PTV D98% >95%) needed to adequately irradiate all patients and to achieve a similar result in 95% of the enrolled patients are reported. Using a group of patients with PCa and based on a 3D planning analysis, we propose new practical guidelines for PCa 2D‑RT based on current criteria for risk category and CTV, and PTV definition.

Introduction

Prostate cancer (PCa) is one of the most common cancers in males. Current guidelines (NCCN) consider radiation therapy (RT) as a therapeutic option in different disease stages using three-dimensional conformal RT (3D-CRT) and Intensity Modulated RT (IMRT) as the standard techniques (1).

The incidence of PCa is lower in developing than in western countries. However, a progressive increase in the incidence of PCa due to the prolonged life expectancy has been recorded (2). Furthermore, available RT technologies in developing countries have several limitations with several centres using only standard simulators and cobalt machines as the treatment planning and delivery technologies, respectively (35).

In the past, PCa irradiation was based on 2D techniques with treatment fields defined with standard simulators (6,7). In the ′80s, further population-based indications for 2D-RT arose from the evaluation of prostate size and anatomical location using computed tomography (CT) scans (8). However, nowadays more detailed information and guidelines are available allowing tailored RT even with 2D technology.

In fact, RT of PCa is based on: i) clear guidelines on target definition related to risk categories (9); ii) treatment planning systems (TPS) to enable 3D dose evaluation with possibilities of computing a customized treatment plan for individual patients by adapting the beams geometry to different beam energies; iii) the possibility of defining standard irradiation geometries based on 3D dose distribution among a patients population.

Optimized 2D-RT based on these new insights could be helpful for centres without advanced RT technologies (3D-CRT, IMRT).

Based on this background, the purpose of this study was to propose practical guidelines for 2D-RT beams definition adapted to different PCa risk categories and different available beam energies.

Materials and methods

From our institution, 20 patients with histological confirmation of PCa, consecutively treated with RT were identified (median age: 72 years; range: 58–77 years; clinical T stage: cT2b: 3, cT2c: 5, cT3a: 9, cT3b: 3). Patients underwent CT-simulation in supine position after 3 days of laxatives to avoid rectal distension. Before CT-simulation commencement, 10 cc of contrast medium (Gastrografin) were injected into the rectum. Scans were performed every 5 mm from 3 cm below the ischial tuberosities to 3 cm above the promontory. Patients underwent pelvic MRI scan. MRI images were fused with CT-simulation images by using the VelocityAI system (Velocity Medical Solutions, Atlanta, GA) based on the B-spine algorithm for deformable registrations. In this way, delineation of the prostate and seminal vesicles was performed on MRI images. The delineated targets were then transferred to CT-simulation images for treatment planning.

Clinical Target Volume definition (CTV) was based on the EORTC guidelines (9). Irrespective of the individual patient's tumor stage, CTV delineation was done for four different categories: i) low-risk PCa: CTV = prostate; ii) intermediate-risk PCa: CTV = prostate + 5 mm radial margin, with inclusion of the caudal (1 cm) portion of the seminal vesicles; iii) high-risk PCa without involvement of the seminal vesicles: Prostate + 5 mm radial margin, with the inclusion of the caudal (2 cm) portion of the seminal vesicles; iv) high-risk PCa with involvement of seminal vesicles: prostate + 5 mm radial margin and inclusion of all the seminal vesicles. All contours were verified by an experienced operator and a senior consultant (GM, FD, AGM). Organs at Risk (OaRs) contours were defined according to the QUANTEC indications (10). The Planning Target Volume (PTV) was defined by adding a margin of 10 mm to the CTV in all directions (11).

For each patient, eight treatment plans were generated. For each of the four risk categories, two box technique treatment plans were calculated using a cobalt source or 10 MV photons. A fixed Source-Axis Distance (SAD) of 100 cm for Linear Accelerator and 80 cm for the cobalt unit was used. The beams weights were 20% (anterior-posterior and posterior-anterior beams) and 30% (lateral beams) to reduce the dose to the rectum, small bowel, and bladder. Beams were drawn using the standard collimators (without multileaf collimators). Standard collimators were initially placed at 5 mm distance with respect to the PTV margins. Then the minimum dose (defined as D98%) was evaluated. Fields sizes were gradually increased in steps of 5 mm to achieve the minimum PTV dose constraint (D98% >95%). This progressive optimization was carried out with an iterative procedure, with several evaluations of cumulative dose/volume histograms and beams eye-view dose paintings. In this way, it was possible to identify the field sizes to be increased based on observed ‘cold spots’ sites.

Once the final plan was achieved, distances of the field edges from a set of reference points (Tables IIV) were measured. Both the maximum and the 95th percentile of the distances were identified. The latter value was taken as the ‘recommended’ value for radiation fields margin.

Table I.

Field definition: Low risk prostate cancer.

Table I.

Field definition: Low risk prostate cancer.

Treatment machine

FieldMarginDescriptionCobalt 6010 MV LINAC
Anterior-posteriorLateralFrom the center of the symphisis pubis (laterally) [A]5.7 (5.7)4.5 (5.0)
InferiorFrom the bottom of ischial tuberosities (above) [B]0.9 (0.9)1.4 (1.8)
SuperiorFrom the top of the symphisis pubis (above) [C]5.4 (6.7)4.9 (5.7)
LateralAnteriorFrom the posterior margin of the symphisis pubis (posteriorly) [D]0.3 (0.4)0.4 (0.5)
PosteriorFrom the most anterior point of the rectum (posteriorly) [E]4.7 (5.9)3.3 (3.7)
InferiorFrom the bottom of ischial tuberosities (above)0.9 (0.9)1.4 (1.8)
SuperiorFrom the top of the symphisis pubis (above)5.4 (6.7)4.9 (5.7)

[i] Reported measures represent the minimal individual field margins needed to respect the constraint D98 (minimal dose) >95%. Measures are expressed in cm. Indicated measures (those not in brackets) represent the 95th percentile of the measured distances (recommended margins). The values presented in round brackets indicate the maximum measured distances. The letters presented in square brackets correspond to the letter indicators in Figs. 1 and 2.

Table IV.

Field definition: High-risk prostate cancer with seminal vesicle involvement.

Table IV.

Field definition: High-risk prostate cancer with seminal vesicle involvement.

Treatment machine

FieldsMarginDescriptionCobalt 6010 MV LINAC
Anterior-posteriorLateralFrom the center of the symphisis pubis (laterally) [A]7.7 (9.8)6.7 (6.9)
InferiorFrom the bottom of ischial tuberosities (above) [B]0.4 (0.6)1.0 (1.3)
SuperiorFrom the top of the symphisis pubis (above) [C]8.7 (9.1)6.6 (7.3)
LateralAnteriorFrom the posterior margin of the symphisis pubis (posteriorly) [D]0.3 (0.4)0.3 (0.4)
PosteriorFrom the most anterior point of the rectum (posteriorly) [E]6.7 (8.1)5.1 (6.0)
InferiorFrom the bottom of ischial tuberosities (above)0.4 (0.6)1.0 (1.3)
SuperiorFrom the top of the symphisis pubis (above)8.7 (9.1)6.6 (7.3)

[i] Reported measures represent the minimal individual field margins needed to respect the constraint D98 (minimal dose) >95%. Measures are expressed in cm. Indicated measures (those not in brackets) represent the 95th percentile of the measured distances (recommended margins). The values presented in round brackets indicate the maximum measured distances. The letters presented in square brackets correspond to the letter indicators in Figs. 1 and 2.

The study was approved by the institutional board High Technology Center for Research and Education-Ethical Committee (Campobasso, Italy) and it is registered in an international public registry (ClinicalTrials.gov Identifier: NCT03339531). Written informed consent was obtained from all of the enrolled patients for the use of their images in this study prior to the analysis.

Results

Tables IIV show the results of the analysis in terms of fields margins from radiological landmarks margins in the various patient's categories: Low risk, intermediate risk, high risk, and high risk with involvement of seminal vesicles. Both the field margins needed to adequately irradiate all patients of the analysed sample and distances sufficient to achieve the same result in 95% of the enrolled patients are reported. The latter dimensions were defined as the ‘recommended’ margins. Figs. 1 and 2 show the distances to be considered between fields margins and the radiological landmarks.

Discussion

A planning study on real patients' population was performed to suggest personalized treatment margins for 2D-RT. A box technique was used because it is easy to plan with a conventional simulator and dose conformity produced to the target. Furthermore, previous analysis showed that this technique produces planning results comparable to those achieved with more complex techniques (e.g., 6 beams) (12). Definition of anatomical structures like seminal vesicles and prostate apex location was performed with pelvic MRI co-registration. This integration was used based on the advantages of MRI in prostatic target definition as previously clearly demonstrated (13). Particularly, a study of Villeirs and colleagues showed that the fusion of MRI and CT in PCa contouring results in a moderate decrease of the CTV but a relevant decrease of inter-observer variation especially at the prostate apex (14).

Before CT-simulation, a small amount of contrast medium was injected into the rectum. This preparation although not required for CT-simulation was used to attain the same conditions for conventional simulation. In fact, the purpose of this study was to provide practical guidelines for this planning method. CTV to PTV margin of 10 mm was used based on a randomized trial which demonstrated that this margin produces the same clinical results compared to larger margins (11). This result was confirmed by Creak and colleagues who reported no evidence of a difference in PSA control according to CTV to PTV margin (1 cm vs. 1.5 cm) (15). It must be acknowledged that CTV to PTV margin lower than one centimetre is currently used. However, we considered this margin appropriate being that our suggestions are mostly addressed to centres without electronic portal imaging devices or more advanced image-guided technologies.

In this analysis, irradiation beams of different energies were simulated including beams produced by a cobalt machine. We must recognize that the use of cobalt machines is currently considered obsolete especially for PCa treatment. However, in many developing countries RT departments it is the only available treatment device (3,4). The possibility of effective dose delivery with this type of treatment unit respecting the current dose/volume constraints remains uncertain. In particular, it is doubtful the possibility of an effective delivery to high tumor dose with safe OaRs irradiation using the box technique despite its practical advantages. It is generally believed that using only 4 beams, the delivery of >60 Gy doses is impossible without reaching an excessive dosage to superficial tissues. In fact, PCa treatment with cobalt machines was often performed with rotational techniques. However, we still included in this analysis also irradiation with a cobalt machine due to the following reasons:

i) Doses lower than the ones currently considered standard (>70–75 Gy) (i) may still be useful in post-operative treatment; (ii) some randomized studies showed a significant biochemical and clinical benefit by delivering 60 Gy to the prostatic bed (1618); ii) lower standard doses might still be effective if combined with androgen deprivation therapy (ADT); several randomized studies demonstrated a significant advantage in terms of specific or overall survival by combining ADT to RT at lower doses (65–70 Gy) than those currently considered as standards (>70–75 Gy) (1923);

iii) the current recommended ‘standard doses’ were defined mainly based on biochemical relapse-free survival advantage and not in terms of overall survival (11,2428); the use of high doses in other words was less associated with a significant improvement of ‘clinical’ outcomes;

iv) in addition, a meta-analysis including 7 randomized clinical trials compared the results achieved with conventional RT dose and high-dose RT. The latter resulted significantly associated with improved biochemical control but there was no difference in terms of mortality rate and specific prostate cancer mortality rate. Furthermore, a subgroup analysis showed that a dose of 64 Gy is associated with a 5-year biochemical relapse-free survival of 72, 61 and 40% in low, intermediate and high-risk PCa, respectively (29). Obviously, these results cannot be defined as optimal but may be acceptable in health systems where other alternative therapies or RT techniques are not available.

In our analysis we have not dealt with the problem of OaRs and planning organ at risk volumes. The main reason is that using a 2D-RT technique it is not possible to calculate the DVHs and to evaluate the constraints of OaRs including planning organ at risk volumes. However, the technique proposed by us is intended to be used with relatively low doses (60–64 Gy). In accordance to the QUANTEC, the maximum bladder dose should be less than 65 Gy and the V65 Gy of the rectum must be less than 25%, it is reasonably likely that these constraints are respected. Guidelines for PCa 2D-RT were obviously available in the past. However, these were mainly based on ‘expert's opinion’ or population-based CT measurements of prostate and seminal vesicles (6,8). Our study presents obvious differences in terms of: i) precise MRI-based prostate and seminal vesicles contouring; ii) use of an additional margin between prostate and CTV according to risk category; iii) CTV to PTV margin validated by the results of a clinical trial (11); iv) definition of field margins adapted to different energy beams.

Probably in clinical practice it is possible to further optimize our instructions by customizing them to individual patients even with 2D technology. These optimizations can be implemented with simple diagnostic integrations feasible with a standard simulator.

Use of retrograde urethrography and cystography for example could enable an individualized location of the prostate apex and base, respectively (30,31). In addition, it should be noted that the recommended margins in our study are based on the 95th percentile of the obtained measurement. This means that they may be considered adequate in 95% of patients. This choice derives from the need to obtain a compromise between tumor control probability and the risk of side effects. However, in the tables also the maximum value of the measured distance, i.e. the sizes appropriate in 100% of the evaluated sample was indicated. Therefore, in case of simulation images showing a reduced OaRs involvement, the planner can use the larger value to increase the likelihood of complete target ‘coverage’. Although the limits of PCa irradiation with a cobalt machine have been previously mentioned, this analysis represents the basis for a subsequent study that has been planned in our center with the aim of defining the dose which can be safely administered with this kind of machine. The study will be conducted based on the current OaRs dose/volume constraints (10).

Our study was limited to prostate +/- seminal vesicles irradiation. However, according to current guidelines in high-risk patients, prophylactic irradiation of the pelvic lymph nodes is recommended (1). Therefore, a further study was planned to provide 2D indications for pelvic fields design based on current guidelines for nodal CTV definition (32). In conclusion, we aimed at providing convenient 2D PCa target delineation tools. In the last years, our team worked on the optimization of 2D-RT in palliative treatments (3335). Worth noting is that 2D-RT is still in use in several centers in the world. Therefore, we think that other similar studies based on advanced radiological technologies could be performed to optimize 2D-RT techniques in other tumors for less equipped departments.

Acknowledgements

Not applicable.

Funding

No funding was received.

Availability of data and materials

All data generated or analyzed during the present study are included in this published article.

Authors' contributions

MB, SC, FD, GM, TW, KAFMU, MAS and AGM conceived and designed the present study. SC, MB, MP, EG, GS, IC, AAW and AGM planned the treatments, and analyzed and interpreted the data. MB, FD, IC, AAW, GM, TW, KAFMU, MAS and AGM drafted the article. IC, AAW, TW, KAFMU, MAS and AGM critically revised the manuscript for important intellectual content. All authors have read and approved the final manuscript.

Ethics approval and consent to participate

The present study was approved by the institutional board High Technology Center for Research and Education-Ethical Committee (Campobasso, Italy), and it is registered in an international public registry (ClinicalTrials.gov Identifier: NCT03339531). Written informed consent was obtained from all of the enrolled patients for the use of their images in this study prior to the analysis.

Patient consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

References

1 

Mohler J, Bahnson RR, Boston B, Busby JE, D'Amico A, Eastham JA, Enke CA, George D, Horwitz EM, Huben RP, et al: NCCN clinical practice guidelines in oncology: Prostate cancer. J Natl Compr Canc Netw. 8:162–200. 2010. View Article : Google Scholar : PubMed/NCBI

2 

Adebamowo CA and Akarolo-Anthony S: Cancer in Africa: Opportunities for collaborative research and training. Afr J Med Med Sci (38 Suppl 2). S5–S13. 2009.

3 

Barton MB, Frommer M and Shafiq J: Role of radiotherapy in cancer control in low-income and middle-income countries. Lancet Oncol. 7:584–595. 2006. View Article : Google Scholar : PubMed/NCBI

4 

Kigula Mugambe JB and Wegoye P: Pattern and experience with cancers treated with the Chinese GWGP80 cobalt unit at Mulago Hospital, Kampala. East Afr Med J. 77:523–525. 2000.PubMed/NCBI

5 

Page BR, Hudson AD, Brown DW, Shulman AC, Abdel-Wahab M, Fisher BJ and Patel S: Cobalt, linac, or other: What is the best solution for radiation therapy in developing countries? Int J Radiat Oncol Biol Phys. 89:476–480. 2014. View Article : Google Scholar : PubMed/NCBI

6 

Zelefsky MJ, Valicenti RK, Hunt M and Perez CA: Low-risk prostate cancer. Perez and Brady's Principles and Practice of Radiation Oncology. Halperin EC, Perez CA, Brady LW, Wazer DE, Freeman C and Prosnitz LR: 5th. Lippincott Williams & Wilkins; pp. 1280–1311. 2007

7 

Hussey DH: Carcinoma of the prostate. Textbook of Radiotherapy. Fletcher GH: 3rd. Lea & Febiger; Philadelphia: pp. 894–914. 1980

8 

Pilepich MV, Prasad SC and Perez CA: Computed tomography in definitive radiotherapy of prostatic carcinoma, part 2: Definition of target volume. Int J Radiat Oncol Biol Phys. 8:235–239. 1982. View Article : Google Scholar : PubMed/NCBI

9 

Boehmer D, Maingon P, Poortmans P, Baron MH, Miralbell R, Remouchamps V, Scrase C, Bossi A and Bolla M; EORTC radiation oncology group, : Guidelines for primary radiotherapy of patients with prostate cancer. Radiother Oncol. 79:259–269. 2006. View Article : Google Scholar : PubMed/NCBI

10 

Bentzen SM, Constine LS, Deasy JO, Eisbruch A, Jackson A, Marks LB, Ten Haken RK and Yorke ED: Quantitative analyses of normal tissue effects in the clinic (QUANTEC): An introduction to the scientific issues. Int J Radiat Oncol Biol Phys. 76 (3 Suppl):S3–S9. 2010. View Article : Google Scholar : PubMed/NCBI

11 

Dearnaley DP, Hall E, Lawrence D, Huddart RA, Eeles R, Nutting CM, Gadd J, Warrington A, Bidmead M and Horwich A: Phase III pilot study of dose escalation using conformal radiotherapy in prostate cancer: PSA control and side effects. Br J Cancer. 92:488–498. 2005. View Article : Google Scholar : PubMed/NCBI

12 

Khoo VS, Bedford JL, Webb S and Dearnaley DP: Class solutions for conformal external beam prostate radiotherapy. Int J Radiat Oncol Biol Phys. 55:1109–1120. 2003. View Article : Google Scholar : PubMed/NCBI

13 

Smith WL, Lewis C, Bauman G, Rodrigues G, D'Souza D, Ash R, Ho D, Venkatesan V, Downey D and Fenster A: Prostate volume contouring: A 3D analysis of segmentation using 3DTRUS, CT, and MR. Int J Radiat Oncol Biol Phys. 67:1238–1247. 2007. View Article : Google Scholar : PubMed/NCBI

14 

Villeirs GM, Van Vaerenbergh K, Vakaet L, Bral S, Claus F, De Neve WJ, Verstraete KL and De Meerleer GO: Interobserver delineation variation using CT versus combined CT + MRI in intensity-modulated radiotherapy for prostate cancer. Strahlenther Onkol. 181:424–430. 2005. View Article : Google Scholar : PubMed/NCBI

15 

Creak A, Hall E, Horwich A, Eeles R, Khoo V, Huddart R, Parker C, Griffin C, Bidmead M, Warrington J and Dearnaley D: Randomised pilot study of dose escalation using conformal radiotherapy in prostate cancer: Long-term follow-up. Br J Cancer. 109:651–657. 2013. View Article : Google Scholar : PubMed/NCBI

16 

Bolla M, van Poppel H, Collette L, van Cangh P, Vekemans K, Da Pozzo L, de Reijke TM, Verbaeys A, Bosset JF, van Velthoven R, et al: Postoperative radiotherapy after radical prostatectomy: A randomised controlled trial (EORTC trial 22911). Lancet. 366:572–578. 2005. View Article : Google Scholar : PubMed/NCBI

17 

Swanson GP, Hussey MA, Tangen CM, Chin J, Messing E, Canby-Hagino E, Forman JD, Thompson IM and Crawford ED; SWOG 8794, : Predominant treatment failure in postprostatectomy patients is local: Analysis of patterns of treatment failure in SWOG 8794. J Clin Oncol. 25:2225–2229. 2007. View Article : Google Scholar : PubMed/NCBI

18 

Wiegel T, Bottke D, Steiner U, Siegmann A, Golz R, Störkel S, Willich N, Semjonow A, Souchon R, Stöckle M, et al: Phase III postoperative adjuvant radiotherapy after radical prostatectomy compared with radical prostatectomy alone in pT3 prostate cancer with postoperative undetectable prostate-specific antigen: ARO 96-02/AUO AP 09/95. J Clin Oncol. 27:2924–2930. 2009. View Article : Google Scholar : PubMed/NCBI

19 

Pilepich MV, Winter K, John MJ, Mesic JB, Sause W, Rubin P, Lawton C, Machtay M and Grignon D: Phase III radiation therapy oncology group (RTOG) trial 86-10 of androgen deprivation adjuvant to definitive radiotherapy in locally advanced carcinoma of the prostate. Int J Radiat Oncol Biol Phys. 50:1243–1252. 2001. View Article : Google Scholar : PubMed/NCBI

20 

Pilepich MV, Winter K, Lawton CA, Krisch RE, Wolkov HB, Movsas B, Hug EB, Asbell SO and Grignon D: Androgen suppression adjuvant to definitive radiotherapy in prostate carcinoma-long-term results of phase III RTOG 85-31. Int J Radiat Oncol Biol Phys. 61:1285–1290. 2005. View Article : Google Scholar : PubMed/NCBI

21 

Bolla M, Van Tienhoven G, Warde P, Dubois JB, Mirimanoff RO, Storme G, Bernier J, Kuten A, Sternberg C, Billiet I, et al: External irradiation with or without long-term androgen suppression for prostate cancer with high metastatic risk: 10-year results of an EORTC randomised study. Lancet Oncol. 11:1066–1073. 2010. View Article : Google Scholar : PubMed/NCBI

22 

Denham JW, Steigler A, Lamb DS, Joseph D, Turner S, Matthews J, Atkinson C, North J, Christie D, Spry NA, et al: Short-term neoadjuvant androgen deprivation and radiotherapy for locally advanced prostate cancer: 10-year data from the TROG 96.01 randomised trial. Lancet Oncol. 12:451–459. 2011. View Article : Google Scholar : PubMed/NCBI

23 

Nguyen PL, Chen MH, Beard CJ, Suh WW, Renshaw AA, Loffredo M, McMahon E, Kantoff PW and D'Amico AV: Radiation with or without 6 months of androgen suppression therapy in intermediate- and high-risk clinically localized prostate cancer: A postrandomization analysis by risk group. Int J Radiat Oncol Biol Phys. 77:1046–1052. 2010. View Article : Google Scholar : PubMed/NCBI

24 

Shipley WU, Verhey LJ, Munzenrider JE, Suit HD, Urie MM, McManus PL, Young RH, Shipley JW, Zietman AL, Biggs PJ, et al: Advanced prostate cancer: The results of a randomized comparative trial of high dose irradiation boosting with conformal protons compared with conventional dose irradiation using photons alone. Int J Radiat Oncol Biol Phys. 32:3–12. 1995. View Article : Google Scholar : PubMed/NCBI

25 

Pollack A, Zagars GK, Starkschall G, Antolak JA, Lee JJ, Huang E, von Eschenbach AC, Kuban DA and Rosen I: Prostate cancer radiation dose response: Results of the M. D. Anderson phase III randomized trial. Int J Radiat Oncol Biol Phys. 53:1097–1105. 2002. View Article : Google Scholar : PubMed/NCBI

26 

Zietman AL, DeSilvio ML, Slater JD, Rossi CJ Jr, Miller DW, Adams JA and Shipley WU: Comparison of conventional-dose vs. high-dose conformal radiation therapy in clinically localized adenocarcinoma of the prostate: A randomized controlled trial. JAMA. 294:1233–1239. 2005. View Article : Google Scholar : PubMed/NCBI

27 

Sathya JR, Davis IR, Julian JA, Guo Q, Daya D, Dayes IS, Lukka HR and Levine M: Randomized trial comparing iridium implant plus external-beam radiation therapy with external-beam radiation therapy alone in node-negative locally advanced cancer of the prostate. J Clin Oncol. 23:1192–1199. 2005. View Article : Google Scholar : PubMed/NCBI

28 

Peeters ST, Heemsbergen WD, Koper PC, van Putten WL, Slot A, Dielwart MF, Bonfrer JM, Incrocci L and Lebesque JV: Dose-response in radiotherapy for localized prostate cancer: Results of the Dutch multicenter randomized phase III trial comparing 68 Gy of radiotherapy with 78 Gy. J Clin Oncol. 24:1990–1996. 2006. View Article : Google Scholar : PubMed/NCBI

29 

Viani GA, Stefano EJ and Afonso SL: Higher-than-conventional radiation doses in localized prostate cancer treatment: A meta-analysis of randomized, controlled trials. Int J Radiat Oncol Biol Phys. 74:1405–1418. 2009. View Article : Google Scholar : PubMed/NCBI

30 

Roach M III, Pickett B, Holland J, Zapotowski KA, Marsh DL and Tatera BS: The role of the urethrogram during simulation for localized prostate cancer. Int J Radiat Oncol Biol Phys. 25:299–307. 1993. View Article : Google Scholar : PubMed/NCBI

31 

Liu YM, Ling S, Langen KM, Shinohara K, Weinberg V, Pouliot J and Roach M III: Prostate movement during simulation resulting from retrograde urethrogram compared with ‘natural’ prostate movement. Int J Radiat Oncol Biol Phys. 60:470–475. 2004. View Article : Google Scholar : PubMed/NCBI

32 

Lawton CA, Michalski J, El-Naqa I, Buyyounouski MK, Lee WR, Menard C, O'Meara E, Rosenthal SA, Ritter M and Seider M: RTOG GU Radiation oncology specialists reach consensus on pelvic lymph node volumes for high-risk prostate cancer. Int J Radiat Oncol Biol Phys. 74:383–387. 2009. View Article : Google Scholar : PubMed/NCBI

33 

Buwenge M, Marinelli A, Deodato F, Macchia G, Wondemagegnhu T, Salah T, Cammelli S, Uddin AFMK, Sumon MA, Donati CM, et al: Definition of fields margins for palliative radiotherapy of pancreatic carcinoma. Mol Clin Oncol. 8:715–718. 2018.PubMed/NCBI

34 

Morganti AG, Marinelli A, Buwenge M, Macchia G, Deodato F, Massaccesi M, Kigula-Mugambe J, Wondemagegnhu T, Dawotola D, Caravatta L, et al: Palliative two-dimensional radiotherapy of pancreatic carcinoma: A feasibility study. Tumori. 99:488–492. 2013. View Article : Google Scholar : PubMed/NCBI

35 

Buwenge M, Cilla S, Cammelli S, Macchia G, Arcelli A, Farina E, Frakulli R, Panni V, Wondemagegnhu T, Uddin AFMK, et al: Feasibility of 2D-conformal radiotherapy for pancreatic carcinoma. Oncol Lett. 16:5939–5945. 2018.PubMed/NCBI

Related Articles

Journal Cover

July 2019
Volume 11 Issue 1

Print ISSN: 2049-9450
Online ISSN:2049-9469

Sign up for eToc alerts

Recommend to Library

Copy and paste a formatted citation
APA
Buwenge, M., Perrone, M., Siepe, G., Capocaccia, I., Woldemariam, A.A., Wondemagegnhu, T. ... Morganti, A.G. (2019). Definition of fields margins for the optimized 2D radiotherapy of prostate carcinoma . Molecular and Clinical Oncology, 11, 37-42. https://doi.org/10.3892/mco.2019.1855
MLA
Buwenge, M., Perrone, M., Siepe, G., Capocaccia, I., Woldemariam, A. A., Wondemagegnhu, T., Uddin, K. A., Sumon, M. A., Galofaro, E., Macchia, G., Deodato, F., Cilla, S., Morganti, A. G."Definition of fields margins for the optimized 2D radiotherapy of prostate carcinoma ". Molecular and Clinical Oncology 11.1 (2019): 37-42.
Chicago
Buwenge, M., Perrone, M., Siepe, G., Capocaccia, I., Woldemariam, A. A., Wondemagegnhu, T., Uddin, K. A., Sumon, M. A., Galofaro, E., Macchia, G., Deodato, F., Cilla, S., Morganti, A. G."Definition of fields margins for the optimized 2D radiotherapy of prostate carcinoma ". Molecular and Clinical Oncology 11, no. 1 (2019): 37-42. https://doi.org/10.3892/mco.2019.1855